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Sample records for awake freely behaving

  1. Bidirectional synaptic plasticity in the dentate gyrus of the awake freely behaving mouse

    PubMed Central

    Koranda, Jessica L.; Masino, Susan A.; Blaise, J. Harry

    2008-01-01

    There is significant interest in in vivo synaptic plasticity in mice due to the many relevant genetic mutants now available. Nevertheless, use of in vivo models remains limited. To date long-term potentiation (LTP) has been studied infrequently, and long-term depression (LTD) has not been characterized in the mouse in vivo. Herein we describe protocols and improved methodologies we developed to record hippocampal synaptic plasticity reliably from the dentate gyrus of the awake freely behaving mouse. Seven days prior to recording, we implanted microelectrodes encapsulated within a lightweight, low-profile headstage assembly. On the day of recording, we induced either LTP or LTD in the awake freely behaving animal and monitored subsequent changes in population spike amplitude for at least 24 hrs. Using this protocol we attained 80% success in inducing and maintaining either LTP or LTD. Recording from a chronic implant using this improved methodology is best suited to reveal naturally occurring brain activity, and avoids both acute effects of local electrode insertion and drifts in neuronal excitability associated with anesthesia. Ultimately a reliable freely behaving mouse model of bidirectional synaptic plasticity is invaluable for full characterization of genetic models of disease states and manipulations of the mechanisms implicated in learning and memory. PMID:17875326

  2. A novel vibrotactile system for stimulating the glabrous skin of awake freely behaving rats during operant conditioning.

    PubMed

    Devecioğlu, İsmail; Güçlü, Burak

    2015-03-15

    Rat skin is innervated by mechanoreceptive fibers similar to those in other mammals. Tactile experiments with behaving rats mostly focus on the vibrissal system which does not exist in humans. The aim of this study was to design and implement a novel vibrotactile system to stimulate the glabrous skin of behaving rats during operant conditioning. A computer-controlled vibrotactile system was developed for various tasks in which the volar surface of unrestrained rats' fore- and hindpaws was stimulated in an operant chamber. The operant chamber was built from off-the-shelf components. A highly accurate electrodynamic shaker with a novel multi-probe design was used for generating mechanical displacements. Twenty-five rats were trained for four sequential tasks: (A) middle-lever (trial start signal) press, (B) side-lever press with an associated visual cue, (C) similar to (B) with the addition of an auditory/tactile stimulus, (D) auditory/tactile detection (yes/no) task. Out of 9 rats which could complete the tactile version of this training schedule, 5 had over 70% accuracy in the tactile version of the detection task. Unlike actuators for stimulating whiskers, this system does not require a particular head/body alignment and can be used with freely behaving animals. The vibrotactile system was found to be effective for conditioning freely behaving rats based on stimuli applied on the glabrous skin. However, detection accuracies were lower compared to those in tasks involving whisker stimulation reported previously, probably due to differences in cortical processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Magnetic tracking of eye position in freely behaving chickens

    PubMed Central

    Schwarz, Jason S.; Sridharan, Devarajan; Knudsen, Eric I.

    2013-01-01

    Research on the visual system of non-primates, such as birds and rodents, is increasing. Evidence that neural responses can differ dramatically between head-immobilized and freely behaving animals underlines the importance of studying visual processing in ethologically relevant contexts. In order to systematically study visual responses in freely behaving animals, an unobtrusive system for monitoring eye-in-orbit position in real time is essential. We describe a novel system for monitoring eye position that utilizes a head-mounted magnetic displacement sensor coupled with an eye-implanted magnet. This system is small, lightweight, and offers high temporal and spatial resolution in real time. We use the system to demonstrate the stability of the eye and the stereotypy of eye position during two different behavioral tasks in chickens. This approach offers a viable alternative to search coil and optical eye tracking techniques for high resolution tracking of eye-in-orbit position in behaving animals. PMID:24312023

  4. Automated imaging of neuronal activity in freely behaving Caenorhabditis elegans.

    PubMed

    Ben Arous, Juliette; Tanizawa, Yoshinori; Rabinowitch, Ithai; Chatenay, Didier; Schafer, William R

    2010-03-30

    In order to understand how neuronal circuits control locomotory patterns it is necessary to record neuronal activity of freely behaving animals. Here, using a new automated system for simultaneous recording of behavior and neuronal activity in freely moving Caenorhabditis elegans on standard agar plates, we show that spontaneous reversals from forward to backward locomotion reflect precisely the activity of the AVA command interneurons. We also witness spontaneous activity transients in the PLM sensory neurons during free behavior of the worm in standard conditions. We show that these activity transients are coupled to short spontaneous forward accelerations of the worm. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  5. A novel paraplegia model in awake behaving macaques.

    PubMed

    Krucoff, Max O; Zhuang, Katie; MacLeod, David; Yin, Allen; Byun, Yoon Woo; Manson, Roberto Jose; Turner, Dennis A; Oliveira, Laura; Lebedev, Mikhail A

    2017-09-01

    Lower limb paralysis from spinal cord injury (SCI) or neurological disease carries a poor prognosis for recovery and remains a large societal burden. Neurophysiological and neuroprosthetic research have the potential to improve quality of life for these patients; however, the lack of an ethical and sustainable nonhuman primate model for paraplegia hinders their advancement. Therefore, our multidisciplinary team developed a way to induce temporary paralysis in awake behaving macaques by creating a fully implantable lumbar epidural catheter-subcutaneous port system that enables easy and reliable targeted drug delivery for sensorimotor blockade. During treadmill walking, aliquots of 1.5% lidocaine with 1:200,000 epinephrine were percutaneously injected into the ports of three rhesus macaques while surface electromyography (EMG) recorded muscle activity from their quadriceps and gastrocnemii. Diminution of EMG amplitude, loss of voluntary leg movement, and inability to bear weight were achieved for 60-90 min in each animal, followed by a complete recovery of function. The monkeys remained alert and cooperative during the paralysis trials and continued to take food rewards, and the ports remained functional after several months. This technique will enable recording from the cortex and/or spinal cord in awake behaving nonhuman primates during the onset, maintenance, and resolution of paraplegia for the first time, thus opening the door to answering basic neurophysiological questions about the acute neurological response to spinal cord injury and recovery. It will also negate the need to permanently injure otherwise high-value research animals for certain experimental paradigms aimed at developing and testing neural interface decoding algorithms for patients with lower extremity dysfunction.NEW & NOTEWORTHY A novel implantable lumbar epidural catheter-subcutaneous port system enables targeted drug delivery and induction of temporary paraplegia in awake, behaving nonhuman

  6. Wireless Neural Stimulation in Freely Behaving Small Animals

    PubMed Central

    Arfin, Scott K.; Long, Michael A.; Fee, Michale S.; Sarpeshkar, Rahul

    2009-01-01

    We introduce a novel wireless, low-power neural stimulation system for use in freely behaving animals. The system consists of an external transmitter and a miniature, implantable wireless receiver–stimulator. The implant uses a custom integrated chip to deliver biphasic current pulses to four addressable bipolar electrodes at 32 selectable current levels (10 μA to 1 mA). To achieve maximal battery life, the chip enters a sleep mode when not needed and can be awakened remotely when required. To test our device, we implanted bipolar stimulating electrodes into the songbird motor nucleus HVC (formerly called the high vocal center) of zebra finches. Single-neuron recordings revealed that wireless stimulation of HVC led to a strong increase of spiking activity in its downstream target, the robust nucleus of the arcopallium. When we used this device to deliver biphasic pulses of current randomly during singing, singing activity was prematurely terminated in all birds tested. Thus our device is highly effective for remotely modulating a neural circuit and its corresponding behavior in an untethered, freely behaving animal. PMID:19386759

  7. Autonomous head-mounted electrophysiology systems for freely behaving primates.

    PubMed

    Gilja, Vikash; Chestek, Cindy A; Nuyujukian, Paul; Foster, Justin; Shenoy, Krishna V

    2010-10-01

    Recent technological advances have led to new light-weight battery-operated systems for electrophysiology. Such systems are head mounted, run for days without experimenter intervention, and can record and stimulate from single or multiple electrodes implanted in a freely behaving primate. Here we discuss existing systems, studies that use them, and how they can augment traditional, physically restrained, 'in-rig' electrophysiology. With existing technical capabilities, these systems can acquire multiple signal classes, such as spikes, local field potential, and electromyography signals, and can stimulate based on real-time processing of recorded signals. Moving forward, this class of technologies, along with advances in neural signal processing and behavioral monitoring, have the potential to dramatically expand the scope and scale of electrophysiological studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Neural circuit activity in freely behaving zebrafish (Danio rerio).

    PubMed

    Issa, Fadi A; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L; Papazian, Diane M

    2011-03-15

    Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions.

  9. Neural circuit activity in freely behaving zebrafish (Danio rerio)

    PubMed Central

    Issa, Fadi A.; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L.; Papazian, Diane M.

    2011-01-01

    Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions. PMID:21346131

  10. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans.

    PubMed

    Nguyen, Jeffrey P; Shipley, Frederick B; Linder, Ashley N; Plummer, George S; Liu, Mochi; Setru, Sagar U; Shaevitz, Joshua W; Leifer, Andrew M

    2016-02-23

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. We present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. This instrument provides whole-brain imaging with cellular resolution in an unrestrained and behaving animal. We use spinning-disk confocal microscopy to capture 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s at 6 head-volumes/s. A suite of three cameras monitor neuronal fluorescence and the animal's position and orientation. Custom software tracks the 3D position of the animal's head in real time and two feedback loops adjust a motorized stage and objective to keep the animal's head within the field of view as the animal roams freely. We observe calcium transients from up to 77 neurons for over 4 min and correlate this activity with the animal's behavior. We characterize noise in the system due to animal motion and show that, across worms, multiple neurons show significant correlations with modes of behavior corresponding to forward, backward, and turning locomotion.

  11. Imaging the Dynamics of Neocortical Population Activity in Behaving and Freely Moving Mammals.

    PubMed

    Grinvald, Amiram; Petersen, Carl C H

    2015-01-01

    The development of functional imaging techniques applicable to neuroscience and covering a wide range of spatial and temporal scales has greatly facilitated the exploration of the relationships between cognition, behaviour and electrical brain activity. For mammals, the neocortex plays a particularly profound role in generating sensory perception, controlling voluntary movement, higher cognitive functions and planning goal-directed behaviours. Since these remarkable functions of the neocortex cannot be explored in simple model preparations or in anesthetised animals, the neural basis of behaviour must be explored in awake behaving subjects. Because neocortical function is highly distributed across many rapidly interacting regions, it is essential to measure spatiotemporal dynamics of cortical activity in real-time. Extensive work in anesthetised mammals has shown that in vivo Voltage-Sensitive Dye Imaging (VSDI) reveals the neocortical population membrane potential dynamics at millisecond temporal resolution and subcolumnar spatial resolution. Here, we describe recent advances indicating that VSDI is also already well-developed for exploring cortical function in behaving monkeys and mice. The first animal model, the non-human primate, is well-suited for fundamental exploration of higher-level cognitive function and behavior. The second animal model, the mouse, benefits from a rich arsenal of molecular and genetic technologies. In the monkey, imaging from the same patch of cortex, repeatedly, is feasible for a long period of time, up to a year. In the rodent, VSDI is applicable to freely moving and awake head-restrained mice. Interactions between different cortical areas and different cortical columns can therefore now be dynamically mapped through VSDI and related to the corresponding behaviour. Thus by applying VSDI to mice and monkeys one can begin to explore how behaviour emerges from neuronal activity in neuronal networks residing in different cortical areas.

  12. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Nguyen, Jeffrey; Shipley, Frederick; Linder, Ashley; Plummer, George; Liu, Mochi; Setru, Sagar; Shaevitz, Joshua; Leifer, Andrew

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. Acquiring this data, however, is challenging because it is difficult to track and image individual neurons as an animal deforms its posture and moves many body lengths. Here, we present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s are recorded at 6 head-volumes/s using spinning disk confocal microscopy. At the same time, we record low magnification images of the animal to measure the animals behavior and track its head as it moves. We develop a time independent neuronal matching algorithm that uses non-rigid point set registration and machine learning to correctly match neurons across time. Using this method, we are able to observe calcium transients from up to 90 neurons for over 4 min and correlate the neural activity with the animal's behavior.

  13. Chronic monitoring of cortical hemodynamics in behaving, freely-moving rats using a miniaturized head-mounted optical microscope

    NASA Astrophysics Data System (ADS)

    Sigal, Iliya; Gad, Raanan; Koletar, Margaret; Ringuette, Dene; Stefanovic, Bojana; Levi, Ofer

    2016-03-01

    Growing interest within the neurophysiology community in assessing healthy and pathological brain activity in animals that are awake and freely-behaving has triggered the need for optical systems that are suitable for such longitudinal studies. In this work we report label-free multi-modal imaging of cortical hemodynamics in the somatosensory cortex of awake, freely-behaving rats, using a novel head-mounted miniature optical microscope. The microscope employs vertical cavity surface emitting lasers (VCSELs) at three distinct wavelengths (680 nm, 795 nm, and 850 nm) to provide measurements of four hemodynamic markers: blood flow speeds, HbO, HbR, and total Hb concentration, across a > 2 mm field of view. Blood flow speeds are extracted using Laser Speckle Contrast Imaging (LSCI), while oxygenation measurements are performed using Intrinsic Optical Signal Imaging (IOSI). Longitudinal measurements on the same animal are made possible over the course of > 6 weeks using a chronic window that is surgically implanted into the skull. We use the device to examine changes in blood flow and blood oxygenation in superficial cortical blood vessels and tissue in response to drug-induced absence-like seizures, correlating motor behavior with changes in blood flow and blood oxygenation in the brain.

  14. Sampling phasic dopamine signaling with fast-scan cyclic voltammetry in awake, behaving rats.

    PubMed

    Fortin, S M; Cone, J J; Ng-Evans, S; McCutcheon, J E; Roitman, M F

    2015-01-05

    Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique that permits the in vivo measurement of extracellular fluctuations in multiple chemical species. The technique is frequently utilized to sample sub-second (phasic) concentration changes of the neurotransmitter dopamine in awake and behaving rats. Phasic dopamine signaling is implicated in reinforcement, goal-directed behavior, and locomotion, and FSCV has been used to investigate how rapid changes in striatal dopamine concentration contribute to these and other behaviors. This unit describes the instrumentation and construction, implantation, and use of components required to sample and analyze dopamine concentration changes in awake rats with FSCV. Copyright © 2015 John Wiley & Sons, Inc.

  15. Photoacoustic detection of functional responses in the motor cortex of awake behaving monkey during forelimb movement

    NASA Astrophysics Data System (ADS)

    Jo, Janggun; Zhang, Hongyu; Cheney, Paul D.; Yang, Xinmai

    2012-11-01

    Photoacoustic (PA) imaging was applied to detect the neuronal activity in the motor cortex of an awake, behaving monkey during forelimb movement. An adult macaque monkey was trained to perform a reach-to-grasp task while PA images were acquired through a 30-mm diameter implanted cranial chamber. Increased PA signal amplitude results from an increase in regional blood volume and is interpreted as increased neuronal activity. Additionally, depth-resolved PA signals enabled the study of functional responses in deep cortical areas. The results demonstrate the feasibility of utilizing PA imaging for studies of functional activation of cerebral cortex in awake monkeys performing behavioral tasks.

  16. Sampling phasic dopamine signaling with fast-scan cyclic voltammetry in awake behaving rats

    PubMed Central

    Fortin, SM; Cone, JJ; Ng-Evans, S; McCutcheon, JE; Roitman, MF

    2015-01-01

    Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique which permits the in vivo measurement of extracellular fluctuations in multiple chemical species. The technique is frequently utilized to sample sub-second (phasic) concentration changes of the neurotransmitter dopamine in awake and behaving rats. Phasic dopamine signaling is implicated in reinforcement, goal-directed behavior, and locomotion and FSCV has been used to investigate how rapid changes in striatal dopamine concentration contribute to these and other behaviors. This unit describes the instrumentation and construction, implantation, and use of necessary components required to sample and analyze dopamine concentration changes in awake rats with FSCV. PMID:25559005

  17. Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system

    PubMed Central

    Sigal, Iliya; Koletar, Margaret M.; Ringuette, Dene; Gad, Raanan; Jeffrey, Melanie; Carlen, Peter L.; Stefanovic, Bojana; Levi, Ofer

    2016-01-01

    We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 − 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy. PMID:27699123

  18. Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system.

    PubMed

    Sigal, Iliya; Koletar, Margaret M; Ringuette, Dene; Gad, Raanan; Jeffrey, Melanie; Carlen, Peter L; Stefanovic, Bojana; Levi, Ofer

    2016-09-01

    We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 - 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy.

  19. Evolving Models of Pavlovian Conditioning: Cerebellar Cortical Dynamics in Awake Behaving Mice.

    PubMed

    ten Brinke, Michiel M; Boele, Henk-Jan; Spanke, Jochen K; Potters, Jan-Willem; Kornysheva, Katja; Wulff, Peer; IJpelaar, Anna C H G; Koekkoek, Sebastiaan K E; De Zeeuw, Chris I

    2015-12-01

    Three decades of electrophysiological research on cerebellar cortical activity underlying Pavlovian conditioning have expanded our understanding of motor learning in the brain. Purkinje cell simple spike suppression is considered to be crucial in the expression of conditional blink responses (CRs). However, trial-by-trial quantification of this link in awake behaving animals is lacking, and current hypotheses regarding the underlying plasticity mechanisms have diverged from the classical parallel fiber one to the Purkinje cell synapse LTD hypothesis. Here, we establish that acquired simple spike suppression, acquired conditioned stimulus (CS)-related complex spike responses, and molecular layer interneuron (MLI) activity predict the expression of CRs on a trial-by-trial basis using awake behaving mice. Additionally, we show that two independent transgenic mouse mutants with impaired MLI function exhibit motor learning deficits. Our findings suggest multiple cerebellar cortical plasticity mechanisms underlying simple spike suppression, and they implicate the broader involvement of the olivocerebellar module within the interstimulus interval.

  20. Evolving Models of Pavlovian Conditioning: Cerebellar Cortical Dynamics in Awake Behaving Mice

    PubMed Central

    ten Brinke, Michiel M.; Boele, Henk-Jan; Spanke, Jochen K.; Potters, Jan-Willem; Kornysheva, Katja; Wulff, Peer; IJpelaar, Anna C.H.G.; Koekkoek, Sebastiaan K.E.; De Zeeuw, Chris I.

    2015-01-01

    Summary Three decades of electrophysiological research on cerebellar cortical activity underlying Pavlovian conditioning have expanded our understanding of motor learning in the brain. Purkinje cell simple spike suppression is considered to be crucial in the expression of conditional blink responses (CRs). However, trial-by-trial quantification of this link in awake behaving animals is lacking, and current hypotheses regarding the underlying plasticity mechanisms have diverged from the classical parallel fiber one to the Purkinje cell synapse LTD hypothesis. Here, we establish that acquired simple spike suppression, acquired conditioned stimulus (CS)-related complex spike responses, and molecular layer interneuron (MLI) activity predict the expression of CRs on a trial-by-trial basis using awake behaving mice. Additionally, we show that two independent transgenic mouse mutants with impaired MLI function exhibit motor learning deficits. Our findings suggest multiple cerebellar cortical plasticity mechanisms underlying simple spike suppression, and they implicate the broader involvement of the olivocerebellar module within the interstimulus interval. PMID:26655909

  1. Miniature microscopes for large-scale imaging of neuronal activity in freely behaving rodents.

    PubMed

    Ziv, Yaniv; Ghosh, Kunal K

    2015-06-01

    Recording neuronal activity in behaving subjects has been instrumental in studying how information is represented and processed by the brain. Recent advances in optical imaging and bioengineering have converged to enable time-lapse, cell-type specific recordings of neuronal activities from large neuronal populations in deep-brain structures of freely behaving rodents. We will highlight these advancements, with an emphasis on miniaturized integrated microscopy for large-scale imaging in freely behaving mice. This technology potentially enables studies that were difficult to perform using previous generation imaging and current electrophysiological techniques. These studies include longitudinal and population-level analyses of neuronal representations associated with different types of naturalistic behaviors and cognitive or emotional processes.

  2. Functional recordings from awake, behaving rodents through a microchannel based regenerative neural interface

    NASA Astrophysics Data System (ADS)

    Gore, Russell K.; Choi, Yoonsu; Bellamkonda, Ravi; English, Arthur

    2015-02-01

    Objective. Neural interface technologies could provide controlling connections between the nervous system and external technologies, such as limb prosthetics. The recording of efferent, motor potentials is a critical requirement for a peripheral neural interface, as these signals represent the user-generated neural output intended to drive external devices. Our objective was to evaluate structural and functional neural regeneration through a microchannel neural interface and to characterize potentials recorded from electrodes placed within the microchannels in awake and behaving animals. Approach. Female rats were implanted with muscle EMG electrodes and, following unilateral sciatic nerve transection, the cut nerve was repaired either across a microchannel neural interface or with end-to-end surgical repair. During a 13 week recovery period, direct muscle responses to nerve stimulation proximal to the transection were monitored weekly. In two rats repaired with the neural interface, four wire electrodes were embedded in the microchannels and recordings were obtained within microchannels during proximal stimulation experiments and treadmill locomotion. Main results. In these proof-of-principle experiments, we found that axons from cut nerves were capable of functional reinnervation of distal muscle targets, whether regenerating through a microchannel device or after direct end-to-end repair. Discrete stimulation-evoked and volitional potentials were recorded within interface microchannels in a small group of awake and behaving animals and their firing patterns correlated directly with intramuscular recordings during locomotion. Of 38 potentials extracted, 19 were identified as motor axons reinnervating tibialis anterior or soleus muscles using spike triggered averaging. Significance. These results are evidence for motor axon regeneration through microchannels and are the first report of in vivo recordings from regenerated motor axons within microchannels in a small

  3. Long-term Potentiation of Perforant Pathway-dentate Gyrus Synapse in Freely Behaving Mice

    PubMed Central

    Blaise, J. Harry

    2013-01-01

    Studies of long-term potentiation of synaptic efficacy, an activity-dependent synaptic phenomenon having properties that make it attractive as a potential cellular mechanism underlying learning and information storage, have long been used to elucidate the physiology of various neuronal circuits in the hippocampus, amygdala, and other limbic and cortical structures. With this in mind, transgenic mouse models of neurological diseases represent useful platforms to conduct long-term potentiation (LTP) studies to develop a greater understanding of the role of genes in normal and abnormal synaptic communication in neuronal networks involved in learning, emotion and information processing. This article describes methodologies for reliably inducing LTP in the freely behaving mouse. These methodologies can be used in studies of transgenic and knockout freely behaving mouse models of neurodegenerative diseases. PMID:24327052

  4. Neural recording stability of chronic electrode arrays in freely behaving primates.

    PubMed

    Linderman, Michael D; Gilja, Vikash; Santhanam, Gopal; Afshar, Afsheen; Ryu, Stephen; Meng, Teresa H; Shenoy, Krishna V

    2006-01-01

    Chronically implanted electrode arrays have enabled a broad range of advances, particularly in the field of neural prosthetics. Those successes motivate development of prototype implantable prosthetic processors for long duration, continuous use in freely behaving subjects. However, traditional experimental protocols have provided limited information regarding the stability of the electrode arrays and their neural recordings. In this paper we present preliminary results derived from long duration neural recordings in a freely behaving primate which show variations in action potential shape and RMS noise across a range of time scales. These preliminary results suggest that spike sorting algorithms can no longer assume stable neural signals and will need to transition to adaptive signal processing methodologies to maximize performance.

  5. Imaging large-scale cellular activity in spinal cord of freely behaving mice

    PubMed Central

    Sekiguchi, Kohei J.; Shekhtmeyster, Pavel; Merten, Katharina; Arena, Alexander; Cook, Daniela; Hoffman, Elizabeth; Ngo, Alexander; Nimmerjahn, Axel

    2016-01-01

    Sensory information from mechanoreceptors and nociceptors in the skin plays key roles in adaptive and protective motor behaviours. To date, very little is known about how this information is encoded by spinal cord cell types and their activity patterns, particularly under freely behaving conditions. To enable stable measurement of neuronal and glial cell activity in behaving mice, we have developed fluorescence imaging approaches based on two- and miniaturized one-photon microscopy. We show that distinct cutaneous stimuli activate overlapping ensembles of dorsal horn neurons, and that stimulus type and intensity is encoded at the single-cell level. In contrast, astrocytes show large-scale coordinated calcium responses to intense but not weak sensory inputs. Sensory-evoked activity is potently suppressed by anaesthesia. By revealing the cellular and computational logic of spinal cord networks under behaving conditions, our approach holds promise for better understanding of healthy and aberrant spinal cord processes. PMID:27121084

  6. MATLAB-based automated patch-clamp system for awake behaving mice.

    PubMed

    Desai, Niraj S; Siegel, Jennifer J; Taylor, William; Chitwood, Raymond A; Johnston, Daniel

    2015-08-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585-587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8-9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice.

  7. MATLAB-based automated patch-clamp system for awake behaving mice

    PubMed Central

    Siegel, Jennifer J.; Taylor, William; Chitwood, Raymond A.; Johnston, Daniel

    2015-01-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585–587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8–9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice. PMID:26084901

  8. Functional clustering of neurons in motor cortex determined by cellular resolution imaging in awake behaving mice

    PubMed Central

    Dombeck, Daniel A.; Graziano, Michael S.; Tank, David W.

    2010-01-01

    Macroscopic (millimeter scale) functional clustering is a hallmark characteristic of motor cortex spatial organization in awake behaving mammals; however, almost no information is known about the functional micro-organization (~100 microns scale). Here, we optically recorded intracellular calcium transients of layer 2/3 neurons with cellular resolution over ~200 micron diameter fields in the forelimb motor cortex of mobile, head-restrained mice during two distinct movements (running and grooming). We showed that the temporal correlation between neurons was statistically larger the closer the neurons were to each other. We further explored this correlation by using two separate methods to spatially segment the neurons within each imaging field: K-means clustering and correlations between single neuron activity and mouse movements. The two methods segmented the neurons similarly and led to the conclusion that the origin of the inverse relationship between correlation and distance seen statistically was two-fold: clusters of highly temporally correlated neurons were often spatially distinct from one another and (even when the clusters were spatially intermingled) within the clusters, the more correlated the neurons were to each other, the shorter the distance between them. Our results represent a direct observation of functional clustering within the micro-circuitry of the awake mouse motor cortex. PMID:19889987

  9. Decoding of intentional actions from scalp electroencephalography (EEG) in freely-behaving infants.

    PubMed

    Hernandez, Zachery R; Cruz-Garza, Jesus; Tse, Teresa; Contreras-Vidal, Jose L

    2014-01-01

    The mirror neuron system (MNS) in humans is thought to enable an individual's understanding of the meaning of actions performed by others and the potential imitation and learning of those actions. In humans, electroencephalographic (EEG) changes in sensorimotor a-band at central electrodes, which desynchronizes both during execution and observation of goal-directed actions (i.e., μ suppression), have been considered an analog to MNS function. However, methodological and developmental issues, as well as the nature of generalized μ suppression to imagined, observed, and performed actions, have yet to provide a mechanistic relationship between EEG μ-rhythm and MNS function, and the extent to which EEG can be used to infer intent during MNS tasks remains unknown. In this study we present a novel methodology using active EEG and inertial sensors to record brain activity and behavioral actions from freely-behaving infants during exploration, imitation, attentive rest, pointing, reaching and grasping, and interaction with an actor. We used 5-band (1-4Hz) EEG as input to a dimensionality reduction algorithm (locality-preserving Fisher's discriminant analysis, LFDA) followed by a neural classifier (Gaussian mixture models, GMMs) to decode the each MNS task performed by freely-behaving 6-24 month old infants during interaction with an adult actor. Here, we present results from a 20-month male infant to illustrate our approach and show the feasibility of EEG-based classification of freely occurring MNS behaviors displayed by an infant. These results, which provide an alternative to the μ-rhythm theory of MNS function, indicate the informative nature of EEG in relation to intentionality (goal) for MNS tasks which may support action-understanding and thus bear implications for advancing the understanding of MNS function.

  10. Action Potential Waveform Variability Limits Multi-Unit Separation in Freely Behaving Rats

    PubMed Central

    Stratton, Peter; Cheung, Allen; Wiles, Janet; Kiyatkin, Eugene; Sah, Pankaj; Windels, François

    2012-01-01

    Extracellular multi-unit recording is a widely used technique to study spontaneous and evoked neuronal activity in awake behaving animals. These recordings are done using either single-wire or mulitwire electrodes such as tetrodes. In this study we have tested the ability of single-wire electrodes to discriminate activity from multiple neurons under conditions of varying noise and neuronal cell density. Using extracellular single-unit recording, coupled with iontophoresis to drive cell activity across a wide dynamic range, we studied spike waveform variability, and explored systematic differences in single-unit spike waveform within and between brain regions as well as the influence of signal-to-noise ratio (SNR) on the similarity of spike waveforms. We also modelled spike misclassification for a range of cell densities based on neuronal recordings obtained at different SNRs. Modelling predictions were confirmed by classifying spike waveforms from multiple cells with various SNRs using a leading commercial spike-sorting system. Our results show that for single-wire recordings, multiple units can only be reliably distinguished under conditions of high recording SNR (≥4) and low neuronal density (≈20,000/ mm3). Physiological and behavioural changes, as well as technical limitations typical of awake animal preparations, reduce the accuracy of single-channel spike classification, resulting in serious classification errors. For SNR <4, the probability of misclassifying spikes approaches 100% in many cases. Our results suggest that in studies where the SNR is low or neuronal density is high, separation of distinct units needs to be evaluated with great caution. PMID:22719894

  11. Tactile responses in the granule cell layer of cerebellar folium crus IIa of freely behaving rats

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Bower, J. M.

    2001-01-01

    We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

  12. Tactile responses in the granule cell layer of cerebellar folium crus IIa of freely behaving rats

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Bower, J. M.

    2001-01-01

    We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

  13. Autonomous Head-mounted Electrophysiology Systems for Freely-Behaving Primates

    PubMed Central

    Nuyujukian, Paul; Foster, Justin; Shenoy, Krishna V.

    2011-01-01

    Recent technological advances have led to new lightweight battery-operated systems for electrophysiology. Such systems are head mounted, run for days without experimenter intervention, and can record and stimulate from single or multiple electrodes implanted in a freely-behaving primates. Here we discuss existing systems, studies that use them, and how they can augment traditional, physically restrained, “in-rig” electrophysiology. With existing technical capabilities these systems can acquire multiple signal classes, such as spikes, local field potential, and electromyography signals, and can stimulate based on real-time processing of recorded signals. Moving forward, this class of technologies, along with advances in neural signal processing and behavioral monitoring, have the potential to dramatically expand the scope and scale of electrophysiological studies. PMID:20655733

  14. Dynamics of cortical dendritic membrane potential and spikes in freely behaving rats.

    PubMed

    Moore, Jason J; Ravassard, Pascal M; Ho, David; Acharya, Lavanya; Kees, Ashley L; Vuong, Cliff; Mehta, Mayank R

    2017-03-24

    Neural activity in vivo is primarily measured using extracellular somatic spikes, which provide limited information about neural computation. Hence, it is necessary to record from neuronal dendrites, which can generate dendritic action potentials (DAPs) in vitro, which can profoundly influence neural computation and plasticity. We measured neocortical sub- and suprathreshold dendritic membrane potential (DMP) from putative distal-most dendrites using tetrodes in freely behaving rats over multiple days with a high degree of stability and submillisecond temporal resolution. DAP firing rates were several-fold larger than somatic rates. DAP rates were also modulated by subthreshold DMP fluctuations, which were far larger than DAP amplitude, indicating hybrid, analog-digital coding in the dendrites. Parietal DAP and DMP exhibited egocentric spatial maps comparable to pyramidal neurons. These results have important implications for neural coding and plasticity. Copyright © 2017, American Association for the Advancement of Science.

  15. Rodent Scope: A User-Configurable Digital Wireless Telemetry System for Freely Behaving Animals

    PubMed Central

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz–3 kHz) and low frequency field potentials (4 Hz–3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m. PMID:24587144

  16. Rodent scope: a user-configurable digital wireless telemetry system for freely behaving animals.

    PubMed

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz-3 kHz) and low frequency field potentials (4 Hz-3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m.

  17. Methods of single unit recording from medullary neural substrates in awake, behaving guinea pigs.

    PubMed

    Chang, F C; Scott, T R; Harper, R M

    1988-11-01

    An electrophysiological procedure that permits extracellular single neuronal recording in the medulla of unanesthetized, freely behaving animals is described. System components consist of 1) a flexible, single-strand microwire as recording electrode; 2) a miniature, skull-mounted miniature microdrive used for isolation of single unit activity; and 3) a head-mounted voltage follower that conditions and stabilizes the neuronal signals prior to amplification and transmission for further processing. A unique advantage of this procedure is the latitude and provision for microwire replacement in the event that multiple penetrations are desired or the tip of the microwire recording electrode is insulated as a result of gliomatosis. With minor modification, this technique can be used for single unit recording virtually anywhere along the supra-segmental neuraxis. Technical aspects of this procedure, together with details of design and fabrication of implantable devices, chronic instrumentation procedure, and potentials for other chronic applications, are discussed.

  18. Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat

    PubMed Central

    Alves, Joseph Andrews; Boerner, Barbara Ciralli

    2016-01-01

    Quadrupedal mammals typically synchronize their respiration with body movements during rhythmic locomotion. In the rat, fast respiration is coupled to head movements during sniffing behavior, but whether respiration is entrained by stride dynamics is not known. We recorded intranasal pressure, head acceleration, instantaneous speed, and ultrasonic vocalizations from male and female adult rats while freely behaving in a social environment. We used high-speed video recordings of stride to understand how head acceleration signals relate to locomotion and developed techniques to identify episodes of sniffing, walking, trotting, and galloping from the recorded variables. Quantitative analysis of synchrony between respiration and head acceleration rhythms revealed that respiration and locomotion movements were coordinated but with a weaker coupling than expected from previous work in other mammals. We have recently shown that rats behaving in social settings produce high rates of ultrasonic vocalizations during locomotion bouts. Accordingly, rats emitted vocalizations in over half of the respiratory cycles during fast displacements. We present evidence suggesting that emission of these calls disrupts the entrainment of respiration by stride. The coupling between these two variables is thus flexible, such that it can be overridden by other behavioral demands. PMID:27525126

  19. Evaluation of a Closed Loop Inductive Power Transmission System on an Awake Behaving Animal Subject

    PubMed Central

    Kiani, Mehdi; Kwon, Ki Yong; Zhang, Fei; Oweiss, Karim; Ghovanloo, Maysam

    2011-01-01

    This paper presents in vivo experimental results for a closed loop wireless power transmission system to implantable devices on an awake behaving animal subject. In this system, wireless power transmission takes place across an inductive link, controlled by a commercial off-the-shelf (COTS) radio frequency identification (RFID) transceiver (TRF7960) operating at 13.56 MHz. Induced voltage on the implantable secondary coil is rectified, digitized by a 10-bit analog to digital converter, and transmitted back to the primary via back telemetry. Transmitter (Tx) and receiver (Rx) circuitry were mounted on the back of an adult rat with a nominal distance of ~7 mm between their coils. Our experiments showed that the closed loop system was able to maintain the Rx supply voltage at the designated 3.8 V despite changes in the coils’ relative distance and alignment due to animal movements. The Tx power consumption changed between 410 ~ 560 mW in order to deliver 27 mW to the receiver. The open loop system, on the other hand, showed undesired changes in the Rx supply voltage while the Tx power consumption was constant at 660 mW. PMID:22256112

  20. Evaluation of a closed loop inductive power transmission system on an awake behaving animal subject.

    PubMed

    Kiani, Mehdi; Kwon, Ki Yong; Zhang, Fei; Oweiss, Karim; Ghovanloo, Maysam

    2011-01-01

    This paper presents in vivo experimental results for a closed loop wireless power transmission system to implantable devices on an awake behaving animal subject. In this system, wireless power transmission takes place across an inductive link, controlled by a commercial off-the-shelf (COTS) radio frequency identification (RFID) transceiver (TRF7960) operating at 13.56 MHz. Induced voltage on the implantable secondary coil is rectified, digitized by a 10-bit analog to digital converter, and transmitted back to the primary via back telemetry. Transmitter (Tx) and receiver (Rx) circuitry were mounted on the back of an adult rat with a nominal distance of ~7 mm between their coils. Our experiments showed that the closed loop system was able to maintain the Rx supply voltage at the designated 3.8 V despite changes in the coils' relative distance and alignment due to animal movements. The Tx power consumption changed between 410 ~ 560 mW in order to deliver 27 mW to the receiver. The open loop system, on the other hand, showed undesired changes in the Rx supply voltage while the Tx power consumption was constant at 660 mW.

  1. A wirelessly powered and controlled device for optical neural control of freely-behaving animals

    NASA Astrophysics Data System (ADS)

    Wentz, Christian T.; Bernstein, Jacob G.; Monahan, Patrick; Guerra, Alexander; Rodriguez, Alex; Boyden, Edward S.

    2011-08-01

    Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly receiving power using a resonant RF power link and storing the energy in an adaptive supercapacitor circuit, which can algorithmically control one or more headborne LEDs via a microcontroller. The device can deliver approximately 2 W of power to the LEDs in steady state, and 4.3 W in bursts. We also present an optional radio transceiver module (1 g) which, when added to the base headborne device, enables real-time updating of light delivery protocols; dozens of devices can be controlled simultaneously from one computer. We demonstrate use of the technology to wirelessly drive cortical control of movement in mice. These devices may serve as prototypes for clinical ultra-precise neural prosthetics that use light as the modality of biological control.

  2. A wirelessly powered and controlled device for optical neural control of freely-behaving animals.

    PubMed

    Wentz, Christian T; Bernstein, Jacob G; Monahan, Patrick; Guerra, Alexander; Rodriguez, Alex; Boyden, Edward S

    2011-08-01

    Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly receiving power using a resonant RF power link and storing the energy in an adaptive supercapacitor circuit, which can algorithmically control one or more headborne LEDs via a microcontroller. The device can deliver approximately 2 W of power to the LEDs in steady state, and 4.3 W in bursts. We also present an optional radio transceiver module (1 g) which, when added to the base headborne device, enables real-time updating of light delivery protocols; dozens of devices can be controlled simultaneously from one computer. We demonstrate use of the technology to wirelessly drive cortical control of movement in mice. These devices may serve as prototypes for clinical ultra-precise neural prosthetics that use light as the modality of biological control.

  3. A Wirelessly Powered and Controlled Device for Optical Neural Control of Freely-Behaving Animals

    PubMed Central

    Wentz, Christian T.; Bernstein, Jacob G.; Monahan, Patrick; Guerra, Alexander; Rodriguez, Alex; Boyden, Edward S.

    2011-01-01

    Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists’ capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted LED, tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the high-frequency pulse trains often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 grams capable of wirelessly receiving power using a resonant RF power link and storing the energy in an adaptive supercapacitor circuit, which can algorithmically control one or more headborne LEDs via a microcontroller. The device can deliver approximately 2W of power to the LEDs in steady state, and 4.3W in bursts. We also present an optional radio transceiver module (1 gram) which, when added to the base headborne device, enables real-time updating of light delivery protocols; dozens of devices can be simultaneously controlled from one computer. We demonstrate use of the technology to wirelessly drive cortical control of movement in mice. These devices may serve as prototypes for clinical ultra-precise neural prosthetics that use light as the modality of biological control. PMID:21701058

  4. 512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice

    PubMed Central

    Xie, Kun; Fox, Grace E.; Liu, Jun; Tsien, Joe Z.

    2016-01-01

    The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse’s small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages – namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli – such as an earthquake and fear-inducing foot-shock – trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors. PMID:27378865

  5. 512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice.

    PubMed

    Xie, Kun; Fox, Grace E; Liu, Jun; Tsien, Joe Z

    2016-01-01

    The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse's small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages - namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli - such as an earthquake and fear-inducing foot-shock - trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors.

  6. Anesthetized- and awake-patched whole-cell recordings in freely moving rats using UV-cured collar-based electrode stabilization.

    PubMed

    Lee, Doyun; Shtengel, Gleb; Osborne, Jason E; Lee, Albert K

    2014-12-01

    Intracellular recording allows precise measurement and manipulation of individual neurons, but it requires stable mechanical contact between the electrode and the cell membrane, and thus it has remained challenging to perform in behaving animals. Whole-cell recordings in freely moving animals can be obtained by rigidly fixing ('anchoring') the pipette electrode to the head; however, previous anchoring procedures were slow and often caused substantial pipette movement, resulting in loss of the recording or of recording quality. We describe a UV-transparent collar and UV-cured adhesive technique that rapidly (within 15 s) anchors pipettes in place with virtually no movement, thus substantially improving the reliability, yield and quality of freely moving whole-cell recordings. Recordings are first obtained from anesthetized or awake head-fixed rats. UV light cures the thin adhesive layers linking pipette to collar to head. Then, the animals are rapidly and smoothly released for recording during unrestrained behavior. The anesthetized-patched version can be completed in ∼4-7 h (excluding histology) and the awake-patched version requires ∼1-4 h per day for ∼2 weeks. These advances should greatly facilitate studies of neuronal integration and plasticity in identified cells during natural behaviors.

  7. Spike count, spike timing and temporal information in the cortex of awake, freely moving rats

    PubMed Central

    Scaglione, Alessandro; Foffani, Guglielmo; Moxon, Karen A.

    2014-01-01

    Objective Sensory processing of peripheral information is not stationary but is, in general, a dynamic process related to the behavioral state of the animal. Yet the link between the state of the behavior and the encoding properties of neurons is unclear. This report investigates the impact of the behavioral state on the encoding mechanisms used by cortical neurons for both detection and discrimination of somatosensory stimuli in awake, freely moving, rats. Approach Neuronal activity was recorded from the primary somatosensory cortex of five rats under two different behavioral states (quiet vs. whisking) while electrical stimulation of increasing stimulus strength was delivered to the mystacial pad. Information theoretical measures were then used to measure the contribution of different encoding mechanisms to the information carried by neurons in response to the whisker stimulation. Main Results We found that the behavioral state of the animal modulated the total amount of information conveyed by neurons and that the timing of individual spikes increased the information compared to the total count of spikes alone. However, the temporal information, i.e. information exclusively related to when the spikes occur, was not modulated by behavioral state. Significance We conclude that information about somatosensory stimuli is modulated by the behavior of the animal and this modulation is mainly expressed in the spike count while the temporal information is more robust to changes in behavioral state. PMID:25024291

  8. Spike count, spike timing and temporal information in the cortex of awake, freely moving rats

    NASA Astrophysics Data System (ADS)

    Scaglione, Alessandro; Foffani, Guglielmo; Moxon, Karen A.

    2014-08-01

    Objective. Sensory processing of peripheral information is not stationary but is, in general, a dynamic process related to the behavioral state of the animal. Yet the link between the state of the behavior and the encoding properties of neurons is unclear. This report investigates the impact of the behavioral state on the encoding mechanisms used by cortical neurons for both detection and discrimination of somatosensory stimuli in awake, freely moving, rats. Approach. Neuronal activity was recorded from the primary somatosensory cortex of five rats under two different behavioral states (quiet versus whisking) while electrical stimulation of increasing stimulus strength was delivered to the mystacial pad. Information theoretical measures were then used to measure the contribution of different encoding mechanisms to the information carried by neurons in response to the whisker stimulation. Main results. We found that the behavioral state of the animal modulated the total amount of information conveyed by neurons and that the timing of individual spikes increased the information compared to the total count of spikes alone. However, the temporal information, i.e. information exclusively related to when the spikes occur, was not modulated by behavioral state. Significance. We conclude that information about somatosensory stimuli is modulated by the behavior of the animal and this modulation is mainly expressed in the spike count while the temporal information is more robust to changes in behavioral state.

  9. In vivo analysis of proprioceptive coding and its antidromic modulation in the freely behaving crayfish.

    PubMed

    Le Ray, Didier; Combes, Denis; Déjean, Cyril; Cattaert, Daniel

    2005-08-01

    Although sensory nerves in vitro are known to convey both orthodromic (sensory) and antidromic (putatively modulating) action potentials, in most cases very little is known about their bidirectional characteristics in intact animals. Here, we have investigated both the sensory coding properties and antidromic discharges that occur during real walking in the freely behaving crayfish. The activity of the sensory nerve innervating the proprioceptor CBCO, a chordotonal organ that monitors both angular movement and position of the coxo-basipodite (CB) joint, which is implicated in vertical leg movements, was recorded chronically along with the electromyographic activity of the muscles that control CB joint movements. Two wire electrodes placed on the sensory nerve were used to discriminate orthodromic from antidromic action potentials and thus allowed for analysis of both sensory coding and antidromic discharges. A distinction is proposed between 3 main classes of sensory neuron, according to their firing in relation to levator muscle activity during free walking. In parallel, we describe 2 types of antidromic activity: one produced exclusively during motor activity and a second produced both during and in the absence of motor activity. A negative correlation was found between the activity of sensory neurons in each of the 3 classes and identified antidromic discharges during walking. Finally, a state-dependent plasticity of CBCO nerve activity has been found by which the distribution of sensory orthodromic and antidromic activity changes with the physiological state of the biomechanical apparatus.

  10. Direct Imaging of Hippocampal Epileptiform Calcium Motifs Following Kainic Acid Administration in Freely Behaving Mice

    PubMed Central

    Berdyyeva, Tamara K.; Frady, E. Paxon; Nassi, Jonathan J.; Aluisio, Leah; Cherkas, Yauheniya; Otte, Stephani; Wyatt, Ryan M.; Dugovic, Christine; Ghosh, Kunal K.; Schnitzer, Mark J.; Lovenberg, Timothy; Bonaventure, Pascal

    2016-01-01

    Prolonged exposure to abnormally high calcium concentrations is thought to be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized calcium activity during seizures in the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographic (EEG) measurements with microendoscopic calcium imaging of pyramidal cells in the CA1 hippocampal region of freely behaving mice treated with the pro-convulsant kainic acid (KA). We observed that KA administration led to systematic patterns of epileptiform calcium activity: a series of large-scale, intensifying flashes of increased calcium fluorescence concurrent with a cluster of low-amplitude EEG waveforms. This was accompanied by a steady increase in cellular calcium levels (>5 fold increase relative to the baseline), followed by an intense spreading calcium wave characterized by a 218% increase in global mean intensity of calcium fluorescence (n = 8, range [114–349%], p < 10−4; t-test). The wave had no consistent EEG phenotype and occurred before the onset of motor convulsions. Similar changes in calcium activity were also observed in animals treated with 2 different proconvulsant agents, N-methyl-D-aspartate (NMDA) and pentylenetetrazol (PTZ), suggesting the measured changes in calcium dynamics are a signature of seizure activity rather than a KA-specific pathology. Additionally, despite reducing the behavioral severity of KA-induced seizures, the anticonvulsant drug valproate (VA, 300 mg/kg) did not modify the observed abnormalities in calcium dynamics. These results confirm the presence of pathological calcium activity preceding convulsive motor seizures and support calcium as a candidate signaling molecule in a pathway connecting seizures to subsequent cellular damage. Integrating in vivo calcium imaging with traditional assessment of seizures could potentially increase translatability of pharmacological

  11. A ketogenic diet reduces long-term potentiation in the dentate gyrus of freely behaving rats.

    PubMed

    Koranda, Jessica L; Ruskin, David N; Masino, Susan A; Blaise, J Harry

    2011-08-01

    Ketogenic diets are very low in carbohydrates and can reduce epileptic seizures significantly. This dietary therapy is particularly effective in pediatric and drug-resistant epilepsy. Hypothesized anticonvulsant mechanisms of ketogenic diets focus on increased inhibition and/or decreased excitability/excitation. Either of these consequences might not only reduce seizures, but also could affect normal brain function and synaptic plasticity. Here, we characterized effects of a ketogenic diet on hippocampal long-term potentiation, a widely studied form of synaptic plasticity. Adult male rats were placed on a control or ketogenic diet for 3 wk before recording. To maintain the most physiological conditions possible, we assessed synaptic transmission and plasticity using chronic in vivo recordings in freely behaving animals. Rats underwent stereotaxic surgery to chronically implant a recording electrode in the hippocampal dentate gyrus and a stimulating electrode in the perforant path; they recovered for 1 wk. After habituation and stable baseline recording, 5-Hz theta-burst stimulation was delivered to induce long-term potentiation. All animals showed successful plasticity, demonstrating that potentiation was not blocked by the ketogenic diet. Compared with rats fed a control diet, rats fed a ketogenic diet demonstrated significantly diminished long-term potentiation. This decreased potentiation lasted for at least 48 h. Reduced potentiation in ketogenic diet-fed rats is consistent with a general increase in neuronal inhibition (or decrease in excitability) and decreased seizure susceptibility. A better understanding of the effects of ketogenic diets on synaptic plasticity and learning is important, as diet-based therapy is often prescribed to children with epilepsy.

  12. A ketogenic diet reduces long-term potentiation in the dentate gyrus of freely behaving rats

    PubMed Central

    Koranda, Jessica L.; Ruskin, David N.; Masino, Susan A.

    2011-01-01

    Ketogenic diets are very low in carbohydrates and can reduce epileptic seizures significantly. This dietary therapy is particularly effective in pediatric and drug-resistant epilepsy. Hypothesized anticonvulsant mechanisms of ketogenic diets focus on increased inhibition and/or decreased excitability/excitation. Either of these consequences might not only reduce seizures, but also could affect normal brain function and synaptic plasticity. Here, we characterized effects of a ketogenic diet on hippocampal long-term potentiation, a widely studied form of synaptic plasticity. Adult male rats were placed on a control or ketogenic diet for 3 wk before recording. To maintain the most physiological conditions possible, we assessed synaptic transmission and plasticity using chronic in vivo recordings in freely behaving animals. Rats underwent stereotaxic surgery to chronically implant a recording electrode in the hippocampal dentate gyrus and a stimulating electrode in the perforant path; they recovered for 1 wk. After habituation and stable baseline recording, 5-Hz theta-burst stimulation was delivered to induce long-term potentiation. All animals showed successful plasticity, demonstrating that potentiation was not blocked by the ketogenic diet. Compared with rats fed a control diet, rats fed a ketogenic diet demonstrated significantly diminished long-term potentiation. This decreased potentiation lasted for at least 48 h. Reduced potentiation in ketogenic diet-fed rats is consistent with a general increase in neuronal inhibition (or decrease in excitability) and decreased seizure susceptibility. A better understanding of the effects of ketogenic diets on synaptic plasticity and learning is important, as diet-based therapy is often prescribed to children with epilepsy. PMID:21613596

  13. Head-mounted LED for optogenetic experiments of freely-behaving animal

    NASA Astrophysics Data System (ADS)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  14. A novel method for modeling facial allodynia associated with migraine in awake and freely moving rats

    PubMed Central

    Wieseler, Julie; Ellis, Amanda; Sprunger, David; Brown, Kim; McFadden, Andrew; Mahoney, John; Rezvani, Niloofar; Maier, Steven F.; Watkins, Linda R.

    2009-01-01

    Migraine is a neurovascular disorder that induces debilitating headaches associated with multiple symptoms including facial allodynia, characterized by heightened responsivity to normally innocuous mechanical stimuli. It is now well accepted that immune activation and immune-derived inflammatory mediators enhance pain responsivity, including in the trigeminal system. Nociceptive (“pain” responsive) trigeminal nerves densely innervate the cranial meninges. We have recently proposed that the meninges may serve as a previously unidentified, key interface between the peripheral immune system and the CNS with potential implications for understanding underlying migraine mechanisms. Our focus here is the development of a model for facial allodynia associated with migraine. We developed a model wherein an indwelling catheter is placed between the skull and dura, allowing immunogenic stimuli to be administered over the dura in awake and freely moving rats. Since the catheter does not contact the brain itself, any proinflammatory cytokines induced following manipulation derive from resident or recruited meningeal immune cells. While surgery alone does not alter immune activation markers, TNF or IL6 mRNA and/or protein, it does decrease gene expression and increase protein expression of IL-1 at 4 days after surgery. Using this model we show the induction of facial allodynia in response to supradural administration of either the HIV glycoprotein gp120 or inflammatory soup (bradykinin, histamine, serotonin, and prostaglandin E2), and the induction of hindpaw allodynia in our model after inflammatory soup. This model allows time and dose dependent assessment of the relationship between changes in meningeal inflammation and corresponding exaggerated pain behaviors. PMID:19837113

  15. Construction of microdrive arrays for chronic neural recordings in awake behaving mice.

    PubMed

    Chang, Eric H; Frattini, Stephen A; Robbiati, Sergio; Huerta, Patricio T

    2013-07-05

    State-of-the-art electrophysiological recordings from the brains of freely behaving animals allow researchers to simultaneously examine local field potentials (LFPs) from populations of neurons and action potentials from individual cells, as the animal engages in experimentally relevant tasks. Chronically implanted microdrives allow for brain recordings to last over periods of several weeks. Miniaturized drives and lightweight components allow for these long-term recordings to occur in small mammals, such as mice. By using tetrodes, which consist of tightly braided bundles of four electrodes in which each wire has a diameter of 12.5 μm, it is possible to isolate physiologically active neurons in superficial brain regions such as the cerebral cortex, dorsal hippocampus, and subiculum, as well as deeper regions such as the striatum and the amygdala. Moreover, this technique insures stable, high-fidelity neural recordings as the animal is challenged with a variety of behavioral tasks. This manuscript describes several techniques that have been optimized to record from the mouse brain. First, we show how to fabricate tetrodes, load them into driveable tubes, and gold-plate their tips in order to reduce their impedance from MΩ to KΩ range. Second, we show how to construct a custom microdrive assembly for carrying and moving the tetrodes vertically, with the use of inexpensive materials. Third, we show the steps for assembling a commercially available microdrive (Neuralynx VersaDrive) that is designed to carry independently movable tetrodes. Finally, we present representative results of local field potentials and single-unit signals obtained in the dorsal subiculum of mice. These techniques can be easily modified to accommodate different types of electrode arrays and recording schemes in the mouse brain.

  16. Rapid whole brain imaging of neural activity in freely behaving larval zebrafish (Danio rerio).

    PubMed

    Cong, Lin; Wang, Zeguan; Chai, Yuming; Hang, Wei; Shang, Chunfeng; Yang, Wenbin; Bai, Lu; Du, Jiulin; Wang, Kai; Wen, Quan

    2017-09-20

    The internal brain dynamics that link sensation and action are arguably better studied during natural animal behaviors. Here we report on a novel volume imaging and 3D tracking technique that monitors whole brain neural activity in freely swimming larval zebrafish (Danio rerio). We demonstrated the capability of our system through functional imaging of neural activity during visually evoked and prey capture behaviors in larval zebrafish.

  17. A novel electrode-pipette design for simultaneous recording of extracellular spikes and iontophoretic drug application in awake behaving monkeys.

    PubMed

    Thiele, A; Delicato, L S; Roberts, M J; Gieselmann, M A

    2006-12-15

    We developed a novel design of an electrode-pipette combination (EPC) which allows access to brain structures in awake behaving primates without the need for guide tubes or to mechanically open the dura prior to electrode insertion. The EPC consists of an etched tungsten in glass electrode flanked by two pipettes which allow for local and highly controlled iontophoretic administration of neuroactive substances. These EPCs have excellent single cell isolation properties and are sturdy enough to penetrate the primate dura for up to 8 weeks following either a craniotomy or a dura scrape (i.e. even after substantial built up of fibrous scar tissue). We show that the EPCs can be used to selectively manipulate the cholinergic system in primate V1 during passive fixation and while animals perform an attentionally demanding task.

  18. Imaging Circulating Tumor Cells in Freely Moving Awake Small Animals Using a Miniaturized Intravital Microscope

    PubMed Central

    Sasportas, Laura Sarah; Gambhir, Sanjiv Sam

    2014-01-01

    Metastasis, the cause for 90% of cancer mortality, is a complex and poorly understood process involving the invasion of circulating tumor cells (CTCs) into blood vessels. These cells have potential prognostic value as biomarkers for early metastatic risk. But their rarity and the lack of specificity and sensitivity in measuring them render their interrogation by current techniques very challenging. How and when these cells are circulating in the blood, on their way to potentially give rise to metastasis, is a question that remains largely unanswered. In order to provide an insight into this "black box" using non-invasive imaging, we developed a novel miniature intravital microscopy (mIVM) strategy capable of real-time long-term monitoring of CTCs in awake small animals. We established an experimental 4T1-GL mouse model of metastatic breast cancer, in which tumor cells express both fluorescent and bioluminescent reporter genes to enable both single cell and whole body tumor imaging. Using mIVM, we monitored blood vessels of different diameters in awake mice in an experimental model of metastasis. Using an in-house software algorithm we developed, we demonstrated in vivo CTC enumeration and computation of CTC trajectory and speed. These data represent the first reported use we know of for a miniature mountable intravital microscopy setup for in vivo imaging of CTCs in awake animals. PMID:24497977

  19. Differential Responses of Thalamic Reticular Neurons to Nociception in Freely Behaving Mice

    PubMed Central

    Huh, Yeowool; Cho, Jeiwon

    2016-01-01

    Pain serves an important protective role. However, it can also have debilitating adverse effects if dysfunctional, such as in pathological pain conditions. As part of the thalamocortical circuit, the thalamic reticular nucleus (TRN) has been implicated to have important roles in controlling nociceptive signal transmission. However studies on how TRN neurons, especially how TRN neuronal subtypes categorized by temporal bursting firing patterns—typical bursting, atypical bursting and non-bursting TRN neurons—contribute to nociceptive signal modulation is not known. To reveal the relationship between TRN neuronal subtypes and modulation of nociception, we simultaneously recorded behavioral responses and TRN neuronal activity to formalin induced nociception in freely moving mice. We found that typical bursting TRN neurons had the most robust response to nociception; changes in tonic firing rate of typical TRN neurons exactly matched changes in behavioral nociceptive responses, and burst firing rate of these neurons increased significantly when behavioral nociceptive responses were reduced. This implies that typical TRN neurons could critically modulate ascending nociceptive signals. The role of other TRN neuronal subtypes was less clear; atypical bursting TRN neurons decreased tonic firing rate after the second peak of behavioral nociception and the firing rate of non-bursting TRN neurons mostly remained at baseline level. Overall, our results suggest that different TRN neuronal subtypes contribute differentially to processing formalin induced sustained nociception in freely moving mice. PMID:27917114

  20. A wireless neural recording system with a precision motorized microdrive for freely behaving animals

    PubMed Central

    Hasegawa, Taku; Fujimoto, Hisataka; Tashiro, Koichiro; Nonomura, Mayu; Tsuchiya, Akira; Watanabe, Dai

    2015-01-01

    The brain is composed of many different types of neurons. Therefore, analysis of brain activity with single-cell resolution could provide fundamental insights into brain mechanisms. However, the electrical signal of an individual neuron is very small, and precise isolation of single neuronal activity from moving subjects is still challenging. To measure single-unit signals in actively behaving states, establishment of technologies that enable fine control of electrode positioning and strict spike sorting is essential. To further apply such a single-cell recording approach to small brain areas in naturally behaving animals in large spaces or during social interaction, we developed a compact wireless recording system with a motorized microdrive. Wireless control of electrode placement facilitates the exploration of single neuronal activity without affecting animal behaviors. Because the system is equipped with a newly developed data-encoding program, the recorded data are readily compressed almost to theoretical limits and securely transmitted to a host computer. Brain activity can thereby be stably monitored in real time and further analyzed using online or offline spike sorting. Our wireless recording approach using a precision motorized microdrive will become a powerful tool for studying brain mechanisms underlying natural or social behaviors. PMID:25597933

  1. The olfactory bulb theta rhythm follows all frequencies of diaphragmatic respiration in the freely behaving rat

    PubMed Central

    Rojas-Líbano, Daniel; Frederick, Donald E.; Egaña, José I.; Kay, Leslie M.

    2014-01-01

    Sensory-motor relationships are part of the normal operation of sensory systems. Sensing occurs in the context of active sensor movement, which in turn influences sensory processing. We address such a process in the rat olfactory system. Through recordings of the diaphragm electromyogram (EMG), we monitored the motor output of the respiratory circuit involved in sniffing behavior, simultaneously with the local field potential (LFP) of the olfactory bulb (OB) in rats moving freely in a familiar environment, where they display a wide range of respiratory frequencies. We show that the OB LFP represents the sniff cycle with high reliability at every sniff frequency and can therefore be used to study the neural representation of motor drive in a sensory cortex. PMID:24966821

  2. A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats

    PubMed Central

    Holtzman, Tahl; Ruther, Patrick; Dalley, Jeffrey W.; Lopez, Alberto; Rossi, Mark A.; Barter, Joseph W.; Salas-Meza, Daniel; Herwik, Stanislav; Holzhammer, Tobias; Morizio, James; Yin, Henry H.

    2011-01-01

    To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems. PMID:21765934

  3. A wireless multi-channel recording system for freely behaving mice and rats.

    PubMed

    Fan, David; Rich, Dylan; Holtzman, Tahl; Ruther, Patrick; Dalley, Jeffrey W; Lopez, Alberto; Rossi, Mark A; Barter, Joseph W; Salas-Meza, Daniel; Herwik, Stanislav; Holzhammer, Tobias; Morizio, James; Yin, Henry H

    2011-01-01

    To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems.

  4. An Arbitrary Waveform Wearable Neuro-stimulator System for Neurophysiology Research on Freely Behaving Animals.

    PubMed

    Samani, Mohsen Mosayebi; Mahnam, Amin; Hosseini, Nasrin

    2014-04-01

    Portable wireless neuro-stimulators have been developed to facilitate long-term cognitive and behavioral studies on the central nervous system in freely moving animals. These stimulators can provide precisely controllable input(s) to the nervous system, without distracting the animal attention with cables connected to its body. In this study, a low power backpack neuro-stimulator was developed for animal brain researches that can provides arbitrary stimulus waveforms for the stimulation, while it is small and light weight to be used for small animals including rats. The system consists of a controller that uses an RF link to program and activate a small and light microprocessor-based stimulator. A Howland current source was implemented to produce precise current controlled arbitrary waveform stimulations. The system was optimized for ultra-low power consumption and small size. The stimulator was first tested for its electrical specifications. Then its performance was evaluated in a rat experiment when electrical stimulation of medial longitudinal fasciculus induced circling behavior. The stimulator is capable of delivering programmed stimulations up to ± 2 mA with adjusting steps of 1 μA, accuracy of 0.7% and compliance of 6 V. The stimulator is 15 mm × 20 mm × 40 mm in size, weights 13.5 g without battery and consumes a total power of only 5.l mW. In the experiment, the rat could easily carry the stimulator and demonstrated the circling behavior for 0.1 ms current pulses of above 400 μA. The developed system has a competitive size and weight, whereas providing a wide range of operation and the flexibility of generating arbitrary stimulation patterns ideal for long-term experiments in the field of cognitive and neuroscience research.

  5. An Arbitrary Waveform Wearable Neuro-stimulator System for Neurophysiology Research on Freely Behaving Animals

    PubMed Central

    Samani, Mohsen Mosayebi; Mahnam, Amin; Hosseini, Nasrin

    2014-01-01

    Portable wireless neuro-stimulators have been developed to facilitate long-term cognitive and behavioral studies on the central nervous system in freely moving animals. These stimulators can provide precisely controllable input(s) to the nervous system, without distracting the animal attention with cables connected to its body. In this study, a low power backpack neuro-stimulator was developed for animal brain researches that can provides arbitrary stimulus waveforms for the stimulation, while it is small and light weight to be used for small animals including rats. The system consists of a controller that uses an RF link to program and activate a small and light microprocessor-based stimulator. A Howland current source was implemented to produce precise current controlled arbitrary waveform stimulations. The system was optimized for ultra-low power consumption and small size. The stimulator was first tested for its electrical specifications. Then its performance was evaluated in a rat experiment when electrical stimulation of medial longitudinal fasciculus induced circling behavior. The stimulator is capable of delivering programmed stimulations up to ± 2 mA with adjusting steps of 1 μA, accuracy of 0.7% and compliance of 6 V. The stimulator is 15 mm × 20 mm × 40 mm in size, weights 13.5 g without battery and consumes a total power of only 5.l mW. In the experiment, the rat could easily carry the stimulator and demonstrated the circling behavior for 0.1 ms current pulses of above 400 μA. The developed system has a competitive size and weight, whereas providing a wide range of operation and the flexibility of generating arbitrary stimulation patterns ideal for long-term experiments in the field of cognitive and neuroscience research. PMID:24761373

  6. Magneto-thermal genetic deep brain stimulation of motor behaviors in awake, freely moving mice.

    PubMed

    Munshi, Rahul; Qadri, Shahnaz M; Zhang, Qian; Castellanos Rubio, Idoia; Del Pino, Pablo; Pralle, Arnd

    2017-08-15

    Establishing how neurocircuit activation causes particular behaviors requires modulating the activity of specific neurons. Here, we demonstrate that magnetothermal genetic stimulation provides tetherless deep brain activation sufficient to evoke motor behavior in awake mice. The approach uses alternating magnetic fields to heat superparamagnetic nanoparticles on the neuronal membrane. Neurons heat-sensitized by expressing TRPV1 are activated with magnetic field application. Magnetothermal genetic stimulation in the motor cortex evoked ambulation, deep brain stimulation in the striatum caused rotation around the body-axis, and stimulation near the ridge between ventral and dorsal striatum caused freezing-of-gait. The duration of the behavior correlated tightly with field application. This approach provides genetically and spatially targetable, repeatable and temporarily precise activation of deep-brain circuits without need for surgical implantation of any device.

  7. A non-invasive head-holding device for chronic neural recordings in awake behaving monkeys

    PubMed Central

    Amemori, Satoko; Amemori, Ken-ichi; Cantor, Margaret L.; Graybiel, Ann M.

    2014-01-01

    Background We have developed a novel head-holding device for behaving non-human primates that affords stability suitable for reliable chronic electrophysiological recording experiments. The device is completely non-invasive, and thus avoids the risk of infection and other complications that can occur with the use of conventional, surgically implanted head-fixation devices. New method The device consists of a novel non-invasive head mold and bar clamp holder, and is customized to the shape of each monkey’s head. The head-holding device that we introduce, combined with our recording system and reflection-based eye-tracking system, allows for chronic behavioral experiments and single-electrode or multi-electrode recording, as well as manipulation of brain activity. Results and comparison with existing methods With electrodes implanted chronically in multiple brain regions, we could record neural activity from cortical and subcortical structures with stability equal to that recorded with conventional head-post fixation. Consistent with the non-invasive nature of the device, we could record neural signals for more than two years with a single implant. Importantly, the monkeys were able to hold stable eye fixation positions while held by this device, demonstrating the possibility of analyzing eye movement data with only the gentle restraint imposed by the non-invasive head-holding device. Conclusions We show that the head-holding device introduced here can be extended to the head holding of smaller animals, and note that it could readily be adapted for magnetic resonance brain imaging over extended periods of time. PMID:25448381

  8. Synchronized Activity in The Main and Accessory Olfactory Bulbs and Vomeronasal Amygdala Elicited by Chemical Signals in Freely Behaving Mice.

    PubMed

    Pardo-Bellver, Cecília; Martínez-Bellver, Sergio; Martínez-García, Fernando; Lanuza, Enrique; Teruel-Martí, Vicent

    2017-08-30

    Chemosensory processing in mammals involves the olfactory and vomeronasal systems, but how the activity of both circuits is integrated is unknown. In our study, we recorded the electrophysiological activity in the olfactory bulbs and the vomeronasal amygdala in freely behaving mice exploring a battery of neutral and conspecific stimuli. The exploration of stimuli, including a neutral stimulus, induced synchronic activity in the olfactory bulbs characterized by a dominant theta rhythmicity, with specific theta-gamma coupling, distinguishing between vomeronasal and olfactory structures. The correlated activation of the bulbs suggests a coupling between the stimuli internalization in the nasal cavity and the vomeronasal pumping. In the amygdala, male stimuli are preferentially processed in the medial nucleus, whereas female cues induced a differential response in the posteromedial cortical amygdala. Thus, particular theta-gamma patterns in the olfactory network modulates the integration of chemosensory information in the amygdala, allowing the selection of an appropriate behaviour.

  9. Awake behaving electrophysiological correlates of forelimb hyperreflexia, weakness and disrupted muscular synchronization following cervical spinal cord injury in the rat

    PubMed Central

    Ganzer, Patrick Daniel; Meyers, Eric Christopher; Sloan, Andrew Michael; Maliakkal, Reshma; Ruiz, Andrea; Kilgard, Michael Paul; Rennaker, Robert LeMoine

    2016-01-01

    Spinal cord injury usually occurs at the level of the cervical spine and results in profound impairment of forelimb function. In this study, we recorded awake behaving intramuscular electromyography (EMG) from the biceps and triceps muscles of the impaired forelimb during volitional and reflexive forelimb movements before and after unilateral cervical spinal cord injury (cSCI) in rats. C5/C6 hemicontusion reduced volitional forelimb strength by more than 50% despite weekly rehabilitation for one month post-injury. Triceps EMG during volitional strength assessment was reduced by more than 60% following injury, indicating reduced descending drive. Biceps EMG during reflexive withdrawal from a thermal stimulus was increased by 500% following injury, indicating flexor withdrawal hyperreflexia. The reduction in volitional forelimb strength was significantly correlated with volitional and reflexive biceps EMG activity. Our results support the hypothesis that biceps hyperreflexia and descending volitional drive both significantly contribute to forelimb strength deficits after cSCI and provide new insight into dynamic muscular dysfunction after cSCI. The use of multiple automated quantitative measures of forelimb dys-function in the rodent cSCI model will likely aid the search for effective regenerative, pharmacological, and neuroprosthetic treatments for spinal cord injury. PMID:27033345

  10. A Chronic Implant to Record Electroretinogram, Visual Evoked Potentials and Oscillatory Potentials in Awake, Freely Moving Rats for Pharmacological Studies

    PubMed Central

    Guarino, Irene; Loizzo, Stefano; Lopez, Luisa; Fadda, Antonello; Loizzo, Alberto

    2004-01-01

    Electroretinogram (ERG), widely used to study the pharmacological effects of drugs in animal models (e.g., diabetic retinopathy), is usually recorded in anesthetized rats. We report here a novel simple method to obtain chronic implantation of electrodes for simultaneous recording at the retinal and cortical levels in freely moving, unanesthetized animals. We recorded cortical (VEPs) and retinal (ERGs) responses evoked by light (flash) stimuli in awake rats and compared the results in the same rats anesthetized with urethane (0.6 mg/kg) before and after the monocular administration of scopolamine methyl bromide (1‰solution). We also compared the retinal responses with those derived from a classic acute corneal electrode. Anesthesia induced consistent changes of several VEP and ERG parameters like an increase of both latency and amplitude. In particular, the analysis of the variation of latency, amplitude, and spectral content of rapid oscillatory potentials could be important for a functional evaluation of the visual system in unanesthetized versus anesthetized animals. PMID:15656271

  11. Odor-Taste Convergence in the Nucleus of the Solitary Tract of the Awake Freely Licking Rat

    PubMed Central

    Escanilla, Olga D.; Victor, Jonathan D.

    2015-01-01

    Flavor is produced by the integration of taste, olfaction, texture, and temperature, currently thought to occur in the cortex. However, previous work has shown that brainstem taste-related nuclei also respond to multisensory inputs. Here, we test the hypothesis that taste and olfaction interact in the nucleus of the solitary tract (NTS; the first neural relay in the central gustatory pathway) in awake, freely licking rats. Electrophysiological recordings of taste and taste + odor responses were conducted in an experimental chamber following surgical electrode implantation and recovery. Tastants (0.1 m NaCl, 0.1 m sucrose, 0.01 m citric acid, and 0.0001 m quinine) were delivered for five consecutive licks interspersed with five licks of artificial saliva rinse delivered on a VR5 schedule. Odorants were n-amyl acetate (banana), acetic acid (vinegar), octanoic acid (rancid), and phenylethyl alcohol (floral). For each cell, metric space analyses were used to quantify the information conveyed by spike count, by the rate envelope, and by individual spike timing. Results revealed diverse effects of odorants on taste-response magnitude and latency across cells. Importantly, NTS cells were more competent at discriminating taste + odor stimuli versus tastants presented alone for all taste qualities using both rate and temporal coding. The strong interaction of odorants and tastants at the NTS underscores its role as the initial node in the neural circuit that controls food identification and ingestion. PMID:25904782

  12. The Neurochip-2: an autonomous head-fixed computer for recording and stimulating in freely behaving monkeys.

    PubMed

    Zanos, Stavros; Richardson, Andrew G; Shupe, Larry; Miles, Frank P; Fetz, Eberhard E

    2011-08-01

    The Neurochip-2 is a second generation, battery-powered device for neural recording and stimulating that is small enough to be carried in a chamber on a monkey's head. It has three recording channels, with user-adjustable gains, filters, and sampling rates, that can be optimized for recording single unit activity, local field potentials, electrocorticography, electromyography, arm acceleration, etc. Recorded data are stored on a removable, flash memory card. The Neurochip-2 also has three separate stimulation channels. Two "programmable-system-on-chips" (PSoCs) control the data acquisition and stimulus output. The PSoCs permit flexible real-time processing of the recorded data, such as digital filtering and time-amplitude window discrimination. The PSoCs can be programmed to deliver stimulation contingent on neural events or deliver preprogrammed stimuli. Access pins to the microcontroller are also available to connect external devices, such as accelerometers. The Neurochip-2 can record and stimulate autonomously for up to several days in freely behaving monkeys, enabling a wide range of novel neurophysiological and neuroengineering experiments. © 2011 IEEE

  13. Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

    PubMed

    Arneodo, Ezequiel M; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B

    2012-01-01

    Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

  14. The Neurochip-2: An Autonomous Head-Fixed Computer for Recording and Stimulating in Freely Behaving Monkeys

    PubMed Central

    Zanos, Stavros; Richardson, Andrew G.; Shupe, Larry; Miles, Frank P.; Fetz, Eberhard E.

    2011-01-01

    The Neurochip-2 is a second generation, battery-powered device for neural recording and stimulating that is small enough to be carried in a chamber on a monkey’s head. It has three recording channels, with user-adjustable gains, filters, and sampling rates, that can be optimized for recording single unit activity, local field potentials, electrocorticography, electromyography, arm acceleration, etc. Recorded data are stored on a removable, flash memory card. The Neurochip-2 also has three separate stimulation channels. Two “programmable-system-on-chips” (PSoCs) control the data acquisition and stimulus output. The PSoCs permit flexible real-time processing of the recorded data, such as digital filtering and time-amplitude window discrimination. The PSoCs can be programmed to deliver stimulation contingent on neural events or deliver preprogrammed stimuli. Access pins to the microcontroller are also available to connect external devices, such as accelerometers. The Neurochip-2 can record and stimulate autonomously for up to several days in freely behaving monkeys, enabling a wide range of novel neurophysiological and neuroengineering experiments. PMID:21632309

  15. Prosthetic Avian Vocal Organ Controlled by a Freely Behaving Bird Based on a Low Dimensional Model of the Biomechanical Periphery

    PubMed Central

    Arneodo, Ezequiel M.; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B.

    2012-01-01

    Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform. PMID:22761555

  16. FlyLimbTracker: An active contour based approach for leg segment tracking in unmarked, freely behaving Drosophila

    PubMed Central

    Delgado-Gonzalo, Ricard; Benton, Richard; Unser, Michael

    2017-01-01

    Understanding the biological underpinnings of movement and action requires the development of tools for quantitative measurements of animal behavior. Drosophila melanogaster provides an ideal model for developing such tools: the fly has unparalleled genetic accessibility and depends on a relatively compact nervous system to generate sophisticated limbed behaviors including walking, reaching, grooming, courtship, and boxing. Here we describe a method that uses active contours to semi-automatically track body and leg segments from video image sequences of unmarked, freely behaving D. melanogaster. We show that this approach yields a more than 6-fold reduction in user intervention when compared with fully manual annotation and can be used to annotate videos with low spatial or temporal resolution for a variety of locomotor and grooming behaviors. FlyLimbTracker, the software implementation of this method, is open-source and our approach is generalizable. This opens up the possibility of tracking leg movements in other species by modifications of underlying active contour models. PMID:28453566

  17. Afferent Input Selects NMDA Receptor Subtype to Determine the Persistency of Hippocampal LTP in Freely Behaving Mice

    PubMed Central

    Ballesteros, Jesús J.; Buschler, Arne; Köhr, Georg; Manahan-Vaughan, Denise

    2016-01-01

    The glutamatergic N-methyl-D-aspartate receptor (NMDAR) is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2) mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP) in vivo. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistence in freely behaving mice. We applied differing high-frequency stimulation (HFS) patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT) mice, that endured for <1 h (early (E)-LTP), (LTP, 2–4 h) or >24 h (late (L)-LTP). In GluN2A-knockout (KO) mice, E-LTP (HFS, 50 pulses) was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 × 50 pulses) and L-LTP (HFS, 4 × 50 pulses) were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E-LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged

  18. Dysregulated information processing by medium spiny neurons in striatum of freely behaving mouse models of Huntington's disease.

    PubMed

    Miller, Benjamin R; Walker, Adam G; Shah, Anand S; Barton, Scott J; Rebec, George V

    2008-10-01

    Huntington's disease (HD) is an autosomal dominant condition that compromises behavioral output. Dysfunction of medium spiny neurons (MSNs), which are the sole output system of the striatum, is thought to underlie HD pathophysiology. What is not known is how HD alters MSN information processing during behavior, which likely drives the HD behavioral phenotype. We recorded from populations of MSNs in two freely behaving and symptomatic HD mouse models: R6/2 transgenics are based on a C57BL/6J*CBA/J background and show robust behavioral symptoms, whereas knock-in (KI) mice have a 129sv background and express relatively mild behavioral signs. At the single-unit level, we found that the MSN firing rate was elevated in R6/2 but not in KI mice compared with their respective wild-type (WT) controls. In contrast, burst activity, which corresponds to periods of high-frequency firing, was altered in both HD models compared with WT. At the population level, we found that correlated firing between pairs of MSNs was a prominent feature in WT that was reduced in both HD models. Similarly, coincident bursts, which are bursts between pairs of neurons that overlap in time and occur more often in pairs of MSNs that exhibit correlated firing, were decreased in HD mice. Our results indicate an important role in both bursting and correlated burst firing for information processing in MSNs. Dysregulation of this processing scheme, moreover, is a key component of HD pathophysiology regardless of the severity of HD symptoms, genetic construct, and background strain of the mouse models.

  19. Effects on serotonin of (-)nicotine and dimethylphenylpiperazinium in the dorsal raphe and nucleus accumbens of freely behaving rats.

    PubMed

    Ma, Z; Strecker, R E; McKenna, J T; Thakkar, M M; McCarley, R W; Tao, R

    2005-01-01

    The aim of this study was to investigate the neurochemical mechanism underlying the effect of nicotine and dimethylphenylpiperazinium (DMPP) on 5-hydroxytryptamine (5-HT) release in the dorsal raphe nucleus and nucleus accumbens of freely behaving rats. For comparison, lobeline, cytisine and RJR-2403 were also investigated. It was found that all drugs, when infused locally, evoked an increase of 5-HT in the dorsal raphe nucleus. However, the magnitudes of the 5-HT increase were comparatively different between the drugs in the ranking of their potency: DMPP>RJR 2403>nicotine>lobeline>cytisine. Both methyllycaconitine, a nicotinic acetylcholine receptor (nAChR) antagonist and methyllycaconitine, a selective alpha7-containing nAChR antagonist blocked the effects of nicotine and DMPP, suggesting that alpha7 subunit mediated the increases in 5-HT. However, DMPP was reported to increase 5-HT using non-nAChR mechanism [Lendvai B, Sershen H, Lajtha A, Santha E, Baranyi M, Vizi ES (1996) Differential mechanisms involved in the effect of nicotinic agonists DMPP and lobeline to release [3H]5-HT from rat hippocampal slices. Neuropharmacology 35:1769-1777]. To test if 5-HT carriers were involved, a selective 5-HT reuptake inhibitor citalopram (1 microM) was infused into the dorsal raphe nucleus before administration of nicotine or DMPP. As a result, citalopram significantly blocked the effect of DMPP, whereas it had no influence on nicotine. Finally, the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) was used to test whether the increases in 5-HT were depolarization-dependent. Administration of 8-OH-DPAT (0.1 mg/kg, s.c.) produced significant decreases in 5-HT in the animals treated with nicotine. In contrast, the effect of DMPP was not altered by 8-OH-DPAT, suggesting that the increases in 5-HT were independent of cell membrane depolarization. In conclusion, there are different mechanisms involved in nicotine- and DMPP-evoked increases in 5-HT. This

  20. A movable microelectrode array for chronic basal ganglia single-unit electrocorticogram co-recording in freely behaving rats.

    PubMed

    Zheng, Xiaobin; Zeng, Jia; Chen, Ting; Lin, Yuanxiang; Yu, Lianghong; Li, Ying; Lin, Zhangya; Wu, Xiyue; Chen, Fuyong; Kang, Dezhi; Zhang, Shizhong

    2014-09-01

    The basal ganglia-cortical circuits are important for information process to brain function. However, chronic recording of single-unit activities in the basal ganglia nucleus has not yet been well established. We present a movable bundled microwire array for chronic subthalamic nucleus (STN) single-unit electrocorticogram co-recording. The electrode assembly contains a screw-advanced microdrive and a microwire array. The array consists of a steel guide tube, five recording wires and one referenced wire which form the shape of a guiding hand, and one screw electrode for cortico-recording. The electrode can acquire stable cortex oscillation-driven STN firing units in rats under different behaving conditions for 8 weeks. We achieved satisfying signal-to-noise ratio, portions of cells retaining viability, and spike waveform similarities across the recording sections. Using this method, we investigated neural correlations of the basal ganglia-cortical circuits in different behaving conditions. This method will become a powerful tool for multi-region recording to study normal statements or movement disorders.

  1. A1 receptor mediated adenosinergic regulation of perifornical-lateral hypothalamic area neurons in freely behaving rats

    PubMed Central

    Rai, Seema; Kumar, Sunil; Alam, Md. Aftab; Szymusiak, Ronald; McGinty, Dennis; Alam, Md. Noor

    2010-01-01

    The perifornical-lateral hypothalamic area (PF-LHA) plays a central role in the regulation of behavioral arousal. The PF-LHA contains several neuronal types including wake-active hypocretin (HCRT) neurons that have been implicated in the promotion and/or maintenance of behavioral arousal. Adenosine is an endogenous sleep factor and recent evidence suggests that activation and blockade of adenosine A1 receptors within the PF-LHA promote and suppress sleep, respectively. Although, an in vitro study indicates that adenosine inhibits HCRT neurons via A1 receptor, the in vivo effects of A1 receptor mediated adenosinergic transmission on PF-LHA neurons including HCRT neurons are not known. First, we determined the effects of N6-cyclopentyladenosine (CPA), an adenosine A1 receptor agonist, on the sleep-wake discharge activity of the PF-LHA neurons recorded via microwires placed adjacent to the microdialysis probe used for its delivery. Second, we determined the effects of CPA and that of an A1 receptor antagonist, 1,3-dipropyl-8-phenylxanthine (CPDX) into the PF-LHA on cFos-protein immunoreactivity (Fos-IR) in HCRT and non-HCRT neurons around the microdialysis probe used for their delivery. The effect of CPA was studied in rats that were kept awake during lights-off phase, whereas the effect of CPDX was examined in undisturbed rats during lights-on phase. CPA significantly suppressed the sleep-wake discharge activity of PF-LHA neurons. Doses of CPA (50μM) and CPDX (50μM) that suppressed and induced arousal, respectively, in our earlier study (Alam et al., 2009), significantly suppressed and increased Fos-IR in HCRT and non-HCRT neurons. These findings suggest that wake-promoting PF-LHA system is subject to increased endogenous adenosinergic inhibition and that adenosine acting via A1 receptors, in part, inhibits HCRT neurons to promote sleep. PMID:20109537

  2. Hippocampal EEG and Unit Activity Responses to Modulation of Serotonergic Median Raphe Neurons in the Freely Behaving Rat

    PubMed Central

    Nitz, Douglas A.; McNaughton, Bruce L.

    1999-01-01

    Hippocampal EEG, GABAergic interneurons, and principal cells were recorded simultaneously as rats foraged within one of three environments both before and after modulation of serotonergic inputs to the hippocampus. Median raphe microinjections of the 5-HT1a receptor agonist 8-OH-DPAT were made to produce inhibition of serotonergic neurons in this region. Such microinjections produced behavioral arousal and increases in the amplitude of hippocampal EEG theta. Consistent with the pattern of serotonergic innervation of the hippocampus, the GABAergic interneuron population was affected differentially by the microinjections. Principal cells were generally unaffected by the manipulation and maintained robust spatial firing correlates within the foraging environment. The results provide basic data on the relationship between serotonergic median raphe neurons and hippocampal activity in a behaving animal. The data suggest that behavioral responses to manipulation of the serotonergic system are mediated by brain regions other than the hippocampus or are mediated through changes in the activity of hippocampal interneurons. PMID:10327240

  3. Electrophysiological properties of ventromedial medulla neurons in response to noxious and non-noxious stimuli in the awake, freely moving rat: a single-unit study.

    PubMed

    Oliveras, J L; Vos, B; Martin, G; Montagne, J

    1989-05-01

    The spontaneous and evoked activities of ventromedial medulla (VMM) neurons have been recorded in the chronic, awake, freely moving rat. The vast majority of neurons located at the level of the nucleus raphé magnus exhibited an irregular and variable (2-16 Hz) spontaneous activity and were activated by either cutaneous or auditory stimuli. Within this convergent neuronal class the neurons were activated by either cutaneous noxious and non-noxious inputs. The threshold for cutaneous activation was likely very low since a majority of units responded to air puffs, but the application of controlled brushing and pin-prick revealed that the VMM convergent neurons responded more for the noxious mechanical stimulation. Similar findings were found with pinch application. For both innocuous and noxious stimuli, the cutaneous receptive field was extremely extensive (almost all of the body); however, the application of the controlled brushing showed that for this innocuous stimulation, the most sensitive regions were the tail, back, snout and vibrissae and, to a lesser extent, the flank and paws. Preliminary experiments indicated that both the spontaneous and evoked activities of VMM convergent neurons were inhibited during stressful manipulations such as scruff lifting or defense reactions. These data contrast with other studies on VMM single unit recordings in anesthetized rats since the majority of these studies did not emphasize the VMM convergent group; in addition, with one exception, we did not find neurons exclusively driven by noxious inputs. Without excluding a role of the VMM convergent group in pain descending control systems, we proposed that this neuronal class is perhaps also involved in pain transmission or in general processess such as alertness and stress. Experiments are proposed in order to precisely determine the involvement of the VMM convergent neurons in alertness versus sensory discriminative aspects of nociception in the awake, freely moving rat.

  4. [Halothane anesthesia decreases the level of interstitial striatal dopamine of awake freely moving rats in an in vivo microdialysis study].

    PubMed

    Adachi, Y; Uchihashi, Y; Watanabe, K; Satoh, T

    2000-02-01

    We investigated the effect of halothane on the level of interstitial dopamine of in vivo awake, free moving rats brain striatum using microdialysis techniques. Rats were implanted a microdialysis probe to right striatum of the brain and administered 1.5% of halothane (approximately 1.2 MAC) for 1 or 2 hours, and dialysates from the probe were determined every 20 minutes. Halothane anesthesia reduced the amount of dopamine derived from dialysate, and after discontinuation of halothane and at emergence from anesthesia, the level of dopamine was increased. The levels of metabolites of dopamine during anesthesia were increased lineally in a time dependent manner. We hypothesized that halothane might increase the rate of re-uptake of dopamine at nerve endings and decreased level of interstitial dopamine is compensated by dopamine releases during anesthesia.

  5. Changes in ensemble activity of hippocampus CA1 neurons induced by chronic morphine administration in freely behaving mice.

    PubMed

    Liu, F; Jiang, H; Zhong, W; Wu, X; Luo, J

    2010-12-15

    The hippocampus plays an important role in the formation of new memories and spatial navigation. Recently, growing evidence supports the view that it is also involved in addiction to opiates and other drugs. Theoretical and experimental studies suggest that hippocampal neural-network oscillations at specific frequencies and unit firing patterns reflect information of learning and memory encoding. Here, using multichannel recordings from the hippocampal CA1 area in behaving mice, we investigated the phase correlations between the theta (4-10 Hz) and gamma (40-100 Hz) oscillations, and the timing of spikes modulated by these oscillations. Local field potentials and single unit recordings in the CA1 area of mice receiving chronic morphine treatment revealed that the power of the theta rhythm was strongly increased; at the same time, the theta frequency during different behavioral states shifted markedly, and the characteristic coupling of theta and gamma oscillations was altered. Surprisingly, though the gamma oscillation frequency changed, the power of gamma lacking theta did not. Moreover, the timing of pyramidal cell spikes relative to the theta rhythm and the timing of interneuron spikes relative to the gamma rhythm changed during chronic morphine administration. Furthermore, these responses were impaired by a selective D1/D5 receptor antagonist intra-hippocampus injection. These results indicate that chronic morphine administration induced the changes of ensemble activity in the CA1 area, and these changes were dependent on local dopamine receptor activation.

  6. Zolpidem reduces hippocampal neuronal activity in freely behaving mice: a large scale calcium imaging study with miniaturized fluorescence microscope.

    PubMed

    Berdyyeva, Tamara; Otte, Stephani; Aluisio, Leah; Ziv, Yaniv; Burns, Laurie D; Dugovic, Christine; Yun, Sujin; Ghosh, Kunal K; Schnitzer, Mark J; Lovenberg, Timothy; Bonaventure, Pascal

    2014-01-01

    Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an adeno-associated viral vector to express the calcium sensor GCaMP3 in CA1 pyramidal cells under control of the CaMKII promoter and a miniaturized microscope to observe cellular dynamics. We visualized these dynamics with and without a systemic administration of Zolpidem, a GABAA agonist that is the most commonly prescribed drug for the treatment of insomnia in the United States. Despite growing concerns about the potential adverse effects of Zolpidem on memory and cognition, it remained unclear whether Zolpidem alters neuronal activity in the hippocampus, a brain area critical for cognition and memory. Zolpidem, when delivered at a dose known to induce and prolong sleep, strongly suppressed CA1 calcium signaling. The rate of calcium transients after Zolpidem administration was significantly lower compared to vehicle treatment. To factor out the contribution of changes in locomotor or physiological conditions following Zolpidem treatment, we compared the cellular activity across comparable epochs matched by locomotor and physiological assessments. This analysis revealed significantly depressive effects of Zolpidem regardless of the animal's state. Individual hippocampal CA1 pyramidal cells differed in their responses to Zolpidem with the majority (∼ 65%) significantly decreasing the rate of calcium transients, and a small subset (3%) showing an unexpected and significant increase. By linking molecular mechanisms with the dynamics of neural circuitry and behavioral states, this approach has the potential to contribute substantially to the development of new therapeutics for the treatment of CNS disorders.

  7. Zolpidem Reduces Hippocampal Neuronal Activity in Freely Behaving Mice: A Large Scale Calcium Imaging Study with Miniaturized Fluorescence Microscope

    PubMed Central

    Berdyyeva, Tamara; Otte, Stephani; Aluisio, Leah; Ziv, Yaniv; Burns, Laurie D.; Dugovic, Christine; Yun, Sujin; Ghosh, Kunal K.; Schnitzer, Mark J.; Lovenberg, Timothy; Bonaventure, Pascal

    2014-01-01

    Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an adeno-associated viral vector to express the calcium sensor GCaMP3 in CA1 pyramidal cells under control of the CaMKII promoter and a miniaturized microscope to observe cellular dynamics. We visualized these dynamics with and without a systemic administration of Zolpidem, a GABAA agonist that is the most commonly prescribed drug for the treatment of insomnia in the United States. Despite growing concerns about the potential adverse effects of Zolpidem on memory and cognition, it remained unclear whether Zolpidem alters neuronal activity in the hippocampus, a brain area critical for cognition and memory. Zolpidem, when delivered at a dose known to induce and prolong sleep, strongly suppressed CA1 calcium signaling. The rate of calcium transients after Zolpidem administration was significantly lower compared to vehicle treatment. To factor out the contribution of changes in locomotor or physiological conditions following Zolpidem treatment, we compared the cellular activity across comparable epochs matched by locomotor and physiological assessments. This analysis revealed significantly depressive effects of Zolpidem regardless of the animal’s state. Individual hippocampal CA1 pyramidal cells differed in their responses to Zolpidem with the majority (∼65%) significantly decreasing the rate of calcium transients, and a small subset (3%) showing an unexpected and significant increase. By linking molecular mechanisms with the dynamics of neural circuitry and behavioral states, this approach has the potential to contribute substantially to the development of new therapeutics for the treatment of CNS disorders. PMID:25372144

  8. Mechanical characteristics of rat vibrissae: resonant frequencies and damping in isolated whiskers and in the awake behaving animal.

    PubMed

    Hartmann, Mitra J; Johnson, Nicholas J; Towal, R Blythe; Assad, Christopher

    2003-07-23

    We investigated the natural resonance properties and damping characteristics of rat macrovibrissae (whiskers). Isolated whiskers rigidly fixed at the base showed first-mode resonance peaks between 27 and 260 Hz, principally depending on whisker length. These experimentally measured resonant frequencies were matched using a theoretical model of the whisker as a conical cantilever beam, with Young's modulus as the only free parameter. The best estimate for Young's modulus was approximately 3-4 GPa. Results of both vibration and impulse experiments showed that the whiskers are strongly damped, with damping ratios between 0.11 and 0.17. In the behaving animal, whiskers that deflected past an object were observed to resonate but were damped significantly more than isolated whiskers. The time course of damping varied depending on the individual whisker and the phase of the whisking cycle, which suggests that the rat may modulate biomechanical parameters that affect damping. No resonances were observed for whiskers that did not contact the object or during free whisking in air. Finally, whiskers on the same side of the face were sometimes observed to move in opposite directions over the full duration of a whisk. We discuss the potential roles of resonance during natural exploratory behavior and specifically suggest that resonant oscillations may be important in the rat's tactile detection of object boundaries.

  9. Mechanical characteristics of rat vibrissae: resonant frequencies and damping in isolated whiskers and in the awake behaving animal

    NASA Technical Reports Server (NTRS)

    Hartmann, Mitra J.; Johnson, Nicholas J.; Towal, R. Blythe; Assad, Christopher

    2003-01-01

    We investigated the natural resonance properties and damping characteristics of rat macrovibrissae (whiskers). Isolated whiskers rigidly fixed at the base showed first-mode resonance peaks between 27 and 260 Hz, principally depending on whisker length. These experimentally measured resonant frequencies were matched using a theoretical model of the whisker as a conical cantilever beam, with Young's modulus as the only free parameter. The best estimate for Young's modulus was approximately 3-4 GPa. Results of both vibration and impulse experiments showed that the whiskers are strongly damped, with damping ratios between 0.11 and 0.17. In the behaving animal, whiskers that deflected past an object were observed to resonate but were damped significantly more than isolated whiskers. The time course of damping varied depending on the individual whisker and the phase of the whisking cycle, which suggests that the rat may modulate biomechanical parameters that affect damping. No resonances were observed for whiskers that did not contact the object or during free whisking in air. Finally, whiskers on the same side of the face were sometimes observed to move in opposite directions over the full duration of a whisk. We discuss the potential roles of resonance during natural exploratory behavior and specifically suggest that resonant oscillations may be important in the rat's tactile detection of object boundaries.

  10. A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants

    PubMed Central

    Cruz-Garza, Jesus G.; Hernandez, Zachery R.; Tse, Teresa; Caducoy, Eunice; Abibullaev, Berdakh; Contreras-Vidal, Jose L.

    2015-01-01

    Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing “in action and in context”. This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks. PMID:26485409

  11. Somatosensory evoked response and jaw opening reflex elicited by tooth pulp stimulation in awake freely moving rats.

    PubMed

    Barek, Stephane; Rusina, Robert; Pollin, Bernard; Azerad, Jean

    2007-04-01

    Investigation of pain and nociception refers to different models. Depending upon the intensity of stimulation, unmyelinated pulpal fibers or periodontal A-fibers can be stimulated producing a short or a long latency jaw opening reflex of the digastric muscle. This paper investigates the different components of the jaw opening reflex in addition to the correlation between afferent fibers involved in the cortical evoked response. Fifteen awake male rats were implanted with tooth pulp stimulation electrodes, digastric and cortical recording electrodes. Ten rats were submitted to recordings after a single tooth pulp stimulation, while five rats were using conditioning and test stimulation. Tooth pulp evoked potentials and digastric EMG were simultaneously recorded. A multiresolution denoising method was used for signal processing. Following tooth pulp stimulation, a cortical response was produced including the following peaks: P6.5 +/- 1.1, N11 +/- 1.2, P17 +/- 1.2, P27 +/- 2.9, N53 +/- 7.5, P69 +/- 5.8, P88 +/- 13, N160 +/- 9.7, P204 +/- 14.2. The distribution and amplitude of these peaks are correlated to the stimulation intensity (r=0.96, p<0.01). An interaction between the different components of the jaw opening reflex was identified on EMG, following a conditioning shock, where a cortical evoked response showed a P30 +/- 2.7 peak which was observed concurrently with the jaw opening long latency reflex. Our results identify the interaction between the different components of the jaw opening reflex and the correlation to the cortical evoked response.

  12. Taste coding in the parabrachial nucleus of the pons in awake, freely licking rats and comparison with the nucleus of the solitary tract.

    PubMed

    Weiss, Michael S; Victor, Jonathan D; Di Lorenzo, Patricia M

    2014-04-01

    In the rodent, the parabrachial nucleus of the pons (PbN) receives information about taste directly from the nucleus of the solitary tract (NTS). Here we examined how information about taste quality (sweet, sour, salty, and bitter) is conveyed in the PbN of awake, freely licking rats, with a focus on how this information is transformed from the incoming NTS signals. Awake rats with electrodes in the PbN had free access to a lick spout that delivered taste stimuli (5 consecutive licks; 100 mM NaCl, 10 mM citric acid, 0.01 mM quinine HCl, or 100 mM sucrose and water) or water (as a rinse) on a variable-ratio schedule. To assess temporal coding, a family of metrics that quantifies the similarity of two spike trains in terms of spike count and spike timing was used. PbN neurons (n = 49) were generally broadly tuned across taste qualities with variable response latencies. Some PbN neurons were quiescent during lick bouts, and others, some taste responsive, showed time-locked firing to the lick pattern. Compared with NTS neurons, spike timing played a larger role in signaling taste in the first 2 s of the response, contributing significantly in 78% (38/49) of PbN cells compared with 45% of NTS cells. Also, information from temporal coding increased at a faster rate as the response unfolded over time in PbN compared with NTS. Collectively, these data suggest that taste-related information from NTS converges in the PbN to enable a subset of PbN cells to carry a larger information load.

  13. Taste coding in the parabrachial nucleus of the pons in awake, freely licking rats and comparison with the nucleus of the solitary tract

    PubMed Central

    Weiss, Michael S.; Victor, Jonathan D.

    2013-01-01

    In the rodent, the parabrachial nucleus of the pons (PbN) receives information about taste directly from the nucleus of the solitary tract (NTS). Here we examined how information about taste quality (sweet, sour, salty, and bitter) is conveyed in the PbN of awake, freely licking rats, with a focus on how this information is transformed from the incoming NTS signals. Awake rats with electrodes in the PbN had free access to a lick spout that delivered taste stimuli (5 consecutive licks; 100 mM NaCl, 10 mM citric acid, 0.01 mM quinine HCl, or 100 mM sucrose and water) or water (as a rinse) on a variable-ratio schedule. To assess temporal coding, a family of metrics that quantifies the similarity of two spike trains in terms of spike count and spike timing was used. PbN neurons (n = 49) were generally broadly tuned across taste qualities with variable response latencies. Some PbN neurons were quiescent during lick bouts, and others, some taste responsive, showed time-locked firing to the lick pattern. Compared with NTS neurons, spike timing played a larger role in signaling taste in the first 2 s of the response, contributing significantly in 78% (38/49) of PbN cells compared with 45% of NTS cells. Also, information from temporal coding increased at a faster rate as the response unfolded over time in PbN compared with NTS. Collectively, these data suggest that taste-related information from NTS converges in the PbN to enable a subset of PbN cells to carry a larger information load. PMID:24381029

  14. Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats.

    PubMed

    Li, Yu-Ting; Wickens, Jeffery R; Huang, Yi-Ling; Pan, Wynn H T; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

    2013-08-01

    Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg(-1) cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous monitoring of dopamine levels during animal learning

  15. Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats

    NASA Astrophysics Data System (ADS)

    Li, Yu-Ting; Wickens, Jeffery R.; Huang, Yi-Ling; Pan, Wynn H. T.; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

    2013-08-01

    Objective. Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. Approach. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. Main results. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg-1 cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. Significance. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous

  16. Supradural inflammatory soup in awake and freely moving rats induces facial allodynia that is blocked by putative immune modulators.

    PubMed

    Wieseler, Julie; Ellis, Amanda; McFadden, Andrew; Stone, Kendra; Brown, Kimberley; Cady, Sara; Bastos, Leandro F; Sprunger, David; Rezvani, Niloofar; Johnson, Kirk; Rice, Kenner C; Maier, Steven F; Watkins, Linda R

    2017-03-16

    Facial allodynia is a migraine symptom that is generally considered to represent a pivotal point in migraine progression. Treatment before development of facial allodynia tends to be more successful than treatment afterwards. As such, understanding the underlying mechanisms of facial allodynia may lead to a better understanding of the mechanisms underlying migraine. Migraine facial allodynia is modeled by applying inflammatory soup (histamine, bradykinin, serotonin, prostaglandin E2) over the dura. Whether glial and/or immune activation contributes to such pain is unknown. Here we tested if trigeminal nucleus caudalis (Sp5C) glial and/or immune cells are activated following supradural inflammatory soup, and if putative glial/immune inhibitors suppress the consequent facial allodynia. Inflammatory soup was administered via bilateral indwelling supradural catheters in freely moving rats, inducing robust and reliable facial allodynia. Gene expression for microglial/macrophage activation markers, interleukin-1β, and tumor necrosis factor-α increased following inflammatory soup along with robust expression of facial allodynia. This provided the basis for pursuing studies of the behavioral effects of 3 diverse immunomodulatory drugs on facial allodynia. Pretreatment with either of two compounds broadly used as putative glial/immune inhibitors (minocycline, ibudilast) prevented the development of facial allodynia, as did treatment after supradural inflammatory soup but prior to the expression of facial allodynia. Lastly, the toll-like receptor 4 (TLR4) antagonist (+)-naltrexone likewise blocked development of facial allodynia after supradural inflammatory soup. Taken together, these exploratory data support that activated glia and/or immune cells may drive the development of facial allodynia in response to supradural inflammatory soup in unanesthetized male rats.

  17. Flat-floored air-lifted platform: a new method for combining behavior with microscopy or electrophysiology on awake freely moving rodents.

    PubMed

    Kislin, Mikhail; Mugantseva, Ekaterina; Molotkov, Dmitry; Kulesskaya, Natalia; Khirug, Stanislav; Kirilkin, Ilya; Pryazhnikov, Evgeny; Kolikova, Julia; Toptunov, Dmytro; Yuryev, Mikhail; Giniatullin, Rashid; Voikar, Vootele; Rivera, Claudio; Rauvala, Heikki; Khiroug, Leonard

    2014-06-29

    It is widely acknowledged that the use of general anesthetics can undermine the relevance of electrophysiological or microscopical data obtained from a living animal's brain. Moreover, the lengthy recovery from anesthesia limits the frequency of repeated recording/imaging episodes in longitudinal studies. Hence, new methods that would allow stable recordings from non-anesthetized behaving mice are expected to advance the fields of cellular and cognitive neurosciences. Existing solutions range from mere physical restraint to more sophisticated approaches, such as linear and spherical treadmills used in combination with computer-generated virtual reality. Here, a novel method is described where a head-fixed mouse can move around an air-lifted mobile homecage and explore its environment under stress-free conditions. This method allows researchers to perform behavioral tests (e.g., learning, habituation or novel object recognition) simultaneously with two-photon microscopic imaging and/or patch-clamp recordings, all combined in a single experiment. This video-article describes the use of the awake animal head fixation device (mobile homecage), demonstrates the procedures of animal habituation, and exemplifies a number of possible applications of the method.

  18. Long-Lasting Visuo-Vestibular Mismatch in Freely-Behaving Mice Reduces the Vestibulo-Ocular Reflex and Leads to Neural Changes in the Direct Vestibular Pathway.

    PubMed

    Carcaud, Julie; França de Barros, Filipa; Idoux, Erwin; Eugène, Daniel; Reveret, Lionel; Moore, Lee E; Vidal, Pierre-Paul; Beraneck, Mathieu

    2017-01-01

    Calibration of the vestibulo-ocular reflex (VOR) depends on the presence of visual feedback. However, the cellular mechanisms associated with VOR modifications at the level of the brainstem remain largely unknown. A new protocol was designed to expose freely behaving mice to a visuo-vestibular mismatch during a 2-week period. This protocol induced a 50% reduction of the VOR. In vivo pharmacological experiments demonstrated that the VOR reduction depends on changes located outside the flocculus/paraflocculus complex. The cellular mechanisms associated with the VOR reduction were then studied in vitro on brainstem slices through a combination of vestibular afferent stimulation and patch-clamp recordings of central vestibular neurons. The evoked synaptic activity demonstrated that the efficacy of the synapses between vestibular afferents and central vestibular neurons was decreased. In addition, a long-term depression protocol failed to further decrease the synapse efficacy, suggesting that the VOR reduction might have occurred through depression-like mechanisms. Analysis of the intrinsic membrane properties of central vestibular neurons revealed that the synaptic changes were supplemented by a decrease in the spontaneous discharge and excitability of a subpopulation of neurons. Our results provide evidence that a long-lasting visuo-vestibular mismatch leads to changes in synaptic transmission and intrinsic properties of central vestibular neurons in the direct VOR pathway. Overall, these results open new avenues for future studies on visual and vestibular interactions conducted in vivo and in vitro.

  19. Long-Lasting Visuo-Vestibular Mismatch in Freely-Behaving Mice Reduces the Vestibulo-Ocular Reflex and Leads to Neural Changes in the Direct Vestibular Pathway

    PubMed Central

    Carcaud, Julie; França de Barros, Filipa; Eugène, Daniel; Reveret, Lionel; Moore, Lee E.; Vidal, Pierre-Paul

    2017-01-01

    Abstract Calibration of the vestibulo-ocular reflex (VOR) depends on the presence of visual feedback. However, the cellular mechanisms associated with VOR modifications at the level of the brainstem remain largely unknown. A new protocol was designed to expose freely behaving mice to a visuo-vestibular mismatch during a 2-week period. This protocol induced a 50% reduction of the VOR. In vivo pharmacological experiments demonstrated that the VOR reduction depends on changes located outside the flocculus/paraflocculus complex. The cellular mechanisms associated with the VOR reduction were then studied in vitro on brainstem slices through a combination of vestibular afferent stimulation and patch-clamp recordings of central vestibular neurons. The evoked synaptic activity demonstrated that the efficacy of the synapses between vestibular afferents and central vestibular neurons was decreased. In addition, a long-term depression protocol failed to further decrease the synapse efficacy, suggesting that the VOR reduction might have occurred through depression-like mechanisms. Analysis of the intrinsic membrane properties of central vestibular neurons revealed that the synaptic changes were supplemented by a decrease in the spontaneous discharge and excitability of a subpopulation of neurons. Our results provide evidence that a long-lasting visuo-vestibular mismatch leads to changes in synaptic transmission and intrinsic properties of central vestibular neurons in the direct VOR pathway. Overall, these results open new avenues for future studies on visual and vestibular interactions conducted in vivo and in vitro. PMID:28303261

  20. Taste coding of complex naturalistic taste stimuli and traditional taste stimuli in the parabrachial pons of the awake, freely licking rat.

    PubMed

    Sammons, Joshua D; Weiss, Michael S; Victor, Jonathan D; Di Lorenzo, Patricia M

    2016-07-01

    Several studies have shown that taste-responsive cells in the brainstem taste nuclei of rodents respond to sensory qualities other than gustation. Such data suggest that cells in the classical gustatory brainstem may be better tuned to respond to stimuli that engage multiple sensory modalities than to stimuli that are purely gustatory. Here, we test this idea by recording the electrophysiological responses to complex, naturalistic stimuli in single neurons in the parabrachial pons (PbN, the second neural relay in the central gustatory pathway) in awake, freely licking rats. Following electrode implantation and recovery, we presented both prototypical and naturalistic taste stimuli and recorded the responses in the PbN. Prototypical taste stimuli (NaCl, sucrose, citric acid, and caffeine) and naturalistic stimuli (clam juice, grape juice, lemon juice, and coffee) were matched for taste quality and intensity (concentration). Umami (monosodium glutamate + inosine monophosphate) and fat (diluted heavy cream) were also tested. PbN neurons responded to naturalistic stimuli as much or more than to prototypical taste stimuli. Furthermore, they convey more information about naturalistic stimuli than about prototypical ones. Moreover, multidimensional scaling analyses showed that across unit responses to naturalistic stimuli were more widely separated than responses to prototypical taste stimuli. Interestingly, cream evoked a robust and widespread response in PbN cells. Collectively, these data suggest that natural foods are more potent stimulators of PbN cells than purely gustatory stimuli. Probing PbN cells with pure taste stimuli may underestimate the response repertoire of these cells. Copyright © 2016 the American Physiological Society.

  1. Are ventromedial medulla neuronal properties modified by chronic peripheral inflammation? A single-unit study in the awake, freely moving polyarthritic rat.

    PubMed

    Montagne-Clavel, J; Olivéras, J L

    1994-09-19

    In the present work, we recorded the neuronal properties of the ventromedial medulla, a brainstem structure involved in the descending spinal control systems related to nociception, in awake, freely moving healthy and polyarthritic rats. These animals were rendered polyarthritic with a subcutaneous administration of the Freund's adjuvant into the tail, and studied at 20 and 30 days post-inoculation. At the ventromedial medulla level, the single-unit activities were recorded by means of a chronically implanted device supporting a 50 microns platinum-iridium wire as the recording electrode. With a total of 308 recorded neurons, we determined that in both healthy rats, i.e. animals having received mineral oil only and arthritic rats, there were ventromedial medulla units with common physiological properties, but also changes. In agreement with the results from anesthetized arthritic rats at spinal and thalamic levels, the systematic analysis of the responses to light touch and mechanical shock revealed that the 'multimodal, multireceptive' units, excited by innocuous and noxious stimuli, were much more responsive to both modalities in arthritic rats. Approximately 7% of these neurons displayed a 'paroxysmal' spontaneous activity, also reported in the literature for other structures. In addition, we recorded a significant number of neurons inhibited or excited-inhibited by innocuous and noxious cutaneous stimulations, and a few with a regular spontaneous activity, also responding, which has never been the case in healthy rats. We conclude that a peripheral chronic inflammation, such as arthritis, can produce changes of the ventromedial medulla neuronal properties, as compared to healthy animals. Consequently, in addition to its classical role in the spinal control of nociception, the ventromedial medulla is able to develop some form of plasticity in the case of persistent pain of peripheral origin.

  2. [The effect of sevoflurane and isoflurane on striatal dopamine of awake freely moving rats observed in an in vivo microdialysis study].

    PubMed

    Adachi, Y; Taoda, M; Uchihashi, Y; Watanabe, K; Satoh, T

    1999-09-01

    We investigated the effect of sevoflurane and isoflurane on the level of interstitial dopamine of in vivo awake, free moving rats brain striatum using microdialysis techniques. Rats were implanted with a microdialysis probe to the right striatum of the brain and administered with 1.2 MAC of each volatile anesthetics for 1 hour, and dialysates from the probe were determined every 20 minutes. Both anesthetics reduced the amount of dopamine derived from dialysate, and increased the efflux of dopamine with pretreatment of nomifensine 10mg. kg-1 i.p. The change of metabolites of dopamine during anesthesia was increased. No significant difference was found between sevoflurane and isoflurane. We hypothesized that these anesthetics might have special actions on interactions between metabolism and re-uptake of dopamine in rats striatum during anesthesia.

  3. Electrophysiological recordings from behaving animals--going beyond spikes.

    PubMed

    Chorev, Edith; Epsztein, Jérôme; Houweling, Arthur R; Lee, Albert K; Brecht, Michael

    2009-10-01

    Most of our current knowledge about the neural control of behavior is based on electrophysiology. Here we review advances and limitations of current electrophysiological recording techniques applied in behaving animals. Extracellular recording methods have improved with respect to sampling density and miniaturization, and our understanding of the nature of the recorded signals has advanced. Juxtacellular recordings have become increasingly popular as they allow identification of the recorded neurons. Juxtacellular recordings are relatively easy to apply in behaving animals and can be used to stimulate individual neurons. Methods for intracellular recordings in awake behaving animals also advanced, and it has become clear that long-duration intracellular recordings are possible even in freely moving animals. We conclude that the electrophysiological methods repertoire has greatly diversified in recent years and that the field has moved beyond what used to be a mere spike counting business.

  4. Frequency Facilitation at Mossy Fiber–CA3 Synapses of Freely Behaving Rats Contributes to the Induction of Persistent LTD via an Adenosine-A1 Receptor-Regulated Mechanism

    PubMed Central

    Hagena, Hardy

    2010-01-01

    Frequency facilitation (FF), comprising a rapid and multiple-fold increase in the magnitude of evoked field potentials, is elicited by low-frequency stimulation (LFS) at mossy fiber–CA3 synapses. Here, we show that in freely behaving rats, FF reliably occurs in response to 1 and 2Hz but not in response to 0.25-, 0.3-, or 0.5-Hz LFS. Strikingly, prolonged (∼600 s) FF was tightly correlated to the induction of long-term depression (LTD) in freely moving animals. Although LFS at 2 Hz elicited unstable FF and unstable LTD, application of LFS at 1 Hz elicited pronounced FF, as well as robust LTD that persisted for over 24 h. This correlation of prolonged FF with LTD was absent at stimulation frequencies that did not induce FF. The adenosine-A1 receptor appears to participate in these effects: Application of adenosine-A1, but not adenosine-A3, receptor antagonists enhanced mossy fiber synaptic transmission and occluded FF. Furthermore, adenosine-A1 receptor antagonism resulted in more stable FF at 1 or 2 Hz and elicited more potent LTD. These data support the fact that FF contributes to the enablement of long-term information storage at mossy fiber–CA3 synapses and that the adenosine-A1 receptor may regulate the thresholds for this process. PMID:19903765

  5. Awake intubation.

    PubMed

    Peiris, Kawshala; Frerk, Chris

    2008-03-01

    Securing the airway is a core skill in anaesthesia, the gold standard of which is tracheal intubation. Normally this is achieved after induction of anaesthesia. However, some circumstances demand an awake approach. Awake intubation can be achieved via several methods. Using the fibreoptic laryngoscope is the most widely used technique in the UK with minimal patient discomfort and a wide margin of safety. When compared with attempts at difficult direct laryngoscopy, awake fibreoptic intubation provides excellent cardiovascular stability when performed under good topical anaesthesia and conscious sedation. Understanding the equipment used as well as preparing the patient and being aware of potential pitfalls are important elements to performing a successful awake intubation.

  6. Longitudinal testing of hippocampal plasticity reveals the onset and maintenance of endogenous human Aß-induced synaptic dysfunction in individual freely behaving pre-plaque transgenic rats: rapid reversal by anti-Aß agents.

    PubMed

    Qi, Yingjie; Klyubin, Igor; Harney, Sarah C; Hu, NengWei; Cullen, William K; Grant, Marianne K; Steffen, Julia; Wilson, Edward N; Do Carmo, Sonia; Remy, Stefan; Fuhrmann, Martin; Ashe, Karen H; Cuello, A Claudio; Rowan, Michael J

    2014-12-24

    Long before synaptic loss occurs in Alzheimer's disease significant harbingers of disease may be detected at the functional level. Here we examined if synaptic long-term potentiation is selectively disrupted prior to extracellular deposition of Aß in a very complete model of Alzheimer's disease amyloidosis, the McGill-R-Thy1-APP transgenic rat. Longitudinal studies in freely behaving animals revealed an age-dependent, relatively rapid-onset and persistent inhibition of long-term potentiation without a change in baseline synaptic transmission in the CA1 area of the hippocampus. Thus the ability of a standard 200 Hz conditioning protocol to induce significant NMDA receptor-dependent short- and long-term potentiation was lost at about 3.5 months of age and this deficit persisted for at least another 2-3 months, when plaques start to appear. Consistent with in vitro evidence for a causal role of a selective reduction in NMDA receptor-mediated synaptic currents, the deficit in synaptic plasticity in vivo was associated with a reduction in the synaptic burst response to the conditioning stimulation and was overcome using stronger 400 Hz stimulation. Moreover, intracerebroventricular treatment for 3 days with an N-terminally directed monoclonal anti- human Aß antibody, McSA1, transiently reversed the impairment of synaptic plasticity. Similar brief treatment with the BACE1 inhibitor LY2886721 or the γ-secretase inhibitor MRK-560 was found to have a comparable short-lived ameliorative effect when tracked in individual rats. These findings provide strong evidence that endogenously generated human Aß selectively disrupts the induction of long-term potentiation in a manner that enables potential therapeutic options to be assessed longitudinally at the pre-plaque stage of Alzheimer's disease amyloidosis.

  7. Imaging neuronal populations in behaving rodents: paradigms for studying neural circuits underlying behavior in the mammalian cortex.

    PubMed

    Chen, Jerry L; Andermann, Mark L; Keck, Tara; Xu, Ning-Long; Ziv, Yaniv

    2013-11-06

    Understanding the neural correlates of behavior in the mammalian cortex requires measurements of activity in awake, behaving animals. Rodents have emerged as a powerful model for dissecting the cortical circuits underlying behavior attributable to the convergence of several methods. Genetically encoded calcium indicators combined with viral-mediated or transgenic tools enable chronic monitoring of calcium signals in neuronal populations and subcellular structures of identified cell types. Stable one- and two-photon imaging of neuronal activity in awake, behaving animals is now possible using new behavioral paradigms in head-fixed animals, or using novel miniature head-mounted microscopes in freely moving animals. This mini-symposium will highlight recent applications of these methods for studying sensorimotor integration, decision making, learning, and memory in cortical and subcortical brain areas. We will outline future prospects and challenges for identifying the neural underpinnings of task-dependent behavior using cellular imaging in rodents.

  8. Imaging Neuronal Populations in Behaving Rodents: Paradigms for Studying Neural Circuits Underlying Behavior in the Mammalian Cortex

    PubMed Central

    Andermann, Mark L.; Keck, Tara; Xu, Ning-Long; Ziv, Yaniv

    2013-01-01

    Understanding the neural correlates of behavior in the mammalian cortex requires measurements of activity in awake, behaving animals. Rodents have emerged as a powerful model for dissecting the cortical circuits underlying behavior attributable to the convergence of several methods. Genetically encoded calcium indicators combined with viral-mediated or transgenic tools enable chronic monitoring of calcium signals in neuronal populations and subcellular structures of identified cell types. Stable one- and two-photon imaging of neuronal activity in awake, behaving animals is now possible using new behavioral paradigms in head-fixed animals, or using novel miniature head-mounted microscopes in freely moving animals. This mini-symposium will highlight recent applications of these methods for studying sensorimotor integration, decision making, learning, and memory in cortical and subcortical brain areas. We will outline future prospects and challenges for identifying the neural underpinnings of task-dependent behavior using cellular imaging in rodents. PMID:24198355

  9. Acute intracerebral treatment with amyloid-beta (1–42) alters the profile of neuronal oscillations that accompany LTP induction and results in impaired LTP in freely behaving rats

    PubMed Central

    Kalweit, Alexander Nikolai; Yang, Honghong; Colitti-Klausnitzer, Jens; Fülöp, Livia; Bozsó, Zsolt; Penke, Botond; Manahan-Vaughan, Denise

    2015-01-01

    Accumulation of amyloid plaques comprises one of the major hallmarks of Alzheimer’s disease (AD). In rodents, acute treatment with amyloid-beta (Aβ; 1–42) elicits immediate debilitating effects on hippocampal long-term potentiation (LTP). Whereas LTP contributes to synaptic information storage, information is transferred across neurons by means of neuronal oscillations. Furthermore, changes in theta-gamma oscillations, that appear during high-frequency stimulation (HFS) to induce LTP, predict whether successful LTP will occur. Here, we explored if intra-cerebral treatment with Aβ(1–42), that prevents LTP, also results in alterations of hippocampal oscillations that occur during HFS of the perforant path-dentate gyrus synapse in 6-month-old behaving rats. HFS resulted in LTP that lasted for over 24 h. In Aβ-treated animals, LTP was significantly prevented. During HFS, spectral power for oscillations below 100 Hz (δ, θ, α, β and γ) was significantly higher in Aβ-treated animals compared to controls. In addition, the trough-to-peak amplitudes of theta and gamma cycles were higher during HFS in Aβ-treated animals. We also observed a lower amount of envelope-to-signal correlations during HFS in Aβ-treated animals. Overall, the characteristic profile of theta-gamma oscillations that accompany successful LTP induction was disrupted. These data indicate that alterations in network oscillations accompany Aβ-effects on hippocampal LTP. This may comprise an underlying mechanism through which disturbances in synaptic information storage and hippocampus-dependent memory occurs in AD. PMID:25999827

  10. Chronic wide-field imaging of brain hemodynamics in behaving animals

    PubMed Central

    Miao, Peng; Zhang, Lingke; Li, Miao; Zhang, Yiguang; Feng, Shihan; Wang, Qihong; Thakor, Nitish V.

    2016-01-01

    Chronically monitoring cerebral activities in awake and freely moving status is very important in physiological and pathological studies. We present a novel standalone micro-imager for monitoring the cerebral blood flow (CBF) and total hemoglobin (HbT) activities in freely moving animals using the laser speckle contrast imaging (LSCI) and optical intrinsic signal (OIS) methods. A new cranial window method, using contact lens and wide field optics, is also proposed to achieve the chronic and wide-field imaging of rat’s cerebral cortex. The hemodynamic activities of rats’ cortex were measured for the first time without restriction of cables or fibers in awake and behaving animals. Chronic imaging showed the increase of CBF and HbT in motor cortex when the rats were climbing on the cage wall. Interestingly, the CBF activation of supplying vessel was smaller than that of parenchyma. Furthermore, after the climbing, CBF demonstrated fully return to the baseline while HbT showed a delayed recovery. The standalone micro-imager technology provides new possibilities of brain imaging in cognitive neuroscience studies. PMID:28101429

  11. Anatomical and functional neuroimaging in awake, behaving marmosets.

    PubMed

    Silva, Afonso C

    2017-03-01

    The common marmoset (Callithrix jacchus) is a small New World monkey that has gained significant recent interest in neuroscience research, not only because of its compatibility with gene editing techniques, but also due to its tremendous versatility as an experimental animal model. Neuroimaging modalities, including anatomical (MRI) and functional magnetic resonance imaging (fMRI), complemented by two-photon laser scanning microscopy and electrophysiology, have been at the forefront of unraveling the anatomical and functional organization of the marmoset brain. High-resolution anatomical MRI of the marmoset brain can be obtained with remarkable cytoarchitectonic detail. Functional MRI of the marmoset brain has been used to study various sensory systems, including somatosensory, auditory, and visual pathways, while resting-state fMRI studies have unraveled functional brain networks that bear great correspondence to those previously described in humans. Two-photon laser scanning microscopy of the marmoset brain has enabled the simultaneous recording of neuronal activity from thousands of neurons with single cell spatial resolution. In this article, we aim to review the main results obtained by our group and by our colleagues in applying neuroimaging techniques to study the marmoset brain. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 373-389, 2017. © 2016 Wiley Periodicals, Inc.

  12. Chronic detachable headphones for acoustic stimulation in freely moving animals

    PubMed Central

    Nodal, Fernando R.; Keating, Peter; King, Andrew J.

    2010-01-01

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets’ performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals. PMID:20346981

  13. Coding odor identity and odor value in awake rodents

    PubMed Central

    Nuñez-Parra, Alexia; Li, Anan; Restrepo, Diego

    2014-01-01

    In the last decade, drastic changes in the understanding of the role of the olfactory bulb and piriform cortex in odor detection have taken place through awake behaving recording in rodents. It is clear that odor responses in mitral and granule cells are strikingly different in the olfactory bulb of anesthetized vs. awake animals. In addition, sniff recording has evidenced that mitral cell responses to odors during the sniff can convey information on the odor identity and sniff phase. Moreover, we review studies that show that the mitral cell conveys not only information on odor identity but also on whether the odor is rewarded or not (odor value). Finally, we discuss how the substantial increase in awake behaving recording raises questions for future studies. PMID:24767484

  14. Micro-device combining electrophysiology and optical imaging for functional brain monitoring in freely moving animals

    NASA Astrophysics Data System (ADS)

    Miao, Peng; Wang, Qihong; Zhang, Lingke; Li, Miao; Thakor, Nitish V.

    2017-02-01

    Monitoring brain activities in awake and freely moving status is very important in physiological and pathological studies of brain functions. In this study, we developed a new standalone micro-device combining electrophysiology and optical imaging for monitoring the cerebral blood flow and neural activities with more feasibility for freely moving animals.

  15. Effects of stimulus frequency and age on bidirectional synaptic plasticity in the dentate gyrus of freely moving rats.

    PubMed

    Blaise, J Harry; Bronzino, Joseph D

    2003-08-01

    We investigated the frequency-dependent transition from homosynaptic long-term depression (LTD) to long-term potentiation (LTP) at the lateral perforant pathway/dentate gyrus synapse in adult (90 days of age) and immature (15 days of age) awake, freely moving rats. Dentate-evoked field potentials were recorded and analyzed using the population spike amplitude and the field EPSP slope measures following sustained stimulation (900 pulses) of the lateral perforant pathway at various frequencies (1, 3, 7, 30, 50, or 200 Hz). Our results indicate that both the strength and the direction (LTP or LTD) of synaptic plasticity vary as a function of activation frequency: sustained low-frequency stimulation ranging from 1 to 7 Hz results in depression of activated synapses, whereas high-frequency stimulation (30-200 Hz) produces potentiation. In addition, a significant (P < 0.01) ontogenetic shift in the frequency of transition from LTD to LTP was observed; the transition frequency in immature animals was significantly lower than that obtained in adult animals. These observations agree strongly with the prediction of the Bienenstock-Cooper-Munro theory of synapse modification, indicating perhaps a neurophysiological basis for this theoretical model of learning in the dentate gyrus of awake behaving rats.

  16. Fully Awake Breast Reduction.

    PubMed

    Filson, Simon A; Yarhi, Danielle; Ramon, Yitzhak

    2016-11-01

    The authors present 25 cases and an in-depth 4-minute video of fully awake aesthetic breast reduction, which was made possible by thoracic epidural anesthesia. There are obvious and important advantages to this technique. Not only does this allow for intraoperative patient cooperation (i.e., patient self-positioning and opinion for comparison of breasts), meaning a shorter and more efficient intraoperative time, there also is a reduction in postoperative pain, complications, recovery, and discharge times. The authors have also enjoyed great success and no complications with this technique in over 150 awake abdominoplasty/total body lift patients. The authors feel that the elimination of the need for general anesthesia by thoracic epidural sensorial-only anesthesia is a highly effective and efficient technique, with very few disadvantages/complications, providing advantages to both patients and surgeons. Therapeutic, IV.

  17. A low-cost, multiplexed μECoG system for high-density recordings in freely-moving rodents

    PubMed Central

    Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

    2016-01-01

    Objective Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely-behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely-moving rats. Approach Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely-moving awake animals. Main results We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ~10 seconds by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in

  18. A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents

    NASA Astrophysics Data System (ADS)

    Insanally, Michele; Trumpis, Michael; Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

    2016-04-01

    Objective. Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. Approach. Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. Main results. We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ∼10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance. This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision

  19. Swept confocally-aligned planar excitation (SCAPE) microscopy for high speed volumetric imaging of behaving organisms

    PubMed Central

    Bouchard, Matthew B.; Voleti, Venkatakaushik; Mendes, César S.; Lacefield, Clay; Grueber, Wesley B.; Mann, Richard S.; Bruno, Randy M.; Hillman, Elizabeth M. C.

    2014-01-01

    We report a new 3D microscopy technique that allows volumetric imaging of living samples at ultra-high speeds: Swept, confocally-aligned planar excitation (SCAPE) microscopy. While confocal and two-photon microscopy have revolutionized biomedical research, current implementations are costly, complex and limited in their ability to image 3D volumes at high speeds. Light-sheet microscopy techniques using two-objective, orthogonal illumination and detection require a highly constrained sample geometry, and either physical sample translation or complex synchronization of illumination and detection planes. In contrast, SCAPE microscopy acquires images using an angled, swept light-sheet in a single-objective, en-face geometry. Unique confocal descanning and image rotation optics map this moving plane onto a stationary high-speed camera, permitting completely translationless 3D imaging of intact samples at rates exceeding 20 volumes per second. We demonstrate SCAPE microscopy by imaging spontaneous neuronal firing in the intact brain of awake behaving mice, as well as freely moving transgenic Drosophila larvae. PMID:25663846

  20. Swept confocally-aligned planar excitation (SCAPE) microscopy for high speed volumetric imaging of behaving organisms.

    PubMed

    Bouchard, Matthew B; Voleti, Venkatakaushik; Mendes, César S; Lacefield, Clay; Grueber, Wesley B; Mann, Richard S; Bruno, Randy M; Hillman, Elizabeth M C

    2015-02-01

    We report a new 3D microscopy technique that allows volumetric imaging of living samples at ultra-high speeds: Swept, confocally-aligned planar excitation (SCAPE) microscopy. While confocal and two-photon microscopy have revolutionized biomedical research, current implementations are costly, complex and limited in their ability to image 3D volumes at high speeds. Light-sheet microscopy techniques using two-objective, orthogonal illumination and detection require a highly constrained sample geometry, and either physical sample translation or complex synchronization of illumination and detection planes. In contrast, SCAPE microscopy acquires images using an angled, swept light-sheet in a single-objective, en-face geometry. Unique confocal descanning and image rotation optics map this moving plane onto a stationary high-speed camera, permitting completely translationless 3D imaging of intact samples at rates exceeding 20 volumes per second. We demonstrate SCAPE microscopy by imaging spontaneous neuronal firing in the intact brain of awake behaving mice, as well as freely moving transgenic Drosophila larvae.

  1. Awake right hemisphere brain surgery.

    PubMed

    Hulou, M Maher; Cote, David J; Olubiyi, Olutayo I; Smith, Timothy R; Chiocca, E Antonio; Johnson, Mark D

    2015-12-01

    We report the indications and outcomes of awake right hemispheric brain surgery, as well as a rare patient with crossed aphasia. Awake craniotomies are often performed to protect eloquent cortex. We reviewed the medical records for 35 of 96 patients, in detail, who had awake right hemisphere brain operations. Intraoperative cortical mapping of motor and/or language function was performed in 29 of the 35 patients. A preoperative speech impairment and left hand dominance were the main indicators for awake right-sided craniotomies in patients with right hemisphere lesions. Four patients with lesion proximity to eloquent areas underwent awake craniotomies without cortical mapping. In addition, one patient had a broncho-pulmonary fistula, and another had a recent major cardiac procedure that precluded awake surgery. An eloquent cortex representation was identified in 14 patients (48.3%). Postoperatively, seven of 17 patients (41.1%) who presented with weakness, experienced improvements in their motor functions, 11 of 16 (68.7%) with seizures became seizure-free, and seven of nine (77.7%) with moderate to severe headaches and one of two with a visual field deficit improved significantly. There were also improvements in speech and language functions in all patients who presented with speech difficulties. A right sided awake craniotomy is an excellent option for left handed patients, or those with right sided cortical lesions that result in preoperative speech impairments. When combined with intraoperative cortical mapping, both speech and motor function can be well preserved.

  2. Real-time dopamine measurement in awake monkeys.

    PubMed

    Schluter, Erik W; Mitz, Andrew R; Cheer, Joseph F; Averbeck, Bruno B

    2014-01-01

    Fast-scan cyclic voltammetry (FSCV) is often used to measure real-time dopamine (DA) concentrations in awake, behaving rodents. Extending this technique to work in monkeys would provide a platform for advanced behavioral studies and a primate model for preclinical research. The present study demonstrates the feasibility of DA recordings in two awake monkeys (Macaca mulatta) using a mixture of techniques adapted from rodent, primate and brain slice work. We developed a long carbon fiber electrode to operate in the larger primate brain. This electrode was lowered into the striatum each day using a recording chamber and a detachable micromanipulator system. A manipulator also moved one or more tungsten stimulating electrodes into either the nearby striatum or the ventral tegmental area/substantia nigra pars compacta (VTA/SNc). We developed an electrical stimulation controller to reduce artifacts during electrical stimulation. We also introduce a stimulation-based methodology for estimating distances between electrodes in the brain. Dopamine responses within the striatum were evoked by either stimulation of the striatum near the FSCV electrode, or stimulation within the VTA/SNc. Unexpected juice rewards also evoked dopamine responses in the ventral striatum. Thus, we demonstrate that robust dopamine responses can be recorded from awake, behaving primates with FSCV. In addition, we describe how a stimulation technique borrowed from the neuroprosthetics field can activate the distributed monkey midbrain dopamine system in a way that mimics rodent VTA stimulation.

  3. Awake craniotomy for tumor resection

    PubMed Central

    Attari, Mohammadali; Salimi, Sohrab

    2013-01-01

    Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit. PMID:24223378

  4. Long-term imaging in awake mice using removable cranial windows

    PubMed Central

    Glickfeld, Lindsey L.; Kerlin, Aaron M.; Reid, R. Clay; Bonin, Vincent; Schafer, Dorothy P.; Andermann, Mark L.

    2015-01-01

    Cranial window implants in head-fixed rodents are becoming a preparation of choice for stable optical access to large areas of cortex over extended periods of time. Here, we provide a highly detailed and reliable surgical protocol for a cranial window implantation procedure for chronic widefield and cellular imaging in awake, head-fixed mice, which enables subsequent window removal and replacement in the weeks and months following the initial craniotomy. This protocol has facilitated awake, chronic imaging in adolescent as well as adult mice over several months from a large number of cortical brain regions; targeted virus and tracer injections from data obtained using prior awake functional mapping; and functionally-targeted two-photon imaging across all cortical layers in awake mice using a microprism attachment to the cranial window. Collectively, these procedures extend the reach of chronic imaging of cortical function and dysfunction in behaving animals. PMID:25275789

  5. Swept confocally-aligned planar excitation (SCAPE) microscopy for high-speed volumetric imaging of behaving organisms

    NASA Astrophysics Data System (ADS)

    Bouchard, Matthew B.; Voleti, Venkatakaushik; Mendes, César S.; Lacefield, Clay; Grueber, Wesley B.; Mann, Richard S.; Bruno, Randy M.; Hillman, Elizabeth M. C.

    2015-02-01

    We report a three-dimensional microscopy technique—swept, confocally-aligned planar excitation (SCAPE) microscopy—that allows volumetric imaging of living samples at ultrahigh speeds. Although confocal and two-photon microscopy have revolutionized biomedical research, current implementations are costly, complex and limited in their ability to image three-dimensional volumes at high speeds. Light-sheet microscopy techniques using two-objective, orthogonal illumination and detection require a highly constrained sample geometry and either physical sample translation or complex synchronization of illumination and detection planes. In contrast, SCAPE microscopy acquires images using an angled, swept light sheet in a single-objective, en face geometry. Unique confocal descanning and image rotation optics map this moving plane onto a stationary high-speed camera, permitting completely translationless three-dimensional imaging of intact samples at rates exceeding 20 volumes per second. We demonstrate SCAPE microscopy by imaging spontaneous neuronal firing in the intact brain of awake behaving mice, as well as freely moving transgenic Drosophila larvae.

  6. Cellular level brain imaging in behaving mammals: an engineering approach.

    PubMed

    Hamel, Elizabeth J O; Grewe, Benjamin F; Parker, Jones G; Schnitzer, Mark J

    2015-04-08

    Fluorescence imaging offers expanding capabilities for recording neural dynamics in behaving mammals, including the means to monitor hundreds of cells targeted by genetic type or connectivity, track cells over weeks, densely sample neurons within local microcircuits, study cells too inactive to isolate in extracellular electrical recordings, and visualize activity in dendrites, axons, or dendritic spines. We discuss recent progress and future directions for imaging in behaving mammals from a systems engineering perspective, which seeks holistic consideration of fluorescent indicators, optical instrumentation, and computational analyses. Today, genetically encoded indicators of neural Ca(2+) dynamics are widely used, and those of trans-membrane voltage are rapidly improving. Two complementary imaging paradigms involve conventional microscopes for studying head-restrained animals and head-mounted miniature microscopes for imaging in freely behaving animals. Overall, the field has attained sufficient sophistication that increased cooperation between those designing new indicators, light sources, microscopes, and computational analyses would greatly benefit future progress.

  7. Effects of a ketogenic diet on hippocampal plasticity in freely moving juvenile rats

    PubMed Central

    Blaise, J Harry; Ruskin, David N; Koranda, Jessica L; Masino, Susan A

    2015-01-01

    Ketogenic diets are low-carbohydrate, sufficient protein, high-fat diets with anticonvulsant activity used primarily as a treatment for pediatric epilepsy. The anticonvulsant mechanism is thought to involve elevating inhibition and/or otherwise limiting excitability in the brain. Such a mechanism, however, might also significantly affect normal brain activity and limit synaptic plasticity, effects that would be important to consider in the developing brain. To assess ketogenic diet effects on synaptic transmission and plasticity, electrophysiological recordings were performed at the perforant path/dentate gyrus synapse in awake, freely-behaving juvenile male rats. Electrodes were implanted 1 week prior to recording. Animals were fed regular chow or a ketogenic diet ad libitum for 3 weeks before recording. Although the ketogenic diet did not significantly alter baseline excitability (assessed by input–output curves) or short-term plasticity (using the paired-pulse ratio), it did reduce the magnitude of long-term potentiation at all poststimulation timepoints out to the last time measured (48 h). The results suggest an effect of ketogenic diet-feeding on the induction magnitude but not the maintenance of long-term potentiation. The lack of effect of the diet on baseline transmission and the paired-pulse ratio suggests a mechanism that limits excitation preferentially in conditions of strong stimulation, consonant with clinical reports in which the ketogenic diet alleviates seizures without a major impact on normal brain activity. Limiting plasticity in a seizure-susceptible network may limit seizure-induced epileptogenesis which may subserve the ongoing benefit of the ketogenic diet in epilepsy. PMID:26009636

  8. Effects of a ketogenic diet on hippocampal plasticity in freely moving juvenile rats.

    PubMed

    Blaise, J Harry; Ruskin, David N; Koranda, Jessica L; Masino, Susan A

    2015-05-01

    Ketogenic diets are low-carbohydrate, sufficient protein, high-fat diets with anticonvulsant activity used primarily as a treatment for pediatric epilepsy. The anticonvulsant mechanism is thought to involve elevating inhibition and/or otherwise limiting excitability in the brain. Such a mechanism, however, might also significantly affect normal brain activity and limit synaptic plasticity, effects that would be important to consider in the developing brain. To assess ketogenic diet effects on synaptic transmission and plasticity, electrophysiological recordings were performed at the perforant path/dentate gyrus synapse in awake, freely-behaving juvenile male rats. Electrodes were implanted 1 week prior to recording. Animals were fed regular chow or a ketogenic diet ad libitum for 3 weeks before recording. Although the ketogenic diet did not significantly alter baseline excitability (assessed by input-output curves) or short-term plasticity (using the paired-pulse ratio), it did reduce the magnitude of long-term potentiation at all poststimulation timepoints out to the last time measured (48 h). The results suggest an effect of ketogenic diet-feeding on the induction magnitude but not the maintenance of long-term potentiation. The lack of effect of the diet on baseline transmission and the paired-pulse ratio suggests a mechanism that limits excitation preferentially in conditions of strong stimulation, consonant with clinical reports in which the ketogenic diet alleviates seizures without a major impact on normal brain activity. Limiting plasticity in a seizure-susceptible network may limit seizure-induced epileptogenesis which may subserve the ongoing benefit of the ketogenic diet in epilepsy. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  9. Optical methods and integrated systems for brain imaging in awake, untethered animals

    NASA Astrophysics Data System (ADS)

    Murari, Kartikeya

    Imaging is a powerful tool for biomedical research offering non-contact and minimally or non-invasive means of investigating at multiple scales---from single molecules to large populations of cells. Imaging in awake, behaving animals is an emerging field that offers the additional advantage of being able to study physiological processes and structures in a more natural state than what is possible in tissue slices or even in anesthetized animals. To date, most imaging in awake animals has used optical fiber bundles or electrical cables to transfer signals to traditional imaging-system components. However, the fibers or cables tether the animal and greatly limit the kind and duration of animal behavior that can be studied using imaging methods. This work involves three distinct yet related approaches to fulfill the goal of imaging in unanesthetized, unrestrained animals---optical techniques for functional and structural imaging, development of novel photodetectors and the design of miniaturized imaging systems. I hypothesized that the flow within vessels might act as a contrast-enhancing agent and improve the visualization of vascular architecture using laser speckle imaging. When imaging rodent cerebral vasculature I saw a two to four fold increase in the contrast-to-noise ratios and was able to visualize 10--30% more vascular features over reflectance techniques. I designed a complementary metal oxide semiconductor (CMOS) photodetector array that was comparable in sensitivity and noise performance to cooled CCD sensors, able to image fluorescence from a single cell, while running at faster frame rates. Next, I designed an imaging system weighing under 6 grams and occupying less than 4 cm3. The system incorporated multispectral illumination, adjustable focusing optics and the high-sensitivity CMOS imager. I was able to implement a variety of optical modalities with the system and performed reflectance, fluorescence, spectroscopic and laser speckle imaging with my

  10. Surgeon-patient communication during awake procedures.

    PubMed

    Smith, Claire S; Guyton, Kristina; Pariser, Joseph J; Siegler, Mark; Schindler, Nancy; Langerman, Alexander

    2017-06-01

    Surgeons are increasingly performing procedures on awake patients. Communication during such procedures is complex and underexplored in the literature. Surgeons were recruited from the faculty of 2 hospitals to participate in an interview regarding their approaches to communication during awake procedures. Three researchers used the constant comparative method to transcribe, code, and review interviews until saturation was reached. Twenty-three surgeons described the advantages and disadvantages of awake procedures, their communication with the awake patient, their interactions with staff and with trainees, the environment of awake procedures, and how communication in this context is taught and learned. Surgeons recognized communication during awake procedures as important and reported varied strategies for ensuring patient comfort in this context. However, they also acknowledged challenges with multiparty communication during awake procedures, especially in balancing commitments to teaching with their duty to comfort the patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Are Girls Behaving like Boys?

    ERIC Educational Resources Information Center

    Arnott, Rosie

    2008-01-01

    This article explores some of the issues that have given rise to the perception of an increase in aggressive behaviour by females. It asserts that merely comparing girls' behaviour with that of boys, especially the claim that "girls are behaving like boys", trivialises the very real issues associated with females and aggression. This paper will…

  12. Imaging dopamine release with Positron Emission Tomography (PET) and (11)C-raclopride in freely moving animals.

    PubMed

    Patel, Vinal D; Lee, Dianne E; Alexoff, David L; Dewey, Stephen L; Schiffer, Wynne K

    2008-07-01

    We investigated an imaging strategy that provides simultaneous measurements of radiotracer binding and behavior in awake, freely moving animals. In this strategy, animals are injected intravenously (i.v.) through a catheterized line and permitted to move freely for 30 min during uptake of the imaging agent, in this case 11C-raclopride. After this Awake Uptake period, animals are anesthetized and scanned for 25 min. We tested the utility of this strategy for measuring changes in striatal 11C-raclopride binding under control conditions (awake and freely moving in the home cage) and with several drug challenges: a loading dose of unlabeled raclopride, pretreatment with methamphetamine (METH) or pretreatment with gamma-vinyl-GABA [S+-GVG] followed by METH. An additional group of animals underwent a stress paradigm that we have previously shown increases brain dopamine. For drug challenge experiments, the change in 11C-raclopride binding was compared to data from animals that were anesthetized for the uptake period ("Anesthetized Uptake") and full time activity curves were used to calculate 11C-raclopride binding. Regardless of the drug treatment protocol, there was no difference in 11C-raclopride striatum to cerebellum ratio between the Awake versus the Anesthetized Uptake conditions. Awake and Anesthetized groups demonstrated over 90% occupancy of dopamine receptors with a loading dose of cold raclopride, both groups demonstrated approximately 30% reduction in 11C-raclopride binding from METH pretreatment and this effect was modulated to the same degree by GVG under both uptake conditions. Restraint during Awake Uptake decreased 11C-raclopride binding by 29%. These studies support a unique molecular imaging strategy in which radiotracer uptake occurs in freely moving animals, after which they are anesthetized and scanned. This imaging strategy extends the applicability of small animal PET to include functional neurotransmitter imaging and the neurochemical correlates

  13. Large-Scale Chronically Implantable Precision Motorized Microdrive Array for Freely Behaving Animals

    PubMed Central

    Yamamoto, Jun; Wilson, Matthew A.

    2008-01-01

    Multiple single-unit recording has become one of the most powerful in vivo electro-physiological techniques for studying neural circuits. The demand has been increasing for small and lightweight chronic recording devices that allow fine adjustments to be made over large numbers of electrodes across multiple brain regions. To achieve this, we developed precision motorized microdrive arrays that use a novel motor multiplexing headstage to dramatically reduce wiring while preserving precision of the microdrive control. Versions of the microdrive array were chronically implanted on both rats (21 microdrives) and mice (7 microdrives), and relatively long-term recordings were taken. PMID:18667539

  14. Patterns of neural circuit activation and behavior during dominance hierarchy formation in freely behaving crayfish.

    PubMed

    Herberholz, J; Issa, F A; Edwards, D H

    2001-04-15

    Creation of a dominance hierarchy within a population of animals typically involves a period of agonistic activity in which winning and losing decide relative positions in the hierarchy. Among crayfish, fighting between size-matched animals leads to an abrupt change of behavior as the new subordinate retreats and escapes from the attacks and approaches of the dominant (Issa et al., 1999). We used high-speed videography and electrical recordings of aquarium field potentials to monitor the release of aggressive and defensive behavior, including the activation of neural circuits for four different tail-flip behaviors. We found that the sequence of tail-flip circuit excitation traced the development of their dominance hierarchy. Offensive tail flipping, attacks, and approaches by both animals were followed by a sharp rise in the frequency of nongiant and medial giant escape tail flips and a fall in the frequency of offensive tail flips of the new subordinate. These changes suggest that sudden, coordinated changes in the excitability of a set of neural circuits in one animal produce the changes in behavior that mark its transition to subordinate status.

  15. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure.

    PubMed

    Claussen, Catherine M; Dafny, Nachum

    2015-09-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long-term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization was also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals were observed for the 2.5 and 10.0mg/kg MPD exposed groups. For 2.5mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0mg/kg MPD and the behaviorally sensitized 10.0mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and then to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Sensory Flow as a Basis for a Novel Distance Cue in Freely Behaving Electric Fish.

    PubMed

    Hofmann, Volker; Sanguinetti-Scheck, Juan Ignacio; Gómez-Sena, Leonel; Engelmann, Jacob

    2017-01-11

    The sensory input that an animal receives is directly linked to its motor activity. Behavior thus enables animals to influence their sensory input, a concept referred to as active sensing. How such behavior can serve as a scaffold for generating sensory information is of general scientific interest. In this article, we investigate how behavior can shape sensory information by using some unique features of the sensorimotor system of the weakly electric fish. Based on quantitative behavioral characterizations and computational reconstruction of sensory input, we show how electrosensory flow is actively created during highly patterned, spontaneous behavior in Gnathonemus petersii. The spatiotemporal structure of the sensory input provides information for the computation of a novel distance cue, which allows for a continuous estimation of distance. This has significant advantages over previously known nondynamic distance estimators as determined from electric image blur. Our investigation of the sensorimotor interactions in pulsatile electrolocation shows, for the first time, that the electrosensory flow contains behaviorally relevant information accessible only through active behavior. As patterned sensory behaviors are a shared feature of (active) sensory systems, our results have general implications for the understanding of (active) sensing, with the proposed sensory flow-based measure being potentially pertinent to a broad range of sensory modalities. Acquisition of sensory information depends on motion, as either an animal or its sensors move. Behavior can thus actively influence the sensory flow; and in this way, behavior can be seen as a manifestation of the brain's integrative functions. The properties of the active pulsatile electrolocation system in Gnathonemus petersii allow for the sensory input to be computationally reconstructed, enabling us to link the informational content of spatiotemporal sensory dynamics to behavior. Our study reveals a novel sensory cue for estimating depth that is actively generated by the fishes' behavior. The physical and behavioral similarities between electrolocation and other active sensory systems suggest that this may be a mechanism shared by (active) sensory systems. Copyright © 2017 the authors 0270-6474/17/370302-11$15.00/0.

  17. Operant conditioning of neural activity in freely behaving monkeys with intracranial reinforcement.

    PubMed

    Eaton, Ryan W; Libey, Tyler; Fetz, Eberhard E

    2017-03-01

    Operant conditioning of neural activity has typically been performed under controlled behavioral conditions using food reinforcement. This has limited the duration and behavioral context for neural conditioning. To reward cell activity in unconstrained primates, we sought sites in nucleus accumbens (NAc) whose stimulation reinforced operant responding. In three monkeys, NAc stimulation sustained performance of a manual target-tracking task, with response rates that increased monotonically with increasing NAc stimulation. We recorded activity of single motor cortex neurons and documented their modulation with wrist force. We conditioned increased firing rates with the monkey seated in the training booth and during free behavior in the cage using an autonomous head-fixed recording and stimulating system. Spikes occurring above baseline rates triggered single or multiple electrical pulses to the reinforcement site. Such rate-contingent, unit-triggered stimulation was made available for periods of 1-3 min separated by 3-10 min time-out periods. Feedback was presented as event-triggered clicks both in-cage and in-booth, and visual cues were provided in many in-booth sessions. In-booth conditioning produced increases in single neuron firing probability with intracranial reinforcement in 48 of 58 cells. Reinforced cell activity could rise more than five times that of non-reinforced activity. In-cage conditioning produced significant increases in 21 of 33 sessions. In-cage rate changes peaked later and lasted longer than in-booth changes, but were often comparatively smaller, between 13 and 18% above non-reinforced activity. Thus intracranial stimulation reinforced volitional increases in cortical firing rates during both free behavior and a controlled environment, although changes in the latter were more robust.NEW & NOTEWORTHY Closed-loop brain-computer interfaces (BCI) were used to operantly condition increases in muscle and neural activity in monkeys by delivering activity-dependent stimuli to an intracranial reinforcement site (nucleus accumbens). We conditioned increased firing rates with the monkeys seated in a training booth and also, for the first time, during free behavior in a cage using an autonomous head-fixed BCI. Copyright © 2017 the American Physiological Society.

  18. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure

    PubMed Central

    Claussen, Catherine M; Dafny, Nachum

    2016-01-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0 mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization were also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals was observed for the 2.5 and 10.0 mg/kg MPD exposed groups. For 2.5 mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0 mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0 mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0 mg/kg MPD and the behaviorally sensitized 10.0 mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and than to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure. PMID:26101057

  19. Stimulation of the nucleus accumbens as behavioral reward in awake behaving monkeys.

    PubMed

    Bichot, Narcisse P; Heard, Matthew T; Desimone, Robert

    2011-08-15

    It has been known that monkeys will repeatedly press a bar for electrical stimulation in several different brain structures. We explored the possibility of using electrical stimulation in one such structure, the nucleus accumbens, as a substitute for liquid reward in animals performing a complex task, namely visual search. The animals had full access to water in the cage at all times on days when stimulation was used to motivate them. Electrical stimulation was delivered bilaterally at mirror locations in and around the accumbens, and the animals' motivation to work for electrical stimulation was quantified by the number of trials they performed correctly per unit of time. Acute mapping revealed that stimulation over a large area successfully supported behavioral performance during the task. Performance improved with increasing currents until it reached an asymptotic, theoretically maximal level. Moreover, stimulation with chronically implanted electrodes showed that an animal's motivation to work for electrical stimulation was at least equivalent to, and often better than, when it worked for liquid reward while on water control. These results suggest that electrical stimulation in the accumbens is a viable method of reward in complex tasks. Because this method of reward does not necessitate control over water or food intake, it may offer an alternative to the traditional liquid or food rewards in monkeys, depending on the goals and requirements of the particular research project.

  20. A miniaturized chronic microelectrode drive for awake behaving head restrained mice and rats.

    PubMed

    Haiss, Florent; Butovas, Sergejus; Schwarz, Cornelius

    2010-03-15

    The present work introduces an electrode microdrive system small enough to be placed into two distinct brain areas in head-fixed mice. To meet the space constraint imposed by the size of mice and the additional presence of a head post, the size and weight of the components were minimized. In the current version, an individual microdrive moves an array of four Reitboeck type electrodes. We report about successful implantation in rats and mice using one or two microdrives. Using two of these devices in individual mice/rats, the recording of parallel single and multi-unit as well as local field potential from prefrontal, motor, somatosensory cortex and hippocampus is demonstrated. The system can be easily constructed with machinery and equipment present in most neurophysiology labs. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  1. Chronic imaging of movement-related Purkinje cell calcium activity in awake behaving mice

    PubMed Central

    Gaffield, Michael A.; Amat, Samantha B.; Bito, Haruhiko

    2015-01-01

    Purkinje cells (PCs) are a major site of information integration and plasticity in the cerebellum, a brain region involved in motor task refinement. Thus PCs provide an ideal location for studying the mechanisms necessary for cerebellum-dependent motor learning. Increasingly, sophisticated behavior tasks, used in combination with genetic reporters and effectors of activity, have opened up the possibility of studying cerebellar circuits during voluntary movement at an unprecedented level of quantitation. However, current methods used to monitor PC activity do not take full advantage of these advances. For example, single-unit or multiunit electrode recordings, which provide excellent temporal information regarding electrical activity, only monitor a small population of cells and can be quite invasive. Bolus loading of cell-permeant calcium (Ca2+) indicators is short-lived, requiring same-day imaging immediately after surgery and/or indicator injection. Genetically encoded Ca2+ indicators (GECIs) overcome many of these limits and have garnered considerable use in many neuron types but only limited use in PCs. Here we employed these indicators to monitor Ca2+ activity in PCs over several weeks. We could repeatedly image from the same cerebellar regions across multiple days and observed stable activity. We used chronic imaging to monitor PC activity in crus II, an area previously linked to licking behavior, and identified a region of increased activity at the onset of licking. We then monitored this same region after training tasks to initiate voluntary licking behavior in response to different sensory stimuli. In all cases, PC Ca2+ activity increased at the onset of rhythmic licking. PMID:26561609

  2. Sweet and bitter taste in the brain of awake behaving animals

    PubMed Central

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J. P.; Zuker, Charles S.

    2015-01-01

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviors, preventing the ingestion of toxic substances, and helping ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste permits the identification of energy-rich nutrients while bitter warns against the intake of potentially noxious chemicals1. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain2. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map3,4, with each taste quality encoded by distinct cortical fields4. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal’s internal representation, sensory perception, and behavioral actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviors in the absence of sensory input. PMID:26580015

  3. Sweet and bitter taste in the brain of awake behaving animals.

    PubMed

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J P; Zuker, Charles S

    2015-11-26

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviours, preventing the ingestion of toxic substances, and helping to ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste allows the identification of energy-rich nutrients whereas bitter warns against the intake of potentially noxious chemicals. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map, with each taste quality encoded by distinct cortical fields. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal's internal representation, sensory perception, and behavioural actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviours in the absence of sensory input.

  4. Spatial cognition in a virtual reality home-cage extension for freely moving rodents.

    PubMed

    Kaupert, Ursula; Thurley, Kay; Frei, Katja; Bagorda, Francesco; Schatz, Alexej; Tocker, Gilad; Rapoport, Sophie; Derdikman, Dori; Winter, York

    2017-04-01

    Virtual reality (VR) environments are a powerful tool to investigate brain mechanisms involved in the behavior of animals. With this technique, animals are usually head fixed or secured in a harness, and training for cognitively more complex VR paradigms is time consuming. A VR apparatus allowing free animal movement and the constant operator-independent training of tasks would enable many new applications. Key prospective usages include brain imaging of animal behavior when carrying a miniaturized mobile device such as a fluorescence microscope or an optetrode. Here, we introduce the Servoball, a spherical VR treadmill based on the closed-loop tracking of a freely moving animal and feedback counterrotation of the ball. Furthermore, we present the complete integration of this experimental system with the animals' group home cage, from which single individuals can voluntarily enter through a tunnel with radio-frequency identification (RFID)-automated access control and commence experiments. This automated animal sorter functions as a mechanical replacement of the experimenter. We automatically trained rats using visual or acoustic cues to solve spatial cognitive tasks and recorded spatially modulated entorhinal cells. When electrophysiological extracellular recordings from awake behaving rats were performed, head fixation can dramatically alter results, so that any complex behavior that requires head movement is impossible to achieve. We circumvented this problem with the use of the Servoball in open-field scenarios, as it allows the combination of open-field behavior with the recording of nerve cells, along with all the flexibility that a virtual environment brings. This integrated home cage with a VR arena experimental system permits highly efficient experimentation for complex cognitive experiments.NEW & NOTEWORTHY Virtual reality (VR) environments are a powerful tool for the investigation of brain mechanisms. We introduce the Servoball, a VR treadmill for freely

  5. Awake operative videothoracoscopic pulmonary resections.

    PubMed

    Pompeo, Eugenio; Mineo, Tommaso C

    2008-08-01

    The authors' initial experience with awake videothoracoscopic lung resection suggests that these procedures can be easily and safely performed under sole thoracic epidural anesthesia with no mortality and negligible morbidity. One major concern was that operating on a ventilating lung would render surgical maneuvers more difficult because of the lung movements and lack of a sufficient operating space. Instead, the open pneumothorax created after trocar insertion produces a satisfactory lung collapse that does not hamper surgical maneuvers. These results contradict the accepted assumption that the main prerequisite for allowing successful thoracoscopic lung surgery is general anesthesia with one-lung ventilation. No particular training is necessary to accomplish an awake pulmonary resection for teams experienced in thoracoscopic surgery, and conversions to general anesthesia are mainly caused by the presence of extensive fibrous pleural adhesions or the development of intractable panic attacks. Overall, awake pulmonary resection is easily accepted and well tolerated by patients, as confirmed by the high anesthesia satisfaction score, which was better than in nonawake control patients. Nonetheless, thoracic epidural anesthesia has potential complications, including epidural hematoma, spinal cord injury, and phrenic nerve palsy caused by inadvertently high anesthetic level, but these never occurred in the authors' experience. Further concerns relate to patient participation in operating room conversations or risk for development of perioperative panic attacks. However, the authors have found that reassuring the patient during the procedure, explaining step-by-step what is being performed, and even showing the ongoing procedure on the operating video can greatly improve the perioperative wellness and expectations of patients, particularly if the procedure is performed for oncologic diseases. Panic attacks occurred in few patients and could be usually managed through

  6. Freely oriented portable superconducting magnet

    DOEpatents

    Schmierer, Eric N.; Prenger, F. Coyne; Hill, Dallas D.

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  7. Friction-based stabilization of juxtacellular recordings in freely moving rats.

    PubMed

    Herfst, Lucas; Burgalossi, Andrea; Haskic, Kurt; Tukker, John J; Schmidt, Martin; Brecht, Michael

    2012-07-01

    Virtually nothing is known about the activity of morphologically identified neurons in freely moving mammals. Here we describe stabilization and positioning techniques that allow juxtacellular recordings from labeled single neurons in awake, freely moving animals. This method involves the use of a friction-based device that allows stabilization of the recording pipette by friction forces. Friction is generated by a clamplike mechanism that tightens a sliding pipette holder to a preimplanted pipette guide. The interacting surfaces are smoothed to optical quality (<5-nm roughness) to enable micrometer stepping precision of the device during operation. Our method allows recordings from identified neurons in freely moving animals, and thus opens new perspectives for analyzing the role of identified neurons in the control of behavior.

  8. Friction-based stabilization of juxtacellular recordings in freely moving rats

    PubMed Central

    Herfst, Lucas; Haskic, Kurt; Tukker, John J.; Schmidt, Martin; Brecht, Michael

    2012-01-01

    Virtually nothing is known about the activity of morphologically identified neurons in freely moving mammals. Here we describe stabilization and positioning techniques that allow juxtacellular recordings from labeled single neurons in awake, freely moving animals. This method involves the use of a friction-based device that allows stabilization of the recording pipette by friction forces. Friction is generated by a clamplike mechanism that tightens a sliding pipette holder to a preimplanted pipette guide. The interacting surfaces are smoothed to optical quality (<5-nm roughness) to enable micrometer stepping precision of the device during operation. Our method allows recordings from identified neurons in freely moving animals, and thus opens new perspectives for analyzing the role of identified neurons in the control of behavior. PMID:22514297

  9. Topical capsaicin application causes cold hypersensitivity in awake monkeys.

    PubMed

    Kamo, Hiroshi; Honda, Kuniya; Kitagawa, Junichi; Tsuboi, Yoshiyuki; Kondo, Masahiro; Taira, Masato; Yamashita, Akiko; Katsuyama, Narumi; Masuda, Yuji; Kato, Takafumi; Iwata, Koichi

    2008-06-01

    Recent animal studies have demonstrated that many trigeminal ganglion neurons co-express TRPV1 and TRPA1 receptors following peripheral inflammation. In the present study, we examined whether cold receptors were sensitized by capsaicin in awake monkeys. Two monkeys were trained to detect a change in cold stimulus temperature (30 degrees C to 0.5, 1.0, 1.5 or 2.0 degrees C) applied to the facial skin. A total of 589 trials were studied, and the number of escape and hold-through trials and detection latency were measured. The number of escape trials was increased after capsaicin treatment, whereas that of hold-through trials was decreased. Detection latency was significantly decreased after capsaicin treatment. The present findings suggest that topical application of capsaicin to the facial skin induces reversible hypersensitivity to a facial cold stimulus in behaving monkeys.

  10. MAC-awake of sevoflurane in children.

    PubMed

    Davidson, Andrew J; Wong, Aaron; Knottenbelt, Graham; Sheppard, Suzette; Donath, Susan; Frawley, Geoff

    2008-08-01

    Age influences the potency of anesthetic agents, but there is little information on how age influences MAC-awake. MAC-awake may be an important aspect of anesthesia potency for the prevention of awareness during anesthesia. The aim of this study was to measure MAC-awake in a range of ages in children. After institutional ethics approval and informed parental consent 60 children were enrolled; 20 in each of three age groups (2 to <5, 5 to <8 and 8-12 years). Children were excluded if they had opioids, sedative premedication or a procedure likely to cause any residual discomfort. All children had sevoflurane anesthesia. At the end of the procedure the sevoflurane was decreased to the target concentration. Once the target endtidal concentration was achieved it was maintained for 10 min before a standard stimulus was applied and an observer determined if the child was awake. The Dixon up-down method was used to determine progression of subsequent concentrations and MAC-awake (ED50) for the three age groups were obtained using the probit model. This study found evidence for a difference in ED50 between age groups (P = 0.008). The MAC-awake was highest in the youngest group (0.66%) and similar in the older groups (0.45% and 0.43%). Although MAC-awake changes with age, in the ages where awareness has been reported, MAC-awake was found to be relatively low, and therefore it seems unlikely that age-specific changes to MAC-awake are a cause for awareness in children aged 5-12 years.

  11. Pediatric Awake Craniotomy for Brain Lesions.

    PubMed

    Akay, Ali; Rükşen, Mete; Çetin, H Yurday; Seval, H Özer; İşlekel, Sertaç

    2016-01-01

    Awake craniotomy is a special method to prevent motor deficits during the resection of lesions that are located in, or close to, functional areas. Although it is more commonly performed in adult patients, reports of pediatric cases undergoing awake craniotomy are limited in the literature. In our clinic, where we frequently use awake craniotomy in adult patients, we performed this method in 2 selected pediatric cases for lesion surgery. At an early age, these 2 cases diagnosed with epilepsy presented cerebral lesions, but since the lesions enclosed functional areas, surgical resection was not regarded as a treatment option at this time. In these 2 pediatric cases, we successfully completed lesion surgery with awake craniotomy. The method and the techniques employed during surgery are presented concomitant with other reports in the literature.

  12. Noninvasive high-speed photoacoustic tomography of cerebral hemodynamics in awake-moving rats.

    PubMed

    Tang, Jianbo; Xi, Lei; Zhou, Junli; Huang, Hua; Zhang, Tao; Carney, Paul R; Jiang, Huabei

    2015-08-01

    We present a noninvasive method of photoacoustic tomography (PAT) for imaging cerebral hemodynamics in awake-moving rats. The wearable PAT (wPAT) system has a size of 15 mm in height and 33 mm in diameter, and a weight of ~8 g (excluding cabling). The wPAT achieved an imaging rate of 3.33 frames/s with a lateral resolution of 243 μm. Animal experiments were designed to show wPAT feasibility for imaging cerebral hemodynamics on awake-moving animals. Results showed that the cerebral oxy-hemoglobin and deoxy-hemoglobin changed significantly in response to hyperoxia; and, after the injection of pentylenetetrazol (PTZ), cerebral blood volume changed faster over time and larger in amplitude for rats in awake-moving state compared with rats under anesthesia. By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamics in normal and diseased states.

  13. Noninvasive high-speed photoacoustic tomography of cerebral hemodynamics in awake-moving rats

    PubMed Central

    Tang, Jianbo; Xi, Lei; Zhou, Junli; Huang, Hua; Zhang, Tao; Carney, Paul R; Jiang, Huabei

    2015-01-01

    We present a noninvasive method of photoacoustic tomography (PAT) for imaging cerebral hemodynamics in awake-moving rats. The wearable PAT (wPAT) system has a size of 15 mm in height and 33 mm in diameter, and a weight of ~8 g (excluding cabling). The wPAT achieved an imaging rate of 3.33 frames/s with a lateral resolution of 243 μm. Animal experiments were designed to show wPAT feasibility for imaging cerebral hemodynamics on awake-moving animals. Results showed that the cerebral oxy-hemoglobin and deoxy-hemoglobin changed significantly in response to hyperoxia; and, after the injection of pentylenetetrazol (PTZ), cerebral blood volume changed faster over time and larger in amplitude for rats in awake-moving state compared with rats under anesthesia. By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamics in normal and diseased states. PMID:26082016

  14. High-resolution optical imaging of functional brain architecture in the awake monkey.

    PubMed

    Grinvald, A; Frostig, R D; Siegel, R M; Bartfeld, E

    1991-12-15

    Optical imaging of the functional architecture of cortex, based on intrinsic signals, is a useful tool for the study of the development, organization, and function of the living mammalian brain. This relatively noninvasive technique is based on small activity-dependent changes of the optical properties of cortex. Thus far, functional imaging has been performed only on anesthetized animals. Here we establish that this technique is also suitable for exploring the brain of awake behaving primates. We designed a chronic sealed chamber and mounted it on the skull of a cynomolgus monkey (Macaca fascicularis) over the primary visual cortex to permit imaging through a transparent glass window. Restriction of head position alone was sufficient to eliminate movement noise in awake monkey imaging experiments. High-resolution imaging of the ocular dominance columns and the cytochrome oxidase blobs was achieved simply by taking pictures of the exposed cortex when the awake monkey was viewing video movies alternatively with each eye. Furthermore, the functional maps could be obtained without synchronization of the data acquisition to the animal's respiration and the electrocardiogram. The wavelength dependency and time course of the intrinsic signal were similar in anesthetized and awake monkeys, indicating that the signal sources were the same. We therefore conclude that optical imaging is well suited for exploring functional organization related to higher cognitive brain functions of the primate as well as providing a diagnostic tool for delineating functional cortical borders and assessing proper functions of human patients during neurosurgery.

  15. Optimised Motion Tracking for Positron Emission Tomography Studies of Brain Function in Awake Rats

    PubMed Central

    Kyme, Andre Z.; Zhou, Victor W.; Meikle, Steven R.; Baldock, Clive; Fulton, Roger R.

    2011-01-01

    Positron emission tomography (PET) is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (<100 ms error), a sampling rate of >20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration). Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET. PMID:21747951

  16. Optimised motion tracking for positron emission tomography studies of brain function in awake rats.

    PubMed

    Kyme, Andre Z; Zhou, Victor W; Meikle, Steven R; Baldock, Clive; Fulton, Roger R

    2011-01-01

    Positron emission tomography (PET) is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (<100 ms error), a sampling rate of >20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration). Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET.

  17. Cavity Resonator Wireless Power Transfer System for Freely Moving Animal Experiments.

    PubMed

    Mei, Henry; Thackston, Kyle A; Bercich, Rebecca A; Jefferys, John G R; Irazoqui, Pedro P

    2017-04-01

    The goal of this paper is to create a large wireless powering arena for powering small devices implanted in freely behaving rodents. We design a cavity resonator based wireless power transfer (WPT) system and utilize our previously developed optimal impedance matching methodology to achieve effective WPT performance for operating sophisticated implantable devices, made with miniature receive coils (<8 mm in diameter), within a large volume (dimensions: 60.96 cm × 60.96 cm × 30 cm). We provide unique cavity design and construction methods which maintains electromagnetic performance of the cavity while promoting its utility as a large animal husbandry environment. In addition, we develop a biaxial receive resonator system to address device orientation insensitivity within the cavity environment. Functionality is demonstrated with chronic experiments involving rats implanted with our custom designed bioelectric recording device. We demonstrate an average powering fidelity of 93.53% over nine recording sessions across nine weeks, indicating nearly continuous device operation for a freely behaving rat within the large cavity resonator space. We have developed and demonstrated a cavity resonator based WPT system for long term experiments involving freely behaving small animals. This cavity resonator based WPT system offers an effective and simple method for wirelessly powering miniaturized devices implanted in freely moving small animals within the largest space.

  18. Evaluation of Language Function under Awake Craniotomy.

    PubMed

    Kanno, Aya; Mikuni, Nobuhiro

    2015-01-01

    Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.

  19. Predicting sleepiness during an awake craniotomy.

    PubMed

    Itoi, Chihiro; Hiromitsu, Kentaro; Saito, Shoko; Yamada, Ryoji; Shinoura, Nobusada; Midorikawa, Akira

    2015-12-01

    An awake craniotomy is a safe neurological surgical technique that minimizes the risk of brain damage. During the course of this surgery, the patient is asked to perform motor or cognitive tasks, but some patients exhibit severe sleepiness. Thus, the present study investigated the predictive value of a patient's preoperative neuropsychological background in terms of sleepiness during an awake craniotomy. Thirty-seven patients with brain tumor who underwent awake craniotomy were included in this study. Prior to craniotomy, the patient evaluated cognitive status, and during the surgery, each patient's performance and attitude toward cognitive tasks were recorded by neuropsychologists. The present findings showed that the construction and calculation abilities of the patients were moderately correlated with their sleepiness. These results indicate that the preoperative cognitive functioning of patients was related to their sleepiness during the awake craniotomy procedure and that the patients who exhibited sleepiness during an awake craniotomy had previously experienced reduced functioning in the parietal lobe. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Evaluation of Language Function under Awake Craniotomy

    PubMed Central

    KANNO, Aya; MIKUNI, Nobuhiro

    2015-01-01

    Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758

  1. Patient perceptions of "awake" brain tumour surgery.

    PubMed

    Whittle, I R; Midgley, S; Georges, H; Pringle, A-M; Taylor, R

    2005-03-01

    Awake brain tumour surgery allows intraoperative patient assessment and is done to optimise safe tumour removal. It is an established technique but little is known about patient perceptions of the procedure. Fifteen adult patients filled out a dedicated questionnaire to assess 10 aspects of patient perceptions of the procedure. All patients, who were awake for a median of 45 minutes (range 10-105), stated they were adequately prepared for the operation. Most recollected various aspects of the procedure, although 3 patients (20%) had little memory of actually being awake during the surgery despite being cooperative. A minority reported more than minor discomfort (20%), fear (15%) or anxiety (29%), and most felt they coped with the cortical stimulations and functional testing well. Sources of discomfort and pain were the cranial pin holding device, operative position, inadequate infiltration of the cranial wound with local anesthetic, a full bladder causing a desire to micturate and a hard and uncomfortable operating table. These results, are very similar to a previous American report using a different anesthetic technique, in that most patients tolerate awake craniotomy remarkably well if the procedure is explained to them and some simple precautions are taken. Additionally between 8%-37% of patients (95% Confidence Interval, summing data from the two studies, n = 35) will have no recollection of being awake. Ways of minimising discomfort and problems of anxiety in this patient cohort are discussed.

  2. Do you BEHAVE? - Application of the BehavePlus fire modeling system

    Treesearch

    Pat Andrews

    2010-01-01

    The BehavePlus fire modeling system is the successor to BEHAVE, which was first used in the field in 1984. It is public domain software, available for free use on personal computers. Information on user communities and fire management applications can be useful in designing next generation systems. Several sources of information about BehavePlus are summarized to...

  3. Hydrodynamics of freely swimming flagellates

    NASA Astrophysics Data System (ADS)

    Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas; Bohr, Tomas; Andersen, Anders

    2016-11-01

    Flagellates are a diverse group of unicellular organisms forming an important part of the marine ecosystem. The arrangement of flagella around the cell serves as a key trait optimizing and compromising essential functions. With micro-particle image velocimetry we observed time-resolved near-cell flows around freely swimming flagellates, and we developed an analytical model based on the Stokes flow around a solid sphere propelled by a variable number of differently placed, temporally varying point forces, each representing one flagellum. The model allows us to reproduce the observed flow patterns and swimming dynamics, and to extract quantities such as swimming velocities and prey clearance rates as well as flow disturbances revealing the organism to flow-sensing predators. Our results point to optimal flagellar arrangements and beat patterns, and essential trade-offs. For biflagellates with two symmetrically arranged flagella we contrasted two species using undulatory and ciliary beat patterns, respectively, and found breast-stroke type beat patterns with equatorial power strokes to be favorable for fast as well as quiet swimming. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

  4. Awake animal SPECT: Overview and initial results

    SciTech Connect

    Weisenberger, A G; Majewski, S; McKisson, J; Popov, V; Proffitt, J; Stolin, A; Baba, J S; Goddard, J S; Lee, S J; Smith, M F; Tsui, B; Pomper, M

    2009-02-01

    A SPECT / X-ray CT system configured at Johns Hopkins University to image the biodistribution of radiopharmaceuticals in unrestrained, un-anesthetized mice has been constructed and tested on awake mice. The system was built by Thomas Jefferson National Accelerator Facility and Oak Ridge National Laboratory. SPECT imaging is accomplished using two gamma cameras, 10 cm × 20 cm in size based on a 2 × 4 array of Hamamatsu H8500 flat panel position sensitive photomultiplier tubes. A real-time optical tracking system utilizing three infrared cameras provides time stamped pose data of an awake mouse head during a SPECT scan. The six degrees of freedom (three translational and three rotational) pose data are used for motion correction during 3-D tomographic list-mode iterative image reconstruction. SPECT reconstruction of awake, unrestrained mice with motion compensation for head movement has been accomplished.

  5. Awake Animal Imaging Motion Tracking Software

    SciTech Connect

    Goddard, James

    2010-03-15

    The Awake Animal Motion Tracking Software code calculates the 3D movement of the head motion of a live, awake animal during a medical imaging scan. In conjunction with markers attached to the head, images acquired from multiple cameras are processed and marker locations precisely determined. Using off-line camera calibration data, the 3D positions of the markers are calculated along with a 6 degree of freedom position and orientation (pose) relative to a fixed initial position. This calculation is performed in real time at frame rates up to 30 frames per second. A time stamp with microsecond accuracy from a time base source is attached to each pose measurement.

  6. Reading Wide Awake: Politics, Pedagogies, and Possibilities

    ERIC Educational Resources Information Center

    Shannon, Patrick

    2011-01-01

    In his new book, popular author Patrick Shannon examines reading as agency--why reading critically is essential to civic engagement and a healthy democracy. We follow the author on a journey of self discovery as he practices "wide-awake reading" with a variety of everyday texts, from radio programs to legal documents to more traditional books and…

  7. A Toolbox for Optophysiological Experiments in Freely Moving Rats

    PubMed Central

    Hardung, Stefanie; Alyahyay, Mansour; Eriksson, David; Diester, Ilka

    2017-01-01

    Simultaneous recordings and manipulations of neural circuits that control the behavior of animals is one of the key techniques in modern neuroscience. Rapid advances in optogenetics have led to a variety of probes combining multichannel readout and optogenetic write in. Given the complexity of the brain, it comes as no surprise that the choice of the device is constrained by several factors such as the animal model, the structure and location of the brain area of interest, as well as the behavioral read out. Here we provide an overview of available devices for chronic simultaneous neural recordings and optogenetic manipulation in awake behaving rats. We focus on two fixed arrays and two moveable drives. For both options, we present data from one custom-made (in house) and one commercially available device. Here we provide evidence that simultaneous neural recordings and optogenetic manipulations are feasible with all four tested devices. Further we give detailed information about the recording quality, and also contrast the different features of the probes. As we provide detailed information about equipment and building procedures for combined chronic multichannel readout and optogenetic control with maximum performance at minimized costs, this overview might help especially researchers who want to enter the field of in vivo optophysiology. PMID:28553206

  8. Second-by-Second Measures of L-Glutamate in the Prefrontal Cortex and Striatum of Freely Moving Mice

    PubMed Central

    Hascup, K. N.; Hascup, E. R.; Pomerleau, F.; Huettl, P.; Gerhardt, G. A.

    2012-01-01

    L-Glutamate (Glu) is the main excitatory neurotransmitter in the mammalian central nervous system, and it is involved in most aspects of normal brain function, including cognition, memory and learning, plasticity, and motor movement. Although micro-dialysis techniques have been used to study Glu, the slow temporal resolution of the technique may be inadequate to properly examine tonic and phasic Glu. Thus, our laboratory has developed an enzyme-based microelectrode array (MEA) with fast response time and low detection limits for Glu. We have modified the MEA design to allow for reliable measures in the brain of awake, freely moving mice. In this study, we chronically implanted the MEA in prefrontal cortex (PFC) or striatum (Str) of awake, freely moving C57BL/6 mice. We successfully measured Glu levels 7 days postimplantation without loss of MEA sensitivity. In addition, we determined resting (tonic) Glu levels to be 3.3 μM in the PFC and 5.0 μM in the Str. Resting Glu levels were subjected to pharmacological manipulation with tetrodotoxin (TTX) and DL-threo-β-hydroxyaspartate (THA). TTX significantly (p < 0.05) decreased resting Glu by 20%, whereas THA significantly (p < 0.05) increased resting Glu by 60%. Taken together, our data show that chronic recordings of tonic and phasic clearance of exogenously applied Glu can be carried out in awake mice for at least 7 days in vivo, allowing for longer term studies of Glu regulation. PMID:18024788

  9. Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit.

    PubMed

    Kenkel, W M; Yee, J R; Moore, K; Madularu, D; Kulkarni, P; Gamber, K; Nedelman, M; Ferris, C F

    2016-03-22

    Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were 'odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology.

  10. Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit

    PubMed Central

    Kenkel, W M; Yee, J R; Moore, K; Madularu, D; Kulkarni, P; Gamber, K; Nedelman, M; Ferris, C F

    2016-01-01

    Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were ‘odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology. PMID:27003189

  11. Examination of Rapid Dopamine Dynamics with Fast Scan Cyclic Voltammetry During Intra-oral Tastant Administration in Awake Rats.

    PubMed

    Wickham, Robert J; Park, Jinwoo; Nunes, Eric J; Addy, Nii A

    2015-08-12

    Rapid, phasic dopamine (DA) release in the mammalian brain plays a critical role in reward processing, reinforcement learning, and motivational control. Fast scan cyclic voltammetry (FSCV) is an electrochemical technique with high spatial and temporal (sub-second) resolution that has been utilized to examine phasic DA release in several types of preparations. In vitro experiments in single-cells and brain slices and in vivo experiments in anesthetized rodents have been used to identify mechanisms that mediate dopamine release and uptake under normal conditions and in disease models. Over the last 20 years, in vivo FSCV experiments in awake, freely moving rodents have also provided insight of dopaminergic mechanisms in reward processing and reward learning. One major advantage of the awake, freely moving preparation is the ability to examine rapid DA fluctuations that are time-locked to specific behavioral events or to reward or cue presentation. However, one limitation of combined behavior and voltammetry experiments is the difficulty of dissociating DA effects that are specific to primary rewarding or aversive stimuli from co-occurring DA fluctuations that mediate reward-directed or other motor behaviors. Here, we describe a combined method using in vivo FSCV and intra-oral infusion in an awake rat to directly investigate DA responses to oral tastants. In these experiments, oral tastants are infused directly to the palate of the rat--bypassing reward-directed behavior and voluntary drinking behavior--allowing for direct examination of DA responses to tastant stimuli.

  12. Teachers Behaving Unprofessionally: Stories from Students

    ERIC Educational Resources Information Center

    Gibson, Angela M.; Wang, Jinhao; Slate, John R.

    2009-01-01

    In this study, the researchers analyzed stories told by students (n = 80) of their poorest K-12 teachers who behaved in an unprofessional manner. Nine dominant themes were identified: poor teaching; learning not occurring; poor communication with students; uncaring; no explanations; being overly emotional; high school teachers; off-task behaviors;…

  13. Path to AWAKE: Evolution of the concept

    NASA Astrophysics Data System (ADS)

    Caldwell, A.; Adli, E.; Amorim, L.; Apsimon, R.; Argyropoulos, T.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Cascella, M.; Chattopadhyay, S.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Elsen, E.; Farmer, J.; Fartoukh, S.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Geschonke, G.; Goddard, B.; Gorn, A. A.; Grulke, O.; Gschwendtner, E.; Hansen, J.; Hessler, C.; Hillenbrand, S.; Hofle, W.; Holloway, J.; Huang, C.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Kersevan, R.; Kumar, N.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Lu, W.; Machacek, J.; Mandry, S.; Martin, I.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Meddahi, M.; Merminga, L.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Müller, A.-S.; Najmudin, Z.; Noakes, T. C. Q.; Norreys, P.; Osterhoff, J.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pozimski, J.; Pukhov, A.; Reimann, O.; Rieger, K.; Roesler, S.; Ruhl, H.; Rusnak, T.; Salveter, F.; Savard, N.; Schmidt, J.; von der Schmitt, H.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Simon, F.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Tajima, T.; Tarkeshian, R.; Timko, H.; Trines, R.; Tückmantel, T.; Tuev, P. V.; Turner, M.; Velotti, F.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Yakimenko, V.; Zhang, H.; Zimmermann, F.

    2016-09-01

    This paper describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability - a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of the AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1].

  14. Hippocampal awake replay in fear memory retrieval

    PubMed Central

    Wu, Chun-Ting; Haggerty, Daniel; Kemere, Caleb; Ji, Daoyun

    2017-01-01

    Hippocampal place cells are key to episodic memories. How these cells participate in memory retrieval remains unclear. Here, after rats acquired a fear memory by receiving mild foot-shocks at a shock zone of a track, we analyzed place cells when the animals were placed back to the track and displayed an apparent memory retrieval behavior: avoidance of the shock zone. We found that place cells representing the shock zone were reactivated, despite the fact that the animals did not enter the shock zone. This reactivation occurred in ripple-associated awake replay of place cell sequences encoding the paths from the animal’s current positions to the shock zone, but not in place cell sequences within individual cycles of theta oscillation. The result reveals a specific place cell pattern underlying the inhibitory avoidance behavior and provides strong evidence for the involvement of awake replay in fear memory retrieval. PMID:28218916

  15. Awake, Offline Processing during Associative Learning.

    PubMed

    Bursley, James K; Nestor, Adrian; Tarr, Michael J; Creswell, J David

    2016-01-01

    Offline processing has been shown to strengthen memory traces and enhance learning in the absence of conscious rehearsal or awareness. Here we evaluate whether a brief, two-minute offline processing period can boost associative learning and test a memory reactivation account for these offline processing effects. After encoding paired associates, subjects either completed a distractor task for two minutes or were immediately tested for memory of the pairs in a counterbalanced, within-subjects functional magnetic resonance imaging study. Results showed that brief, awake, offline processing improves memory for associate pairs. Moreover, multi-voxel pattern analysis of the neuroimaging data suggested reactivation of encoded memory representations in dorsolateral prefrontal cortex during offline processing. These results signify the first demonstration of awake, active, offline enhancement of associative memory and suggest that such enhancement is accompanied by the offline reactivation of encoded memory representations.

  16. Awake, Offline Processing during Associative Learning

    PubMed Central

    Nestor, Adrian; Tarr, Michael J.; Creswell, J. David

    2016-01-01

    Offline processing has been shown to strengthen memory traces and enhance learning in the absence of conscious rehearsal or awareness. Here we evaluate whether a brief, two-minute offline processing period can boost associative learning and test a memory reactivation account for these offline processing effects. After encoding paired associates, subjects either completed a distractor task for two minutes or were immediately tested for memory of the pairs in a counterbalanced, within-subjects functional magnetic resonance imaging study. Results showed that brief, awake, offline processing improves memory for associate pairs. Moreover, multi-voxel pattern analysis of the neuroimaging data suggested reactivation of encoded memory representations in dorsolateral prefrontal cortex during offline processing. These results signify the first demonstration of awake, active, offline enhancement of associative memory and suggest that such enhancement is accompanied by the offline reactivation of encoded memory representations. PMID:27119345

  17. Path to AWAKE: Evolution of the concept

    DOE PAGES

    Caldwell, A.; Adli, E.; Amorim, L.; ...

    2016-01-02

    This study describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability – a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of themore » AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1] .« less

  18. Path to AWAKE: Evolution of the concept

    SciTech Connect

    Caldwell, A.; Adli, E.; Amorim, L.; Apsimon, R.; Argyropoulos, T.; Assmann, R.; Bachmann, A. -M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Cascella, M.; Chattopadhyay, S.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Elsen, E.; Farmer, J.; Fartoukh, S.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Geschonke, G.; Goddard, B.; Gorn, A. A.; Grulke, O.; Gschwendtner, E.; Hansen, J.; Hessler, C.; Hillenbrand, S.; Hofle, W.; Holloway, J.; Huang, C.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Kersevan, R.; Kumar, N.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Lu, W.; Machacek, J.; Mandry, S.; Martin, I.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Meddahi, M.; Merminga, L.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Müller, A. -S.; Najmudin, Z.; Noakes, T. C. Q.; Norreys, P.; Osterhoff, J.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pozimski, J.; Pukhov, A.; Reimann, O.; Rieger, K.; Roesler, S.; Ruhl, H.; Rusnak, T.; Salveter, F.; Savard, N.; Schmidt, J.; von der Schmitt, H.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Simon, F.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Tajima, T.; Tarkeshian, R.; Timko, H.; Trines, R.; Tückmantel, T.; Tuev, P. V.; Turner, M.; Velotti, F.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Yakimenko, V.; Zhang, H.; Zimmermann, F.

    2016-01-02

    This study describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability – a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of the AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1] .

  19. Hippocampal awake replay in fear memory retrieval.

    PubMed

    Wu, Chun-Ting; Haggerty, Daniel; Kemere, Caleb; Ji, Daoyun

    2017-04-01

    Hippocampal place cells are key to episodic memories. How these cells participate in memory retrieval remains unclear. After rats acquired a fear memory by receiving mild footshocks in a shock zone on a track, we analyzed place cells when the animals were placed on the track again and displayed an apparent memory retrieval behavior: avoidance of the shock zone. We found that place cells representing the shock zone were reactivated, despite the fact that the animals did not enter the shock zone. This reactivation occurred in ripple-associated awake replay of place cell sequences encoding the paths from the animal's current positions to the shock zone but not in place cell sequences within individual cycles of theta oscillation. The result reveals a specific place-cell pattern underlying inhibitory avoidance behavior and provides strong evidence for the involvement of awake replay in fear memory retrieval.

  20. Rapid changes in glutamate levels in the posterior hypothalamus across sleep-wake states in freely behaving rats.

    PubMed

    John, Joshi; Ramanathan, Lalini; Siegel, Jerome M

    2008-12-01

    The histamine-containing posterior hypothalamic region (PH-TMN) plays a key role in sleep-wake regulation. We investigated rapid changes in glutamate release in the PH-TMN across the sleep-wake cycle with a glutamate biosensor that allows the measurement of glutamate levels at 1- to 4-s resolution. In the PH-TMN, glutamate levels increased in active waking (AW) and rapid eye movement (REM) sleep compared with quiet waking and nonrapid eye movement (NREM) sleep. There was a rapid (0.6 +/- 1.8 s) and progressive increase in glutamate levels at REM sleep onset. A reduction in glutamate levels consistently preceded the offset of REM sleep by 8 +/- 3 s. Short-duration sleep deprivation resulted in a progressive increase in glutamate levels in the PH-TMN, perifornical-lateral hypothalamus (PF-LH), and cortex. We found that in the PF-LH, glutamate levels took a longer time to return to basal values compared with the time it took for glutamate levels to increase to peak values during AW onset. This is in contrast to other regions we studied in which the return to baseline values after AW was quicker than their rise with waking onset. In summary, we demonstrated an increase in glutamate levels in the PH-TMN with REM/AW onset and a drop in glutamate levels before the offset of REM. High temporal resolution measurement of glutamate levels reveals dynamic changes in release linked to the initiation and termination of REM sleep.

  1. The relationship between gamma frequency and running speed differs for slow and fast gamma rhythms in freely behaving rats

    PubMed Central

    Zheng, Chenguang; Bieri, Kevin Wood; Trettel, Sean Gregory; Colgin, Laura Lee

    2015-01-01

    In hippocampal area CA1 of rats, the frequency of gamma activity has been shown to increase with running speed (Ahmed and Mehta, 2012). This finding suggests that different gamma frequencies simply allow for different timings of transitions across cell assemblies at varying running speeds, rather than serving unique functions. However, accumulating evidence supports the conclusion that slow (~25–55 Hz) and fast (~60–100 Hz) gamma are distinct network states with different functions. If slow and fast gamma constitute distinct network states, then it is possible that slow and fast gamma frequencies are differentially affected by running speed. In this study, we tested this hypothesis and found that slow and fast gamma frequencies change differently as a function of running speed in hippocampal areas CA1 and CA3, and in the superficial layers of the medial entorhinal cortex (MEC). Fast gamma frequencies increased with increasing running speed in all three areas. Slow gamma frequencies changed significantly less across different speeds. Furthermore, at high running speeds, CA3 firing rates were low, and MEC firing rates were high, suggesting that CA1 transitions from CA3 inputs to MEC inputs as running speed increases. These results support the hypothesis that slow and fast gamma reflect functionally distinct states in the hippocampal network, with fast gamma driven by MEC at high running speeds and slow gamma driven by CA3 at low running speeds. PMID:25601003

  2. The relationship between gamma frequency and running speed differs for slow and fast gamma rhythms in freely behaving rats.

    PubMed

    Zheng, Chenguang; Bieri, Kevin Wood; Trettel, Sean Gregory; Colgin, Laura Lee

    2015-08-01

    In hippocampal area CA1 of rats, the frequency of gamma activity has been shown to increase with running speed (Ahmed and Mehta, 2012). This finding suggests that different gamma frequencies simply allow for different timings of transitions across cell assemblies at varying running speeds, rather than serving unique functions. However, accumulating evidence supports the conclusion that slow (∼25-55 Hz) and fast (∼60-100 Hz) gamma are distinct network states with different functions. If slow and fast gamma constitute distinct network states, then it is possible that slow and fast gamma frequencies are differentially affected by running speed. In this study, we tested this hypothesis and found that slow and fast gamma frequencies change differently as a function of running speed in hippocampal areas CA1 and CA3, and in the superficial layers of the medial entorhinal cortex (MEC). Fast gamma frequencies increased with increasing running speed in all three areas. Slow gamma frequencies changed significantly less across different speeds. Furthermore, at high running speeds, CA3 firing rates were low, and MEC firing rates were high, suggesting that CA1 transitions from CA3 inputs to MEC inputs as running speed increases. These results support the hypothesis that slow and fast gamma reflect functionally distinct states in the hippocampal network, with fast gamma driven by MEC at high running speeds and slow gamma driven by CA3 at low running speeds.

  3. Synaptic depression in the CA1 region of freely behaving mice is highly dependent on afferent stimulation parameters

    PubMed Central

    Goh, Jinzhong J.; Manahan-Vaughan, Denise

    2012-01-01

    Persistent synaptic plasticity has been subjected to intense study in the decades since it was first described. Occurring in the form of long-term potentiation (LTP) and long-term depression (LTD), it shares many cellular and molecular properties with hippocampus-dependent forms of persistent memory. Recent reports of both LTP and LTD occurring endogenously under specific learning conditions provide further support that these forms of synaptic plasticity may comprise the cellular correlates of memory. Most studies of synaptic plasticity are performed using in vitro or in vivo preparations where patterned electrical stimulation of afferent fibers is implemented to induce changes in synaptic strength. This strategy has proven very effective in inducing LTP, even under in vivo conditions. LTD in vivo has proven more elusive: although LTD occurs endogenously under specific learning conditions in both rats and mice, its induction has not been successfully demonstrated with afferent electrical stimulation alone. In this study we screened a large spectrum of protocols that are known to induce LTD either in hippocampal slices or in the intact rat hippocampus, to clarify if LTD can be induced by sole afferent stimulation in the mouse CA1 region in vivo. Low frequency stimulation at 1, 2, 3, 5, 7, or 10 Hz given in the range of 100 through 1800 pulses produced, at best, short-term depression (STD) that lasted for up to 60 min. Varying the administration pattern of the stimuli (e.g., 900 pulses given twice at 5 min intervals), or changing the stimulation intensity did not improve the persistency of synaptic depression. LTD that lasts for at least 24 h occurs under learning conditions in mice. We conclude that a coincidence of factors, such as afferent activity together with neuromodulatory inputs, play a decisive role in the enablement of LTD under more naturalistic (e.g., learning) conditions. PMID:23355815

  4. Strain-Dependent Variations in Spatial Learning and in Hippocampal Synaptic Plasticity in the Dentate Gyrus Of Freely Behaving Rats

    PubMed Central

    Manahan-Vaughan, Denise; Schwegler, Herbert

    2011-01-01

    Hippocampal synaptic plasticity is believed to comprise the cellular basis for spatial learning. Strain-dependent differences in synaptic plasticity in the CA1 region have been reported. However, it is not known whether these differences extend to other synapses within the trisynaptic circuit, although there is evidence for morphological variations within that path. We investigated whether Wistar and Hooded Lister (HL) rat strains express differences in synaptic plasticity in the dentate gyrus in vivo. We also explored whether they exhibit differences in the ability to engage in spatial learning in an eight-arm radial maze. Basal synaptic transmission was stable over a 24-h period in both rat strains, and the input–output relationship of both strains was not significantly different. Paired-pulse analysis revealed significantly less paired-pulse facilitation in the HL strain when pulses were given 40–100 ms apart. Low frequency stimulation at 1 Hz evoked long-term depression (>24 h) in Wistar and short-term depression (<2 h) in HL rats; 200 Hz stimulation induced long-term potentiation (>24 h) in Wistar, and a transient, significantly smaller potentiation (<1 h) in HL rats, suggesting that HL rats have higher thresholds for expression of persistent synaptic plasticity. Training for 10 days in an eight-arm radial maze revealed that HL rats master the working memory task faster than Wistar rats, although both strains show an equivalent performance by the end of the trial period. HL rats also perform more efficiently in a double working and reference memory task. On the other hand, Wistar rats show better reference memory performance on the final (8–10) days of training. Wistar rats were less active and more anxious than HL rats. These data suggest that strain-dependent variations in hippocampal synaptic plasticity occur in different hippocampal synapses. A clear correlation with differences in spatial learning is not evident however. PMID:21436876

  5. [AWAKE CRANIOTOMY: IN SEARCH FOR OPTIMAL SEDATION].

    PubMed

    Kulikova, A S; Sel'kov, D A; Kobyakov, G L; Shmigel'skiy, A V; Lubnin, A Yu

    2015-01-01

    Awake craniotomy is a "gold standard"for intraoperative brain language mapping. One of the main anesthetic challenge of awake craniotomy is providing of optimal sedation for initial stages of intervention. The goal of this study was comparison of different technics of anesthesia for awake craniotomy. Materials and methods: 162 operations were divided in 4 groups: 76 cases with propofol sedation (2-4mg/kg/h) without airway protection; 11 cases with propofol sedation (4-5 mg/kg/h) with MV via LMA; 36 cases of xenon anesthesia; and 39 cases with dexmedetomidine sedation without airway protection. Results and discussion: brain language mapping was successful in 90% of cases. There was no difference between groups in successfulness of brain mapping. However in the first group respiratory complications were more frequent. Three other technics were more safer Xenon anesthesia was associated with ultrafast awakening for mapping (5±1 min). Dexmedetomidine sedation provided high hemodynamic and respiratory stability during the procedure.

  6. A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex

    PubMed Central

    Veith, Vera K.; Quigley, Cliodhna; Treue, Stefan

    2016-01-01

    The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations. PMID:27023110

  7. Measuring neural coupling from non-Gaussian power spectra of voltage traces taken from awake behaving animals

    NASA Astrophysics Data System (ADS)

    Masimore, Beth; Kakalios, James; Redish, A. David

    2003-05-01

    Brains consist of complex networks of neurons possessing highly non-linear interactions, suggesting that neural systems will show cooperative dynamics. Previous studies of the non-Gaussian statistics of 1/f noise in spin glasses and amorphous semiconductors have revealed important information concerning interaction kinetics not available through other techniques. Five male Brown-Norway-Cross rats were chronically implanted with arrays of microwire electrodes from which local field potentials (LFPs) were recorded from the dorsocentral striatum as the animals performed complex navigational tasks. The power spectra displayed a frequency dependence significantly different from 1/f. The correlation coefficients of the Fourier transform of the LFPs from striatum showed significant non-zero correlations between frequencies separated by less than three octaves. This novel technique may be useful in measuring functional interactions in neural systems.

  8. Ammonia encephalopathy and awake craniotomy for brain language mapping: cause of failed awake craniotomy.

    PubMed

    Villalba Martínez, G; Fernández-Candil, J L; Vivanco-Hidalgo, R M; Pacreu Terradas, S; León Jorba, A; Arroyo Pérez, R

    2015-05-01

    We report the case of an aborted awake craniotomy for a left frontotemporoinsular glioma due to ammonia encephalopathy on a patient taking Levetiracetam, valproic acid and clobazam. This awake mapping surgery was scheduled as a second-stage procedure following partial resection eight days earlier under general anesthesia. We planned to perform the surgery with local anesthesia and sedation with remifentanil and propofol. After removal of the bone flap all sedation was stopped and we noticed slow mentation and excessive drowsiness prompting us to stop and control the airway and proceed with general anesthesia. There were no post-operative complications but the patient continued to exhibit bradypsychia and hand tremor. His ammonia level was found to be elevated and was treated with an infusion of l-carnitine after discontinuation of the valproic acid with vast improvement. Ammonia encephalopathy should be considered in patients treated with valproic acid and mental status changes who require an awake craniotomy with patient collaboration.

  9. Calcium neuroimaging in behaving zebrafish larvae using a turn-key light field camera

    NASA Astrophysics Data System (ADS)

    Cruz Perez, Carlos; Lauri, Antonella; Symvoulidis, Panagiotis; Cappetta, Michele; Erdmann, Arne; Westmeyer, Gil Gregor

    2015-09-01

    Reconstructing a three-dimensional scene from multiple simultaneously acquired perspectives (the light field) is an elegant scanless imaging concept that can exceed the temporal resolution of currently available scanning-based imaging methods for capturing fast cellular processes. We tested the performance of commercially available light field cameras on a fluorescent microscopy setup for monitoring calcium activity in the brain of awake and behaving reporter zebrafish larvae. The plenoptic imaging system could volumetrically resolve diverse neuronal response profiles throughout the zebrafish brain upon stimulation with an aversive odorant. Behavioral responses of the reporter fish could be captured simultaneously together with depth-resolved neuronal activity. Overall, our assessment showed that with some optimizations for fluorescence microscopy applications, commercial light field cameras have the potential of becoming an attractive alternative to custom-built systems to accelerate molecular imaging research on cellular dynamics.

  10. Miniature stereo radio transmitter for simultaneous recording of multiple single-neuron signals from behaving owls.

    PubMed

    Nieder, A

    2000-09-15

    Wireless radiotelemetric transmission of neuronal activity is an elegant technique to study brain-behavior interaction in unrestrained animals. In the current study, a miniature FM-stereo radio transmitter is described that permitted simultaneous recordings from two microelectrodes in behaving barn owls. Input from two independent channels is multiplexed to form a stereo composite signal that modulates a radio frequency carrier. The high quality of broadcasted extracellular signals enabled separation of single units based on differences in spike waveforms. Recording several single cells from different electrodes allows the possibility of investigating correlations between small, distributed neuronal ensembles. Multi-channel radiotelemetry that meets the demands of modern electrophysiology might open a new perspective for combined behavioral/neurophysiological approaches in freely-behaving animals.

  11. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

    PubMed Central

    Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

    2014-01-01

    A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays. PMID:25096831

  12. Awake craniotomy and multilingualism: language testing during anaesthesia for awake craniotomy in a bilingual patient.

    PubMed

    Costello, T G

    2014-08-01

    An awake craniotomy for epilepsy surgery is presented where a bilingual patient post-operatively reported temporary aphasia of his first language (Spanish). This case report discusses the potential causes for this clinical presentation and methods to prevent the occurrence of this in future patients undergoing this form of surgery.

  13. Awake Craniotomy Anesthesia: A Comparison of the Monitored Anesthesia Care and Asleep-Awake-Asleep Techniques.

    PubMed

    Eseonu, Chikezie I; ReFaey, Karim; Garcia, Oscar; John, Amballur; Quiñones-Hinojosa, Alfredo; Tripathi, Punita

    2017-08-01

    Commonly used sedation techniques for an awake craniotomy include monitored anesthesia care (MAC), using an unprotected airway, and the asleep-awake-asleep (AAA) technique, using a partially or totally protected airway. We present a comparative analysis of the MAC and AAA techniques, evaluating anesthetic management, perioperative outcomes, and complications in a consecutive series of patients undergoing the removal of an eloquent brain lesion. Eighty-one patients underwent awake craniotomy for an intracranial lesion over a 9-year period performed by a single-surgeon and a team of anesthesiologists. Fifty patients were treated using the MAC technique, and 31 were treated using the AAA technique. A retrospective analysis evaluated anesthetic management, intraoperative complications, postoperative outcomes, pain management, and complications. The MAC and AAA groups had similar preoperative patient and tumor characteristics. Mean operative time was shorter in the MAC group (283.5 minutes vs. 313.3 minutes; P = 0.038). Hypertension was the most common intraoperative complication seen (8% in the MAC group vs. 9.7% in the AAA group; P = 0.794). Intraoperative seizure occurred at a rate of 4% in the MAC group and 3.2% in the AAA group (P = 0.858). Awake cases were converted to general anesthesia in no patients in the MAC group and in 1 patient (3.2%) in the AAA group (P = 0.201). No cases were aborted in either group. The mean hospital length of stay was 3.98 days in the MAC group and 3.84 days in the AAA group (P = 0.833). Both the MAC and AAA sedation techniques provide an efficacious and safe method for managing awake craniotomy cases and produce similar perioperative outcomes, with the MAC technique associated with shorter operative time. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Simultaneous telemetric monitoring of brain glucose and lactate and motion in freely moving rats.

    PubMed

    Rocchitta, Gaia; Secchi, Ottavio; Alvau, Maria Domenica; Farina, Donatella; Bazzu, Gianfranco; Calia, Giammario; Migheli, Rossana; Desole, Maria Speranza; O'Neill, Robert D; Serra, Pier A

    2013-11-05

    A new telemetry system for simultaneous detection of extracellular brain glucose and lactate and motion is presented. The device consists of dual-channel, single-supply miniature potentiostat-I/V converter, a microcontroller unit, a signal transmitter, and a miniaturized microvibration sensor. Although based on simple and inexpensive components, the biotelemetry device has been used for accurate transduction of the anodic oxidation currents generated on the surface of implanted glucose and lactate biosensors and animal microvibrations. The device was characterized and validated in vitro before in vivo experiments. The biosensors were implanted in the striatum of freely moving animals and the biotelemetric device was fixed to the animal's head. Physiological and pharmacological stimulations were given in order to induce striatal neural activation and to modify the motor behavior in awake, untethered animals.

  15. [Awake craniotomy. Considerations in special situations].

    PubMed

    Solera Ruiz, I; Uña Orejón, R; Valero, I; Laroche, F

    2013-01-01

    Awake craniotomy was the earliest surgical procedure known, and it has become fashionable again. In the past it was used for the surgical management of intractable epilepsy, but nowadays, its indications are increasing, and it is a widely recognized technique for the resection of mass lesions involving the eloquent cortex, and for deep brain stimulation. The procedure is safe, provides excellent results, and saves money and resources. The anesthesiologist should know the principles underlying neuroanesthesia, the technique of scalp blockade, and the sedation protocols, as well as feeling comfortable with advanced airway management. The main anesthetic aim is to keep patients cooperating when required (analgesia-based anesthesia). This review attempts to summarize the most recent evidence from the clinical literature, a long as the number of patients undergoing craniotomies in the awake state are increasing, specifically in the pediatric population. Copyright © 2011 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  16. Measurement of intraocular pressure in awake mice.

    PubMed

    Cohan, B E; Bohr, D F

    2001-10-01

    To determine whether the Goldmann applanation tonometer can be modified to measure intraocular pressure (IOP) in the awake mouse. Tonometers with reduction of the biprism angles in the applanating tips and in the weight applied by the instrument were tested in anesthetized mice in calibration experiments. Then a tonometer with the appropriate configuration of tip and weight was used in conscious, unsedated mice. Tonometry in mice required a biprism angle of 36 degrees and weight applied of 25 mg per scale division (2 g full scale). This tonometer was calibrated in mice against manometrically measured IOP and showed good agreement across the range of IOP tested (0-50 mm Hg). In conscious mice the measured mean Goldmann value was 13.7 +/- 3.2 mm Hg (mean +/- SD; 95% confidence interval, 13.1, 14.2 mm Hg). The Goldmann tonometer, the standard for measuring the IOP in the human eye, was modified to measure this fundamental physiologic parameter in the awake mouse. This measurement is required to confirm success in genetically engineering a model in the powerful mouse system, which mimics elevated IOP in humans. The model will open new avenues for studying the causes of the optic neuropathy of glaucoma, the regulation of IOP, and new therapeutic approaches to prevent the irreversible loss of vision from this disease.

  17. Does single cortical spreading depression elicit pain behaviour in freely moving rats?

    PubMed

    Akcali, Didem; Sayin, Aslihan; Sara, Yildirim; Bolay, Hayrunnisa

    2010-10-01

    Behavioural animal studies are critical, particularly to translate results to human beings. Cortical spreading depression (CSD) has been implicated in migraine pathogenesis. We aimed to investigate the effects of CSD on the behaviour of freely moving rats, since available CSD models do not include awake animals. We developed a new model to induce single CSD by applying topical N-methyl-D-aspartate (NMDA) and employed a combination of an automated behavioural analysis system, video camera and ultrasonic vocalisation (USV) calls for the first time. Electrocorticograms were also studied during CSD in freely moving rats. Behaviour associated with cephalic pain was assessed in a group of rats that received sumatriptan. Cortical c-fos immunoreactivity was performed in order to confirm CSD. NMDA induced single CSD in ipsilateral cortex, evoked freezing behaviour (P < 0.01) and increased the number of wet dog shakes (WDS; P < 0.01). Grooming, locomotion, eating, drinking, and circling were not significantly altered among groups. Ultrasonic vocalisations compatible with pain calls (22-27 kHz) were only detected in 3 out of 25 rats. Sumatriptan did not significantly reduce the freezing behaviour. CSD induced significant c-fos expression in ipsilateral cerebral cortex and amygdala (P < 0.01). CSD induces freezing behaviour by invoking anxiety/fear via amygdala activation in freely-moving rats. Single CSD is unlikely to lead to severe pain in freely-moving rats, though the development of mild or vague pain cannot be excluded. The relevance of rat behavioural responses triggered by CSD to migraine symptoms in humans needs further evaluation.

  18. Awake craniotomy for supratentorial gliomas: why, when and how?

    PubMed

    Ibrahim, George M; Bernstein, Mark

    2012-09-01

    Awake craniotomy has become an increasingly utilized procedure in the treatment of supratentorial intra-axial tumors. The popularity of this procedure is partially attributable to improvements in intraoperative technology and anesthetic techniques. The application of awake craniotomy to the field of neuro-oncology has decreased iatrogenic postoperative neurological deficits, allowed for safe maximal tumor resection and improved healthcare resource stewardship by permitting early patient discharge. In this article, we review recent evidence for the utility of awake craniotomy in the resection of gliomas and describe the senior author's experience in performing this procedure. Furthermore, we explore innovative applications of awake craniotomy to outpatient tumor resections and the conduct of neurosurgery in resource-poor settings. We conclude that awake craniotomy is an effective and versatile neurosurgical procedure with expanding applications in neuro-oncology.

  19. Inclusions in freely suspended smectic films

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; Harth, Kirsten

    Smectic liquid crystal phases have a unique property: Like soap solutions, they can form stable freely suspended films. Their aspect ratios can be larger than one million to one. Such films can serve as models for two-dimensional (2D) uids, with or without in-plane anisotropy. Solid or liquid inclusions trapped in these films by capillary forces can move in the film plane and interact with other inclusions, with film thickness gradients or the film boundaries, and even with the local orientation field. We describe preparation techniques to incorporate particles or droplets in thin smectic films, and optical observation methods. Several aspects make inclusions in freely suspended films interesting research objects: They provide rich information on capillary forces as well as surface and interfacial tensions, they can serve as platforms for hydrodynamic studies in 2D, and they may help to understand coalescence dynamics at the transition from 2D to 3D...

  20. Chronic, Wireless Recordings of Large Scale Brain Activity in Freely Moving Rhesus Monkeys

    PubMed Central

    Schwarz, David A.; Lebedev, Mikhail A.; Hanson, Timothy L.; Dimitrov, Dragan F.; Lehew, Gary; Meloy, Jim; Rajangam, Sankaranarayani; Subramanian, Vivek; Ifft, Peter J.; Li, Zheng; Ramakrishnan, Arjun; Tate, Andrew; Zhuang, Katie; Nicolelis, Miguel A.L.

    2014-01-01

    Advances in techniques for recording large-scale brain activity contribute to both the elucidation of neurophysiological principles and the development of brain-machine interfaces (BMIs). Here we describe a neurophysiological paradigm for performing tethered and wireless large-scale recordings based on movable volumetric three-dimensional (3D) multielectrode implants. This approach allowed us to isolate up to 1,800 units per animal and simultaneously record the extracellular activity of close to 500 cortical neurons, distributed across multiple cortical areas, in freely behaving rhesus monkeys. The method is expandable, in principle, to thousands of simultaneously recorded channels. It also allows increased recording longevity (5 consecutive years), and recording of a broad range of behaviors, e.g. social interactions, and BMI paradigms in freely moving primates. We propose that wireless large-scale recordings could have a profound impact on basic primate neurophysiology research, while providing a framework for the development and testing of clinically relevant neuroprostheses. PMID:24776634

  1. A freely-moving monkey treadmill model

    NASA Astrophysics Data System (ADS)

    Foster, Justin D.; Nuyujukian, Paul; Freifeld, Oren; Gao, Hua; Walker, Ross; Ryu, Stephen I.; Meng, Teresa H.; Murmann, Boris; Black, Michael J.; Shenoy, Krishna V.

    2014-08-01

    Objective. Motor neuroscience and brain-machine interface (BMI) design is based on examining how the brain controls voluntary movement, typically by recording neural activity and behavior from animal models. Recording technologies used with these animal models have traditionally limited the range of behaviors that can be studied, and thus the generality of science and engineering research. We aim to design a freely-moving animal model using neural and behavioral recording technologies that do not constrain movement. Approach. We have established a freely-moving rhesus monkey model employing technology that transmits neural activity from an intracortical array using a head-mounted device and records behavior through computer vision using markerless motion capture. We demonstrate the flexibility and utility of this new monkey model, including the first recordings from motor cortex while rhesus monkeys walk quadrupedally on a treadmill. Main results. Using this monkey model, we show that multi-unit threshold-crossing neural activity encodes the phase of walking and that the average firing rate of the threshold crossings covaries with the speed of individual steps. On a population level, we find that neural state-space trajectories of walking at different speeds have similar rotational dynamics in some dimensions that evolve at the step rate of walking, yet robustly separate by speed in other state-space dimensions. Significance. Freely-moving animal models may allow neuroscientists to examine a wider range of behaviors and can provide a flexible experimental paradigm for examining the neural mechanisms that underlie movement generation across behaviors and environments. For BMIs, freely-moving animal models have the potential to aid prosthetic design by examining how neural encoding changes with posture, environment and other real-world context changes. Understanding this new realm of behavior in more naturalistic settings is essential for overall progress of basic

  2. Does Global Astrocytic Calcium Signaling Participate in Awake Brain State Transitions and Neuronal Circuit Function?

    PubMed

    Kjaerby, Celia; Rasmussen, Rune; Andersen, Mie; Nedergaard, Maiken

    2017-02-16

    We continuously need to adapt to changing conditions within our surrounding environment, and our brain needs to quickly shift between resting and working activity states in order to allow appropriate behaviors. These global state shifts are intimately linked to the brain-wide release of the neuromodulators, noradrenaline and acetylcholine. Astrocytes have emerged as a new player participating in the regulation of brain activity, and have recently been implicated in brain state shifts. Astrocytes display global Ca(2+) signaling in response to activation of the noradrenergic system, but whether astrocytic Ca(2+) signaling is causative or correlative for shifts in brain state and neural activity patterns is not known. Here we review the current available literature on astrocytic Ca(2+) signaling in awake animals in order to explore the role of astrocytic signaling in brain state shifts. Furthermore, we look at the development and availability of innovative new methodological tools that are opening up for new ways of visualizing and perturbing astrocyte activity in awake behaving animals. With these new tools at hand, the field of astrocyte research will likely be able to elucidate the causal and mechanistic roles of astrocytes in complex behaviors within a very near future.

  3. An inhomogeneous model universe behaving homogeneously

    NASA Astrophysics Data System (ADS)

    Khosravi, Sh.; Kourkchi, E.; Mansouri, R.; Akrami, Y.

    2008-05-01

    We present a new model universe based on the junction of FRW to flat Lemaitre Tolman Bondi (LTB) solutions of Einstein equations along our past light cone, bringing structures within the FRW models. The model is assumed globally to be homogeneous, i.e. the cosmological principle is valid. Local inhomogeneities within the past light cone are modeled as a flat LTB, whereas those outside the light cone are assumed to be smoothed out and represented by a FRW model. The model is singularity free, always FRW far from the observer along the past light cone, gives way to a different luminosity distance relation as for the CDM/FRW models, a negative deceleration parameter near the observer, and correct linear and non-linear density contrast. As a whole, the model behaves like a FRW model on the past light cone with a special behavior of the scale factor, Hubble and deceleration parameter, mimicking dark energy.

  4. Comparison of Conscious Sedation and Asleep-Awake-Asleep Techniques for Awake Craniotomy.

    PubMed

    Dilmen, Ozlem Korkmaz; Akcil, Eren Fatma; Oguz, Abdulvahap; Vehid, Hayriye; Tunali, Yusuf

    2017-01-01

    Since awake craniotomy (AC) has become a standard of care for supratentorial tumour resection, especially in the motor and language cortex, determining the most appropriate anaesthetic protocol is very important. The aim of this retrospective study is to compare the effectiveness of conscious sedation (CS) to "awake-asleep-awake" (AAA) techniques for supratentorial tumour resection. Forty-two patients undergoing CS and 22 patients undergoing AAA were included in the study. The primary endpoint was to compare the CS and AAA techniques with respect to intraoperative pain and agitation in patients undergoing supratentorial tumour resection. The secondary endpoint was comparison of the other intraoperative complications. This study results show that the incidence of intraoperative agitation and seizure were lower in the AAA group than in the CS group. Intraoperative blood pressures were significantly higher in the CS group than in the AAA group during the pinning and incision, but the level of blood pressures did not need antihypertensive treatment. Otherwise, blood pressures were significantly higher in the AAA group than in the CS group during the neurological examination and the severity of hypertension needed statistically significant more antihypertensive treatment in the AAA group. As a result of hypertension, the amount of intraoperative bleeding was higher in the AAA group than in the CS group. In conclusion, the AAA technique may provide better results with respect to agitation and seizure, but intraoperative hypertension needed a vigilant follow-up especially in the wake-up period.

  5. Detecting location-specific neuronal firing rate increases in the hippocampus of freely-moving monkeys.

    PubMed

    Ludvig, Nandor; Tang, Hai M; Gohil, Baiju C; Botero, Juan M

    2004-07-16

    The spatial properties of the firing of hippocampal neurons have mainly been studied in (a) freely moving rodents, (b) non-human primates seated in a moveable primate chair with head fixed, and (c) epileptic patients subjected to virtual navigation. Although these studies have all revealed the ability of hippocampal neurons to generate spatially selective discharges, the detected firing patterns have been found to be considerably different, even conflicting, in many respects. The present cellular electrophysiological study employed squirrel monkeys (Saimiri sciureus), which moved freely on the walls and floor of a large test chamber. This permitted the examination of the spatial firing of hippocampal neurons in nearly ideal conditions, similar to those used in rodents, yet in a species that belongs to the primate Suborder Anthropoidea. The major findings were that: (1) a group of slow-firing complex-spike cells increased their basal, awake firing rate more than 20-fold, often above 30 spikes/s, when the monkey was in a particular location in the chamber, (2) these location-specific discharges occurred consistently, forming 4-25 s action potential volleys, and (3) fast-firing cells displayed no such electrical activity. Thus, during free movement in three dimensions, primate hippocampal complex-spike cells do generate high-frequency, location-specific action potential volleys. Since these cells are components of the medial temporal lobe memory system, their uncovered firing pattern may well be involved in the formation of declarative memories on places.

  6. A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats

    PubMed Central

    Limnuson, Kanokwan; Narayan, Raj K.; Chiluwal, Amrit; Golanov, Eugene V.; Bouton, Chad E.; Li, Chunyan

    2016-01-01

    Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury. PMID:27594826

  7. Auditory properties in the parabelt regions of the superior temporal gyrus in the awake macaque monkey: an initial survey.

    PubMed

    Kajikawa, Yoshinao; Frey, Stephen; Ross, Deborah; Falchier, Arnaud; Hackett, Troy A; Schroeder, Charles E

    2015-03-11

    The superior temporal gyrus (STG) is on the inferior-lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the "parabelt," which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas.

  8. Auditory Properties in the Parabelt Regions of the Superior Temporal Gyrus in the Awake Macaque Monkey: An Initial Survey

    PubMed Central

    Frey, Stephen; Ross, Deborah; Falchier, Arnaud; Hackett, Troy A.; Schroeder, Charles E.

    2015-01-01

    The superior temporal gyrus (STG) is on the inferior–lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the “parabelt,” which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas. PMID:25762661

  9. The history of awake craniotomy in hospital universiti sains malaysia.

    PubMed

    Wan Hassan, Wan Mohd Nazaruddin

    2013-10-01

    Awake craniotomy is a brain surgery performed on awake patients and is indicated for certain intracranial pathologies. These include procedures that require an awake patient for electrocorticographic mapping or precise electrophysiological recordings, resection of lesions located close to or in the motor and speech of the brain, or minor intracranial procedures that aim to avoid general anaesthesia for faster recovery and earlier discharge. This type of brain surgery is quite new and has only recently begun to be performed in a few neurosurgical centres in Malaysia. The success of the surgery requires exceptional teamwork from the neurosurgeon, neuroanaesthesiologist, and neurologist. The aim of this article is to briefly describe the history of awake craniotomy procedures at our institution.

  10. Mapping brain function in freely moving subjects

    PubMed Central

    Holschneider, Daniel P.; Maarek, Jean-Michel I.

    2014-01-01

    Expression of many fundamental mammalian behaviors such as, for example, aggression, mating, foraging or social behaviors, depend on locomotor activity. A central dilemma in the functional neuroimaging of these behaviors has been the fact that conventional neuroimaging techniques generally rely on immobilization of the subject, which extinguishes all but the simplest activity. Ideally, imaging could occur in freely moving subjects, while presenting minimal interference with the subject’s natural behavior. Here we provide an overview of several approaches that have been undertaken in the past to achieve this aim in both tethered and freely moving animals, as well as in nonrestrained human subjects. Applications of specific radiotracers to single photon emission computed tomography and positron emission tomography are discussed in which brain activation is imaged after completion of the behavioral task and capture of the tracer. Potential applications to clinical neuropsychiatry are discussed, as well as challenges inherent to constraint-free functional neuroimaging. Future applications of these methods promise to increase our understanding of the neural circuits underlying mammalian behavior in health and disease. PMID:15465134

  11. Anaesthesia for awake craniotomy: A retrospective study of 54 cases

    PubMed Central

    Sokhal, Navdeep; Rath, Girija Prasad; Chaturvedi, Arvind; Dash, Hari Hara; Bithal, Parmod Kumar; Chandra, P Sarat

    2015-01-01

    Background and Aims: The anaesthetic challenge of awake craniotomy is to maintain adequate sedation, analgesia, respiratory and haemodynamic stability in an awake patient who should be able to co-operate during intraoperative neurological assessment. The current literature, sharing the experience on awake craniotomy, in Indian context, is minimal. Hence, we carried out a retrospective study with the aim to review and analyse the anaesthetic management and perioperative complications in patients undergoing awake craniotomy, at our centre. Methods: Medical records of 54 patients who underwent awake craniotomy for intracranial lesions over a period of 10 years were reviewed, retrospectively. Data regarding anaesthetic management, intraoperative complications and post-operative course were recorded. Results: Propofol (81.5%) and dexmedetomidine (18.5%) were the main agents used for providing conscious sedation to facilitate awake craniotomy. Hypertension (16.7%) was the most commonly encountered complication during intraoperative period, followed by seizures (9.3%), desaturation (7.4%), tight brain (7.4%), and shivering (5.6%). The procedure had to be converted to general anaesthesia in one of patients owing to refractory brain bulge. The incidence of respiratory and haemodynamic complications were comparable in the both groups (P > 0.05). There was less incidence of intraoperative seizures in patients who received propofol (P = 0.03). In post-operative period, 20% of patients developed new motor deficit. Mean intensive care unit stay was 2.8 ± 1.9 day (1–14 days) and mean hospital stay was 7.0 ± 5.0 day (3–30 days). Conclusions: ‘Conscious sedation’ was the technique of choice for awake craniotomy, at our institute. Fentanyl, propofol, and dexmedetomidine were the main agents used for this purpose. Patients receiving propofol had less incidence of intraoperative seizure. Appropriate selection of patients, understanding the procedure of surgery, and judicious

  12. Awake craniotomy: A qualitative review and future challenges

    PubMed Central

    Ghazanwy, Mahmood; Chakrabarti, Rajkalyan; Tewari, Anurag; Sinha, Ashish

    2014-01-01

    Neurosurgery in awake patients incorporates newer technologies that require the anesthesiologists to update their skills and evolve their methodologies. They need effective communication skills and knowledge of selecting the right anesthetic drugs to ensure adequate analgesia, akinesia, along with patient satisfaction with the anesthetic conduct throughout the procedure. The challenge of providing adequate anesthetic care to an awake patient for intracranial surgery requires more than routine vigilance about anesthetic management. PMID:25422613

  13. Ionic liquids behave as dilute electrolyte solutions

    PubMed Central

    Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

    2013-01-01

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

  14. Ionic liquids behave as dilute electrolyte solutions.

    PubMed

    Gebbie, Matthew A; Valtiner, Markus; Banquy, Xavier; Fox, Eric T; Henderson, Wesley A; Israelachvili, Jacob N

    2013-06-11

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force-distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin-Landau-Verwey-Overbeek theory with an additive repulsive steric (entropic) ion-surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high-free-ion density ionic liquids and ionic liquid blends.

  15. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2013-06-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  16. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S; Endres, Christopher; Foss, Catherine; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard Jr, James Samuel; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander; Weisenberger, Andrew G.; Pomper, Martin

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  17. [Anesthetic considerations for awake craniotomy: case report].

    PubMed

    Freitas, Cassiano Hamacek de; Oliveira, Celso Homero Santos; Rezende, Daniel Câmara de; Romano, Joyce; Silva, Henrique Rodrigues Lemos; Trivellato, Ivana Mares

    2016-10-27

    The conscious patient cooperation during neurological procedures has become necessary for the delimitation of areas to be managed by a neurosurgeon, with better results in the treatment of tumor lesions, vascular or epileptic foci, and lesser sequelae. The need for perioperative awareness (responsiveness to commands) challenges anesthesiologists to further ensure patient safety during the procedure. Several techniques have been described for this purpose. In this case, interaction with the patient during brain tumor resection enabled a broad approach of the tumor lesion, limited by deficits in speech and naming observed during surgical manipulation, avoiding major consequences. The chosen technique was deepening of general anesthesia during surgical times of most painful stimulus with intraoperative awakening of the patient. Patient selection, an exhaustive explanation of the procedure to him, and the selection of drugs are crucial for a successful procedure. Laryngeal mask is useful in times requiring greater depth and anesthetic ventilation control, primarily in situations where endotracheal intubation may be hindered by the position. The continuous infusion of remifentanil and adjuncts in the awake period associated adequate analgesia and full consciousness. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. Virtual reality for freely moving animals.

    PubMed

    Stowers, John R; Hofbauer, Maximilian; Bastien, Renaud; Griessner, Johannes; Higgins, Peter; Farooqui, Sarfarazhussain; Fischer, Ruth M; Nowikovsky, Karin; Haubensak, Wulf; Couzin, Iain D; Tessmar-Raible, Kristin; Straw, Andrew D

    2017-10-01

    Standard animal behavior paradigms incompletely mimic nature and thus limit our understanding of behavior and brain function. Virtual reality (VR) can help, but it poses challenges. Typical VR systems require movement restrictions but disrupt sensorimotor experience, causing neuronal and behavioral alterations. We report the development of FreemoVR, a VR system for freely moving animals. We validate immersive VR for mice, flies, and zebrafish. FreemoVR allows instant, disruption-free environmental reconfigurations and interactions between real organisms and computer-controlled agents. Using the FreemoVR platform, we established a height-aversion assay in mice and studied visuomotor effects in Drosophila and zebrafish. Furthermore, by photorealistically mimicking zebrafish we discovered that effective social influence depends on a prospective leader balancing its internally preferred directional choice with social interaction. FreemoVR technology facilitates detailed investigations into neural function and behavior through the precise manipulation of sensorimotor feedback loops in unrestrained animals.

  19. Intercascade annihilation of freely migrating defects

    SciTech Connect

    Iwase, A. |; Rehn, L.E.; Baldo, P.M.; Funk, L.

    1995-07-10

    To characterize putative interactions between freely migrating defects (FMD) and remnants of energetic displacement cascades, radiation-induced segregation (RIS) in Cu-1 at. % Au was measured by Rutherford backscattering during separate and simultaneous irradiation at 400 {degree}C with 1.5 MeV He and 800 keV Cu ions. The strong RIS observed during only He irradiation was greatly reduced under simultaneous Cu irradiation at approximately the same displacements per atom rate; increasing the Cu flux by a factor of 5 suppressed the RIS from the He beam almost completely. The suppression of RIS at 400 {degree}C disappeared quickly when the Cu irradiation ceased. These results demonstrate that a transient population of interstitial and/or vacancy clusters from the Cu irradiation greatly reduces the survival rate of FMD produced by the He. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  20. Optetrode: a multichannel readout for optogenetic control in freely moving mice

    PubMed Central

    Anikeeva, Polina; Andalman, Aaron S; Witten, Ilana; Warden, Melissa; Goshen, Inbal; Grosenick, Logan; Gunaydin, Lisa A; Frank, Loren M; Deisseroth, Karl

    2014-01-01

    Recent advances in optogenetics have improved the precision with which defined circuit elements can be controlled optically in freely moving mammals; in particular, recombinase-dependent opsin viruses, used with a growing pool of transgenic mice expressing recombinases, allow manipulation of specific cell types. However, although optogenetic control has allowed neural circuits to be manipulated in increasingly powerful ways, combining optogenetic stimulation with simultaneous multichannel electrophysiological readout of isolated units in freely moving mice remains a challenge. We designed and validated the optetrode, a device that allows for colocalized multi-tetrode electrophysiological recording and optical stimulation in freely moving mice. Optetrode manufacture employs a unique optical fiber-centric coaxial design approach that yields a lightweight (2 g), compact and robust device that is suitable for behaving mice. This low-cost device is easy to construct (2.5 h to build without specialized equipment). We found that the drive design produced stable high-quality recordings and continued to do so for at least 6 weeks following implantation. We validated the optetrode by quantifying, for the first time, the response of cells in the medial prefrontal cortex to local optical excitation and inhibition, probing multiple different genetically defined classes of cells in the mouse during open field exploration. PMID:22138641

  1. Awake Surgery for Brain Vascular Malformations and Moyamoya Disease.

    PubMed

    Aoun, Rami James N; Sattur, Mithun G; Krishna, Chandan; Gupta, Amen; Welz, Matthew E; Nanney, Allan D; Koht, Antoun H; Tate, Matthew C; Noe, Katherine H; Sirven, Joseph I; Anderies, Barrett J; Bolton, Patrick B; Trentman, Terry L; Zimmerman, Richard S; Swanson, Kristin R; Bendok, Bernard R

    2017-09-01

    Although a significant amount of experience has accumulated for awake procedures for brain tumor, epilepsy, and carotid surgery, its utility for intracranial neurovascular indications remains largely undefined. Awake surgery for select neurovascular cases offers the advantage of precise brain mapping and robust neurologic monitoring during surgery for lesions in eloquent areas, avoidance of potential hemodynamic instability, and possible faster recovery. It also opens the window for perilesional epileptogenic tissue resection with potentially less risk for iatrogenic injury. Institutional review board approval was obtained for a retrospective review of awake surgeries for intracranial neurovascular indications over the past 36 months from a prospectively maintained quality database. We reviewed patients' clinical indications, clinical and imaging parameters, and postoperative outcomes. Eight consecutive patients underwent 9 intracranial neurovascular awake procedures conducted by the senior author. A standardized "sedated-awake-sedated" protocol was used in all 8 patients. For the 2 patients with arteriovenous malformations and the 3 patients with cavernoma, awake brain surface and white matter mapping was performed before and during microsurgical resection. A neurological examination was obtained periodically throughout all 5 procedures. There were no intraoperative or perioperative complications. Hypotension was avoided during the 2 Moyamoya revascularization procedures in the patient with a history of labile blood pressure. Postoperative imaging confirmed complete arteriovenous malformation and cavernoma resections. No new neurologic deficits or new-onset seizures were noted on 3-month follow-up. Awake surgery appears to be safe for select patients with intracranial neurovascular pathologies. Potential advantages include greater safety, shorter length of stay, and reduced cost. Copyright © 2017. Published by Elsevier Inc.

  2. A family of well behaved charge analogues of a well behaved neutral solution in general relativity

    NASA Astrophysics Data System (ADS)

    Maurya, Sunil Kumar; Gupta, Y. K.

    2011-04-01

    A family of charge analogues of a neutral solution with g 44=(1+ Cr 2)6 has been obtained by using a specific electric intensity, which involves a parameter K. Both neutral and charged solutions are analysed physically subject to the surface density 2×1014 gm/cm3 (neutron star). The neutral solution is well behaved for 0.0< Ca 2≤0.10477 while its charge analogues are well behaved for a wide range of a parameter K (0≤ K≤72) i.e. pressure, density, pressure-density ratio, velocity of sound is monotonically decreasing and the electric intensity is monotonically increasing in nature for the given range of the parameter K. The maximum mass and radius occupied by the neutral solution are 3.4126 M Θ and 18.9227 km for Ca 2=0.10447 respectively. While the red shift at centre Z 0=0.9686 and red shift at the surface Z a =0.4612. For the charged solution, the maximum mass and radius are 5.6111 M Θ and 17.2992 km respectively for K=3.0130 and Ca 2=0.2500, with the red shift Z 0=3.0113 and Z a =1.0538.

  3. Measuring and tracking eye movements of a behaving archer fish by real-time stereo vision.

    PubMed

    Ben-Simon, Avi; Ben-Shahar, Ohad; Segev, Ronen

    2009-11-15

    The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. This behavior also raises many important questions, such as the fish's ability to compensate for air-water refraction and the neural mechanisms underlying target acquisition. While many such questions remain open, significant insights towards solving them can be obtained by tracking the eye and body movements of freely behaving fish. Unfortunately, existing tracking methods suffer from either a high level of invasiveness or low resolution. Here, we present a video-based eye tracking method for accurately and remotely measuring the eye and body movements of a freely moving behaving fish. Based on a stereo vision system and a unique triangulation method that corrects for air-glass-water refraction, we are able to measure a full three-dimensional pose of the fish eye and body with high temporal and spatial resolution. Our method, being generic, can be applied to studying the behavior of marine animals in general. We demonstrate how data collected by our method may be used to show that the hunting behavior of the archer fish is composed of surfacing concomitant with rotating the body around the direction of the fish's fixed gaze towards the target, until the snout reaches in the correct shooting position at water level.

  4. Preparation of the patient and the airway for awake intubation

    PubMed Central

    Ramkumar, Venkateswaran

    2011-01-01

    Awake intubation is usually performed electively in the presence of a difficult airway. A detailed airway examination is time-consuming and often not feasible in an emergency. A simple 1-2-3 rule for airway examination allows one to identify potential airway difficulty within a minute. A more detailed airway examination can give a better idea about the exact nature of difficulty and the course of action to be taken to overcome it. When faced with an anticipated difficult airway, the anaesthesiologist needs to consider securing the airway in an awake state without the use of anaesthetic agents or muscle relaxants. As this can be highly discomforting to the patient, time and effort must be spent to prepare such patients both psychologically and pharmacologically for awake intubation. Psychological preparation is best initiated by an anaesthesiologist who explains the procedure in simple language. Sedative medications can be titrated to achieve patient comfort without compromising airway patency. Additional pharmacological preparation includes anaesthetising the airway through topical application of local anaesthetics and appropriate nerve blocks. When faced with a difficult airway, one should call for the difficult airway cart as well as for help from colleagues who have interest and expertise in airway management. Preoxygenation and monitoring during awake intubation is important. Anxious patients with a difficult airway may need to be intubated under general anaesthesia without muscle relaxants. Proper psychological and pharmacological preparation of the patient by an empathetic anaesthesiologist can go a long way in making awake intubation acceptable for all concerned. PMID:22174458

  5. Changes in Activity of the Same Thalamic Neurons to Repeated Nociception in Behaving Mice.

    PubMed

    Huh, Yeowool; Cho, Jeiwon

    2015-01-01

    The sensory thalamus has been reported to play a key role in central pain sensory modulation and processing, but its response to repeated nociception at thalamic level is not well known. Current study investigated thalamic response to repeated nociception by recording and comparing the activity of the same thalamic neuron during the 1st and 2nd formalin injection induced nociception, with a week interval between injections, in awake and behaving mice. Behaviorally, the 2nd injection induced greater nociceptive responses than the 1st. Thalamic activity mirrored these behavioral changes with greater firing rate during the 2nd injection. Analysis of tonic and burst firing, characteristic firing pattern of thalamic neurons, revealed that tonic firing activity was potentiated while burst firing activity was not significantly changed by the 2nd injection relative to the 1st. Likewise, burst firing property changes, which has been consistently associated with different phases of nociception, were not induced by the 2nd injection. Overall, data suggest that repeated nociception potentiated responsiveness of thalamic neurons and confirmed that tonic firing transmits nociceptive signals.

  6. Diffusion processes in freely suspended smectic films

    NASA Astrophysics Data System (ADS)

    Śliwa, I.; Zakharov, A. V.

    2017-08-01

    A molecular model describing translational diffusion in freely suspended smectic films (FSSFs) in air is proposed. This model is based on the random walk theory and allows calculation of the translational diffusion coefficient (TDC) across smectic layers (along the director). All values necessary for calculating the TDC are obtained within the generalized mean-field model considering not only anisotropic interactions between nearest neighbors of molecules forming FSSFs, but also the stabilizing effect of the smectic/air interface. The spatial inhomogeneity of order parameters over the FSSF section, arising in this case, results in the fact that the surface tension at the smectic/air interface not only suppresses thermal fluctuations in surface layers, but also completely suppresses translational diffusion of molecules from the FSSF to air. The results of calculations of dimensional translational diffusion in the bulk of the FSSF formed by 5- n-alkyl-2-(4- n-(perfluoroalkyl-metyleneoxy))pentyl molecules during its thinning show that the TDC monotonically increases as the smectic film is thinned.

  7. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil.

    PubMed

    Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

    2017-01-01

    Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing. Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

  8. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    Lee, Seung Joon; Weisenberger, A G; McKisson, J; Goddard Jr, James Samuel; Baba, Justin S; Smith, M F

    2011-01-01

    Abstract- Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  9. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    S. Lee, B. Kross, D. Weisenberger, J. McKisson, J.S. Goddard, J.S. Baba, M.S. Smith

    2012-02-01

    Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  10. Implantable electrode for recording nerve signals in awake animals

    NASA Technical Reports Server (NTRS)

    Ninomiya, I.; Yonezawa, Y.; Wilson, M. F.

    1976-01-01

    An implantable electrode assembly consisting of collagen and metallic electrodes was constructed to measure simultaneously neural signals from the intact nerve and bioelectrical noises in awake animals. Mechanical artifacts, due to bodily movement, were negligibly small. The impedance of the collagen electrodes, measured in awake cats 6-7 days after implantation surgery, ranged from 39.8-11.5 k ohms at a frequency range of 20-5 kHz. Aortic nerve activity and renal nerve activity, measured in awake conditions using the collagen electrode, showed grouped activity synchronous with the cardiac cycle. Results indicate that most of the renal nerve activity was from postganglionic sympathetic fibers and was inhibited by the baroceptor reflex in the same cardiac cycle.

  11. Functional magnetic resonance imaging of awake monkeys: some approaches for improving imaging quality

    PubMed Central

    Chen, Gang; Wang, Feng; Dillenburger, Barbara C.; Friedman, Robert M.; Chen, Li M.; Gore, John C.; Avison, Malcolm J.; Roe, Anna W.

    2011-01-01

    Functional magnetic resonance imaging (fMRI), at high magnetic field strength can suffer from serious degradation of image quality because of motion and physiological noise, as well as spatial distortions and signal losses due to susceptibility effects. Overcoming such limitations is essential for sensitive detection and reliable interpretation of fMRI data. These issues are particularly problematic in studies of awake animals. As part of our initial efforts to study functional brain activations in awake, behaving monkeys using fMRI at 4.7T, we have developed acquisition and analysis procedures to improve image quality with encouraging results. We evaluated the influence of two main variables on image quality. First, we show how important the level of behavioral training is for obtaining good data stability and high temporal signal-to-noise ratios. In initial sessions, our typical scan session lasted 1.5 hours, partitioned into short (<10 minutes) runs. During reward periods and breaks between runs, the monkey exhibited movements resulting in considerable image misregistrations. After a few months of extensive behavioral training, we were able to increase the length of individual runs and the total length of each session. The monkey learned to wait until the end of a block for fluid reward, resulting in longer periods of continuous acquisition. Each additional 60 training sessions extended the duration of each session by 60 minutes, culminating, after about 140 training sessions, in sessions that last about four hours. As a result, the average translational movement decreased from over 500 μm to less than 80 μm, a displacement close to that observed in anesthetized monkeys scanned in a 7 T horizontal scanner. Another major source of distortion at high fields arises from susceptibility variations. To reduce such artifacts, we used segmented gradient-echo echo-planar imaging (EPI) sequences. Increasing the number of segments significantly decreased susceptibility

  12. Novelty and Anxiolytic Drugs Dissociate Two Components of Hippocampal Theta in Behaving Rats

    PubMed Central

    Wells, Christine E.; Amos, Doran P.; Jeewajee, Ali; Douchamps, Vincent; Rodgers, John; O’Keefe, John; Burgess, Neil; Lever, Colin

    2013-01-01

    Hippocampal processing is strongly implicated in both spatial cognition and anxiety and is temporally organized by the theta rhythm. However, there has been little attempt to understand how each type of processing relates to the other in behaving animals, despite their common substrate. In freely moving rats, there is a broadly linear relationship between hippocampal theta frequency and running speed over the normal range of speeds used during foraging. A recent model predicts that spatial-translation-related and arousal/anxiety-related mechanisms of hippocampal theta generation underlie dissociable aspects of the theta frequency–running speed relationship (the slope and intercept, respectively). Here we provide the first confirmatory evidence: environmental novelty decreases slope, whereas anxiolytic drugs reduce intercept. Variation in slope predicted changes in spatial representation by CA1 place cells and novelty-responsive behavior. Variation in intercept predicted anxiety-like behavior. Our findings isolate and doubly dissociate two components of theta generation that operate in parallel in behaving animals and link them to anxiolytic drug action, novelty, and the metric for self-motion. PMID:23678110

  13. An Experimental Model of Vasovagal Syncope Induces Cerebral Hypoperfusion and Fainting-Like Behavior in Awake Rats

    PubMed Central

    McBride, Devin W.; Reis, Cesar; Frank, Ethan; Klebe, Damon W.; Zhang, John H.; Applegate, Richard

    2016-01-01

    Vasovagal syncope, a contributing factor to elderly falls, is the transient loss of consciousness caused by decreased cerebral perfusion. Vasovagal syncope is characterized by hypotension, bradycardia, and reduced cerebral blood flow, resulting in fatigue, altered coordination, and fainting. The purpose of this study is to develop an animal model which is similar to human vasovagal syncope and establish an awake animal model of vasovagal syncope. Male Sprague-Dawley rats were subjected to sinusoidal galvanic vestibular stimulation (sGVS). Blood pressure, heart rate, and cerebral blood flow were monitored before, during, and post-stimulation. sGVS resulted in hypotension, bradycardia, and decreased cerebral blood flow. One cohort of animals was subjected to sGVS while freely moving. sGVS in awake animals produced vasovagal syncope-like symptoms, including fatigue and uncoordinated movements; two animals experienced spontaneous falling. Another cohort of animals was preconditioned with isoflurane for several days before being subjected to sGVS. Isoflurane preconditioning before sGVS did not prevent sGVS-induced hypotension or bradycardia, yet isoflurane preconditioning attenuated sGVS-induced cerebral blood flow reduction. The sGVS rat model mimics elements of human vasovagal syncope pathophysiology (hypotension, bradycardia, and decreased cerebral perfusion), including behavioral symptoms such as fatigue and altered balance. This study indicates that the sGVS rat model is similar to human vasovagal syncope and that therapies directed at preventing cerebral hypoperfusion may decrease syncopal episodes and reduce injuries from syncopal falls. PMID:27658057

  14. A method for closed-loop presentation of sensory stimuli conditional on the internal brain-state of awake animals

    PubMed Central

    Rutishauser, Ueli; Kotowicz, Andreas; Laurent, Gilles

    2013-01-01

    Brain activity often consists of interactions between internal—or on-going—and external—or sensory—activity streams, resulting in complex, distributed patterns of neural activity. Investigation of such interactions could benefit from closed-loop experimental protocols in which one stream can be controlled depending on the state of the other. We describe here methods to present rapid and precisely timed visual stimuli to awake animals, conditional on features of the animal’s on-going brain state; those features are the presence, power and phase of oscillations in local field potentials (LFP). The system can process up to 64 channels in real time. We quantified its performance using simulations, synthetic data and animal experiments (chronic recordings in the dorsal cortex of awake turtles). The delay from detection of an oscillation to the onset of a visual stimulus on an LCD screen was 47.5 ms and visual-stimulus onset could be locked to the phase of ongoing oscillations at any frequency ≤40 Hz. Our software’s architecture is flexible, allowing on-the-fly modifications by experimenters and the addition of new closed-loop control and analysis components through plugins. The source code of our system “StimOMatic” is available freely as open-source. PMID:23473800

  15. A method for closed-loop presentation of sensory stimuli conditional on the internal brain-state of awake animals.

    PubMed

    Rutishauser, Ueli; Kotowicz, Andreas; Laurent, Gilles

    2013-04-30

    Brain activity often consists of interactions between internal-or on-going-and external-or sensory-activity streams, resulting in complex, distributed patterns of neural activity. Investigation of such interactions could benefit from closed-loop experimental protocols in which one stream can be controlled depending on the state of the other. We describe here methods to present rapid and precisely timed visual stimuli to awake animals, conditional on features of the animal's on-going brain state; those features are the presence, power and phase of oscillations in local field potentials (LFP). The system can process up to 64 channels in real time. We quantified its performance using simulations, synthetic data and animal experiments (chronic recordings in the dorsal cortex of awake turtles). The delay from detection of an oscillation to the onset of a visual stimulus on an LCD screen was 47.5ms and visual-stimulus onset could be locked to the phase of ongoing oscillations at any frequency ≤40Hz. Our software's architecture is flexible, allowing on-the-fly modifications by experimenters and the addition of new closed-loop control and analysis components through plugins. The source code of our system "StimOMatic" is available freely as open-source.

  16. Integration of silicon-based neural probes and micro-drive arrays for chronic recording of large populations of neurons in behaving animals

    NASA Astrophysics Data System (ADS)

    Michon, Frédéric; Aarts, Arno; Holzhammer, Tobias; Ruther, Patrick; Borghs, Gustaaf; McNaughton, Bruce; Kloosterman, Fabian

    2016-08-01

    Objective. Understanding how neuronal assemblies underlie cognitive function is a fundamental question in system neuroscience. It poses the technical challenge to monitor the activity of populations of neurons, potentially widely separated, in relation to behaviour. In this paper, we present a new system which aims at simultaneously recording from a large population of neurons from multiple separated brain regions in freely behaving animals. Approach. The concept of the new device is to combine the benefits of two existing electrophysiological techniques, i.e. the flexibility and modularity of micro-drive arrays and the high sampling ability of electrode-dense silicon probes. Main results. Newly engineered long bendable silicon probes were integrated into a micro-drive array. The resulting device can carry up to 16 independently movable silicon probes, each carrying 16 recording sites. Populations of neurons were recorded simultaneously in multiple cortical and/or hippocampal sites in two freely behaving implanted rats. Significance. Current approaches to monitor neuronal activity either allow to flexibly record from multiple widely separated brain regions (micro-drive arrays) but with a limited sampling density or to provide denser sampling at the expense of a flexible placement in multiple brain regions (neural probes). By combining these two approaches and their benefits, we present an alternative solution for flexible and simultaneous recordings from widely distributed populations of neurons in freely behaving rats.

  17. Measurement of Electroretinograms and Visually Evoked Potentials in Awake Moving Mice

    PubMed Central

    Tokashiki, Naoyuki; Daigaku, Reiko; Tabata, Kitako; Sugano, Eriko; Tomita, Hiroshi; Nakazawa, Toru

    2016-01-01

    The development of new treatments for intractable retinal diseases requires reliable functional assessment tools for animal models. In vivo measurements of neural activity within visual pathways, including electroretinogram (ERG) and visually evoked potential (VEP) recordings, are commonly used for such purposes. In mice, the ERG and VEPs are usually recorded under general anesthesia, a state that may alter sensory transduction and neurotransmission, but seldom in awake freely moving mice. Therefore, it remains unknown whether the electrophysiological assessment of anesthetized mice accurately reflects the physiological function of the visual pathway. Herein, we describe a novel method to record the ERG and VEPs simultaneously in freely moving mice by immobilizing the head using a custom-built restraining device and placing a rotatable cylinder underneath to allow free running or walking during recording. Injection of the commonly used anesthetic mixture xylazine plus ketamine increased and delayed ERG oscillatory potentials by an average of 67.5% and 36.3%, respectively, compared to unanesthetized mice, while having minimal effects on the a-wave and b-wave. Similarly, components of the VEP were enhanced and delayed by up to 300.2% and 39.3%, respectively, in anesthetized mice. Our method for electrophysiological recording in conscious mice is a sensitive and robust means to assess visual function. It uses a conventional electrophysiological recording system and a simple platform that can be built in any laboratory at low cost. Measurements using this method provide objective indices of mouse visual function with high precision and stability, unaffected by anesthetics. PMID:27257864

  18. Properties of freely suspended liquid crystal films and their applications

    NASA Astrophysics Data System (ADS)

    Yablonskii, S. V.; Bodnarchuk, V. V.; Yoshino, K.

    2016-05-01

    We report the review on the physical properties of the liquid crystal freely suspended films. The importance of the freely suspended films for the study of the fundamental problems of the self-confined systems as well as their practical implementations are demonstrated.

  19. Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

    PubMed Central

    Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

    2013-01-01

    Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli. PMID:24253232

  20. Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

    NASA Astrophysics Data System (ADS)

    Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

    2013-11-01

    Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli.

  1. A wireless multi-channel neural amplifier for freely moving animals.

    PubMed

    Szuts, Tobi A; Fadeyev, Vitaliy; Kachiguine, Sergei; Sher, Alexander; Grivich, Matthew V; Agrochão, Margarida; Hottowy, Pawel; Dabrowski, Wladyslaw; Lubenov, Evgueniy V; Siapas, Athanassios G; Uchida, Naoshige; Litke, Alan M; Meister, Markus

    2011-02-01

    Conventional neural recording systems restrict behavioral experiments to a flat indoor environment compatible with the cable that tethers the subject to recording instruments. To overcome these constraints, we developed a wireless multi-channel system for recording neural signals from rats. The device takes up to 64 voltage signals from implanted electrodes, samples each at 20 kHz, time-division multiplexes them into one signal and transmits that output by radio frequency to a receiver up to 60 m away. The system introduces <4 μV of electrode-referred noise, comparable to wired recording systems, and outperforms existing rodent telemetry systems in channel count, weight and transmission range. This allows effective recording of brain signals in freely behaving animals. We report measurements of neural population activity taken outdoors and in tunnels. Neural firing in the visual cortex was relatively sparse, correlated even across large distances and was strongly influenced by locomotor activity.

  2. Oxytocin and vasopressin modulation of the neural correlates of motivation and emotion: results from functional MRI studies in awake rats.

    PubMed

    Febo, Marcelo; Ferris, Craig F

    2014-09-11

    Oxytocin and vasopressin modulate a range of species typical behavioral functions that include social recognition, maternal-infant attachment, and modulation of memory, offensive aggression, defensive fear reactions, and reward seeking. We have employed novel functional magnetic resonance mapping techniques in awake rats to explore the roles of these neuropeptides in the maternal and non-maternal brain. Results from the functional neuroimaging studies that are summarized here have directly and indirectly confirmed and supported previous findings. Oxytocin is released within the lactating rat brain during suckling stimulation and activates specific subcortical networks in the maternal brain. Both vasopressin and oxytocin modulate brain regions involved unconditioned fear, processing of social stimuli and the expression of agonistic behaviors. Across studies there are relatively consistent brain networks associated with internal motivational drives and emotional states that are modulated by oxytocin and vasopressin. This article is part of a Special Issue entitled Oxytocin and Social Behav.

  3. Tracheal extubation in children: halothane versus isoflurane, anesthetized versus awake.

    PubMed

    Pounder, D R; Blackstock, D; Steward, D J

    1991-04-01

    The authors compared the incidence of respiratory complications and arterial hemoglobin desaturation during emergence from anesthesia in children whose tracheas were extubated while they were anesthetized or after they were awake and to whom halothane or isoflurane had been administered. One hundred children 1-4 yr of age undergoing minor urologic surgery were studied. After a standard induction technique, patients were randomized to receive either isoflurane or halothane. In 50 patients tracheal extubation was performed while they were breathing 2 MAC of either halothane or isoflurane in 100% oxygen. The remaining 50 patients received 2 MAC (volatile agent plus nitrous oxide) during the operation, but tracheal extubation was delayed until they were awake. A blinded observer recorded the incidence of respiratory complications and continuously measured hemoglobin saturation for 15 min after extubation. When tracheal extubation occurred in deeply anesthetized patients, no differences were found between the two volatile agents. When tracheal extubation of awake patients was performed, the use of isoflurane was associated with more episodes of coughing and airway obstruction than was halothane (P less than 0.05). Awake tracheal extubation following either agent was associated with significantly more episodes of hemoglobin desaturation than was tracheal extubation while anesthetized.

  4. Awake Microlaparoscopy with the Insuflow® Device

    PubMed Central

    2002-01-01

    Background and Objectives: Patients undergoing laparoscopy often complain of shoulder pain, shivering, or both following laparoscopy. An increase in awake microlaparoscopic procedures has been reported. The objective of this study was to investigate the usefulness of heating and humidifying the carbon dioxide gas for the pneumoperitoneum with the Insuflow® device (Lexion Medical, St. Paul, Minnesota) during awake microlaparoscopic procedures. Methods: Awake microlaparoscopy was performed with the Insuflow® device for heating and humidifying the carbon dioxide for the pneumoperitoneum. Results: The incidence of transient shoulder pain in the Insuflow® group was 5% compared with 40% in the dry carbon dioxide group. No patient in the Insuflow® group complained of shivering, whereas 55% in the control group had shivering. Fogging of the microlaparoscope lens was decreased in the Insuflow® group. Conclusions: Heating and humidifying the carbon dioxide gas produced fewer patient complaints of shoulder pain and shivering and decreased fogging of the micro-laparoscope lens compared with procedures done with dry carbon dioxide during awake microlaparoscopic procedures. PMID:12166755

  5. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    PubMed

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery.

  6. Awake dynamics and brain-wide direct inputs of hypothalamic MCH and orexin networks

    PubMed Central

    González, J. Antonio; Iordanidou, Panagiota; Strom, Molly; Adamantidis, Antoine; Burdakov, Denis

    2016-01-01

    The lateral hypothalamus (LH) controls energy balance. LH melanin-concentrating-hormone (MCH) and orexin/hypocretin (OH) neurons mediate energy accumulation and expenditure, respectively. MCH cells promote memory and appropriate stimulus-reward associations; their inactivation disrupts energy-optimal behaviour and causes weight loss. However, MCH cell dynamics during wakefulness are unknown, leaving it unclear if they differentially participate in brain activity during sensory processing. By fiberoptic recordings from molecularly defined populations of LH neurons in awake freely moving mice, we show that MCH neurons generate conditional population bursts. This MCH cell activity correlates with novelty exploration, is inhibited by stress and is inversely predicted by OH cell activity. Furthermore, we obtain brain-wide maps of monosynaptic inputs to MCH and OH cells, and demonstrate optogenetically that VGAT neurons in the amygdala and bed nucleus of stria terminalis inhibit MCH cells. These data reveal cell-type-specific LH dynamics during sensory integration, and identify direct neural controllers of MCH neurons. PMID:27102565

  7. Measuring Whole-Brain Neural Dynamics and Behavior of Freely-Moving C. elegans

    NASA Astrophysics Data System (ADS)

    Shipley, Frederick; Nguyen, Jeffrey; Plummer, George; Shaevitz, Joshua; Leifer, Andrew

    2015-03-01

    Bridging the gap between an organism's neural dynamics and its ultimate behavior is the fundamental goal of neuroscience. Previously, to probe neural dynamics, we have been limited to measuring from a limited number of neurons, whether by electrode or optogenetic measurements. Here we present an instrument to simultaneously monitor neural activity from every neuron in a freely moving Caenorhabditis elegans' head, while recording behavior at the same time. Previously, whole-brain imaging has been demonstrated in C. elegans, but only in restrained and anesthetized animals (1). For studying neural coding of behavior it is crucial to study neural activity in freely behaving animals. Neural activity is recorded optically from cells expressing a calcium indicator, GCaMP6. Real time computer vision tracks the worm's position in x-y, while a piezo stage sweeps through the brain in z, yielding five brain-volumes per second. Behavior is recorded under infrared, dark-field imaging. This tool will allow us to directly correlate neural activity with behavior and we will present progress toward this goal. Thank you to the Simons Foundation and Princeton University for supporting this research.

  8. Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

    PubMed Central

    Jun, James J.; Longtin, André; Maler, Leonard

    2014-01-01

    Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals' access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal's body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal's body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors. PMID:24637642

  9. Chromatic and Achromatic Spatial Resolution of Local Field Potentials in Awake Cortex

    PubMed Central

    Jansen, Michael; Li, Xiaobing; Lashgari, Reza; Kremkow, Jens; Bereshpolova, Yulia; Swadlow, Harvey A.; Zaidi, Qasim; Alonso, Jose-Manuel

    2015-01-01

    Local field potentials (LFPs) have become an important measure of neuronal population activity in the brain and could provide robust signals to guide the implant of visual cortical prosthesis in the future. However, it remains unclear whether LFPs can detect weak cortical responses (e.g., cortical responses to equiluminant color) and whether they have enough visual spatial resolution to distinguish different chromatic and achromatic stimulus patterns. By recording from awake behaving macaques in primary visual cortex, here we demonstrate that LFPs respond robustly to pure chromatic stimuli and exhibit ∼2.5 times lower spatial resolution for chromatic than achromatic stimulus patterns, a value that resembles the ratio of achromatic/chromatic resolution measured with psychophysical experiments in humans. We also show that, although the spatial resolution of LFP decays with visual eccentricity as is also the case for single neurons, LFPs have higher spatial resolution and show weaker response suppression to low spatial frequencies than spiking multiunit activity. These results indicate that LFP recordings are an excellent approach to measure spatial resolution from local populations of neurons in visual cortex including those responsive to color. PMID:25416722

  10. High-throughput mapping of brain-wide activity in awake and drug-responsive vertebrates.

    PubMed

    Lin, Xudong; Wang, Shiqi; Yu, Xudong; Liu, Zhuguo; Wang, Fei; Li, Wai Tsun; Cheng, Shuk Han; Dai, Qiuyun; Shi, Peng

    2015-02-07

    The reconstruction of neural activity across complete neural circuits, or brain activity mapping, has great potential in both fundamental and translational neuroscience research. Larval zebrafish, a vertebrate model, has recently been demonstrated to be amenable to whole brain activity mapping in behaving animals. Here we demonstrate a microfluidic array system ("Fish-Trap") that enables high-throughput mapping of brain-wide activity in awake larval zebrafish. Unlike the commonly practiced larva-processing methods using a rigid gel or a capillary tube, which are laborious and time-consuming, the hydrodynamic design of our microfluidic chip allows automatic, gel-free, and anesthetic-free processing of tens of larvae for microscopic imaging with single-cell resolution. Notably, this system provides the capability to directly couple pharmaceutical stimuli with real-time recording of neural activity in a large number of animals, and the local and global effects of pharmacoactive drugs on the nervous system can be directly visualized and evaluated by analyzing drug-induced functional perturbation within or across different brain regions. Using this technology, we tested a set of neurotoxin peptides and obtained new insights into how to exploit neurotoxin derivatives as therapeutic agents. The novel and versatile "Fish-Trap" technology can be readily unitized to study other stimulus (optical, acoustic, or physical) associated functional brain circuits using similar experimental strategies.

  11. Fuel model selection for BEHAVE in midwestern oak savannas

    USGS Publications Warehouse

    Grabner, K.W.; Dwyer, J.P.; Cutter, B.E.

    2001-01-01

    BEHAVE, a fire behavior prediction system, can be a useful tool for managing areas with prescribed fire. However, the proper choice of fuel models can be critical in developing management scenarios. BEHAVE predictions were evaluated using four standardized fuel models that partially described oak savanna fuel conditions: Fuel Model 1 (Short Grass), 2 (Timber and Grass), 3 (Tall Grass), and 9 (Hardwood Litter). Although all four models yielded regressions with R2 in excess of 0.8, Fuel Model 2 produced the most reliable fire behavior predictions.

  12. Awake versus sleep endoscopy: personal experience in 250 OSAHS patients.

    PubMed

    Campanini, A; Canzi, P; De Vito, A; Dallan, I; Montevecchi, F; Vicini, C

    2010-04-01

    Identifying the site of obstruction and the pattern of airway change during sleep are the key points essential to guide surgical treatment decision making for Obstructive Sleep Apnoea-Hypopnoea Syndrome in adults. In this investigation, 250 cases were retrospectively analyzed in order to compare the pharyngolaryngeal endoscopic findings detected in the awake state, with those obtained in drug-induced sedation, by means of the Sleep Endoscopy technique. All endoscopic findings have been classified according to the semi-quantitative NOH staging. The awake and sedation NOH resulted identical in 25% of the cases only, while the discrepancies involved the oropharyngeal and hypopharyngeal sites, respectively in about 33% and 50% of the patients. The laryngeal obstructive role detected during sedation in almost 33% of the cases was both unforeseen and relevant, with all the consequent implications in the treatment choices particularly for the surgical cases.

  13. Awake replay of remote experiences in the hippocampus

    PubMed Central

    Karlsson, Mattias P.; Frank, Loren M.

    2009-01-01

    Hippocampal replay is thought to be essential for the consolidation of event memories in hippocampal–neocortical networks. Replay is present during both sleep and waking behavior, but while sleep replay involves the reactivation of stored representations in the absence of specific sensory inputs, awake replay is thought to depend on sensory input from the current environment. Here we show that stored representations are reactivated during both waking and sleep replay. We found frequent awake replay of sequences of rat hippocampal place cells from a previous experience. This spatially remote replay was as common as local replay of the current environment and was most robust when the animal had recently been in motion as compared to during extended periods of quiescence. These results indicate that the hippocampus consistently replays past experiences during brief pauses in waking behavior, suggesting a role for waking replay in memory consolidation and retrieval. PMID:19525943

  14. Out-of-Body Experience During Awake Craniotomy.

    PubMed

    Bos, Eelke M; Spoor, Jochem K H; Smits, Marion; Schouten, Joost W; Vincent, Arnaud J P E

    2016-08-01

    The out-of-body experience (OBE), during which a person feels as if he or she is spatially removed from the physical body, is a mystical phenomenon because of its association with near-death experiences. Literature implicates the cortex at the temporoparietal junction (TPJ) as the possible anatomic substrate for OBE. We present a patient who had an out-of-body experience during an awake craniotomy for resection of low-grade glioma. During surgery, stimulation of subcortical white matter in the left TPJ repetitively induced OBEs, in which the patient felt as if she was floating above the operating table looking down on herself. We repetitively induced OBE by subcortical stimulation near the left TPJ during awake craniotomy. Diffusion tensor imaging tractography implicated the posterior thalamic radiation as a possible substrate for autoscopic phenomena. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Enclosure for small animals during awake animal imaging

    DOEpatents

    Goddard, Jr., James S

    2013-11-26

    An enclosure or burrow restrains an awake animal during an imaging procedure. A tubular body, made from a radiolucent material that does not attenuate x-rays or gamma rays, accepts an awake animal. A proximal end of the body includes an attachment surface that corresponds to an attachment surface of an optically transparent and optically uniform window. An anti-reflective coating may be applied to an inner surface, an outer surface, or both surfaces of the window. Since the window is a separate element of the enclosure and it is not integrally formed as part of the body, it can be made with optically uniform thickness properties for improved motion tracking of markers on the animal with a camera during the imaging procedure. The motion tracking information is then used to compensate for animal movement in the image.

  16. Thalamic burst mode and inattention in the awake LGNd.

    PubMed

    Bezdudnaya, Tatiana; Cano, Monica; Bereshpolova, Yulia; Stoelzel, Carl R; Alonso, Jose-Manuel; Swadlow, Harvey A

    2006-02-02

    Awake mammals are often inattentive in familiar environments, but must still respond appropriately to relevant visual stimulation. Such "inattentive vision" has received little study, perhaps due to difficulties in controlling eye position in this state. In rabbits, eye position is exceedingly stable in both alert and inattentive states. Here, we exploit this stability to examine temporal filtering of visual information in LGNd neurons as rabbits alternate between EEG-defined states. Within a single second of shifting from alert to an inattentive state, both peak temporal frequency and bandwidth were sharply reduced, and burst frequency increased dramatically. However, spatial dimensions of receptive field centers showed no significant state dependence. We conclude that extremely rapid and significant changes in temporal filtering and bursting occur in the LGNd as awake subjects shift between alert and inattentive states.

  17. Music is Beneficial for Awake Craniotomy Patients: A Qualitative Study.

    PubMed

    Jadavji-Mithani, Radhika; Venkatraghavan, Lashmi; Bernstein, Mark

    2015-01-01

    Patients undergoing awake craniotomy may experience high levels of stress. Minimizing anxiety benefits patients and surgeons. Music has many therapeutic effects in altering human mood and emotion. Tonality of music as conveyed by composition in major or minor keys can have an impact on patients' emotions and thoughts. Assessing the effects of listening to major and minor key musical pieces on patients undergoing awake craniotiomy could help in the design of interventions to alleviate anxiety, stress and tension. Twenty-nine patients who were undergoing awake craniotomy were recruited and randomly assigned into two groups: Group 1 subjects listened to major key music and Group 2 listened to minor key compositions. Subjects completed a demographics questionnaire, a pre- and post-operative Beck Anxiety Inventory (BAI) and a semi-structured open-ended interview. RESULTS were analyzed using modified thematic analysis through open and axial coding. Overall, patients enjoyed the music regardless of the key distinctions and stated they benefitted from listening to the music. No adverse reactions to the music were found. Subjects remarked that the music made them feel more at ease and less anxious before, during and after their procedure. Patients preferred either major key or minor key music but not a combination of both. Those who preferred major key pieces said it was on the basis of tonality while the individuals who selected minor key pieces stated that tempo of the music was the primary factor. Overall, listening to music selections was beneficial for the patients. Future work should further investigate the effects of audio interventions in awake surgery through narrative means.

  18. Methylphenidate-induced awake bruxism: a case report.

    PubMed

    Sivri, Rukiye Çolak; Bilgiç, Ayhan

    2015-01-01

    Methylphenidate (MPH) is a stimulant that is commonly used in the treatment of attention-deficit/hyperactivity disorder in children and adults. Several reports are available regarding the relationship of MPH use and sleep bruxism. We report the case of a 9-year-old boy who presented with severe awake bruxism after his second dose of sustained release form of MPH treatment, which was confirmed on rechallenge. This is the first report of its kind showing such relationship in the literature.

  19. Pediatric awake craniotomy and intra-operative stimulation mapping.

    PubMed

    Balogun, James A; Khan, Osaama H; Taylor, Michael; Dirks, Peter; Der, Tara; Carter Snead Iii, O; Weiss, Shelly; Ochi, Ayako; Drake, James; Rutka, James T

    2014-11-01

    The indications for operating on lesions in or near areas of cortical eloquence balance the benefit of resection with the risk of permanent neurological deficit. In adults, awake craniotomy has become a versatile tool in tumor, epilepsy and functional neurosurgery, permitting intra-operative stimulation mapping particularly for language, sensory and motor cortical pathways. This allows for maximal tumor resection with considerable reduction in the risk of post-operative speech and motor deficits. We report our experience of awake craniotomy and cortical stimulation for epilepsy and supratentorial tumors located in and around eloquent areas in a pediatric population (n=10, five females). The presenting symptom was mainly seizures and all children had normal neurological examinations. Neuroimaging showed lesions in the left opercular (n=4) and precentral or peri-sylvian regions (n=6). Three right-sided and seven left-sided awake craniotomies were performed. Two patients had a history of prior craniotomy. All patients had intra-operative mapping for either speech or motor or both using cortical stimulation. The surgical goal for tumor patients was gross total resection, while for all epilepsy procedures, focal cortical resections were completed without any difficulty. None of the patients had permanent post-operative neurologic deficits. The patient with an epileptic focus over the speech area in the left frontal lobe had a mild word finding difficulty post-operatively but this improved progressively. Follow-up ranged from 6 to 27 months. Pediatric awake craniotomy with intra-operative mapping is a precise, safe and reliable method allowing for resection of lesions in eloquent areas. Further validations on larger number of patients will be needed to verify the utility of this technique in the pediatric population.

  20. Delivering drugs, via microdialysis, into the environment of extracellularly recorded hippocampal neurons in behaving primates.

    PubMed

    Ludvig, N; Nguyen, M C; Botero, J M; Tang, H M; Scalia, F; Scharf, B A; Kral, J G

    2000-02-01

    Hippocampal neurons in primates have been extensively studied with electrophysiological and neuroanatomical methods. Much less effort has been devoted to examining these cells with contemporary pharmacological techniques. Therefore, we modified a recently developed integrative technique (N. Ludvig, P.E. Potter, S.E. Fox, Simultaneous single-cell recording and microdialysis within the same brain site in freely behaving rats: a novel neurobiological method, J. Neurosci. Methods 55 (1994) 31-40 [9] ) for cellular neuropharmacological studies in behaving monkeys. A driveable microelectrode-microdialysis probe guide assembly was implanted stereotaxically into the left hippocampus of squirrel monkeys (Saimiri sciureus) under isoflurane anesthesia. The assembly was covered with a protective cap. After 3 weeks of postsurgical recovery and behavioral training, the experimental subject was seated in a primate chair. For 4-5 h, single-cell recording and microdialysis were simultaneously performed in the hippocampal implantation site. The technique allowed the recording of both complex-spike cells and fast-firing neurons without the use of head restraint. The control microdialysis solution, artificial cerebrospinal fluid (ACSF), was replaced with either 1 M ethanol or 500 microM N-methyl-D-aspartate (NMDA) for 10-30 min intervals. The ethanol perfusions principally suppressed the firing of the neurons in the dialysis area. The NMDA perfusions initially increased the firing of local neurons, then caused electrical silence. These drug delivery/cell recording sessions were performed with 1-4 day intersession intervals over a 1-month period. The described method provides a tool to elaborate the pharmacology of primate hippocampal neurons during behavior and without the confounding effects of systemic drug administrations.

  1. The evolution of brain surgery on awake patients.

    PubMed

    Surbeck, Werner; Hildebrandt, Gerhard; Duffau, Hugues

    2015-01-01

    In the early days of modern neurological surgery, the inconveniences and potential dangers of general anesthesia by chloroform and ether using the so-called "open-drop technique" led to the quest for alternative methods of anesthesia. Besides preventing the feared side effects, the introduction of regional anesthesia revealed another decisive advantage over general anesthesia in neurosurgery: While intraoperative direct cortical stimulation under general anesthesia could only delineate the motor area (by evocation of contralateral muscular contraction), now, the awake patients were able to report sensations elicited by this method. These properties advanced regional anesthesia to the regimen of choice for cranial surgeries in the first half of the 20th century. While technical advances and new drugs led to a progressive return to general anesthesia for neurosurgical procedures, the use of regional anesthesia for epilepsy surgery has only decreased in recent decades. Meanwhile, awake craniotomies regained popularity in oncologically motivated surgeries, especially in craniotomies for diffuse low-grade gliomas. Intraoperative mapping of brain functions using electrical stimulation in awake patients enables not only for increased tumor removal while preserving the functional status of the patients but also opens a window to cognitive neuroscience. Observations during such interventions and their correlation with both pre - and postoperative neuropsychological examinations and functional neuroimaging is progressively leading to new insights into the complex functional anatomy of the human brain. Furthermore, it broadens our knowledge on cerebral network reorganization in the presence of disease-with implications for all disciplines of clinical neuroscience.

  2. Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

    PubMed Central

    Prontera, Andrea; Baroni, Stefano; Marudi, Andrea; Valzania, Franco; Feletti, Alberto; Benuzzi, Francesca; Bertellini, Elisabetta; Pavesi, Giacomo

    2017-01-01

    Introduction Awake craniotomy allows continuous monitoring of patients’ neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic–sedative medication is increasing. Methods Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management. Results The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure. Conclusion In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used. PMID:28424537

  3. Anticoagulation and antiplatelet therapy in awake transcervical injection laryngoplasty.

    PubMed

    Dang, Jennifer H; Liou, Nelson Eddie; Ongkasuwan, Julina

    2017-08-01

    Vocal fold movement impairment (VFMI) due to neuronal injury occurs in 20% to 30% of surgeries in the region of the aortic arch. Early injection laryngoplasty can aid with postoperative pulmonary toilet in these high-risk cardiovascular patients. The purpose of this study is to determine whether continuing antiplatelet and anticoagulation therapy during awake transcervical injection laryngoplasty surgery is safe, and if there is any increase in bleeding complications in these patients. This is a retrospective review of patients undergoing awake injection laryngoplasty surgery for VFMI between 2013 and 2016 at a tertiary academic center specializing in aortic and mediastinal diseases. Records were reviewed for patients regarding baseline antiplatelet or anticoagulation therapy, and whether these medications were stopped or continued preoperatively. The primary outcome was bleeding complications. Of the 95 surgeries reviewed, 44 (46%) were performed for patients on antiplatelet therapy, and 71 (75%) for patients on anticoagulation therapy. None of the patients on antiplatelet therapy had their treatment discontinued. Of the patients on anticoagulation, 13 (16.4%) had their therapy held prior to surgery. There was no observed difference in bleeding complications between patients who were continued on antiplatelet or anticoagulation treatment versus those whose therapy was withheld. These results suggest that patients undergoing awake transcervical injection laryngoplasty for VFMI can be maintained on antiplatelet or anticoagulation therapy without increased risk of bleeding. Further larger studies are needed to confirm these findings. 4. Laryngoscope, 127:1850-1854, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Optical Neuronavigation without Rigid Head Fixation During Awake Surgery.

    PubMed

    Freyschlag, Christian F; Kerschbaumer, Johannes; Eisner, Wilhelm; Pinggera, Daniel; Brawanski, Konstantin R; Petr, Ondra; Bauer, Marlies; Grams, Astrid E; Bodner, Thomas; Seiz, Marcel; Thomé, Claudius

    2017-01-01

    Optical neuronavigation without rigid pin fixation of the head may lead to inaccurate results because of the patient's movements during awake surgery. In this study, we report our results using a skull-mounted reference array for optical tracking in patients undergoing awake craniotomy for eloquent gliomas. Between March 2013 and December 2014, 18 consecutive patients (10 men, 8 women) with frontotemporal (n = 16) or frontoparietal (perirolandic; n = 2) lesions underwent awake craniotomy without rigid pin fixation. All patients had a skull-mounted reference array for optical tracking placed on the forehead. Accuracy of navigation was determined with pointer tip deviation measurements on superficial and bony anatomic structures. Good accuracy was defined as a tip deviation <2 mm. Gross total resection (>98%) was achieved in 7 patients (38%); >90% of tumor was resected in 8 patients (44%). In 3 patients, only subtotal resection or biopsy was performed secondary to stimulation results. In all patients, good accuracy of the optical neuronavigation system could be demonstrated without intraoperative peculiarities or complications. The reference array had to be repositioned because of loosening in 1 patient. Neuronavigation could be reliably applied to support stimulation-based resection. A skull-mounted reference array is a simple and safe method for optical neuronavigation tracking without rigid pin fixation of the patient's head. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Tramadol combined with fentanyl in awake endotracheal intubation

    PubMed Central

    Wang, Sai-Ying; Mei, Yang; Sheng, Hui; Li, Yang; Han, Rui; Quan, Cheng-Xuan; Hu, Zhong-Hua; Ouyang, Wen; Liu, Zhao-Qian

    2013-01-01

    Objective To explore the feasibility and dosage of tramadol combined with fentanyl in awake endotracheal intubation. Methods Using Dixon’s up-and-down sequential design, the study enrolled patients from each of the 20-49, 50-60 and 70-and-above age groups scheduled for elective surgery under general anesthesia. The feasibility and dosage of tramadol combined with fentanyl in awake endotracheal intubation, guided by fiberoptic bronchoscopy, were verified. Results After intravenous injection with fentanyl 2.2 μg/kg and tramadol 2.0 mg/kg in the 20-49 age group, fentanyl 1.6 μg/kg and tramadol 1.9 mg/kg in the 50-69 age group and fentanyl 1 μg/kg and tramadol 1.8 mg/kg in those at the age of 70 or above, the patients achieved conscious sedation without obvious respiratory depression. Meanwhile, under these dosages, the patients could easily tolerate the thyrocricocentesis airway surface anesthesia and fiberoptic bronchoscope guided tracheal intubation. Postoperative follow-up showed that most patients had memory of the intubation process but without significant discomfort. No awake endotracheal intubation-related side effect was noted. Conclusions Fiberoptic bronchoscope guided nasotracheal intubation can be successfully completed with background administration of fentanyl and tramadol. However, the specific dosages need to be tailored in different age of patients. PMID:23825758

  6. Hour-long adaptation in the awake early visual system.

    PubMed

    Stoelzel, Carl R; Huff, Joseph M; Bereshpolova, Yulia; Zhuang, Jun; Hei, Xiaojuan; Alonso, Jose-Manuel; Swadlow, Harvey A

    2015-08-01

    Sensory adaptation serves to adjust awake brains to changing environments on different time scales. However, adaptation has been studied traditionally under anesthesia and for short time periods. Here, we demonstrate in awake rabbits a novel type of sensory adaptation that persists for >1 h and acts on visual thalamocortical neurons and their synapses in the input layers of the visual cortex. Following prolonged visual stimulation (10-30 min), cells in the dorsal lateral geniculate nucleus (LGN) show a severe and prolonged reduction in spontaneous firing rate. This effect is bidirectional, and prolonged visually induced response suppression is followed by a prolonged increase in spontaneous activity. The reduction in thalamic spontaneous activity following prolonged visual activation is accompanied by increases in 1) response reliability, 2) signal detectability, and 3) the ratio of visual signal/spontaneous activity. In addition, following such prolonged activation of an LGN neuron, the monosynaptic currents generated by thalamic impulses in layer 4 of the primary visual cortex are enhanced. These results demonstrate that in awake brains, prolonged sensory stimulation can have a profound, long-lasting effect on the information conveyed by thalamocortical inputs to the visual cortex.

  7. A chronically implantable, hybrid cannula-electrode device for assessing the effects of molecules on electrophysiological signals in freely behaving animals

    PubMed Central

    Greger, Bradley; Kateb, Babak; Gruen, Peter; Patterson, Paul H.

    2009-01-01

    We describe a device for assessing the effects of diffusible molecules on electrophysiological recordings from multiple neurons. This device allows for the infusion of reagents through a cannula located among an array of micro-electrodes. The device can easily be customized to target specific neural structures. It is designed to be chronically implanted so that isolated neural units and local field potentials are recorded over the course of several weeks or months. Multivariate statistical and spectral analysis of electrophysiological signals acquired using this system could quantitatively identify electrical “signatures” of therapeutically useful drugs. PMID:17499854

  8. Sleep-wake and diurnal modulation of nitric oxide in the perifornical-lateral hypothalamic area: real-time detection in freely behaving rats.

    PubMed

    Kostin, A; McGinty, D; Szymusiak, R; Alam, M N

    2013-12-19

    Nitric oxide (NO) has been implicated in the regulation of sleep. The perifornical-lateral hypothalamic area (PF-LHA) is a key wake-promoting region and contains neurons that are active during behavioral or cortical activation. Recently, we found higher levels of NO metabolites (NOx), an indirect measure of NO levels, in the PF-LHA during prolonged waking (SD). However, NO is highly reactive and diffuses rapidly and the NOx assay is not sensitive enough to detect rapid-changes in NO levels across spontaneous sleep-waking states. We used a novel Nafion®-modified Platinum (NF-PT) electrode for real-time detection of NO levels in the PF-LHA across sleep-wake cycles, dark-light phases, and during SD. Sprague-Dawley male rats were surgically prepared for chronic sleep-wake recording and implantation of NF-PT electrode into the PF-LHA. Electroencephalogram (EEG), electromyogram (EMG), and electrochemical current generated by NF-PT electrode were continuously acquired for 5-7days including one day with 3h of SD. In the PF-LHA, NO levels exhibited a waking>rapid eye movement (REM)>non-rapid eye movement (nonREM) sleep pattern (0.56±0.03μM>0.47±0.02μM>0.42±0.02μM; p<0.01). NO levels were also higher during the dark- as compared to the light-phase (0.53±0.03μM vs. 0.44±0.02μM; p<0.01). NO levels increased during 3h of SD as compared to undisturbed control (0.58±0.04μM vs. 0.47±0.01μM; p<0.05). The findings indicate that in the PF-LHA, NO is produced during behavioral or cortical activation. Since elevated levels of NO inhibits most of the PF-LHA neurons that are active during cortical activation, these findings support a hypothesis that NO produced in conjunction with the activation of PF-LHA neurons during waking/SD, inhibits the same neuronal population to promote sleep. Published by Elsevier Ltd.

  9. Crank inertial load affects freely chosen pedal rate during cycling.

    PubMed

    Hansen, Ernst Albin; Jørgensen, Lars Vincents; Jensen, Kurt; Fregly, Benjamin Jon; Sjøgaard, Gisela

    2002-02-01

    Cyclists seek to maximize performance during competition, and gross efficiency is an important factor affecting performance. Gross efficiency is itself affected by pedal rate. Thus, it is important to understand factors that affect freely chosen pedal rate. Crank inertial load varies greatly during road cycling based on the selected gear ratio. Nevertheless, the possible influence of crank inertial load on freely chosen pedal rate and gross efficiency has never been investigated. This study tested the hypotheses that during cycling with sub-maximal work rates, a considerable increase in crank inertial load would cause (1) freely chosen pedal rate to increase, and as a consequence, (2) gross efficiency to decrease. Furthermore, that it would cause (3) peak crank torque to increase if a constant pedal rate was maintained. Subjects cycled on a treadmill at 150 and 250W, with low and high crank inertial load, and with preset and freely chosen pedal rate. Freely chosen pedal rate was higher at high compared with low crank inertial load. Notably, the change in crank inertial load affected the freely chosen pedal rate as much as did the 100W increase in work rate. Along with freely chosen pedal rate being higher, gross efficiency at 250W was lower during cycling with high compared with low crank inertial load. Peak crank torque was higher during cycling at 90rpm with high compared with low crank inertial load. Possibly, the subjects increased the pedal rate to compensate for the higher peak crank torque accompanying cycling with high compared with low crank inertial load.

  10. Hippocampal replay in the awake state: a potential physiological substrate of memory consolidation and retrieval

    PubMed Central

    Carr, Margaret F.; Jadhav, Shantanu P.; Frank, Loren M.

    2011-01-01

    The hippocampus is required for the encoding, consolidation, and retrieval of event memories. While the neural mechanisms that underlie these processes are only partially understood, a series of recent papers point to awake memory replay as a potential contributor to both consolidation and retrieval. Replay is the sequential reactivation of hippocampal place cells that represent previously experienced behavioral trajectories and occurs frequently in the awake state, particularly during periods of relative immobility. Awake replay may reflect trajectories through either the current environment or previously visited environments that are spatially remote. The repetition of learned sequences on a compressed time scale is well suited to promote memory consolidation in distributed circuits beyond the hippocampus, suggesting that consolidation occurs in both the awake and sleeping animal. Moreover, sensory information can influence the content of awake replay, suggesting a role for awake replay in memory retrieval. PMID:21270783

  11. Production of freely-migrating defects during irradiation

    SciTech Connect

    Rehn, L.E.; Okamoto, P.R.

    1986-09-01

    During irradiation at elevated temperatures, vacancy and interstitial defects that escape can produce several different types of microstructural changes. Hence the production rate of freely-migrating defects must be known as a function of irradiating particle species and energy before quantitative correlations can be made between microstructural changes. Our fundamental knowledge of freely-migrating defect production has increased substantially in recent years. Critical experimental findings that led to the improved understanding are reviewed in this paper. A strong similarity is found for the dependence of freely-migrating defect production on primary recoil energy as measured in a variety of metals and alloys by different authors. The efficiency for producing freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the efficiency for creating stable defects at liquid helium temperatures. The stronger decrease can be understood in terms of additional intracascade recombination that results from the nonrandom distribution of defects existing in the primary damage state for high primary recoil energies. Although the existing data base is limited to fcc materials, the strong similarity in the reported investigations suggests that the same dependence of freely-migrating defect production on primary recoil energy may be characteristic of a wide variety of other alloy systems as well. 52 refs., 4 figs.

  12. Automated long-term recording and analysis of neural activity in behaving animals

    PubMed Central

    Wolff, Steffen BE; Normand, Valentin A; Kopelowitz, Evi

    2017-01-01

    Addressing how neural circuits underlie behavior is routinely done by measuring electrical activity from single neurons in experimental sessions. While such recordings yield snapshots of neural dynamics during specified tasks, they are ill-suited for tracking single-unit activity over longer timescales relevant for most developmental and learning processes, or for capturing neural dynamics across different behavioral states. Here we describe an automated platform for continuous long-term recordings of neural activity and behavior in freely moving rodents. An unsupervised algorithm identifies and tracks the activity of single units over weeks of recording, dramatically simplifying the analysis of large datasets. Months-long recordings from motor cortex and striatum made and analyzed with our system revealed remarkable stability in basic neuronal properties, such as firing rates and inter-spike interval distributions. Interneuronal correlations and the representation of different movements and behaviors were similarly stable. This establishes the feasibility of high-throughput long-term extracellular recordings in behaving animals. PMID:28885141

  13. Automated long-term recording and analysis of neural activity in behaving animals.

    PubMed

    Dhawale, Ashesh K; Poddar, Rajesh; Wolff, Steffen Be; Normand, Valentin A; Kopelowitz, Evi; Ölveczky, Bence P

    2017-09-08

    Addressing how neural circuits underlie behavior is routinely done by measuring electrical activity from single neurons in experimental sessions. While such recordings yield snapshots of neural dynamics during specified tasks, they are ill-suited for tracking single-unit activity over longer timescales relevant for most developmental and learning processes, or for capturing neural dynamics across different behavioral states. Here we describe an automated platform for continuous long-term recordings of neural activity and behavior in freely moving rodents. An unsupervised algorithm identifies and tracks the activity of single units over weeks of recording, dramatically simplifying the analysis of large datasets. Months-long recordings from motor cortex and striatum made and analyzed with our system revealed remarkable stability in basic neuronal properties, such as firing rates and inter-spike interval distributions. Interneuronal correlations and the representation of different movements and behaviors were similarly stable. This establishes the feasibility of high-throughput long-term extracellular recordings in behaving animals.

  14. The King Vision™ video laryngoscope for awake intubation: series of cases and literature review

    PubMed Central

    Gaszynska, Ewelina; Gaszynski, Tomasz

    2014-01-01

    Intubation of patients with a supraglottic mass causing obstruction of the glottis remains a difficult problem for the experienced anesthesiologist. Awake fiberscopic endotracheal intubation is the recommended approach in such cases; however, use of a video laryngoscope for awake intubation can be an alternative to a fiberscope. Here we present two cases of awake intubation using a King Vision™ video laryngoscope in patients with a supraglottic mass, and a literature review on use of video laryngoscopes for awake intubation. After topical anesthesia and sedation with opioids, the patients were successfully intubated. PMID:25018634

  15. Calcium imaging with genetically encoded indicators in behaving primates.

    PubMed

    Seidemann, Eyal; Chen, Yuzhi; Bai, Yoon; Chen, Spencer C; Mehta, Preeti; Kajs, Bridget L; Geisler, Wilson S; Zemelman, Boris V

    2016-07-21

    Understanding the neural basis of behaviour requires studying brain activity in behaving subjects using complementary techniques that measure neural responses at multiple spatial scales, and developing computational tools for understanding the mapping between these measurements. Here we report the first results of widefield imaging of genetically encoded calcium indicator (GCaMP6f) signals from V1 of behaving macaques. This technique provides a robust readout of visual population responses at the columnar scale over multiple mm(2) and over several months. To determine the quantitative relation between the widefield GCaMP signals and the locally pooled spiking activity, we developed a computational model that sums the responses of V1 neurons characterized by prior single unit measurements. The measured tuning properties of the GCaMP signals to stimulus contrast, orientation and spatial position closely match the predictions of the model, suggesting that widefield GCaMP signals are linearly related to the summed local spiking activity.

  16. Open Carpal Tunnel Release Outcomes: Performed Wide Awake versus with Sedation.

    PubMed

    Tulipan, Jacob E; Kim, Nayoung; Abboudi, Jack; Jones, Christopher; Liss, Frederic; Kirkpatrick, William; Rivlin, Michael; Wang, Mark L; Matzon, Jonas; Ilyas, Asif M

    2017-08-01

    Background  Carpal tunnel release (CTR) is the most common surgery of the hand, and interest is growing in performing it under local anesthesia without tourniquet. To better understand differences, we hypothesized that patients undergoing CTR under wide-awake local anesthesia with no tourniquet (WALANT) versus sedation (monitored anesthesia care [MAC]) would not result in a difference in outcome. Methods  Consecutive cases of electrodiagnostically confirmed open CTR across multiple surgeons at a single center were prospectively enrolled. Data included demographic data, visual analog scale, Levine-Katz carpal tunnel syndrome scale, QuickDASH questionnaire, customized Likert questionnaire, and complications. Results  There were 81 patients enrolled in the WALANT group and 149 patients in the MAC group. There were no reoperations in either group or any epinephrine-related complications in the WALANT group. Disability and symptom scores did not differ significantly between WALANT and sedation groups at 2 weeks or 3 months. Average postoperative QuickDASH, Levine-Katz, and VAS pain scales were the same in both groups. Both groups of patients reported high levels of satisfaction at 91 versus 96% for the WALANT versus MAC groups, respectively ( p  > 0.05). Patients in each group were likely to request similar anesthesia if they were to undergo surgery again. Conclusion  Patients undergoing open CTR experienced similar levels of satisfaction and outcomes with either the WALANT or MAC techniques. There was no statistically significant difference between either group relative to the tested outcome measures. These data should facilitate surgeons and patients' choosing freely between WALANT and MAC techniques relative to complications and outcomes.

  17. Anxiety in the preoperative phase of awake brain tumor surgery.

    PubMed

    Ruis, Carla; Wajer, Irene Huenges; Robe, Pierre; van Zandvoort, Martine

    2017-06-01

    Awake surgery emerges as a standard of care for brain tumors located in or near eloquent areas. Levels of preoperative anxiety in patients are important, because anxiety can influence cognitive performance and participation, hence altering the outcome of the procedure. In this study we analyzed the prevalence and potential clinical predictors of anxiety in the pre-operative phase of an awake brain tumor surgery. Seventy consecutive candidates for an awake brain tumor surgery were included. All patients received a neuropsychological pre-operative work-up. The Hospital Anxiety and Depression Scale (HADS) was administrated to investigate symptoms of anxiety. Demographic and medical data were extracted from patients' charts. Linear regression analyses, multiple regression analyses, t-tests for parametric and Mann-Whitney U tests for non-parametric data were used to analyze the relation between demographic and medical variables and pre-operative anxiety. Mean score on the anxiety scale of the HADS was 6.1 (SD=4.2, range 1-19) and 25% of the patients scored on or above the cut-off for anxiety symptoms (score >7). Women reported higher levels of anxiety than men (p<0.01). Furthermore, younger patient were more anxious than older patients (p<0.05). No other variables were significantly related to pre-operative anxiety. Merely, one in every four patients reported significant anxiety symptoms in the pre-operative phase. Besides gender and age, none of the other demographic or medical factors were significantly associated with the level of anxiety. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Cerebral autoregulation in awake versus isoflurane-anesthetized rats.

    PubMed

    Hoffman, W E; Edelman, G; Kochs, E; Werner, C; Segil, L; Albrecht, R F

    1991-12-01

    We evaluated regional cerebral and spinal cord blood flow in rats during isoflurane anesthesia. Tissue blood flow was measured in cerebral cortex, subcortex, midbrain, and spinal cord using radioactive microspheres. Blood flow autoregulation was measured within the following arterial blood pressure ranges (mm Hg): 1 = less than 50, 2 = 50-90, 3 = 90-130, 4 = 130-170, 5 = greater than 170. Arterial blood pressure was increased using phenylephrine infusion and decreased with ganglionic blockade and hemorrhage. Three treatment groups were studied: 1 = awake control, 2 = 1.0 minimum alveolar anesthetic concentration (MAC) isoflurane, 3 = 2.0 MAC isoflurane. Autoregulation was seen in awake rats from 50 to 170 mm Hg in all tissues. The autoregulatory coefficient (change in blood flow/change in blood pressure) was increased in midbrain and spinal cord during 1.0 MAC isoflurane and in all tissues during 2.0 MAC isoflurane (P less than 0.05). Within the arterial blood pressure range of 90-130 mm Hg, isoflurane produced the following changes in tissue blood flow (percent of awake control): 1.0 MAC isoflurane: cortex = 87% +/- 8% (P greater than 0.30), subcortex = 124% +/- 11% (P greater than 0.05), midbrain = 263% +/- 20% (P less than 0.001), spinal cord = 278% +/- 19% (P less than 0.001); 2.0 MAC isoflurane: cortex = 137% +/- 13% (P less than 0.05), subcortex = 272% +/- 24% (P less than 0.001), midbrain = 510% +/- 53% (P less than 0.001), spinal cord = 535% +/- 50% (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. [Dexmedetomidine for neurocognitive testing in awake craniotomy: case report.].

    PubMed

    Santos, Marcelo Cursino Pinto Dos; Vinagre, Ronaldo Contreras Oliveira

    2006-08-01

    Tumor resections in the speech areas of the brain are more safely done using cognitive tests to determine their exact location. Patients must be awake, comfortable, and cooperative for the precise identification of the areas to be preserved. The objective of this report is to present a surgical procedure done with the patient awake, without endotracheal intubation, using sevofluorane initially, followed by dexmedetomidine. This technique allowed the realization of motor and speech evaluation tests. Twenty-seven years old male patient, physical status ASA I, with a brain tumor. In the operating room, without pre-anesthetic medication, midazolam (1 mg) was administered, and general anesthesia was induced with propofol (80 mg). Maintenance was done with O2, N2O, and sevofluorane, with a mask, for catheterization of the right radial artery, introduction of a vesical catheter, and infiltration of the surgical site. This phase lasted around 20 minutes, and the infusion of dexmedetomidine was initiated in the last 10 minutes to maintain a level of sedation Ramsay score 2. Cortical mapping followed (75 minutes). Afterwards, tumor resection was done while the patient remained sedated with higher doses of dexmedetomidine. Hemodynamic and respiratory parameters remained stable, and the procedure was performed without complications, lasting a total of five hours. After the surgical procedure the patient was transferred to the ICU. He did not develop any neurological changes, being discharged to a regular ward the following day. Awake craniotomy with the proper mapping of speech and motor cortical areas was successfully done with the continuous infusion of dexmedetomidine. Both the patient and the surgical team were pleased with the technique.

  20. Wireless multi-channel single unit recording in freely moving and vocalizing primates

    PubMed Central

    Roy, Sabyasachi; Wang, Xiaoqin

    2011-01-01

    The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates. PMID:21933683

  1. Quantitative locomotion study of freely swimming micro-organisms using laser diffraction.

    PubMed

    Magnes, Jenny; Susman, Kathleen; Eells, Rebecca

    2012-10-25

    Soil and aquatic microscopic organisms live and behave in a complex three-dimensional environment. Most studies of microscopic organism behavior, in contrast, have been conducted using microscope-based approaches, which limit the movement and behavior to a narrow, nearly two-dimensional focal field.(1) We present a novel analytical approach that provides real-time analysis of freely swimming C. elegans in a cuvette without dependence on microscope-based equipment. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light through the cuvette. We measure oscillation frequencies for freely swimming nematodes. Analysis of the far-field diffraction patterns reveals clues about the waveforms of the nematodes. Diffraction is the process of light bending around an object. In this case light is diffracted by the organisms. The light waves interfere and can form a diffraction pattern. A far-field, or Fraunhofer, diffraction pattern is formed if the screen-to-object distance is much larger than the diffracting object. In this case, the diffraction pattern can be calculated (modeled) using a Fourier transform.(2) C. elegans are free-living soil-dwelling nematodes that navigate in three dimensions. They move both on a solid matrix like soil or agar in a sinusoidal locomotory pattern called crawling and in liquid in a different pattern called swimming.(3) The roles played by sensory information provided by mechanosensory, chemosensory, and thermosensory cells that govern plastic changes in locomotory patterns and switches in patterns are only beginning to be elucidated.(4) We describe an optical approach to measuring nematode locomotion in three dimensions that does not require a microscope and will enable us to begin to explore the complexities of nematode locomotion under different conditions.

  2. Wireless multi-channel single unit recording in freely moving and vocalizing primates.

    PubMed

    Roy, Sabyasachi; Wang, Xiaoqin

    2012-01-15

    The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates.

  3. Submandibular intubation in awake patient of panfacial trauma

    PubMed Central

    Kamra, SK; Khandavilli, HK; Banerjee, P

    2016-01-01

    Maxillofacial trauma patients present with airway problems. Submandibular intubation is an effective means of intubation to avoid tracheostomy for operative procedures. Airway is secured with oral endotracheal intubation in paralyzed patient and tube is then transplaced in sub mental or submandibular region. However there may be instances when paralyzing such trauma patients is not safe and short term tracheostomy is the only airway channel available for conduction of anesthesia. We report a case of submandibular intubation in awake patient of maxillofacial trauma with anticipated intubation problems. PMID:27833492

  4. When the snakes awake: animals and earthquake prediction

    SciTech Connect

    Tributsch, H.

    1982-01-01

    Helmet Tributsch, a physical chemist, searched the literature and collected anecdotal reports of abnormal animal behavior during 77 earthquakes, besides the 1976 Friuli earthquake that destroyed his home village in northern Italy. His findings are presented in ''When the Snakes Awake''. In the book he also describes observations of several other phenomena thought to precede earthquakes--fog, lights and sound--and discusses various hypotheses. On the basis of the available circumstantial evidence, he makes a strong argument for the attribution of these phenomena to an increase in the number of electrostatically charged particles in the atmosphere, generated by the tectonically stressed crust.

  5. Open Abdominal Aortic Aneurysm Replacement in the Awake Patient.

    PubMed

    Meecham, L; Torrance, A; Vijay, S; Burtenshaw, A; Downing, R

    2017-03-01

    Nonintubated aortic surgery using various techniques has been reported, but despite publication of favorable outcomes in select patient groups, awake aortic surgery remains unpopular. Our patient had an abdominal aortic aneurysm that was unsuitable for endovascular repair. Because of the significant respiratory disease, general anesthesia represented an unacceptably high risk. As a result, he underwent open AAA repair via a retroperitoneal approach with the aid of epidural anesthesia. Here, we highlight the benefits of the procedure which offer a select cohort of patients the chance of life-saving surgery.

  6. Long-term Potentiation at Temporoammonic Path-CA1 Synapses in Freely Moving Rats

    PubMed Central

    Gonzalez, Jossina; Villarreal, Desiree M.; Morales, Isaiah S.; Derrick, Brian E.

    2016-01-01

    Hippocampal area CA1 receives direct entorhinal layer III input via the temporoammonic path (TAP) and recent studies implicate TAP-CA1 synapses are important for some aspects of hippocampal memory function. Nonetheless, as few studies have examined TAP-CA1 synaptic plasticity in vivo, the induction and longevity of TAP-CA1 long-term potentiation (LTP) has not been fully characterized. We analyzed CA1 responses following stimulation of the medial aspect of the angular bundle and investigated LTP at medial temporoammonic path (mTAP)-CA1 synapses in freely moving rats. We demonstrate monosynaptic mTAP-CA1 responses can be isolated in vivo as evidenced by observations of independent current sinks in the stratum lacunosum moleculare of both areas CA1 and CA3 following angular bundle stimulation. Contrasting prior indications that TAP input rarely elicits CA1 discharge, we observed mTAP-CA1 responses that appeared to contain putative population spikes in 40% of our behaving animals. Theta burst high frequency stimulation of mTAP afferents resulted in an input specific and N-methyl-D-aspartate (NMDA) receptor-dependent LTP of mTAP-CA1 responses in behaving animals. LTP of mTAP-CA1 responses decayed as a function of two exponential decay curves with time constants (τ) of 2.7 and 148 days to decay 63.2% of maximal LTP. In contrast, mTAP-CA1 population spike potentiation longevity demonstrated a τ of 9.6 days. To our knowledge, these studies provide the first description of mTAP-CA1 LTP longevity in vivo. These data indicate TAP input to area CA1 is a physiologically relevant afferent system that displays robust synaptic plasticity. PMID:26903815

  7. Temporally-structured acquisition of multidimensional optical imaging data facilitates visualization of elusive cortical representations in the behaving monkey.

    PubMed

    Omer, David B; Hildesheim, Rina; Grinvald, Amiram

    2013-11-15

    Fundamental understanding of higher cognitive functions can greatly benefit from imaging of cortical activity with high spatiotemporal resolution in the behaving non-human primate. To achieve rapid imaging of high-resolution dynamics of cortical representations of spontaneous and evoked activity, we designed a novel data acquisition protocol for sensory stimulation by rapidly interleaving multiple stimuli in continuous sessions of optical imaging with voltage-sensitive dyes. We also tested a new algorithm for the "temporally structured component analysis" (TSCA) of a multidimensional time series that was developed for our new data acquisition protocol, but was tested only on simulated data (Blumenfeld, 2010). In addition to the raw data, the algorithm incorporates prior knowledge about the temporal structure of the data as well as input from other information. Here we showed that TSCA can successfully separate functional signal components from other signals referred to as noise. Imaging of responses to multiple visual stimuli, utilizing voltage-sensitive dyes, was performed on the visual cortex of awake monkeys. Multiple cortical representations, including orientation and ocular dominance maps as well as the hitherto elusive retinotopic representation of orientation stimuli, were extracted in only 10s of imaging, approximately two orders of magnitude faster than accomplished by conventional methods. Since the approach is rather general, other imaging techniques may also benefit from the same stimulation protocol. This methodology can thus facilitate rapid optical imaging explorations in monkeys, rodents and other species with a versatility and speed that were not feasible before.

  8. Locomotory adaptations in a free-lying brachiopod.

    PubMed

    Richardson, J R; Watson, J E

    1975-08-01

    Magadina cumingi inhabits an environment of high current energy and mobile sediments by using its pedicle in Pogo-stick fashion as an elevating device. This type of progression is associated with pedicle musculature different from that of attached and other free-lying forms, and some diagnostic differences in muscle attachment areas are evident in preservable hard parts.

  9. Markerless motion tracking of awake animals in positron emission tomography.

    PubMed

    Kyme, Andre; Se, Stephen; Meikle, Steven; Angelis, Georgios; Ryder, Will; Popovic, Kata; Yatigammana, Dylan; Fulton, Roger

    2014-11-01

    Noninvasive functional imaging of awake, unrestrained small animals using motion-compensation removes the need for anesthetics and enables an animal's behavioral response to stimuli or administered drugs to be studied concurrently with imaging. While the feasibility of motion-compensated radiotracer imaging of awake rodents using marker-based optical motion tracking has been shown, markerless motion tracking would avoid the risk of marker detachment, streamline the experimental workflow, and potentially provide more accurate pose estimates over a greater range of motion. We have developed a stereoscopic tracking system which relies on native features on the head to estimate motion. Features are detected and matched across multiple camera views to accumulate a database of head landmarks and pose is estimated based on 3D-2D registration of the landmarks to features in each image. Pose estimates of a taxidermal rat head phantom undergoing realistic rat head motion via robot control had a root mean square error of 0.15 and 1.8 mm using markerless and marker-based motion tracking, respectively. Markerless motion tracking also led to an appreciable reduction in motion artifacts in motion-compensated positron emission tomography imaging of a live, unanesthetized rat. The results suggest that further improvements in live subjects are likely if nonrigid features are discriminated robustly and excluded from the pose estimation process.

  10. Endotracheal Administration of Sufentanil and Tetracaine During Awake Fiberoptic Intubation.

    PubMed

    Ji, Meng; Tao, Jun; Cheng, Min; Wang, Qingli

    2016-01-01

    Combined use of local anesthetics and low-dose opioids enhances the effects of local anesthetics. This study aimed to evaluate the efficacy of combined administration of sufentanil and tetracaine through the cricothyroid membrane during awake nasal intubation using fiberoptic bronchoscopy in patients with difficult airways. Forty patients were divided into 2 groups: group A received endotracheal administration of 25 μg of sufentanil and 2 mL of 1% tetracaine mixture; group B received endotracheal administration of 2 mL 1% tetracaine and routine local anesthetic sprays followed by slow intravenous injection of 25 μg of sufentanil. The results showed that endotracheal intubation was safely completed in all patients and vital signs including blood pressure, heart rate, and pulse oxygen saturation were not significantly different between groups A and B. However, time required for local anesthesia to take effect, time required to complete intubation, cough reflex, patient tolerance during intubation, and hemodynamic indices were significantly better in group A than in group B. In conclusion, our results suggest that endotracheal administration of sufentanil combined with tetracaine is safe, effective, and feasible in the context of awake nasal intubation using fiberoptic bronchoscopy.

  11. Realignment strategies for awake-monkey fMRI data.

    PubMed

    Stoewer, Steffen; Goense, Jozien; Keliris, Georgios A; Bartels, Andreas; Logothetis, Nikos K; Duncan, John; Sigala, Natasha

    2011-12-01

    Functional magnetic resonance imaging (fMRI) experiments with awake nonhuman primates (NHPs) have recently seen a surge of applications. However, the standard fMRI analysis tools designed for human experiments are not optimal for NHP data collected at high fields. One major difference is the experimental setup. Although real head movement is impossible for NHPs, MRI image series often contain visible motion artifacts. Animal body movement results in image position changes and geometric distortions. Since conventional realignment methods are not appropriate to address such differences, algorithms tailored specifically for animal scanning become essential. We have implemented a series of high-field NHP specific methods in a software toolbox, fMRI Sandbox (http://kyb.tuebingen.mpg.de/~stoewer/), which allows us to use different realignment strategies. Here we demonstrate the effect of different realignment strategies on the analysis of awake-monkey fMRI data acquired at high field (7 T). We show that the advantage of using a nonstandard realignment algorithm depends on the amount of distortion in the dataset. While the benefits for less distorted datasets are minor, the improvement of statistical maps for heavily distorted datasets is significant.

  12. Ventilation and respiratory pattern and timing in resting awake cats.

    PubMed

    Jennings, D B; Szlyk, P C

    1985-02-01

    The purpose of this study was to characterize the variability and patterns of spontaneous respiratory behaviour in awake cats. Respiration was measured in six cats over 80 or 90 min by the plethysmographic technique. In three cats, arterial blood gases were measured. Breath frequency (f) and tidal volume (VT) varied considerably breath-to-breath, although on average, these measurements as well as average ventilation remained relatively constant. The incidence of breath ventilation (VT X 60/TTOT) and VT were distributed unimodally but the incidence of breath f had a bimodal distribution. In the low f range, average f was 22.5 breaths/min, and in the high f range, average f was 41.6 breaths/min. The latter range appeared to be associated with purring. Inspiratory duration (TI) was less than expiratory duration (TE) at low f but exceeded TE at high f. For a given breath ventilation there was a predictable f and VT. At shorter TI (higher f) mean inspiratory flow, an index of central respiratory drive, increased but VT decreased. This study indicates that "normal" control respiratory behaviour in awake cats is better described by the range and pattern of breathing than by average values.

  13. Mapping oxygen concentration in the awake mouse brain

    PubMed Central

    Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

    2016-01-01

    Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism. DOI: http://dx.doi.org/10.7554/eLife.12024.001 PMID:26836304

  14. Critical Neural Networks in Awake Surgery for Gliomas

    PubMed Central

    KINOSHITA, Masashi; MIYASHITA, Katsuyoshi; TSUTSUI, Taishi; FURUTA, Takuya; NAKADA, Mitsutoshi

    2016-01-01

    From the embarrassing character commonly infiltrating eloquent brain regions, the surgical resection of glioma remains challenging. Owing to the recent development of in vivo visualization techniques for the human brain, white matter regions can be delineated using diffusion tensor imaging (DTI) as a routine clinical practice in neurosurgery. In confirmation of the results of DTI tractography, a direct electrical stimulation (DES) substantially influences the investigation of cortico-subcortical networks, which can be identified via specific symptoms elicited in the concerned white matter tracts (eg., the arcuate fascicle, superior longitudinal fascicles, inferior fronto-occipital fascicle, inferior longitudinal fascicle, frontal aslant tract, sensori-motor tracts, optic radiation, and so forth). During awake surgery for glioma using DES, it is important to identify the anatomo-functional structure of white matter tracts to identify the surgical boundaries of brain regions not only to achieve maximal resection of the glioma but also to maximally preserve quality of life. However, the risk exists that neurosurgeons may be misled by the inability of DTI to visualize the actual anatomy of the white matter fibers, resulting in inappropriate decisions regarding surgical boundaries. This review article provides information of the critical neuronal network that is necessary to identify and understand in awake surgery for glioma, with special references to white matter tracts and the author’s experiences. PMID:27250817

  15. Characterizing Awake and Anesthetized States Using a Dimensionality Reduction Method.

    PubMed

    Mirsadeghi, M; Behnam, H; Shalbaf, R; Jelveh Moghadam, H

    2016-01-01

    Distinguishing between awake and anesthetized states is one of the important problems in surgery. Vital signals contain valuable information that can be used in prediction of different levels of anesthesia. Some monitors based on electroencephalogram (EEG) such as the Bispectral (BIS) index have been proposed in recent years. This study proposes a new method for characterizing between awake and anesthetized states. We validated our method by obtaining data from 25 patients during the cardiac surgery that requires cardiopulmonary bypass. At first, some linear and non-linear features are extracted from EEG signals. Then a method called "LLE"(Locally Linear Embedding) is used to map high-dimensional features in a three-dimensional output space. Finally, low dimensional data are used as an input to a quadratic discriminant analyzer (QDA). The experimental results indicate that an overall accuracy of 88.4 % can be obtained using this method for classifying the EEG signal into conscious and unconscious states for all patients. Considering the reliability of this method, we can develop a new EEG monitoring system that could assist the anesthesiologists to estimate the depth of anesthesia accurately.

  16. The pharmacokinetics of intravenous fenoldopam in healthy, awake cats.

    PubMed

    O'Neill, K E; Labato, M A; Court, M H

    2016-04-01

    Fenoldopam is a selective dopamine-1 receptor agonist that improves diuresis by increasing renal blood flow and perfusion and causing peripheral vasodilation. Fenoldopam has been shown to induce diuresis and be well-tolerated in healthy cats. It is used clinically in cats with oliguric kidney injury at doses extrapolated from human medicine and canine studies. The pharmacokinetics in healthy beagle dogs has been reported; however, pharmacokinetic data in cats are lacking. The goal of this study was to determine pharmacokinetic data for healthy, awake cats receiving an infusion of fenoldopam. Six healthy, awake, client-owned cats aged 2-6 years old received a 120-min constant rate infusion of fenoldopam at 0.8 μg/kg/min followed by a 20-min washout period. Ascorbate stabilized plasma samples were collected during and after the infusion for the measurement of fenoldopam concentration by HPLC with mass spectrometry detection. This study showed that the geometric mean of the volume of distribution, clearance, and half-life (198 mL/kg, 46 mL/kg/min, and 3.0 mins) is similar to pharmacokinetic parameters for humans. No adverse events were noted. Fenoldopam at a constant rate infusion of 0.8 μg/kg per min was well tolerated in healthy cats. Based on the results, further evaluation of fenoldopam in cats with kidney disease is recommended.

  17. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  18. Awake extracorporeal membrane oxygenation in patients with severe postoperative acute respiratory distress syndrome.

    PubMed

    Yeo, Hye Ju; Cho, Woo Hyun; Kim, Dohyung

    2016-01-01

    A clinical trial of extracorporeal membrane oxygenation (ECMO) as an alternative ventilator tool is being performed as a new indication for ECMO. The purpose of this study was to evaluate the feasibility of awake ECMO to increase the success rate of weaning patients from ECMO and ventilator care during treatment of postoperative severe acute respiratory distress syndrome (ARDS). We retrospectively analyzed the clinical reports of 10 patients who underwent awake ECMO due to postoperative ARDS between August 2012 and May 2015. We analyzed patient history, the partial arterial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, and patient outcome. Seven patients (70%) were weaned from ECMO without difficulty; one patient failed to maintain awake ECMO, was re-intubated after 2 days of awake ECMO, and was re-tried on awake ECMO after 4 days of ventilator care. We weaned that patient from ECMO 2 days later. We weaned a total of eight patients (80%) from awake ECMO. The ECMO duration of surviving patients was 9.13±2.2 days (range, 6-12 days), and mean ventilator use duration was 6.8±4.7 days (range, 2-16 days). Two cases failed awake ECMO and died due to disease aggravation. Awake ECMO was a useful weaning strategy after severe postoperative ARDS, as it avoids long-duration use of mechanical ventilation. Additionally, it is possible for patients to breathe spontaneously, which might prevents respiratory muscle dystrophy.

  19. Neutral atoms behave much like classical spherical capacitors

    SciTech Connect

    Ellenbogen, James C.

    2006-09-15

    The scaling of the capacitance with radius is explored in detail for neutral atoms, and it is found that they behave much like macroscopic spherical capacitors. The quantum capacitances of atoms scale as a linear function of the mean radii of their highest occupied orbitals. The slopes of the linear scaling lines include a dimensionless constant of proportionality {kappa} that is somewhat analogous to a dielectric constant, but for individual atoms. The slope and {kappa} assume discrete values characteristic of elements in different regions of the periodic table. These observations provide a different, electrostatics-based way of understanding the periodic behavior of the elements.

  20. A Magnetic Rotary Optical Fiber Connector for Optogenetic Experiments in Freely Moving Animals

    PubMed Central

    Klorig, David C; Godwin, Dwayne W

    2014-01-01

    Background Performing optogenetic experiments in a behaving animal presents a unique technical challenge. In order to provide an optical path between a fixed light source and a chronically implanted fiber in a freely moving animal, a typical experimental set-up includes a detachable connection between the light source and the head of the animal, as well as a rotary joint to relieve torsional stress during movement. New Method We have combined the functionality of the head mounted connector and the rotary joint into a single integrated device that is inexpensive, simple to build and easy to use. Results A typical rotary connector has a transmission efficiency of 80% with a rotational variability of 4%, but can be configured to have a rotational variability of 2% at the expense of lower transmission efficiency. Depending on configuration, rotational torque ranges from 14 - 180 μN*m, making the rotary connector suitable for use with small animals such as mice. Comparison with Existing Methods Benchmark tests demonstrate that our connectors perform similarly to commercially available solutions in terms of transmission efficiency, rotational variability, and torque but at a fraction of the cost. Unlike currently available solutions, our unique design requires a single optical junction which significantly reduces overall light loss. In addition, magnets allow the connectors and caps to “snap into place” for quick yet reliable connection and disconnection. Conclusions Our rotary connector system offers superior performance, reduced cost, and is easily incorporated into existing optogenetic set-ups. PMID:24613796

  1. An implantable bolus infusion pump for use in freely moving, nontethered rats

    PubMed Central

    HOLSCHNEIDER, D. P.; MAAREK, J.-M. I.; HARIMOTO, J.; YANG, J.; SCREMIN, O. U.

    2014-01-01

    One of the current constraints on functional neuroimaging in animals is that to avoid movement artifacts during data acquisition, subjects need to be immobilized, sedated, or anesthetized. Such measures limit the behaviors that can be examined, and introduce the additional variables of stress or anesthetic agents that may confound meaningful interpretation. This study provides a description of the design and characteristics of a self-contained, implantable microbolus infusion pump (MIP) that allows triggering of a bolus injection at a distance in conscious, behaving rats that are not restrained or tethered. The MIP is externally triggered by a pulse of infrared light and allows in vivo bolus drug delivery. We describe application of this technology to the intravenous bolus delivery of iodo[14C]antipyrine in a freely moving animal, followed immediately by lethal injection, rapid removal of the brain, and analysis of regional cerebral blood flow tissue radioactivity with the use of autoradiography. The ability to investigate changes in brain activation in nonrestrained animals makes the MIP a powerful tool for evaluation of complex behaviors. PMID:12234827

  2. Calcium imaging with genetically encoded indicators in behaving primates

    PubMed Central

    Seidemann, Eyal; Chen, Yuzhi; Bai, Yoon; Chen, Spencer C; Mehta, Preeti; Kajs, Bridget L; Geisler, Wilson S; Zemelman, Boris V

    2016-01-01

    Understanding the neural basis of behaviour requires studying brain activity in behaving subjects using complementary techniques that measure neural responses at multiple spatial scales, and developing computational tools for understanding the mapping between these measurements. Here we report the first results of widefield imaging of genetically encoded calcium indicator (GCaMP6f) signals from V1 of behaving macaques. This technique provides a robust readout of visual population responses at the columnar scale over multiple mm2 and over several months. To determine the quantitative relation between the widefield GCaMP signals and the locally pooled spiking activity, we developed a computational model that sums the responses of V1 neurons characterized by prior single unit measurements. The measured tuning properties of the GCaMP signals to stimulus contrast, orientation and spatial position closely match the predictions of the model, suggesting that widefield GCaMP signals are linearly related to the summed local spiking activity. DOI: http://dx.doi.org/10.7554/eLife.16178.001 PMID:27441501

  3. Anticipating and Resisting the Temptation to Behave Unethically.

    PubMed

    Sheldon, Oliver J; Fishbach, Ayelet

    2015-07-01

    Ethical dilemmas pose a self-control conflict between pursuing immediate benefits through behaving dishonestly and pursuing long-term benefits through acts of honesty. Therefore, factors that facilitate self-control for other types of goals (e.g., health and financial) should also promote ethical behavior. Across four studies, we find support for this possibility. Specifically, we find that only under conditions that facilitate conflict identification--including the consideration of several decisions simultaneously (i.e., a broad decision frame) and perceived high connectedness to the future self--does anticipating a temptation to behave dishonestly in advance promote honesty. We demonstrate these interaction patterns between conflict identification and temptation anticipation in negotiation situations (Study 1), lab tasks (Study 2), and ethical dilemmas in the workplace (Studies 3-4). We conclude that identifying a self-control conflict and anticipating a temptation are two necessary preconditions for ethical decision making. © 2015 by the Society for Personality and Social Psychology, Inc.

  4. The effects of systemically administered taurine and N-pivaloyltaurine on striatal extracellular dopamine and taurine in freely moving rats.

    PubMed

    Salimäki, J; Scriba, G; Piepponen, T P; Rautolahti, N; Ahtee, L

    2003-08-01

    The second most abundant cerebral amino acid, taurine, is widely consumed in the so-called "energy drinks". Therefore, its possible actions on the brain are of great interest. In the present experiments taurine was given intraperitoneally to rats in order to study if it can be administered systemically in large enough amounts to alter cerebral dopaminergic transmission or to induce hypothermia. In addition, the effects of subcutaneously administered lipophilic taurine analogue, N-pivaloyltaurine, were studied. The extracellular striatal taurine and dopamine concentrations were estimated using in vivo microdialysis in awake and freely moving rats, and the rectal temperatures were measured. Taurine at the total dose of 45 mmol/kg i.p. led to a maximally 8-fold increased striatal extracellular taurine concentration, induced a long-lasting hypothermia, and significantly reduced the striatal extracellular dopamine concentration. The latter effect was strengthened by co-treatment with reuptake inhibitor nomifensine. N-pivaloyltaurine (15 mmol/kg in total, s.c.) only slightly elevated the striatal extracellular taurine concentration, failed to alter the rectal temperature, and in contrast to taurine somewhat elevated the striatal extracellular dopamine concentration suggesting a different mechanism or locus of action from that of taurine. Finally, our experiments using brain microdialysis confirmed the earlier findings that taurine is slowly eliminated from the brain. The results clearly indicate that systemically given taurine enters the brain in concentrations that induce pharmacological effects.

  5. The effect of repetitive transcranial magnetic stimulation on monoamine outflow in the nucleus accumbens shell in freely moving rats.

    PubMed

    Löffler, Susanne; Gasca, Fernando; Richter, Lars; Leipscher, Ulrike; Trillenberg, Peter; Moser, Andreas

    2012-10-01

    Evidence exists that modulation of neuronal activity in nucleus accumbens shell region may re-establish normal function in various neuropsychiatric conditions such as drug-withdrawal, obsessive-compulsive disorder, depression and chronic pain. Here, we study the effects of acute repetitive transcranial magnetic stimulation on monoamine outflow in the nucleus accumbens shell in awake and freely moving rats using in vivo microdialysis. To scale the biochemical results to the induced electric field in the rat brain, we obtained a realistic simulation of the stimulation scenario using a finite element model. Applying 20 Hz repetitive transcranial magnetic stimulation in 6 trains of 50 stimuli with 280 μs pulse width at a magnetic field strength of 130% of the individual motor threshold, dopamine as well as serotonin outflow in the nucleus accumbens shell significantly increased compared to sham stimulation. Since the electric field decays rapidly with depth in the rat brain, we can conclude that the modulation in neurotransmitter outflow from the nucleus accumbens shell is presumably a remote effect of cortical stimulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Clustering impact regime with shocks in freely evolving granular gas

    NASA Astrophysics Data System (ADS)

    Isobe, Masaharu

    2017-06-01

    A freely cooling granular gas without any external force evolves from the initial homogeneous state to the inhomogeneous clustering state, at which the energy decay deviates from the Haff's law. The asymptotic behavior of energy in the inelastic hard sphere model have been predicted by several theories, which are based on the mode coupling theory or extension of inelastic hard rods gas. In this study, we revisited the clustering regime of freely evolving granular gas via large-scale molecular dynamics simulation with up to 16.7 million inelastic hard disks. We found novel regime regarding on collisions between "clusters" spontaneously appearing after clustering regime, which can only be identified more than a few million particles system. The volumetric dilatation pattern of semicircular shape originated from density shock propagation are well characterized on the appearing of "cluster impact" during the aggregation process of clusters.

  7. Minimum alveolar concentration-awake of Xenon alone and in combination with isoflurane or sevoflurane.

    PubMed

    Goto, T; Nakata, Y; Ishiguro, Y; Niimi, Y; Suwa, K; Morita, S

    2000-11-01

    The minimum alveolar concentration (MAC)-awake is a traditional index of hypnotic potency of an inhalational anesthetic. The MAC-awake of xenon, an inert gas with anesthetic properties (MAC = 71%), has not been determined. It is also unknown how xenon interacts with isoflurane or sevoflurane on the MAC-awake. In the first part of the study, 90 female patients received xenon, nitrous oxide (N2O), isoflurane, or sevoflurane supplemented with epidural anesthesia (n = 36 for xenon and n = 18 per group for other anesthetics). In the second part, 72 additional patients received either xenon or N2O combined with the 0.5 times MAC-awake concentration of isoflurane or sevoflurane (0.2% and 0.3%, respectively, based on the results of the first part; n = 18 per group). During emergence, the concentration of an assigned anesthetic (xenon or N2O only in the second part) was decreased in 0. 1 MAC decrements every 15 min from 0.8 MAC or from 70% in the case of N2O until the patient followed the command to either open her eyes or to squeeze and release the investigator's hand. The concentration midway between the value permitting the first response to command and that just preventing it was defined as the MAC-awake. The MAC-awake were as follows: xenon, 32.6 +/- 6.1% (mean +/- SD) or 0.46 +/- 0.09 MAC; N2O, 63.3 +/- 7.1% (0.61 +/- 0.07 MAC); isoflurane, 0.40 +/- 0.07% (0.35 +/- 0.06 MAC); and sevoflurane, 0.59 +/- 0.10% (0.35 +/- 0.06 MAC). Addition of the 0.5 MAC-awake concentrations of isoflurane and sevoflurane reduced the MAC-awake of xenon to 0.50 +/- 0.15 and 0.51 +/- 0.16 times its MAC-awake as a sole agent, but that of N2O to the values significantly greater than 0.5 times its MAC-awake as a sole agent (0.68 +/- 0.12 and 0.66 +/- 0.14 times MAC-awake; P < 0.01, analysis of variance and Dunnett's test). The MAC-awake of xenon is 33% or 0.46 times its MAC. In terms of the MAC-fraction, this is smaller than that for N2O but greater than those for isoflurane and sevoflurane

  8. The electron accelerator for the AWAKE experiment at CERN

    NASA Astrophysics Data System (ADS)

    Pepitone, K.; Doebert, S.; Burt, G.; Chevallay, E.; Chritin, N.; Delory, C.; Fedosseev, V.; Hessler, Ch.; McMonagle, G.; Mete, O.; Verzilov, V.; Apsimon, R.

    2016-09-01

    The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

  9. Replicability and heterogeneity of awake unrestrained canine FMRI responses.

    PubMed

    Berns, Gregory S; Brooks, Andrew; Spivak, Mark

    2013-01-01

    Previously, we demonstrated the possibility of fMRI in two awake and unrestrained dogs. Here, we determined the replicability and heterogeneity of these results in an additional 11 dogs for a total of 13 subjects. Based on an anatomically placed region-of-interest, we compared the caudate response to a hand signal indicating the imminent availability of a food reward to a hand signal indicating no reward. 8 of 13 dogs had a positive differential caudate response to the signal indicating reward. The mean differential caudate response was 0.09%, which was similar to a comparable human study. These results show that canine fMRI is reliable and can be done with minimal stress to the dogs.

  10. Behaving as or behaving as if? Children's conceptions of personified robots and the emergence of a new ontological category.

    PubMed

    Severson, Rachel L; Carlson, Stephanie M

    2010-01-01

    Imagining another's perspective is an achievement in social cognition and underlies empathic concern and moral regard. Imagination is also within the realm of fantasy, and may take the form of imaginary play in children and imaginative production in adults. Yet, an interesting and provocative question emerges in the case of personified robots: How do people conceive of life-like robots? Do people imagine about robots' experiences? If so, do these imaginings reflect their actual or pretend beliefs about robots? The answers to these questions bear on the possibility that personified robots represent the emergence of a new ontological category. We draw on simulation theory as a framework for imagining others' internal states as well as a means for imaginative play. We then turn to the literature on people's and, in particular, children's conceptions of personified technologies and raise the question of the veracity of children's beliefs about personified robots (i.e., are they behaving as or behaving as if?). Finally, we consider the suggestion that such personified technologies represent the emergence of a new ontological category and offer some suggestions for future research in this important emerging area of social cognition.

  11. Default-mode-like network activation in awake rodents.

    PubMed

    Upadhyay, Jaymin; Baker, Scott J; Chandran, Prasant; Miller, Loan; Lee, Younglim; Marek, Gerard J; Sakoglu, Unal; Chin, Chih-Liang; Luo, Feng; Fox, Gerard B; Day, Mark

    2011-01-01

    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.

  12. Default-Mode-Like Network Activation in Awake Rodents

    PubMed Central

    Upadhyay, Jaymin; Baker, Scott J.; Chandran, Prasant; Miller, Loan; Lee, Younglim; Marek, Gerard J.; Sakoglu, Unal; Chin, Chih-Liang; Luo, Feng; Fox, Gerard B.; Day, Mark

    2011-01-01

    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess ‘DMN-like’ functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = −0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks. PMID:22125628

  13. Sleep bruxism, awake bruxism and sleep quality among Brazilian dental students: a cross-sectional study.

    PubMed

    Serra-Negra, Júnia Maria; Scarpelli, Ana Carolina; Tirsa-Costa, Débora; Guimarães, Flávia Helena; Pordeus, Isabela Almeida; Paiva, Saul Martins

    2014-01-01

    The aim of the study was to evaluate the association of sleep bruxism, awake bruxism and sleep quality among dental students of the Federal University of Minas Gerais, Belo Horizonte, Brazil. A cross-sectional study was performed including 183 Brazilian dental students aged from 17 to 46 years old. The complete course curriculum consists of 9 semesters. Students enrolled in the first semester, the middle semester and the final semester of the course participated in the survey. The PSQI-BR (the Brazilian version of the Pittsburgh Sleep Questionnaire Index) was used for data collection. The PSQI-BR was distributed during lecture classes. Sleep bruxism and awake bruxism diagnosis was based on self-reported data. Descriptive analysis, Kruskal-Wallis, Mann-Whitney and Poisson regression with robust estimator were the statistical tests used. Sleep bruxism prevalence was 21.5% and awake bruxism prevalence was 36.5%. Sleep duration components were associated with sleep bruxism (PR=1.540; 95% CI: 1.00-2.37) and awake bruxism (PR=1.344; 95% CI: 1,008-1,790). There was an association between awake bruxism and habitual sleep efficiency component (PR=1.323; 95% CI: 1.03-1.70). Sleep disturbance component and awake bruxism were associated (PR=1.533; 95% CI: 1.03-2.27). Poor sleep quality was an important factor among dental students, who reported sleep bruxism as well as among those who presented awake bruxism.

  14. Well behaved anisotropic compact star models in general relativity

    NASA Astrophysics Data System (ADS)

    Jasim, M. K.; Maurya, S. K.; Gupta, Y. K.; Dayanandan, B.

    2016-11-01

    Anisotropic compact star models have been constructed by assuming a particular form of a metric function e^{λ}. We solved the Einstein field equations for determining the metric function e^{ν}. For this purpose we have assumed a physically valid expression of radial pressure (pr). The obtained anisotropic compact star model is representing the realistic compact objects such as PSR 1937 +21. We have done an extensive study about physical parameters for anisotropic models and found that these parameters are well behaved throughout inside the star. Along with these we have also determined the equation of state for compact star which gives the radial pressure is purely the function of density i.e. pr=f(ρ).

  15. Urgent awake thoracoscopic treatment of retained haemothorax associated with respiratory failure

    PubMed Central

    Cristino, Benedetto; Rogliani, Paola; Dauri, Mario

    2015-01-01

    A number of video-assisted thoracoscopic surgery (VATS) procedures are being increasingly performed by awake anesthesia in an attempt of minimizing the surgical- and anesthesia-related traumas. However, so far the usefulness of awake VATS for urgent management of retained haemothorax has been scarcely investigated. Herein we present two patients with retained haemothorax following previous thoracentesis and blunt chest trauma, respectively, who developed acute respiratory failure and underwent successful urgent awake VATS management under local anesthesia through a single trocar access. PMID:26046053

  16. BehavePlus fire modeling system, version 5.0: Variables

    Treesearch

    Patricia L. Andrews

    2009-01-01

    This publication has been revised to reflect updates to version 4.0 of the BehavePlus software. It was originally published as the BehavePlus fire modeling system, version 4.0: Variables in July, 2008.The BehavePlus fire modeling system is a computer program based on mathematical models that describe wildland fire behavior and effects and the...

  17. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    PubMed Central

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2–4s temporal resolution, 2mm slice thickness, and 700 micron in-plane resolution while retaining adequate signal-to-noise ratio. 13C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4T yield T1=46±4s and T2=0.55±0.03s. In the rat brain at 4.7T, analysis of the temporal dynamics of the bSSFP image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T2 of roughly 2–4s and a T1 of 43±24s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. PMID:21432901

  18. Bilateral Discrimination of Tactile Patterns without Whisking in Freely Running Rats.

    PubMed

    Kerekes, Pauline; Daret, Aurélie; Shulz, Daniel E; Ego-Stengel, Valérie

    2017-08-09

    A majority of whisker discrimination tasks in rodents are performed on head-fixed animals to facilitate tracking or control of the sensory inputs. However, head fixation critically restrains the behavior and thus the incoming stimuli compared with those occurring in natural conditions. In this study, we investigated whether freely behaving rats can discriminate fine tactile patterns while running, in particular when stimuli are presented simultaneously on both sides of the snout. We developed a two-alternative forced-choice task in an automated modified T-maze. Stimuli were either a surface with no bars (smooth) or with vertical bars spaced irregularly or regularly. While running at full speed, rats encountered simultaneously the two discriminanda placed on the two sides of the central aisle. Rats learned to recognize regular bars versus a smooth surface in 8 weeks. They solved the task while running at an average speed of 1 m/s, so that the contact with the stimulus lasted <1 typical whisking cycle, precluding the use of active whisking. Whisker-tracking analysis revealed an asymmetry in the position of the whiskers: they oriented toward the rewarded stimulus during successful trials as early as 60 ms after the first possible contact. We showed that the whiskers and activity in the primary somatosensory cortex are involved during the discrimination process. Finally, we identified irregular patterns of bars that the rats can discriminate from the regular one. This novel task shows that freely moving rodents can make simultaneous bilateral tactile discrimination without whisking.SIGNIFICANCE STATEMENT The whisker system of rodents is a widely used model to study tactile processing. Rats show remarkable abilities in discriminating surfaces by actively moving their whiskers (whisking) against stimuli, typically sampling them several times. This motor strategy affects considerably the way that tactile information is acquired and thus the way that neuronal networks

  19. Pediatric awake craniotomy for seizure focus resection with dexmedetomidine sedation-a case report.

    PubMed

    Sheshadri, Veena; Chandramouli, B A

    2016-08-01

    Resection of lesions near the eloquent cortex of brain necessitates awake craniotomy to reduce the risk of permanent neurologic deficits during surgery. There are limited reports of anesthetic management of awake craniotomy in pediatric patients. This report is on use of dexmedetomidine sedation for awake craniotomy in a 11-year-old child, without any airway adjuncts throughout the procedure. Dexmedetomidine infusion administered at a dosage of 0.2 to 0.7μg kg(-1) h(-1) provided adequate sedation for the entire procedure. There were no untoward incidents or any interference with electrocorticography, intraoperative stimulation, and functional mapping. Adequate preoperative visits and counseling of patient and parents regarding course and nature of events along with well-planned intraoperative management are of utmost importance in a pediatric age group for successful intraoperative awake craniotomy.

  20. Elaborate mapping of the posterior visual pathway in awake craniotomy.

    PubMed

    Shahar, Tal; Korn, Akiva; Barkay, Gal; Biron, Tali; Hadanny, Amir; Gazit, Tomer; Nossek, Erez; Ekstein, Margaret; Kesler, Anat; Ram, Zvi

    2017-08-25

    OBJECTIVE Resection of intraaxial tumors adjacent to the optic radiation (OR) may be associated with postoperative visual field (VF) deficits. Intraoperative navigation using MRI-based tractography and electrophysiological monitoring of the visual pathways may allow maximal resection while preserving visual function. In this study, the authors evaluated the value of visual pathway mapping in a series of patients undergoing awake craniotomy for tumor resection. METHODS A retrospective analysis of prospectively collected data was conducted in 18 patients who underwent an awake craniotomy for resection of intraaxial tumors involving or adjacent to the OR. Preoperative MRI-based tractography was used for intraoperative navigation, and intraoperative acquisition of 3D ultrasonography images was performed for real-time imaging and correction of brain shift. Goggles with light-emitting diodes were used as a standard visual stimulus. Direct cortical visual evoked potential (VEP) recording, subcortical recordings from the OR, and subcortical stimulation of the OR were used intraoperatively to assess visual function and proximity of the lesion to the OR. VFs were assessed pre- and postoperatively. RESULTS Baseline cortical VEP recordings were available for 14 patients (77.7%). No association was found between preoperative VF status and baseline presence of cortical VEPs (p = 0.27). Five of the 14 patients (35.7%) who underwent subcortical stimulation of the OR reported seeing phosphenes in the corresponding contralateral VF. There was a positive correlation (r = 0.899, p = 0.04) between the subcortical threshold stimulation intensity (3-11.5 mA) and the distance from the OR. Subcortical recordings from the OR demonstrated a typical VEP waveform in 10 of the 13 evaluated patients (76.9%). These waveforms were present only when recordings were obtained within 10 mm of the OR (p = 0.04). Seven patients (38.9%) had postoperative VF deterioration, and it was associated with a

  1. Teaching and sustainably implementing awake craniotomy in resource-poor settings.

    PubMed

    Howe, Kathryn L; Zhou, Guosheng; July, Julius; Totimeh, Teddy; Dakurah, Thomas; Malomo, Adefolarin O; Mahmud, Muhammad R; Ismail, Nasiru J; Bernstein, Mark A

    2013-12-01

    Awake craniotomy for brain tumor resection has the benefit of avoiding a general anesthetic and decreasing associated costs (e.g., intensive care unit beds and intravenous line insertion). In low- and middle-income countries, significant resource limitations for the system and individual make awake craniotomy an ideal tool, yet it is infrequently used. We sought to determine if awake craniotomy could be effectively taught and implemented safely and sustainably in low- and middle-income countries. A neurosurgeon experienced in the procedure taught awake craniotomy to colleagues in China, Indonesia, Ghana, and Nigeria during the period 2007-2012. Patients were selected on the basis of suspected intraaxial tumor, absence of major dysphasia or confusion, and ability to tolerate the positioning. Data were recorded by the local surgeons and included preoperative imaging, length of hospital admission, final pathology, postoperative morbidity, and mortality. Awake craniotomy was performed for 38 cases of suspected brain tumor; most procedures were completed independently. All patients underwent preoperative computed tomography or magnetic resonance imaging. In 64% of cases, patients remained in the hospital <10 days. The most common pathology was high-grade glioma, followed by meningioma, low-grade glioma, and metastasis. No deaths occurred, and no case required urgent intubation. The most common perioperative and postoperative issue was seizure, with 1 case of permanent postoperative deficit. Awake craniotomy was successfully taught and implemented in 6 neurosurgical centers in China, Indonesia, Ghana, and Nigeria. Awake craniotomy is safe, resource-sparing, and sustainable. The data suggest awake craniotomy has the potential to significantly improve access to neurosurgical care in resource-challenged settings. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Chronic multiscale imaging of neuronal activity in the awake common marmoset

    PubMed Central

    Yamada, Yoshiyuki; Matsumoto, Yoshifumi; Okahara, Norio; Mikoshiba, Katsuhiko

    2016-01-01

    We report a methodology to chronically record in vivo brain activity in the awake common marmoset. Over a month, stable imaging revealed macroscopic sensory maps in the somatosensory cortex and their underlying cellular activity with a high signal-to-noise ratio in the awake but not anesthetized state. This methodology is applicable to other brain regions, and will be useful for studying cortical activity and plasticity in marmosets during learning, development, and in neurological disorders. PMID:27786241

  3. Well-behaved relativistic charged super-dense star models

    NASA Astrophysics Data System (ADS)

    Faruqi, Shahab; Pant, Neeraj

    2012-10-01

    A new class of charged super-dense star models is obtained by using an electric intensity, which involves a parameter, K. The metric describing the model shares its metric potential g 44 with that of Durgapal's fourth solution (J. Phys. A, Math. Gen. 15:2637, 1982). The pressure-free surface is kept at the density ρ b =2×1014 g/cm3 and joins smoothly with the Reissner-Nordstrom solution. The charge analogues are well-behaved for a wide range, 0≤ K≤59, with the optimum value of X=0.264 i.e. the pressure, density, pressure-density ratio and velocity of sound are monotonically decreasing and the electric intensity is monotonically increasing in nature for the given range of the parameter K. The maximum mass and the corresponding radius occupied by the neutral solution are 4.22 M Θ and 20 km, respectively for X=0.264. For the charged solution, the maximum mass and radius are defined by the expressions M≈(0.0059 K+4.22) M Θ and r b ≈-0.021464 K+20 km respectively.

  4. The electroretinogram and visual evoked potential of freely moving rats.

    PubMed

    Szabó-Salfay, O; Pálhalmi, J; Szatmári, E; Barabás, P; Szilágyi, N; Juhász, G

    2001-09-01

    The vascularised rat retina could be one of the most useful experimental objects in visual neuroscience to understand human visual physiological and pathological processes. We report here on a new method of implantation for studying the visual system of freely moving rats that provides a rat model for simultaneous recording at corneal and cortical level and is stable enough to record for months. We implanted light emitting diodes onto the skull behind the eyeball to stimulate the eye with flashes and to light adapt the retina with constant light levels. A multistrand, stainless steel, flexible fine wire electrode placed on the eyeball was used for electroretinogram recording and screw electrodes (left/right visual and parietal cortical) were used to record the visual evoked potential and the electroencephalogram. In the present report we focus on the new method of implantation for recording the corneal flash electroretinogram of normal, freely moving rats simultaneously with the visual evoked cortical potential showing examples in various visual experiments. We also introduce a program for retinogram and visual evoked potential analysis, which defines various measures (latencies, areas, amplitudes, and durations) and draw attention to the benefits of this method for those involved in visual, functional genomic, pharmacological, and human ophthalmologic research.

  5. Freely-tunable broadband polarization rotator for terahertz waves

    NASA Astrophysics Data System (ADS)

    Peng, Ru-Wen; Fan, Ren-Hao; Zhou, Yu; Jiang, Shang-Chi; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

    It is known that commercially-available terahertz (THz) emitters usually generate linearly polarized waves only along certain directions, but in practice, a polarization rotator that is capable of rotating the polarization of THz waves to any direction is particularly desirable and it will have various important applications. In this work, we demonstrate a freely tunable polarization rotator for broadband THz waves using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized THz wave to any desired direction with nearly perfect conversion efficiency. The device performance has been experimentally demonstrated by both THz transmission spectra and direct imaging. The polarization rotation originates from multi wave interference in the three-layer grating structure based on the scattering-matrix analysis. We can expect that this active broadband polarization rotator has wide applications in analytical chemistry, biology, communication technology, imaging, etc.. Reference: R. H. Fan, Y. Zhou, X. P. Ren, R. W. Peng, S. C. Jiang, D. H. Xu, X. Xiong, X. R. Huang, and Mu Wang, Advanced Materials 27,1201(2015). Freely-tunable broadband polarization rotator for terahertz waves.

  6. A freely falling magneto-optical trap drop tower experiment

    NASA Astrophysics Data System (ADS)

    Könemann, T.; Brinkmann, W.; Göklü, E.; Lämmerzahl, C.; Dittus, H.; van Zoest, T.; Rasel, E. M.; Ertmer, W.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Vogel, A.; Johannsen, G.; Wildfang, S.; Bongs, K.; Sengstock, K.; Kajari, E.; Nandi, G.; Walser, R.; Schleich, W. P.

    2007-12-01

    We experimentally demonstrate the possibility of preparing ultracold atoms in the environment of weightlessness at the earth-bound short-term microgravity laboratory Drop Tower Bremen, a facility of ZARM - University of Bremen. Our approach is based on a freely falling magneto-optical trap (MOT) drop tower experiment performed within the ATKAT collaboration (“Atom-Catapult”) as a preliminary part of the QUANTUS pilot project (“Quantum Systems in Weightlessness”) pursuing a Bose-Einstein condensate (BEC) in microgravity at the drop tower [1, 2]. Furthermore we give a complete account of the specific drop tower requirements to realize a compact and robust setup for trapping and cooling neutral rubidium 87Rb atoms in microgravity conditions. We also present the results of the first realized freely falling MOT and further accomplished experiments during several drops. The goal of the preliminary ATKAT pilot project is to initiate a basis for extended atom-optical experiments which aim at realizing, observing and investigating ultracold quantum matter in microgravity.

  7. Towards direct numerical simulation of freely swimming fish.

    NASA Astrophysics Data System (ADS)

    Curet, Oscar; Patankar, Neelesh; Maciver, Malcolm

    2006-11-01

    Swimming mechanisms employed by fish are currently inspiring unique underwater vehicles and robotic devices as well as basic science research into the neural control of movement. Key engineering issues include propulsion efficiency, precise motion control and maneuverability. A numerical scheme that simulates the motion of freely swimming fish will be a valuable design and research tool. We are working towards this goal. In particular we are interested in simulating the motion of a gymnotiform fish that swims by producing undulations of a ventral ribbon fin while keeping its body rigid. We model the fish as a rigid body with an attached undulating membrane. In our numerical scheme the key idea is to assume that the entire fluid-fish domain is a fluid. Then we impose two constraints: the first requires that the fluid in the region occupied by the fish body moves rigidly (a fictitious domain approach), and the second requires that the fluid at the location of the fin has the traveling wave velocity of the fin (an immersed boundary approach). Given the traveling wave form of the fin, the objective is for the numerical scheme to give the swimming velocity of the fish by solving the coupled fluid-fish problem. We will present results for the forces generated by a fin attached to a fixed body and preliminary results for freely swimming fish.

  8. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates

    PubMed Central

    Adelsberger, Helmuth; Zainos, Antonio; Alvarez, Manuel; Romo, Ranulfo; Konnerth, Arthur

    2014-01-01

    Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit “map” of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber–based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains. PMID:24344287

  9. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates.

    PubMed

    Adelsberger, Helmuth; Zainos, Antonio; Alvarez, Manuel; Romo, Ranulfo; Konnerth, Arthur

    2014-01-07

    Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit "map" of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber-based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains.

  10. Structure and Dynamics of Freely Suspended Liquid Crystals

    NASA Technical Reports Server (NTRS)

    Clark, Noel A.

    2004-01-01

    Smectic liquid crystals are phases of rod shaped molecules organized into one dimensionally (1 D) periodic arrays of layers, each layer being between one and two molecular lengths thick. In the least ordered smectic phases, the smectics A and C, each layer is a two dimensional (2D) liquid. Additionally there are a variety of more ordered smectic phases having hexatic short range translational order or 2D crystalline or quasi long range translational order within the layers. The inherent fluid-layer structure and low vapor pressure of smectic liquid crystals enables the long term stabilization of freely suspended, single component, layered fluid films as thin as 30A, a single molecular layer. The layering forces the films to be an integral number of smectic layers thick, quantizing their thickness in layer units and forcing a film of a particular number of layers to be physically homogeneous with respect to its layer structure over its entire area. Optical reflectivity enables the precise determination of the number of layers. These ultrathin freely suspended liquid crystal films are structures of fundamental interest in condensed matter and fluid physics. They are the thinnest known stable fluid structures and have the largest surface-to-volume ratio of any stable fluid preparation, making them ideal for the study of the effects of reduced dimensionality on phase behavior and on fluctuation and interface phenomena. Their low vapor pressure and quantized thickness enable the effective use of microgravity to extend the study of basic capillary phenomena to ultrathin fluid films. Freely suspended films have been a wellspring of new LC physics. They have been used to provide unique experimental conditions for the study of condensed phase transitions in two dimensions. They are the only system in which the hexatic has been unambiguously identified as a phase of matter, and the only physical system in which fluctuations of a 2D XY system and Kosterlitz Thouless phase

  11. The efficacy of combined regional nerve blocks in awake orotracheal fiberoptic intubation

    PubMed Central

    Chatrath, Veena; Sharan, Radhe; Jain, Payal; Bala, Anju; Ranjana; Sudha

    2016-01-01

    Aims of Study: To evaluate the efficacy, hemodynamic changes, and patient comfort during awake fiberoptic intubation done under combined regional blocks. Materials and Methods: In the present observational study, 50 patients of American Society of Anesthesiologists ( ASA) Grade I–II, Mallampati Grade I–IV were given nerve blocks - bilateral glossopharyngeal nerve block, bilateral superior laryngeal nerve block, and recurrent laryngeal nerve block before awake fiberoptic intubation using 2% lidocaine. Results: Procedure was associated with minimal increases in hemodynamic parameters during the procedure and until 3 min after it. Most of the intubations were being carried out within 3 min. Patient comfort was satisfactory with 90% of patients having favorable grades. Discussion: The most common cause of mortality and serious morbidity due to anesthesia is from airway problems. One-third of all anesthetic deaths are due to failure to intubate and ventilate. Awake flexible fiberoptic intubation under local anesthesia is now an accepted technique for managing such situations. In awake patient's anatomy, muscle tone, airway protection, and ventilation are preserved, but it is essential to sufficiently anesthetize the upper airway before the performance of awake fiberoptic bronchoscope-guided intubation to ensure patient comfort and cooperation for which in our study we used the nerve block technique. Conclusion: A properly performed technique of awake fiberoptic intubation done under combined regional nerve blocks provides good intubating conditions, patient comfort and safety and results in minimal hemodynamic changes. PMID:27212757

  12. Awake tracheal intubation using Pentax airway scope in 30 patients: A Case series

    PubMed Central

    Kajekar, Payal; Mendonca, Cyprian; Danha, Rati; Hillermann, Carl

    2014-01-01

    Background and Aims: Pentax airway scope (AWS) has been successfully used for managing difficult intubations. In this case series, we aimed to evaluate the success rate and time taken to complete intubation, when AWS was used for awake tracheal intubation. Methods: We prospectively evaluated the use of AWS for awake tracheal intubation in 30 patients. Indication for awake intubation, intubation time, total time to complete tracheal intubation, laryngoscopic view (Cormack and Lehane grade), total dose of local anaesthetic used, anaesthetists rating and patient's tolerance of the procedure were recorded. Results: The procedure was successful in 25 out of the 30 patients (83%). The mean (standard deviation) intubation time and total time to complete the tracheal intubation was 5.4 (2.4) and 13.9 (3.7) min, respectively in successful cases. The laryngeal view was grade 1 in 24 and grade 2 in one of 25 successful intubations. In three out of the five patients where the AWS failed, awake tracheal intubation was successfully completed with the assistance of flexible fibre optic scope (FOS). Conclusion: Awake tracheal intubation using AWS was successful in 83% of patients. Success rate can be further improved using a combination of AWS and FOS. Anaesthesiologists who do not routinely use FOS may find AWS easier to use for awake tracheal intubation using an oral route. PMID:25197114

  13. Defining hypotension in anesthetized infants by individual awake blood pressure values: a prospective observational study.

    PubMed

    Weber, Frank; Koning, Laurens; Scoones, Gail P

    2017-04-01

    Blood pressure (BP) is the most commonly applied clinical surrogate parameter for tissue perfusion and cerebral autoregulation. Hypotension during anesthesia may contribute to unfavorable outcome in young children. Hypotension in anesthetized infants can be defined using BP values relative to individual awake baseline or absolute BP values. The aim of this study was to investigate the applicability of the two definitions and to compare the incidences of hypotension. This was a prospective observational study in 151 infants <12 months of age. The percentage of successful awake BP measurements was calculated and related to the infant's behavioral state. Hypotension under sevoflurane anesthesia was defined by a decrease of mean arterial pressure (MAP) relative to awake baseline (>20% in infants <6 months, >40% in infants >6 months) or absolute MAP values (<35 mmHg in infants <6 months, <43 mmHg in infants >6 months). The incidences of hypotension using the two definitions were compared. Awake BP values were obtained in 85% of the patients. Calm patients were more likely to allow their BP to be measured than anxious patients. Anxious patients had higher preinduction MAP values than calm patients. The relative BP approach resulted in a higher incidence of postinduction hypotension than using absolute BP values. Awake BP values were unobtainable in 15% of our patients, resulting in the necessity to define hypotension under anesthesia using absolute BP values. Definitions of hypotension using either absolute MAP or values relative to awake baseline are not interchangeable. © 2017 John Wiley & Sons Ltd.

  14. Dynamic resting state functional connectivity in awake and anesthetized rodents.

    PubMed

    Liang, Zhifeng; Liu, Xiao; Zhang, Nanyin

    2015-01-01

    Since its introduction, resting-state functional magnetic resonance imaging (rsfMRI) has been a powerful tool for investigating functional neural networks in both normal and pathological conditions. When measuring resting-state functional connectivity (RSFC), most rsfMRI approaches do not consider its temporal variations and thus only provide the averaged RSFC over the scan time. Recently, there has been a surge of interest to investigate the dynamic characteristics of RSFC in humans, and promising results have been yielded. However, our knowledge regarding the dynamic RSFC in animals remains sparse. In the present study we utilized the single-volume co-activation method to systematically study the dynamic properties of RSFC within the networks of infralimbic cortex (IL) and primary somatosensory cortex (S1) in both awake and anesthetized rats. Our data showed that both IL and S1 networks could be decomposed into several spatially reproducible but temporally changing co-activation patterns (CAPs), suggesting that dynamic RSFC was indeed a characteristic feature in rodents. In addition, we demonstrated that anesthesia profoundly impacted the dynamic RSFC of neural circuits subserving cognitive and emotional functions but had less effects on sensorimotor systems. Finally, we examined the temporal characteristics of each CAP, and found that individual CAPs exhibited consistent temporal evolution patterns. Together, these results suggest that dynamic RSFC might be a general phenomenon in vertebrate animals. In addition, this study has paved the way for further understanding the alterations of dynamic RSFC in animal models of brain disorders.

  15. Intrinsic connectivity of neural networks in the awake rabbit.

    PubMed

    Schroeder, Matthew P; Weiss, Craig; Procissi, Daniel; Disterhoft, John F; Wang, Lei

    2016-04-01

    The way in which the brain is functionally connected into different networks has emerged as an important research topic in order to understand normal neural processing and signaling. Since some experimental manipulations are difficult or unethical to perform in humans, animal models are better suited to investigate this topic. Rabbits are a species that can undergo MRI scanning in an awake and conscious state with minimal preparation and habituation. In this study, we characterized the intrinsic functional networks of the resting New Zealand White rabbit brain using BOLD fMRI data. Group independent component analysis revealed seven networks similar to those previously found in humans, non-human primates and/or rodents including the hippocampus, default mode, cerebellum, thalamus, and visual, somatosensory, and parietal cortices. For the first time, the intrinsic functional networks of the resting rabbit brain have been elucidated demonstrating the rabbit's applicability as a translational animal model. Without the confounding effects of anesthetics or sedatives, future experiments may employ rabbits to understand changes in neural connectivity and brain functioning as a result of experimental manipulation (e.g., temporary or permanent network disruption, learning-related changes, and drug administration).

  16. Spontaneous cortical activity in awake monkeys composed of neuronal avalanches.

    PubMed

    Petermann, Thomas; Thiagarajan, Tara C; Lebedev, Mikhail A; Nicolelis, Miguel A L; Chialvo, Dante R; Plenz, Dietmar

    2009-09-15

    Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems--tissue cultures, acute slices, and anesthetized rats--show that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studies suggest that networks with this property are poised at a critical state that optimizes input processing, information storage, and transfer, but the relevance of avalanches for fully functional cerebral systems has been controversial. Here we show that ongoing cortical synchronization in awake rhesus monkeys carries the signature of neuronal avalanches. Negative LFP deflections (nLFPs) correlate with neuronal spiking and increase in amplitude with increases in local population spike rate and synchrony. These nLFPs form neuronal avalanches that are scale-invariant in space and time and with respect to the threshold of nLFP detection. This dimension, threshold invariance, describes a fractal organization: smaller nLFPs are embedded in clusters of larger ones without destroying the spatial and temporal scale-invariance of the dynamics. These findings suggest an organization of ongoing cortical synchronization that is scale-invariant in its three fundamental dimensions--time, space, and local neuronal group size. Such scale-invariance has ontogenetic and phylogenetic implications because it allows large increases in network capacity without a fundamental reorganization of the system.

  17. Spontaneous cortical activity in awake monkeys composed of neuronal avalanches

    PubMed Central

    Petermann, Thomas; Thiagarajan, Tara C.; Lebedev, Mikhail A.; Nicolelis, Miguel A. L.; Chialvo, Dante R.; Plenz, Dietmar

    2009-01-01

    Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems—tissue cultures, acute slices, and anesthetized rats—show that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studies suggest that networks with this property are poised at a critical state that optimizes input processing, information storage, and transfer, but the relevance of avalanches for fully functional cerebral systems has been controversial. Here we show that ongoing cortical synchronization in awake rhesus monkeys carries the signature of neuronal avalanches. Negative LFP deflections (nLFPs) correlate with neuronal spiking and increase in amplitude with increases in local population spike rate and synchrony. These nLFPs form neuronal avalanches that are scale-invariant in space and time and with respect to the threshold of nLFP detection. This dimension, threshold invariance, describes a fractal organization: smaller nLFPs are embedded in clusters of larger ones without destroying the spatial and temporal scale-invariance of the dynamics. These findings suggest an organization of ongoing cortical synchronization that is scale-invariant in its three fundamental dimensions—time, space, and local neuronal group size. Such scale-invariance has ontogenetic and phylogenetic implications because it allows large increases in network capacity without a fundamental reorganization of the system. PMID:19717463

  18. WIDE AWAKE mediates the circadian timing of sleep onset.

    PubMed

    Liu, Sha; Lamaze, Angelique; Liu, Qili; Tabuchi, Masashi; Yang, Yong; Fowler, Melissa; Bharadwaj, Rajnish; Zhang, Julia; Bedont, Joseph; Blackshaw, Seth; Lloyd, Thomas E; Montell, Craig; Sehgal, Amita; Koh, Kyunghee; Wu, Mark N

    2014-04-02

    How the circadian clock regulates the timing of sleep is poorly understood. Here, we identify a Drosophila mutant, wide awake (wake), that exhibits a marked delay in sleep onset at dusk. Loss of WAKE in a set of arousal-promoting clock neurons, the large ventrolateral neurons (l-LNvs), impairs sleep onset. WAKE levels cycle, peaking near dusk, and the expression of WAKE in l-LNvs is Clock dependent. Strikingly, Clock and cycle mutants also exhibit a profound delay in sleep onset, which can be rescued by restoring WAKE expression in LNvs. WAKE interacts with the GABAA receptor Resistant to Dieldrin (RDL), upregulating its levels and promoting its localization to the plasma membrane. In wake mutant l-LNvs, GABA sensitivity is decreased and excitability is increased at dusk. We propose that WAKE acts as a clock output molecule specifically for sleep, inhibiting LNvs at dusk to promote the transition from wake to sleep. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Functional Connectivity Hubs and Networks in the Awake Marmoset Brain

    PubMed Central

    Belcher, Annabelle M.; Yen, Cecil Chern-Chyi; Notardonato, Lucia; Ross, Thomas J.; Volkow, Nora D.; Yang, Yihong; Stein, Elliot A.; Silva, Afonso C.; Tomasi, Dardo

    2016-01-01

    In combination with advances in analytical methods, resting-state fMRI is allowing unprecedented access to a better understanding of the network organization of the brain. Increasing evidence suggests that this architecture may incorporate highly functionally connected nodes, or “hubs”, and we have recently proposed local functional connectivity density (lFCD) mapping to identify highly-connected nodes in the human brain. Here, we imaged awake nonhuman primates to test whether, like the human brain, the marmoset brain contains FC hubs. Ten adult common marmosets (Callithrix jacchus) were acclimated to mild, comfortable restraint using individualized helmets. Following restraint training, resting BOLD data were acquired during eight consecutive 10 min scans for each subject. lFCD revealed prominent cortical and subcortical hubs of connectivity across the marmoset brain; specifically, in primary and secondary visual cortices (V1/V2), higher-order visual association areas (A19M/V6[DM]), posterior parietal and posterior cingulate areas (PGM and A23b/A31), thalamus, dorsal and ventral striatal areas (caudate, putamen, lateral septal nucleus, and anterior cingulate cortex (A24a). lFCD hubs were highly connected to widespread areas of the brain, and further revealed significant network-network interactions. These data provide a baseline platform for future investigations in a nonhuman primate model of the brain’s network topology. PMID:26973476

  20. Carotid endarterectomy in awake patients: safety, tolerability and results

    PubMed Central

    Mendonça, Célio Teixeira; Fortunato Jr, Jerônimo A.; de Carvalho, Cláudio A.; Weingartner, Janaina; Filho, Otávio R. M.; Rezende, Felipe F.; Bertinato, Luciane P.

    2014-01-01

    Objective To analyze the results of 125 carotid endarterectomies under loco-regional anesthesia, with selective use of shunt and bovine pericardium patch. Methods One hundred and seventeen patients with stenosis ≥ 70% in the internal carotid artery on duplex-scan + arteriography or magnetic resonance angiography underwent 125 carotid endarterectomies. Intraoperative pharmacological cerebral protection included intravenous administration of alfentanil and dexametasone. Clopidogrel, aspirin and statins were used in all cases. Seventy-seven patients were males (65.8%). Mean age was 70.8 years, ranging from 48 to 88 years. Surgery was performed to treat symptomatic stenosis in 69 arteries (55.2%) and asymptomatic stenosis in 56 arteries (44.8%). Results A carotid shunt was used in 3 cases (2.4%) due to signs and symptoms of cerebral ischemia after carotid artery clamping during the operation, and all 3 patients had a good outcome. Bovine pericardium patch was used in 71 arteries ≤ 6 mm in diameter (56.8%). Perioperative mortality was 0.8%: one patient died from a myocardial infarction. Two patients (1.6%) had minor ipsilateral strokes with good recovery, and 2 patients (1.6%) had non-fatal myocardial infarctions with good recovery. The mean follow-up period was 32 months. In the late postoperative period, there was restenosis in only three arteries (2.4%). Conclusion Carotid artery endarterectomy can be safely performed in the awake patient, with low morbidity and mortality rates. PMID:25714212

  1. Dynamic Resting State Functional Connectivity in Awake and Anesthetized Rodents

    PubMed Central

    Liang, Zhifeng; Liu, Xiao; Zhang, Nanyin

    2014-01-01

    Since its introduction, resting-state functional magnetic resonance imaging (rsfMRI) has been a powerful tool for investigating functional neural networks in both normal and pathological conditions. When measuring resting-state functional connectivity (RSFC), most rsfMRI approaches do not consider its temporal variations and thus only provide the averaged RSFC over the scan time. Recently, there has been a surge of interest to investigate the dynamic characteristics of RSFC in humans, and promising results have been yielded. However, our knowledge regarding the dynamic RSFC in animals remains sparse. In the present study we utilized the single-volume coactivation method to systematically study the dynamic properties of RSFC within the networks of infralimbic cortex (IL) and primary somatosensory cortex (S1) in both awake and anesthetized rats. Our data showed that both IL and S1 networks could be decomposed into several spatially reproducible but temporally changing co-activation patterns (CAPs), suggesting that dynamic RSFC was indeed a characteristic feature in rodents. In addition, we demonstrated that anesthesia profoundly impacted the dynamic RSFC of neural circuits subserving cognitive and emotional functions but had less effects on sensorimotor systems. Finally, we examined the temporal characteristics of each CAP, and found that individual CAPs exhibited consistent temporal evolution patterns. Together, these results suggest that dynamic RSFC might be a general phenomenon in vertebrate animals. In addition, this study has paved the way for further understanding the alterations of dynamic RSFC in animal models of brain disorders. PMID:25315787

  2. Spectral context affects temporal processing in awake auditory cortex

    PubMed Central

    Beitel, Ralph E.; Vollmer, Maike; Heiser, Marc A; Schreiner, Christoph E.

    2013-01-01

    Amplitude modulation encoding is critical for human speech perception and complex sound processing in general. The modulation transfer function (MTF) is a staple of auditory psychophysics, and has been shown to predict speech intelligibility performance in a range of adverse listening conditions and hearing impairments, including cochlear implant-supported hearing. Although both tonal and broadband carriers have been employed in psychophysical studies of modulation detection and discrimination, relatively little is known about differences in the cortical representation of such signals. We obtained MTFs in response to sinusoidal amplitude modulation (SAM) for both narrowband tonal carriers and 2-octave bandwidth noise carriers in the auditory core of awake squirrel monkeys. MTFs spanning modulation frequencies from 4 to 512 Hz were obtained using 16 channel linear recording arrays sampling across all cortical laminae. Carrier frequency for tonal SAM and center frequency for noise SAM was set at the estimated best frequency for each penetration. Changes in carrier type affected both rate and temporal MTFs in many neurons. Using spike discrimination techniques, we found that discrimination of modulation frequency was significantly better for tonal SAM than for noise SAM, though the differences were modest at the population level. Moreover, spike trains elicited by tonal and noise SAM could be readily discriminated in most cases. Collectively, our results reveal remarkable sensitivity to the spectral content of modulated signals, and indicate substantial interdependence between temporal and spectral processing in neurons of the core auditory cortex. PMID:23719811

  3. From viscous to elastic sheets: Dynamics of smectic freely floating films

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; Harth, Kirsten; May, Kathrin; Trittel, Torsten

    The dynamics of droplets and bubbles, particularly on microscopic scales, are of considerable importance in biological, environmental, and technical contexts. Soap bubbles, vesicles and components of biological cells are well known examples where the dynamic behavior is significantly influenced by the properties of thin membranes enclosed by fluids. Two-dimensional membrane motions couple to 3D shape transformations. Smectic liquid crystal mesogens form phases with internal molecular layer order. Free-standing films are easily prepared from this class of materials. They represent simple model systems for membrane dynamics and pattern formation in a quasi two-dimensional fluid. These films are usually spanned over a frame, and they can be inflated to bubbles on a support. Recently, closed microscopic shells of liquid-crystalline materials suspended in an outer fluid without contact to a solid support have been introduced and studied. With a special technique, we prepare millimetre to centimetre sized smectic bubbles in air (similar to soap bubbles). Their distinct feature is the fact that any change of surface area is coupled to a restructuring of the layers in the membrane. High-speed cameras are used to observe the shape transformations of freely floating bubbles from a distorted initial shape to a sphere. Bursting dynamics are recorded and compared to models. Most strikingly, an unpreceded cross-over from inviscid to viscous and elastic behaviour with increasing thickness of the membrane is found: Whereas thin bubbles behave almost like inviscid fluids, the relaxation dynamics slows down considerably for larger film thicknesses. Surface wrinkling and formation of extrusions are observed. We will present a characterization and an expalantion for the above phenomena.

  4. Can crystals tell us how whole arcs behave?

    NASA Astrophysics Data System (ADS)

    Davidson, J. P.; Ginibre, C.; Tepley, F. J.

    2011-12-01

    Not entirely. But crystals are invaluable archives of information on how individual magma systems behave. We can now tease out information on the evolutionary histories of a magma system by examining core-rim elemental and isotopic profiles in the context of their textures. Magmatic processes can now be distinguished with some confidence; closed system (fractional) crystallisation is characterised by normal zoning, idiomorphic growth and constant radiogenic isotope ratios, whereas open system contamination, on the face of it similar, is accompanied by varying isotope ratios. Recharge events are not only marked by an abrupt change in isotopic and elemental composition, but also a textural fingerprint, typically a resorption surface, reflecting the instantaneous thermal and chemical disequilibrium consequent to recharge. Plagioclase crystals from the El Chichon 1980 eruption are characterised by several internal dissolution surfaces, which correlate with core-to-rim abrupt drops in 87Sr/86Sr. These are interpreted as reflecting recharge by a primitive magma of magma undergoing progressive fractionation and contamination. Given typical reported plagioclase growth rates, the spacing of these dissolution surfaces corresponds to ~600 years, which is the average eruption frequency of El Chichon in recent times. Recharge, recorded in the crystal archives, may then be the trigger for eruption. Plagioclase crystals from Parinacota Volcano, Central Andes, have yielded an extraordinarily detailed archive of information about magma evolution. Different stages of magmatism through time correspond to different crystal records - i.e. during each recognisable stratigraphic stage magmatic processes were distinct. At least two parental mafic magmas are recognised, with evolution involving mixing/ recharge and contamination. The most detailed core-rim records have actually been inverted according to EC-RAFC models to yield information about contaminant, and contamination rate. In

  5. The near wake of a freely flying European starling

    NASA Astrophysics Data System (ADS)

    Kirchhefer, Adam J.; Kopp, Gregory A.; Gurka, Roi

    2013-05-01

    The wake of a freely flying European starling (Sturnus vulgaris) has been measured using high speed, time-resolved, particle image velocimetry, simultaneously with high speed cameras which imaged the bird. These have been used to generate vector maps that can be associated with the bird's location and wing configuration in the wind tunnel. Time series of measurements have been expressed as composite wake plots which depict segments of the wing beat cycle for various spanwise locations in the wake. Measurements indicate that downwash is not produced during the upstroke, suggesting that the upstroke does not generate lift. As well, the wake velocities imply the presence of streamwise vortical structures, in addition to tip vortices. These two characteristics indicate similarities between the wake of a bird and the wake of a bat, which may be general features of the wakes of flapping wings.

  6. ``Reverse'' Lock-in Regime on a Freely Oscillating Cylinder

    NASA Astrophysics Data System (ADS)

    Atsavapranee, P.; Voorhees, A. V.; Benaroya, H.; Wei, T.

    1998-11-01

    DPIV and flow visualizations were used to characterize the flow in the near wake of a freely oscillating cylinder. A rigid cylinder with a low mass ratio was fixed at one end to a leaf spring and free to oscillate, pendulum-like, at the other end in the cross stream plane. It was found that only a subset of the synchronization range follows the behavior of a ``classical'' lock-in, i.e., when the difference between the natural Strouhal frequency and the natural frequency of the cylinder is small enough, vortex shedding frequency deviates from the linear Strouhal dependence and follows instead the cylinder natural frequency. However, over a range of flow speed in which the response amplitude of the cylinder is significant, it was found that the frequency of oscillation and of vortex shedding follow instead the natural Strouhal frequency, instead of the mechanical natural frequency.

  7. Intersegmental coupling and recovery from perturbations in freely running cockroaches.

    PubMed

    Couzin-Fuchs, Einat; Kiemel, Tim; Gal, Omer; Ayali, Amir; Holmes, Philip

    2015-01-15

    Cockroaches are remarkably stable runners, exhibiting rapid recovery from external perturbations. To uncover the mechanisms behind this important behavioral trait, we recorded leg kinematics of freely running animals in both undisturbed and perturbed trials. Functional coupling underlying inter-leg coordination was monitored before and during localized perturbations, which were applied to single legs via magnetic impulses. The resulting transient effects on all legs and the recovery times to normal pre-perturbation kinematics were studied. We estimated coupling architecture and strength by fitting experimental data to a six-leg-unit phase oscillator model. Using maximum-likelihood techniques, we found that a network with nearest-neighbor inter-leg coupling best fitted the data and that, although coupling strengths vary among preparations, the overall inputs entering each leg are approximately balanced and consistent. Simulations of models with different coupling strengths encountering perturbations suggest that the coupling schemes estimated from our experiments allow animals relatively fast and uniform recoveries from perturbations.

  8. 3D Synthetic Aperture PIV of a Freely Swimming Fish

    NASA Astrophysics Data System (ADS)

    Mendelson, Leah; Techet, Alexandra

    2012-11-01

    Fish owe much of their locomotive success to complex body geometries and wake interactions that cannot be fully characterized by planar experimental techniques including 2D PIV. Volumetric methods are valuable to illustrate and quantify these features, thus providing new insights for bioinspired design. In particular, synthetic aperture particle image velocimetry (SAPIV) uses light field imaging algorithms to reconstruct a 3D particle field which can then be analyzed using a 3D cross-correlation. Previous studies have shown that this technique is able to resolve all three velocity components on the same order length scale and to see around partial occlusions, such as a caudal fin, through the use of multiple cameras. To harness these capabilities for biomimetic use, SAPIV is used to depict the three-dimensional velocity field and vortical structures surrounding a freely swimming Giant danio (Devario aequipinnatus) during straight swims and turning maneuvers.

  9. Structure, Hydrodynamics, and Phase Transition of Freely Suspended Liquid Crystals

    NASA Technical Reports Server (NTRS)

    Clark, Noel A.

    2000-01-01

    Smectic liquid crystals are phases of rod shaped molecules organized into one dimensionally (1D) periodic arrays of layers, each layer being between one and two molecular lengths thick. In the least ordered smectic phases, the smectics A and C, each layer is a two dimensional (2D) liquid. Additionally there are a variety of more ordered smectic phases having hexatic short range translational order or 2D crystalline quasi long range translational order within the layers. The inherent fluid-layer structure and low vapor pressure of smectic liquid crystals enable the long term stabilization of freely suspended, single component, layered fluid films as thin as 30A, a single molecular layer. The layering forces the films to be an integral number of smectic layers thick, quantizing their thickness in layer units and forcing a film of a particular number of layers to be physically homogeneous with respect to its layer structure over its entire area. Optical reflectivity enables the precise determination of the number of layers. These ultrathin freely suspended liquid crystal films are structures of fundamental interest in condensed matter and fluid physics. They are the thinnest known stable condensed phase fluid structures and have the largest surface-to-volume ratio of any stable fluid preparation, making them ideal for the study of the effects of reduced dimensionality on phase behavior and on fluctuation and interface phenomena. Their low vapor pressure and quantized thickness enable the effective use of microgravity to extend the study of basic capillary phenomena to ultrathin fluid films. Freely suspended films have been a wellspring of new liquid crystal physics. They have been used to provide unique experimental conditions for the study of condensed phase transitions in two dimensions. They are the only system in which the hexatic has been unambiguously identified as a phase of matter, and the only physical system in which fluctuations of a 2D XY system and

  10. Two-dimensional microrheology of freely suspended liquid crystal films.

    PubMed

    Eremin, A; Baumgarten, S; Harth, K; Stannarius, R; Nguyen, Z H; Goldfain, A; Park, C S; Maclennan, J E; Glaser, M A; Clark, N A

    2011-12-23

    Smectic liquid crystals form freely-suspended, fluid films of highly uniform structure and thickness, making them ideal systems for studies of hydrodynamics in two dimensions. We have measured particle mobility and shear viscosity by direct observation of the gravitational drift of silica spheres and smectic islands included in these fluid membranes. In thick films, we observe a hydrodynamic regime dominated by lateral confinement effects, with the mobility of the inclusion determined predominantly by coupling of the fluid flow to the fixed boundaries of the film. In thin films, the mobility of inclusions is governed primarily by coupling of the fluid to the surrounding air, as predicted by Saffman-Delbrück theory.

  11. Awake craniotomy induces fewer changes in the plasma amino acid profile than craniotomy under general anesthesia.

    PubMed

    Hol, Jaap W; Klimek, Markus; van der Heide-Mulder, Marieke; Stronks, Dirk; Vincent, Arnoud J; Klein, Jan; Zijlstra, Freek J; Fekkes, Durk

    2009-04-01

    In this prospective, observational, 2-armed study, we compared the plasma amino acid profiles of patients undergoing awake craniotomy to those undergoing craniotomy under general anesthesia. Both experimental groups were also compared with a healthy, age-matched and sex-matched reference group not undergoing surgery. It is our intention to investigate whether plasma amino acid levels provide information about physical and emotional stress, as well as pain during awake craniotomy versus craniotomy under general anesthesia. Both experimental groups received preoperative, perioperative, and postoperative dexamethasone. The plasma levels of 20 amino acids were determined preoperative, perioperative, and postoperatively in all groups and were correlated with subjective markers for pain, stress, and anxiety. In both craniotomy groups, preoperative levels of tryptophan and valine were significantly decreased whereas glutamate, alanine, and arginine were significantly increased relative to the reference group. Throughout time, tryptophan levels were significantly lower in the general anesthesia group versus the awake craniotomy group. The general anesthesia group had a significantly higher phenylalanine/tyrosine ratio, which may suggest higher oxidative stress, than the awake group throughout time. Between experimental groups, a significant increase in large neutral amino acids was found postoperatively in awake craniotomy patients, pain was also less and recovery was faster. A significant difference in mean hospitalization time was also found, with awake craniotomy patients leaving after 4.53+/-2.12 days and general anesthesia patients after 6.17+/-1.62 days; P=0.012. This study demonstrates that awake craniotomy is likely to be physically and emotionally less stressful than general anesthesia and that amino acid profiling holds promise for monitoring postoperative pain and recovery.

  12. The biology of habitat dominance; can microbes behave as weeds?

    PubMed

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-09-01

    Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These 'microbial weeds' are able to dominate the communities that develop in fertile but uncolonized--or at least partially vacant--habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi. Some microbes

  13. The biology of habitat dominance; can microbes behave as weeds?

    PubMed Central

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-01-01

    Summary Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These ‘microbial weeds’ are able to dominate the communities that develop in fertile but uncolonized – or at least partially vacant – habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi

  14. Pharmacokinetics and pharmacodynamics of 4-aminopyridine in awake guinea pigs.

    PubMed

    Capacio, B R; Chang, F C; Spriggs, D; Byers, C E; Matthews, R L; Benton, B J

    1997-08-01

    The selective blockade of potassium channels on excitable membranes by 4-aminopyridine (4-AP) leads to facilitation of neurotransmitter release at a wide variety of synapses. This compound has been shown to be efficacious against lethality induced by saxitoxin (STX) and tetrodotoxin (TTX) in guinea pigs. To characterize the actions of 4-AP in guinea pigs we have investigated its pharmacokinetics (PK) and pharmacodynamics following a 2 mg/kg, intramuscular (im) dose in awake chronically instrumented (IN) animals. Animals were chronically instrumented for electrophysiologic recordings of diaphragmatic electromyogram (DEMG), lead II electrocardiogram (ECGII) and electrocorticogram (ECoG). Also, PK studies were carried out in uninstrumented (UN) guinea pigs. Blood and electrophysiologic data were collected at predetermined time intervals up to 4 hours post 4-AP administration. High performance liquid chromatography was used to determine plasma 4-AP concentrations. For IN and UN animals, plasma concentration-time data best fit a one-compartment model, and PK parameter estimates were similar for both groups. Peak plasma levels were found to occur between 16 and 17 min, and the half-lives of elimination were 65 and 71 min for IN and UN animals respectively. Heart and respiratory rates were elevated as early as 5 and 15 min respectively in response to 4-AP administration. The duration of action was approximately 1-1.5 half-lives of elimination beyond peak plasma levels. Maximum ECoG responses were observed between 12-15 min after 4-AP injection; some residual drug effects were still apparent at 240 min. The difference between the heart and respiratory rates and ECoG profiles suggests that these different physiological systems respond with varying degrees of sensitivity to plasma 4-AP concentrations. The stimulation of these systems is consistent with the action of 4-AP in reversing STX- and TTX-induced cardiorespiratory depression and decreased ECoG power in guinea pigs.

  15. Stability of thalamocortical synaptic transmission across awake brain states

    PubMed Central

    Stoelzel, Carl R.; Bereshpolova, Yulia; Swadlow, Harvey A.

    2009-01-01

    Sensory cortical neurons are highly sensitive to brain state, with many neurons showing changes in spatial and/or temporal response properties and some neurons becoming virtually unresponsive when subjects are not alert. While some of these changes are undoubtedly due to state-related filtering at the thalamic level, another likely source of such effects is the thalamocortical (TC) synapse, where activation of nicotinic receptors on TC terminals have been shown to enhance synaptic transmission in vitro. However, monosynaptic TC synaptic transmission has not been directly examined during different states of alertness. Here, in awake rabbits that shifted between alert and non-alert EEG states, we examined the monosynaptic TC responses and short-term synaptic dynamics generated by spontaneous impulses of single visual and somatosensory TC neurons. We did this using spike-triggered current source density analysis, an approach that enables assessment of monosynaptic extracellular currents generated in different cortical layers by impulses of single TC afferents. Spontaneous firing rates of TC neurons were higher, and burst rates were much lower in the alert state. However, we found no state-related changes in the amplitude of monosynaptic TC responses when TC spikes with similar preceding interspike interval were compared. Moreover, the relationship between the preceding interspike interval of the TC spike and postsynaptic response amplitude was not influenced by state. These data indicate that TC synaptic transmission and dynamics are highly conserved across different states of alertness and that observed state-related changes in receptive field properties that occur at the cortical level result from other mechanisms. PMID:19474312

  16. Mapping the connectome in awake surgery for gliomas: an update.

    PubMed

    Duffau, Hugues

    2017-03-06

    The traditional principle underlying oncological neurosurgery is to remove a tumor mass displacing the brain in order to increase survival. Recently, advances in connectomics enabled an improved understanding of cerebral processing, and led to a paradigmatic shift in tumor surgery based upon interactions between neurooncology and cognitive neurosciences. First, glioma is not a focal tumor invaginated within the parenchyma but a diffuse neoplastic disease migrating in the brain. This concept resulted in a new surgical ideology, i.e., to maximally resect the invaded nervous system on the condition that eloquent neural networks are spared. Second, this led to determine what structures are crucial to preserve the quality of life (QoL) versus those that can be compensated by means of neuroplasticity. Because limitations of functional remodelling are mainly represented by the subcortical connectivity, mapping the connectome during surgery is a priority. Neurosurgeons have to switch from an image-guided surgery to a functional mapping-guided resection, namely, from a technological guidance into the operating theater to a philosophy based on the investigation of the dynamics of delocalized neural circuits throughout resection. Indeed, awake mapping with real-time monitoring of sensorimotor, visuospatial, language, executive and behavioral functions allowed an optimization of the onco-functional balance. Third, surgery should not be seen in isolation, but integrated in a global multistep therapeutic management, especially in low- grade gliomas, opening the window to repeat resections thanks to the potential of remapping over years. Such a "cognitive neurooncological surgery" which aims to improve both QoL and survival must become a "connectomal neurosurgery".

  17. Modulation-Frequency-Specific Adaptation in Awake Auditory Cortex

    PubMed Central

    Beitel, Ralph E.; Vollmer, Maike; Heiser, Marc A.; Schreiner, Christoph E.

    2015-01-01

    Amplitude modulations are fundamental features of natural signals, including human speech and nonhuman primate vocalizations. Because natural signals frequently occur in the context of other competing signals, we used a forward-masking paradigm to investigate how the modulation context of a prior signal affects cortical responses to subsequent modulated sounds. Psychophysical “modulation masking,” in which the presentation of a modulated “masker” signal elevates the threshold for detecting the modulation of a subsequent stimulus, has been interpreted as evidence of a central modulation filterbank and modeled accordingly. Whether cortical modulation tuning is compatible with such models remains unknown. By recording responses to pairs of sinusoidally amplitude modulated (SAM) tones in the auditory cortex of awake squirrel monkeys, we show that the prior presentation of the SAM masker elicited persistent and tuned suppression of the firing rate to subsequent SAM signals. Population averages of these effects are compatible with adaptation in broadly tuned modulation channels. In contrast, modulation context had little effect on the synchrony of the cortical representation of the second SAM stimuli and the tuning of such effects did not match that observed for firing rate. Our results suggest that, although the temporal representation of modulated signals is more robust to changes in stimulus context than representations based on average firing rate, this representation is not fully exploited and psychophysical modulation masking more closely mirrors physiological rate suppression and that rate tuning for a given stimulus feature in a given neuron's signal pathway appears sufficient to engender context-sensitive cortical adaptation. PMID:25878263

  18. Modulation-frequency-specific adaptation in awake auditory cortex.

    PubMed

    Malone, Brian J; Beitel, Ralph E; Vollmer, Maike; Heiser, Marc A; Schreiner, Christoph E

    2015-04-15

    Amplitude modulations are fundamental features of natural signals, including human speech and nonhuman primate vocalizations. Because natural signals frequently occur in the context of other competing signals, we used a forward-masking paradigm to investigate how the modulation context of a prior signal affects cortical responses to subsequent modulated sounds. Psychophysical "modulation masking," in which the presentation of a modulated "masker" signal elevates the threshold for detecting the modulation of a subsequent stimulus, has been interpreted as evidence of a central modulation filterbank and modeled accordingly. Whether cortical modulation tuning is compatible with such models remains unknown. By recording responses to pairs of sinusoidally amplitude modulated (SAM) tones in the auditory cortex of awake squirrel monkeys, we show that the prior presentation of the SAM masker elicited persistent and tuned suppression of the firing rate to subsequent SAM signals. Population averages of these effects are compatible with adaptation in broadly tuned modulation channels. In contrast, modulation context had little effect on the synchrony of the cortical representation of the second SAM stimuli and the tuning of such effects did not match that observed for firing rate. Our results suggest that, although the temporal representation of modulated signals is more robust to changes in stimulus context than representations based on average firing rate, this representation is not fully exploited and psychophysical modulation masking more closely mirrors physiological rate suppression and that rate tuning for a given stimulus feature in a given neuron's signal pathway appears sufficient to engender context-sensitive cortical adaptation. Copyright © 2015 the authors 0270-6474/15/355904-13$15.00/0.

  19. Orexin microinjection in the medullary raphe increases heart rate and arterial pressure but does not reduce tail skin blood flow in the awake rat.

    PubMed

    Luong, L N L; Carrive, P

    2012-01-27

    The rostral medullary raphe region is an important target of hypothalamic orexin neurons; however, little is known of the effect of orexin in this key autonomic and somatic premotor region. Here we tested the effect of orexin-A (3 and 30 pmol) microinjected in the medullary raphe, on heart rate (HR), mean arterial pressure (MAP), tail skin blood flow, body temperature, and behavior in freely moving, awake rats. HR, MAP, and body activity were recorded by radio-telemetry. Changes in tail skin blood flow and body temperature, as well as potential interscapular brown adipose tissue thermogenesis were recorded indirectly by infrared thermography of the skin of the tail, lumbosacral back, and interscapular back areas, respectively. Compared with saline, orexin-A (30 pmol) evoked significant and long lasting increases in HR (+99 bpm), MAP (+11 mmHg), and body activity (grooming, not locomotor activity). However, it did not reduce tail skin blood flow more than saline, and there was no significant increase in body temperature. A small, though significant, thermogenic effect was observed in the interscapular region, but this effect is more likely to have originated from activity in neck and shoulder muscles than brown adipose tissue. Thus, orexin projections to the rostral medullary raphe can mediate significant cardiovascular changes, but does not seem to affect tail skin vasomotor tone or brown adipose tissue in the awake rat. This important brainstem relay may contribute to the cardiovascular changes evoked by arousal and various forms of stress that are associated with activation of orexin neurons.

  20. Large-scale brain networks in the awake, truly resting marmoset monkey.

    PubMed

    Belcher, Annabelle M; Yen, Cecil C; Stepp, Haley; Gu, Hong; Lu, Hanbing; Yang, Yihong; Silva, Afonso C; Stein, Elliot A

    2013-10-16

    Resting-state functional MRI is a powerful tool that is increasingly used as a noninvasive method for investigating whole-brain circuitry and holds great potential as a possible diagnostic for disease. Despite this potential, few resting-state studies have used animal models (of which nonhuman primates represent our best opportunity of understanding complex human neuropsychiatric disease), and no work has characterized networks in awake, truly resting animals. Here we present results from a small New World monkey that allows for the characterization of resting-state networks in the awake state. Six adult common marmosets (Callithrix jacchus) were acclimated to light, comfortable restraint using individualized helmets. Following behavioral training, resting BOLD data were acquired during eight consecutive 10 min scans for each conscious subject. Group independent component analysis revealed 12 brain networks that overlap substantially with known anatomically constrained circuits seen in the awake human. Specifically, we found eight sensory and "lower-order" networks (four visual, two somatomotor, one cerebellar, and one caudate-putamen network), and four "higher-order" association networks (one default mode-like network, one orbitofrontal, one frontopolar, and one network resembling the human salience network). In addition to their functional relevance, these network patterns bear great correspondence to those previously described in awake humans. This first-of-its-kind report in an awake New World nonhuman primate provides a platform for mechanistic neurobiological examination for existing disease models established in the marmoset.

  1. Awake Measures of Nasal Resistance and Upper Airway Resistance on CPAP during Sleep

    PubMed Central

    Masdeu, Maria J.; Seelall, Vijay; Patel, Amit V.; Ayappa, Indu; Rapoport, David M.

    2011-01-01

    Study Objectives: Since on CPAP, the nose is the primary determinant of upper airway resistance, we assess utility of noninvasive measures of nasal resistance during wakefulness as a predictor of directly assessed upper airway resistance on CPAP during sleep in patients with obstructive sleep apnea/hypopnea syndrome. Methods: Patients with complaints of snoring and excessive daytime sleepiness were recruited. 14 subjects underwent daytime evaluations including clinical assessment, subjective questionnaires to assess nasal symptoms and evaluation of nasal resistance with acoustic rhinometry (AR) and active anterior rhinomanometry (RM) in the sitting and supine positions. Patients underwent nocturnal polysomnography on optimal CPAP with measurements of supraglottic pressure to evaluate upper airway resistance. Comparisons were made between nasal resistance using AR and RM during wakefulness, and between AR and RM awake and upper airway resistance during sleep. Results: Our study shows that measures of awake nasal resistance using AR and RM had little or no correlation to each other in the sitting position, whereas there was significant but weak correlation in the supine position. Upper airway resistance measured while on CPAP during sleep did not show significant relationships to any of the awake measures of nasal resistance (AR or RM). Conclusion: Awake measurements of nasal resistance do not seem to be predictive of upper airway resistance during sleep on CPAP. Citation: Masdeu MJ; Seelall V; Patel AV; Ayappa I; Rapoport DM. Awake Measures of Nasal Resistance and Upper Airway Resistance on CPAP during Sleep. J Clin Sleep Med 2011;7(1):31-40. PMID:21344056

  2. Factors determining success of awake and asleep magnetic resonance imaging scans in nonsedated children.

    PubMed

    Vannest, Jennifer; Rajagopal, Akila; Cicchino, Nicole D; Franks-Henry, Julie; Simpson, Sarah M; Lee, Gregory; Altaye, Mekibib; Sroka, Claire; Holland, Scott K

    2014-12-01

    Effective techniques that allow children to complete magnetic resonance imaging (MRI) scans without sedation are high priority for the imaging community. We used behavioral approaches to scan 64 sleeping infants and toddlers younger than 4 years, and 156 awake children aged 2.5 to 18 years, for a neuroimaging research protocol. Infants and their families participated in a desensitization protocol for several days, then scanning was performed at the child's bedtime during natural sleep. For awake young children, a behavioral protocol was used that included tangible reinforcers, exploration of the scanner environment and a brief practice session. Two scan sessions were targeted for awake children. Success rates by participant were quantified in terms of the proportion of requisite scans in each session that were successfully acquired. The average success rate in sleeping infants and toddlers was 0.461. For awake children aged 2.5 to 6 years, success rates for each session were 0.739 and 0.847. For children aged 7 years and older, success rates were over 0.900 for both the sessions. Overall, though success was lower later in a scan session for both sleeping infants and awake young children, our results demonstrate that it is feasible to collect high-quality imaging data using standard imaging sequences in infants and children without sedation.

  3. Associations of Sleep Quality and Awake Physical Activity with Fluctuations in Nocturnal Blood Pressure in Patients with Cardiovascular Risk Factors

    PubMed Central

    Kadoya, Manabu; Koyama, Hidenori; Kurajoh, Masafumi; Naka, Mariko; Miyoshi, Akio; Kanzaki, Akinori; Kakutani, Miki; Shoji, Takuhito; Moriwaki, Yuji; Yamamoto, Tetsuya; Inaba, Masaaki; Namba, Mitsuyoshi

    2016-01-01

    Background Sleep quality and awake physical activity are important behavioral factors involved in the occurrence of cardiovascular diseases, potentially through nocturnal blood pressure (BP) changes. However, the impacts of quantitatively measured sleep quality and awake physical activity on BP fluctuation, and their relationships with several candidate causal factors for nocturnal hypertension are not well elucidated. Methods This cross-sectional study included 303 patients registered in the HSCAA study. Measurements included quantitatively determined sleep quality parameters and awake physical activity obtained by actigraph, nocturnal systolic BP (SBP) fall [100 × (1- sleep SBP/awake SBP ratio)], apnea hypopnea index, urinary sodium and cortisol secretion, plasma aldosterone concentration and renin activity, insulin resistance index, parameters of heart rate variability (HRV), and plasma brain-derived neurotrophic factor (BDNF). Results Simple regression analysis showed that time awake after sleep onset (r = -0.150), a parameter of sleep quality, and awake physical activity (r = 0.164) were significantly correlated with nocturnal SBP fall. Among those, time awake after sleep onset (β = -0.179) and awake physical activity (β = 0.190) were significantly and independently associated with nocturnal SBP fall in multiple regression analysis. In a subgroup of patients without taking anti-hypertensive medications, both time awake after sleep onset (β = -0.336) and awake physical activity (β = 0.489) were more strongly and independently associated with nocturnal SBP falls. Conclusion Sleep quality and awake physical activity were found to be significantly associated with nocturnal SBP fall, and that relationship was not necessarily confounded by candidate causal factors for nocturnal hypertension. PMID:27166822

  4. Freely chosen cadence during a covert manipulation of ambient temperature.

    PubMed

    Hartley, Geoffrey L; Cheung, Stephen S

    2013-01-01

    The present study investigated relationships between changes in power output (PO) to torque (TOR) or freely chosen cadence (FCC) during thermal loading. Twenty participants cycled at a constant rating of perceived exertion while ambient temperature (Ta) was covertly manipulated at 20-min intervals of 20 °C, 35 °C, and 20 °C. The magnitude responses of PO, FCC and TOR were analyzed using repeated-measures ANOVA, while the temporal correlations were analyzed using Auto-Regressive Integrated Moving Averages (ARIMA). Increases in Ta caused significant thermal strain (p < .01), and subsequently, a decrease in PO and TOR magnitude (p < .01), whereas FCC remained unchanged (p = .51). ARIMA indicates that changes in PO were highly correlated to TOR (stationary r2 = .954, p = .04), while FCC was moderately correlated (stationary r2 = .717, p = .01) to PO. In conclusion, changes in PO are caused by a modulation in TOR, whereas FCC remains unchanged and therefore, unaffected by thermal stressors.

  5. Freely Decaying Turbulence in Force-free Electrodynamics

    NASA Astrophysics Data System (ADS)

    Zrake, Jonathan; East, William E.

    2016-02-01

    Freely decaying, relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. Force-free turbulent relaxation is found to exhibit an inverse cascade in all settings and in three dimensions to have a magnetic energy spectrum consistent with the Kolmogorov 5/3 power law. Three-dimensional relaxations also obey the Taylor hypothesis; they settle promptly into the lowest-energy configuration allowed by conservation of the total magnetic helicity. However, in two dimensions, the relaxed state is a force-free equilibrium whose energy greatly exceeds the Taylor minimum and that contains persistent force-free current layers and isolated flux tubes. We explain this behavior in terms of additional topological invariants that exist only in two dimensions, namely the helicity enclosed within each level surface of the magnetic potential function. The speed and completeness of turbulent magnetic free-energy discharge could help account for rapidly variable gamma-ray emission from the Crab Nebula, gamma-ray bursts, blazars, and radio galaxies.

  6. Intersegmental coupling and recovery from perturbations in freely running cockroaches

    PubMed Central

    Couzin-Fuchs, Einat; Kiemel, Tim; Gal, Omer; Ayali, Amir; Holmes, Philip

    2015-01-01

    Cockroaches are remarkably stable runners, exhibiting rapid recovery from external perturbations. To uncover the mechanisms behind this important behavioral trait, we recorded leg kinematics of freely running animals in both undisturbed and perturbed trials. Functional coupling underlying inter-leg coordination was monitored before and during localized perturbations, which were applied to single legs via magnetic impulses. The resulting transient effects on all legs and the recovery times to normal pre-perturbation kinematics were studied. We estimated coupling architecture and strength by fitting experimental data to a six-leg-unit phase oscillator model. Using maximum-likelihood techniques, we found that a network with nearest-neighbor inter-leg coupling best fitted the data and that, although coupling strengths vary among preparations, the overall inputs entering each leg are approximately balanced and consistent. Simulations of models with different coupling strengths encountering perturbations suggest that the coupling schemes estimated from our experiments allow animals relatively fast and uniform recoveries from perturbations. PMID:25609786

  7. Visualizing Nanoscopic Topography and Patterns in Freely Standing Thin Films

    NASA Astrophysics Data System (ADS)

    Sharma, Vivek; Zhang, Yiran; Yilixiati, Subinuer

    Thin liquid films containing micelles, nanoparticles, polyelectrolyte-surfactant complexes and smectic liquid crystals undergo thinning in a discontinuous, step-wise fashion. The discontinuous jumps in thickness are often characterized by quantifying changes in the intensity of reflected monochromatic light, modulated by thin film interference from a region of interest. Stratifying thin films exhibit a mosaic pattern in reflected white light microscopy, attributed to the coexistence of domains with various thicknesses, separated by steps. Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed in the course of this study, we spatially resolve for the first time, the landscape of stratifying freely standing thin films. We distinguish nanoscopic rims, mesas and craters, and follow their emergence and growth. In particular, for thin films containing micelles of sodium dodecyl sulfate (SDS), these topological features involve discontinuous, thickness transitions with concentration-dependent steps of 5-25 nm. These non-flat features result from oscillatory, periodic, supramolecular structural forces that arise in confined fluids, and arise due to complex coupling of hydrodynamic and thermodynamic effects at the nanoscale.

  8. Hippocampal neurochemical and electrophysiological measures from freely moving rats.

    PubMed

    Bronzino, J D; Kehoe, P; Hendriks, R; Vita, L; Golas, B; Vivona, C; Morgane, P J

    1999-01-01

    This paper describes surgical and recording procedures that have been developed which permit the simultaneous monitoring of levels of select neurochemicals (via microdialysis) and measures of dentate-evoked field potentials within the hippocampal formation of freely moving adult rats. To test and evaluate these procedures, they were employed to examine changes in hippocampal neurochemistry and neuronal excitability associated with the establishment and maintenance of hippocampal long-term potentiation (LTP). Measures of hippocampal norepinephrine (NE) and glutamate levels along with measures of the dentate granule cell population spike amplitude (PSA) were obtained before, during, and after tetanization of the medial perforant path using two separate tetanization paradigms. Results obtained using these new procedures in several animals indicated that changes in NE and glutamate levels were strongly correlated with increases in the dentate granule cell PSA measure obtained following tetanization. The results indicate that this newly developed procedure can be effectively used to directly examine the relationship between neurochemical and neurophysiological changes associated with hippocampal neuroplasticity.

  9. Dynamics of a freely-falling maple seed

    NASA Astrophysics Data System (ADS)

    Lee, Injae; Choi, Haecheon

    2016-11-01

    We conduct numerical simulations of a freely-falling maple seed using an immersed boundary method in a non-inertial reference frame. A three-dimensional seed model is obtained by scanning a maple seed. The seed reaches a steady autorotation after a transient period, and a stable leading-edge vortex is attached on the surface of the rotating seed, which increases the drag force during autorotation. In addition, two different approaches are considered to obtain scaling laws describing the relation among the seed weight and geometry, and descending and rotating velocities. The first uses the conservations of mass, linear and angular momentum, and energy. In this approach, a model constant to be determined, called axial induction factor, is obtained from the result of present simulation. The second approach employs a classical steady wing theory in which the vortical strength is scaled with the circulation around a wing and the lift force is modeled by the time derivative of vortical impulse. Available data on various seeds well fall on these scaling laws. Supported by NRF-2014M3C1B1033848.

  10. 3-D Worm Tracker for Freely Moving C. elegans

    PubMed Central

    Kwon, Namseop; Pyo, Jaeyeon; Lee, Seung-Jae; Je, Jung Ho

    2013-01-01

    The manner in which the nervous system regulates animal behaviors in natural environments is a fundamental issue in biology. To address this question, C. elegans has been widely used as a model animal for the analysis of various animal behaviors. Previous behavioral assays have been limited to two-dimensional (2-D) environments, confining the worm motion to a planar substrate that does not reflect three-dimensional (3-D) natural environments such as rotting fruits or soil. Here, we develop a 3-D worm tracker (3DWT) for freely moving C. elegans in 3-D environments, based on a stereoscopic configuration. The 3DWT provides us with a quantitative trajectory, including the position and movement direction of the worm in 3-D. The 3DWT is also capable of recording and visualizing postures of the moving worm in 3-D, which are more complex than those in 2-D. Our 3DWT affords new opportunities for understanding the nervous system function that regulates animal behaviors in natural 3-D environments. PMID:23437394

  11. Freely available conformer generation methods: how good are they?

    PubMed

    Ebejer, Jean-Paul; Morris, Garrett M; Deane, Charlotte M

    2012-05-25

    Conformer generation has important implications in cheminformatics, particularly in computational drug discovery where the quality of conformer generation software may affect the outcome of a virtual screening exercise. We examine the performance of four freely available small molecule conformer generation tools (Balloon, Confab, Frog2, and RDKit) alongside a commercial tool (MOE). The aim of this study is 3-fold: (i) to identify which tools most accurately reproduce experimentally determined structures; (ii) to examine the diversity of the generated conformational set; and (iii) to benchmark the computational time expended. These aspects were tested using a set of 708 drug-like molecules assembled from the OMEGA validation set and the Astex Diverse Set. These molecules have varying physicochemical properties and at least one known X-ray crystal structure. We found that RDKit and Confab are statistically better than other methods at generating low rmsd conformers to the known structure. RDKit is particularly suited for less flexible molecules while Confab, with its systematic approach, is able to generate conformers which are geometrically closer to the experimentally determined structure for molecules with a large number of rotatable bonds (≥10). In our tests RDKit also resulted as the second fastest method after Frog2. In order to enhance the performance of RDKit, we developed a postprocessing algorithm to build a diverse and representative set of conformers which also contains a close conformer to the known structure. Our analysis indicates that, with postprocessing, RDKit is a valid free alternative to commercial, proprietary software.

  12. 3-D worm tracker for freely moving C. elegans.

    PubMed

    Kwon, Namseop; Pyo, Jaeyeon; Lee, Seung-Jae; Je, Jung Ho

    2013-01-01

    The manner in which the nervous system regulates animal behaviors in natural environments is a fundamental issue in biology. To address this question, C. elegans has been widely used as a model animal for the analysis of various animal behaviors. Previous behavioral assays have been limited to two-dimensional (2-D) environments, confining the worm motion to a planar substrate that does not reflect three-dimensional (3-D) natural environments such as rotting fruits or soil. Here, we develop a 3-D worm tracker (3DWT) for freely moving C. elegans in 3-D environments, based on a stereoscopic configuration. The 3DWT provides us with a quantitative trajectory, including the position and movement direction of the worm in 3-D. The 3DWT is also capable of recording and visualizing postures of the moving worm in 3-D, which are more complex than those in 2-D. Our 3DWT affords new opportunities for understanding the nervous system function that regulates animal behaviors in natural 3-D environments.

  13. Near and far wake structures behind freely flying bats

    NASA Astrophysics Data System (ADS)

    Schunk, Cosima; Swartz, Sharon M.; Breuer, Kenneth S.

    2014-11-01

    While pseudo-volumetric reconstructions of the wakes of flying animals, based on transverse (Trefftz) wake measurements, have become a well-established tool in the study of animal aerodynamics in recent years, there are a number of concerns that persist regarding their use in estimating drag and flight efficiency. Here we report on stereo particle image velocimetry (PIV) measurements behind freely flying bats (Eptesicus fuscus) in both the transverse and streamwise planes. The streamwise plane measurements are taken on the wing as well as in the near and far wake region up to eight chord lengths behind the bat. By organizing the data according to the flight speed, wingbeat phase and the spanwise position of the laser sheet on the wing we are able to connect specific features of the wing and body geometry with observed wake structures and thereby construct a detailed time-space map of the wake. Furthermore, we can quantitatively assess wake distortion and assess the validity of lift and drag estimates based on transverse wake measurements. Supported by AFOSR.

  14. FREELY DECAYING TURBULENCE IN FORCE-FREE ELECTRODYNAMICS

    SciTech Connect

    Zrake, Jonathan; East, William E.

    2016-02-01

    Freely decaying, relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. Force-free turbulent relaxation is found to exhibit an inverse cascade in all settings and in three dimensions to have a magnetic energy spectrum consistent with the Kolmogorov 5/3 power law. Three-dimensional relaxations also obey the Taylor hypothesis; they settle promptly into the lowest-energy configuration allowed by conservation of the total magnetic helicity. However, in two dimensions, the relaxed state is a force-free equilibrium whose energy greatly exceeds the Taylor minimum and that contains persistent force-free current layers and isolated flux tubes. We explain this behavior in terms of additional topological invariants that exist only in two dimensions, namely the helicity enclosed within each level surface of the magnetic potential function. The speed and completeness of turbulent magnetic free-energy discharge could help account for rapidly variable gamma-ray emission from the Crab Nebula, gamma-ray bursts, blazars, and radio galaxies.

  15. Functional MR imaging in the awake monkey: effects of motion on dynamic off-resonance and processing strategies.

    PubMed

    Pfeuffer, Josef; Shmuel, Amir; Keliris, Georgios A; Steudel, Thomas; Merkle, Hellmut; Logothetis, Nikos K

    2007-07-01

    Functional MR imaging of the alert, behaving monkey is being used more and more often to detect activation patterns and guide electrophysiological research investigating the neural basis of behavior. Several labs have reported fMRI data from the awake monkey, but none of them has studied and systematically corrected the effects of monkeys' motion on fMRI time series. In this study, a significant refinement of acquisition and correction strategies is reported that can be used to minimize magnetic susceptibility artifacts induced by respiration and by jaw and body movement. Real-time acquisition of sensor signals (e.g., signals induced by jaw and body movement) and MR navigator data were combined to optimize fMRI signal-correction strategies. Within trials, the artifact-induced off-resonance changes were small and mainly reflected the effects of respiration; between trials, movements caused major changes of global frequency and shim (>20 Hz/cm). Several methods were used to assess the stability of the fMRI series: k-space analysis ('dynamic intensity and off-resonance changes in k-space', dubbed DICK and DORK) and image analysis using a Laplace operator and a center-of-mass metric. The variability between trials made it essential to correct for inter-trial variations. On the other hand, images were sufficiently stable with our approach to perform fMRI evaluations on single trials before averaging of trials. Different motion correction strategies were compared: DORK, McFLIRT (rigid body model with three translations and three rotations) and 2D image alignment based on a center-of-mass detection (in-plane translation). The latter yielded the best results and proved to be fast and robust for intra- and inter-trial alignment. Finally, fMRI in the behaving monkey was tested for spatial and temporal reproducibility on a trial-to-trial basis. Highly activated voxels also displayed good reproducibility between trials. On average, the BOLD amplitude response to a short 3-s

  16. Do Friends and Nonfriends Behave Differently? A Social Relations Analysis of Children's Behavior.

    ERIC Educational Resources Information Center

    Simpkins, Sandra D.; Parke, Ross D.

    2002-01-01

    Examined how children behave differently with friends and non-friends. Engaged 123 triads of target children, friends, and unacquainted peers in free-play and planning tasks. Found that children behaved more positively but also exhibited more negative behavior with friends than with non-friends. (KK)

  17. Current status and future needs of the BehavePlus Fire Modeling System

    Treesearch

    Patricia L. Andrews

    2014-01-01

    The BehavePlus Fire Modeling System is among the most widely used systems for wildland fire prediction. It is designed for use in a range of tasks including wildfire behaviour prediction, prescribed fire planning, fire investigation, fuel hazard assessment, fire model understanding, communication and research. BehavePlus is based on mathematical models for fire...

  18. Validation of BEHAVE fire behavior predictions in oak savannas using five fuel models

    Treesearch

    Keith Grabner; John Dwyer; Bruce Cutter

    1997-01-01

    Prescribed fire is a valuable tool in the restoration and management of oak savannas. BEHAVE, a fire behavior prediction system developed by the United States Forest Service, can be a useful tool when managing oak savannas with prescribed fire. BEHAVE predictions of fire rate-of-spread and flame length were validated using four standardized fuel models: Fuel Model 1 (...

  19. Do Friends and Nonfriends Behave Differently? A Social Relations Analysis of Children's Behavior.

    ERIC Educational Resources Information Center

    Simpkins, Sandra D.; Parke, Ross D.

    2002-01-01

    Examined how children behave differently with friends and non-friends. Engaged 123 triads of target children, friends, and unacquainted peers in free-play and planning tasks. Found that children behaved more positively but also exhibited more negative behavior with friends than with non-friends. (KK)

  20. The development of one-stop wide-awake dupuytren's fasciectomy service: a retrospective review

    PubMed Central

    Bismil, QMK; Bismil, MSK; Bismil, Annamma; Neathey, Julia; Gadd, Judith; Roberts, Sue; Brewster, Jennifer

    2012-01-01

    Objectives To detail the transition to a totally one-stop wide-awake (OSWA) Dupuytren's contracture surgical service. Design Retrospective review of Dupuytren's component of last 1000 OSWA cases. Setting The UK's first totally one-stop wide-awake orthopaedic service. Participants 270 patients with Dupuytren's contracture out of the last 1000 OSWA cases. Main outcome measures Surgical outcomes, patient satisfaction and cost-effectiveness and efficiency. Results The OSWA Dupuytren's model is safe, efficient and effective; with a low complication rate, extremely high patient satisfaction; and cost-savings to the nhs of £2500 per case treated. The service saved the NHS approximately £675,000 for the 270 cases presented. Conclusions A totally one-stop wide-awake Dupuytren's Contracture service is practicable and feasible alternative to the conventional treatment pathway, with benefits in terms of efficiency and cost-effectiveness. PMID:22908029

  1. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms 12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy ( 15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  2. The history of awake craniotomy for brain tumor and its spread into Asia.

    PubMed

    July, Julius; Manninen, Pirjo; Lai, Jacob; Yao, Zhenhai; Bernstein, Mark

    2009-05-01

    In ancient times, awake craniotomy was used for trepanation to treat seizures and remove a variety of morbid conditions or even to permit the escape of evil air. In modern times, this technique was initially used for removal of epileptic foci with simultaneous application of brain mapping with electrical current. Further developments brought this technique into use for resection of tumors involving functional cortex. Recently, awake craniotomy has been described as an approach for removal of supratentorial tumors nonselectively, regardless of the involvement of eloquent cortex. It has been used in North America since the 1980s, then Europe, and recently has spread into Asia. Its spread to Asia could have significant impact based on the large population of patients and the low resource utilization associated with awake craniotomy.

  3. [Non-verbal communication of patients submitted to heart surgery: from awaking after anesthesia to extubation].

    PubMed

    Werlang, Sueli da Cruz; Azzolin, Karina; Moraes, Maria Antonieta; de Souza, Emiliane Nogueira

    2008-12-01

    Preoperative orientation is an essential tool for patient's communication after surgery. This study had the objective of evaluating non-verbal communication of patients submitted to cardiac surgery from the time of awaking from anesthesia until extubation, after having received preoperative orientation by nurses. A quantitative cross-sectional study was developed in a reference hospital of the state of Rio Grande do Sul, Brazil, from March to July 2006. Data were collected in the pre and post operative periods. A questionnaire to evaluate non-verbal communication on awaking from sedation was applied to a sample of 100 patients. Statistical analysis included Student, Wilcoxon, and Mann Whittney tests. Most of the patients responded satisfactorily to non-verbal communication strategies as instructed on the preoperative orientation. Thus, non-verbal communication based on preoperative orientation was helpful during the awaking period.

  4. Numerical investigation for one bad-behaved flow in a Pelton turbine

    NASA Astrophysics Data System (ADS)

    Wei, X. Z.; Yang, K.; Wang, H. J.; Gong, R. Z.; Li, D. Y.

    2015-01-01

    The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper.

  5. MAC-awake of isoflurane, enflurane and halothane evaluated by slow and fast alveolar washout.

    PubMed

    Gaumann, D M; Mustaki, J P; Tassonyi, E

    1992-01-01

    End-tidal anaesthetic concentrations at first eye opening in response to a verbal command during recovery from anaesthesia (MAC-awake), were measured for isoflurane (n = 16), enflurane (n = 16) and halothane (n = 14). MAC-awake was measured during either slow or fast alveolar washout. Slow washout was obtained by decreasing anaesthetic concentrations in predetermined steps of 15 min, assuming equilibration between brain and alveolar partial pressures. Fast alveolar washout was obtained by discontinuation of the inhalation anaesthetic, which had been maintained at 1 MAC for at least 15 min. Mean MAC-awake obtained with slow alveolar washout was similar for isoflurane (0.25 (SD 0.03) MAC), and enflurane (0.27 (0.04) MAC) and significantly greater than values obtained by fast alveolar washout (isoflurane: 0.19 (0.03) MAC; enflurane: 0.20 (0.03) MAC). The MAC-awake of isoflurane and enflurane was significantly less than that of halothane, which was 0.59 (0.10) MAC as evaluated by the slow and 0.50 (0.05) MAC as evaluated by the fast alveolar washout method. Recovery time from anaesthesia with fast alveolar washout was 8.8 (4.0) min for halothane, which was not different from isoflurane (15 (2.5) min), but significantly shorter than for enflurane (22 (10) min), reflecting differences in the anaesthetic concentration gradient between MAC and MAC-awake values. These data do not support the hypothesis of a uniform ratio between MAC and MAC-awake values.

  6. Stimulus-specific adaptation in auditory thalamus of young and aged awake rats

    PubMed Central

    Richardson, Ben D.; Hancock, Kenneth E.

    2013-01-01

    Novel stimulus detection by single neurons in the auditory system, known as stimulus-specific adaptation (SSA), appears to function as a real-time filtering/gating mechanism in processing acoustic information. Particular stimulus paradigms allowing for quantification of a neuron's ability to detect novel or deviant stimuli have been used to examine SSA in the inferior colliculus, medial geniculate body (MGB), and auditory cortex of anesthetized rodents. However, the study of SSA in awake animals is limited to auditory cortex. The present study used individually advanceable tetrodes to record single-unit responses from auditory thalamus (MGB) of awake young adult and aged Fischer Brown Norway (FBN) rats to 1) examine the presence of SSA in the MGB of awake rats and 2) determine whether SSA is altered by aging in MGB. MGB single units in awake FBN rats displayed SSA in response to two stimulus paradigms: the oddball paradigm and a random blocked/interleaved presentation of a set of frequencies. SSA levels were modestly, but nonsignificantly, increased in the nonlemniscal regions of the MGB and at lower stimulus intensities, where 27 of 57 (47%) young adult MGB units displayed SSA. The present findings provide the initial description of SSA in the MGB of awake rats and support SSA as being qualitatively independent of arousal level or anesthetized state. Finally, contrary to previous studies in auditory cortex of anesthetized rats, MGB units in aged rats showed SSA levels indistinguishable from SSA levels in young adult rats, suggesting that SSA in MGB was not impacted by aging in an awake preparation. PMID:23904489

  7. Tumescent Local Anesthesia for Hand Surgery: Improved Results, Cost Effectiveness, and Wide-Awake Patient Satisfaction

    PubMed Central

    Martin, Alison

    2014-01-01

    This is a review article of the wide-awake approach to hand surgery. More than 95% of all hand surgery can now be performed without a tourniquet. Epinephrine is injected with lidocaine for hemostasis and anesthesia instead of a tourniquet and sedation. This is sedation-free surgery, much like a visit to a dental office. The myth of danger of using epinephrine in the finger is reviewed. The wide awake technique is greatly improving results in tendon repair, tenolysis, and tendon transfer. Here, we will explain its advantages. PMID:25075350

  8. [Awake Nasotracheal Intubation for a 4-Year-old Boy with an Oral Penetrating Toothbrush Injury].

    PubMed

    Kobayashi, Naoya; Ando, Kokichi; Saito, Kazutomo; Toyama, Hiroaki; Fudeta, Hiroto; Yamauchi, Masanori

    2015-09-01

    We report a case of an oral penetrating injury caused by a toothbrush in a 4-year-old 17-kg boy. The toothbrush was lodged in the right cervical region through the oral cavity, and emergency surgery for removal was planned under general anesthesia. Although mask ventilation was not possible because of the protruding toothbrush handle, awake nasotracheal intubation was successfully performed with a fiber-scope and intravenous fentanyl 25 μg. We conclude that appropriate analgesics could facilitate awake intubation in pediatric patients.

  9. Awake surgery between art and science. Part I: clinical and operative settings

    PubMed Central

    Talacchi, Andrea; Santini, Barbara; Casagrande, Francesca; Alessandrini, Franco; Zoccatelli, Giada; Squintani, Giovanna M.

    Summary Awake surgery requires coordinated teamwork and communication between the surgeon and the anesthesiologist, as he monitors the patient, the neuroradiologist as he interprets the images for intraoperative confirmation, and the neuropsychologist and neurophysiologist as they evaluate in real-time the patient’s responses to commands and questions. To improve comparison across published studies on clinical assessment and operative settings in awake surgery, we reviewed the literature, focusing on methodological differences and aims. In complex, interdisciplinary medical care, such differences can affect the outcome and the cost-benefit ratio of the treatment. Standardization of intraoperative mapping and related controversies will be discussed in Part II. PMID:24139657

  10. Awake surgery between art and science. Part I: clinical and operative settings.

    PubMed

    Talacchi, Andrea; Santini, Barbara; Casagrande, Francesca; Alessandrini, Franco; Zoccatelli, Giada; Squintani, Giovanna M

    2013-01-01

    Awake surgery requires coordinated teamwork and communication between the surgeon and the anesthesiologist, as he monitors the patient, the neuroradiologist as he interprets the images for intraoperative confirmation, and the neuropsychologist and neurophysiologist as they evaluate in real-time the patient's responses to commands and questions. To improve comparison across published studies on clinical assessment and operative settings in awake surgery, we reviewed the literature, focusing on methodological differences and aims. In complex, interdisciplinary medical care, such differences can affect the outcome and the cost-benefit ratio of the treatment. Standardization of intraoperative mapping and related controversies will be discussed in Part II.

  11. Planet-disc interaction on a freely moving mesh

    NASA Astrophysics Data System (ADS)

    Muñoz, D. J.; Kratter, K.; Springel, V.; Hernquist, L.

    2014-12-01

    General-purpose, moving-mesh schemes for hydrodynamics have opened the possibility of combining the accuracy of grid-based numerical methods with the flexibility and automatic resolution adaptivity of particle-based methods. Due to their supersonic nature, Keplerian accretion discs are in principle a very attractive system for applying such freely moving-mesh techniques. However, the high degree of symmetry of simple accretion disc models can be difficult to capture accurately by these methods, due to the generation of geometric grid noise and associated numerical diffusion, which is absent in polar grids. To explore these and other issues, in this work we study the idealized problem of two-dimensional planet-disc interaction with the moving-mesh code AREPO. We explore the hydrodynamic evolution of discs with planets through a series of numerical experiments that vary the planet mass, the disc viscosity and the mesh resolution, and compare the resulting surface density, vortensity field and tidal torque with results from the literature. We find that the performance of the moving-mesh code in this problem is in accordance with published results, showing good consistency with grid codes written in polar coordinates. We also conclude that grid noise and mesh distortions do not introduce excessive numerical diffusion. Finally, we show how the moving-mesh approach can help in resolving an outstanding challenge for polar-coordinate grid codes, namely the successful implementation of adaptive mesh refinement in regions of high density around planets and planetary wakes, while retaining the background flow at low resolution.

  12. Three-dimensional spatial representation in freely swimming fish.

    PubMed

    Burt de Perera, Theresa; Holbrook, Robert I

    2012-08-01

    Research on spatial cognition has focused on how animals encode the horizontal component of space. However, most animals travel vertically within their environments, particularly those that fly or swim. Pelagic fish move with six degrees of freedom and must integrate these components to navigate accurately--how do they do this? Using an assay based on associative learning of the vertical and horizontal components of space within a rotating Y-maze, we found that fish (Astyanax fasciatus) learned and remembered information from both horizontal and vertical axes when they were presented either separately or as an integrated three-dimensional unit. When information from the two components conflicted, the fish used the previously learned vertical information in preference to the horizontal. This not only demonstrates that the horizontal and vertical components are stored separately in the fishes' representation of space (simplifying the problem of 3D navigation), but also suggests that the vertical axis contains particularly salient spatial cues--presumably including hydrostatic pressure. To explore this latter possibility, we developed a physical theoretical model that shows how fish could determine their absolute depth using pressure. We next considered full volumetric spatial cognition. Astyanax were trained to swim towards a reward in a Y-maze that could be rotated, before the arms were removed during probe trials. The subjects were tracked in three dimensions as they swam freely through the surrounding cubic tank. The results revealed that fish are able to accurately encode metric information in a volume, and that the error accrued in the horizontal and vertical axes whilst swimming in probe trials was similar. Together, these experiments demonstrate that unlike in surface-bound rats, the vertical component of the representation of space is vitally important to fishes. We hypothesise that the representation of space in the brain of vertebrates could ultimately be

  13. Satellite Meteorology Education Resources Freely Available from COMET°

    NASA Astrophysics Data System (ADS)

    Abshire, W. E.; Dills, P. N.

    2011-12-01

    The COMET° Program (www.comet.ucar.edu) receives funding from NOAA NESDIS, EUMETSAT, and the Meteorological Service of Canada to support education and training efforts in satellite meteorology. These partnerships enable COMET to create educational materials of global interest on the application of products from geostationary and polar-orbiting remote sensing platforms. Recently, COMET's satellite education programs have focused on both current and next generation satellites and their relevance to operational forecasters and other communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, MSC, and other user communities, COMET stimulates greater utilization of satellite data and products. COMET also continues to broaden the scope of its training to include materials on the EUMETSAT Polar-orbiting System (EPS) and Meteosat geostationary satellites. EPS represents an important contribution to the Initial Joint Polar System between NOAA and EUMETSAT, while Meteosat Second Generation imaging capabilities provide an authentic proving ground for the next-generation GOES-R imager. This presentation provides an overview of COMET's recent satellite education efforts including courses and publications that focus on topics like multispectral RGB products, detecting atmospheric dust, and climate monitoring from satellites. Over 50 satellite-focused self-paced online materials are freely available via the Satellite Topic area of the MetEd Web site (www.meted.ucar.edu/topics/modules/satellite) and COMET's Environmental Satellite Resource Center (ESRC)(www.meted.ucar.edu/esrc). The ESRC, another important resource developed for use by the geosciences and education communities, is a searchable, database driven Web site that provides easy access to a wide range of useful information and training materials on Earth-observing satellites. Simple free online registration is required to access all training materials and the

  14. Turbulent Rayleigh-Benard convection with freely moving boundary

    NASA Astrophysics Data System (ADS)

    Zhong, Jin-Qiang

    In thermal convection, coherent flow structures emerge at high Rayleigh numbers as a result of intrinsic hydrodynamic instability and self-organization. They range from small-scale thermal plumes that are produced near both the top and the bottom boundaries to large-scale circulations across the entire convective volume. These flow structures exert viscous forces upon any boundary. Such forces will affect a boundary which is free to deform or change position. In our experiment, we study the dynamics of a free boundary that floats on the upper surface of a convective fluid. This seemingly passive boundary is subjected solely to viscous stress underneath. However, the boundary thermally insulates the fluid, modifying the bulk flow. As a consequence, the interaction between the free boundary and the convective fluid results in rich dynamics including periodic evolution of thr flow structures and predictable motions of the free boundary. Here I present two sets of experiments on thermal convection with freely moving top boundary. The first experiment is conducted in a rectangular geometry. We discover that as the sizes of the free boundary increases, the convection system transits from a nearly-periodic oscillation state into a local trapped state. A phenomenological numerical model explains this dynamcal transition. The second set of experiment is conducted in an annular geometry, where a periodic boundary condition is satisfied for both the flow structures and the free boundary. In a long time scale, persistent rotations of the free boundary along the circular path inside the convection cell are observed. In short time scales, the free boundary rotates in a hopping fashion. Consequently, through temperature distribution measurements, we observe the regular evolutions of the flow patterns in the convective fluid.

  15. Interplay between viscosity and elasticity in freely expanding liquid sheets

    NASA Astrophysics Data System (ADS)

    Arora, Srishti; Ligoure, Christian; Ramos, Laurence

    2016-12-01

    We investigate the dynamics of freely expanding liquid sheets prepared with fluids with different rheological properties: (i) Viscous fluids with a zero-shear viscosity η0 in the range 1 -1000 mPa s and (ii) viscoelastic fluids whose linear viscoelastic behavior in the frequency range 0.1 -100 rad/s can be accounted for by a Maxwell fluid model, whose characteristic elastic modulus G0, relaxation time τ , and zero-shear viscosity η0=G0τ , can be tuned over several orders of magnitude. The sheets are produced by a drop of fluid impacting a small cylindrical solid target. For viscoelastic fluids, we show that, when τ is shorter than the typical lifetime of the sheet (˜10 ms), the dynamics of the sheet is similar to that of Newtonian viscous liquids with equal zero-shear viscosity. In that case, for little viscous samples (η0≲30 mPa s), the maximal expansion of the sheet dmax is independent of η0, whereas for more viscous samples, dmax decreases as η0 increases. We provide a simple model for the dependence of the maximal expansion of the sheet with the viscosity that accounts well for our experimental data. By contrast, when τ is longer than the typical lifetime of the sheet, the behavior drastically differs. The sheet expansion is strongly enhanced as compared to that of viscous samples with comparable zero-shear viscosity, but is heterogeneous with the occurrence of cracks, revealing the elastic nature of the viscoelastic fluid.

  16. Navigating freely-available software tools for metabolomics analysis.

    PubMed

    Spicer, Rachel; Salek, Reza M; Moreno, Pablo; Cañueto, Daniel; Steinbeck, Christoph

    2017-01-01

    The field of metabolomics has expanded greatly over the past two decades, both as an experimental science with applications in many areas, as well as in regards to data standards and bioinformatics software tools. The diversity of experimental designs and instrumental technologies used for metabolomics has led to the need for distinct data analysis methods and the development of many software tools. To compile a comprehensive list of the most widely used freely available software and tools that are used primarily in metabolomics. The most widely used tools were selected for inclusion in the review by either ≥ 50 citations on Web of Science (as of 08/09/16) or the use of the tool being reported in the recent Metabolomics Society survey. Tools were then categorised by the type of instrumental data (i.e. LC-MS, GC-MS or NMR) and the functionality (i.e. pre- and post-processing, statistical analysis, workflow and other functions) they are designed for. A comprehensive list of the most used tools was compiled. Each tool is discussed within the context of its application domain and in relation to comparable tools of the same domain. An extended list including additional tools is available at https://github.com/RASpicer/MetabolomicsTools which is classified and searchable via a simple controlled vocabulary. This review presents the most widely used tools for metabolomics analysis, categorised based on their main functionality. As future work, we suggest a direct comparison of tools' abilities to perform specific data analysis tasks e.g. peak picking.

  17. The Sleep Elaboration-Awake Pruning (SEAP) theory of memory: long term memories grow in complexity during sleep and undergo selection while awake. Clinical, psychopharmacological and creative implications.

    PubMed

    Charlton, Bruce G; Andras, Peter

    2009-07-01

    Long term memory (LTM) systems need to be adaptive such that they enhance an organism's reproductive fitness and self-reproducing in order to maintain their complexity of communications over time in the face of entropic loss of information. Traditional 'representation-consolidation' accounts conceptualize memory adaptiveness as due to memories being 'representations' of the environment, and the longevity of memories as due to 'consolidation' processes. The assumption is that memory representations are formed while an animal is awake and interacting with the environment, and these memories are consolidated mainly while the animal is asleep. So the traditional view of memory is 'instructionist' and assumes that information is transferred from the environment into the brain. By contrast, we see memories as arising endogenously within the brain's LTM system mainly during sleep, to create complex but probably maladaptive memories which are then simplified ('pruned') and selected during the awake period. When awake the LTM system is brought into a more intense interaction with past and present experience. Ours is therefore a 'selectionist' account of memory, and could be termed the Sleep Elaboration-Awake Pruning (or SEAP) theory. The SEAP theory explains the longevity of memories in the face of entropy by the tendency for memories to grow in complexity during sleep; and explains the adaptiveness of memory by selection for consistency with perceptions and previous memories during the awake state. Sleep is therefore that behavioural state during which most of the internal processing of the system of LTM occurs; and the reason sleep remains poorly understood is that its primary activity is the expansion of long term memories. By re-conceptualizing the relationship between memory, sleep and the environment; SEAP provides a radically new framework for memory research, with implications for the measurement of memory and the design of empirical investigations in clinical

  18. Observation of Vortex Crystals in Freely Relaxing 2D Turbulence.*

    NASA Astrophysics Data System (ADS)

    Driscoll, C. Fred

    1998-03-01

    Magnetically confined electron columns evolve as near-ideal incompressible 2D fluids, allowing quantitative study of vortices and self-organization in freely relaxing turbulence. The electron density is proportional to the vorticity ζ (r,θ , t) of the flow, and can be accurately measured at any given time using a phosphor screen and a high-resolution camera. Initially turbulent states are observed to relax through the processes of vortex advection, merger, and filamentation. Initial conditions with Nv = 50 - 100 vortices typically relax as Nv ∝ t^- ξ, with 0.4 <= ξ <= 1.1, in general agreement with dynamic scaling theories. However, for some initial conditions, we observe this turbulent relaxation to be halted by the formation of ordered patterns of vortices (``vortex crystals'') rotating as a rigid pattern within a weaker background of vorticity.^1 After a crystal forms, the random vortex motions damp with time, and we measure ``cooling'' of the crystal pattern. Although vortex crystals have been observed in dissipative systems such as rotating liquid helium, here the flow is essentially inviscid on the cooling timescale. We find that total circulation, angular momentum, and energy are conserved to within a few percent during the initial relaxation. The vortex crystal state persists until weak diffusive or viscous processes dissipate the vortices after thousands of turnover times. Recent 2D vortex-in-cell simulations have reproduced the vortex crystal states and cooling rates; this supports the belief that the cooling occurs in incompressible, inviscid fluid flow. Other experiments and theory have studied the dynamics of various types of vortex patches moving through a background of vorticity: enhanced vorticity ``clumps'' move up a background vorticity gradient, whereas decreased vorticity ``holes'' move down a gradient. Surprisingly, many characteristics of the final vortex crystal states can be predicted by maximization of entropy subject to integral

  19. A model to investigate postoperative ileus with strain gauge transducers in awake rats.

    PubMed

    Huge, A; Kreis, M E; Jehle, E C; Ehrlein, H J; Starlinger, M; Becker, H D; Zittel, T T

    1998-02-01

    Postoperative ileus influences patients well-being, hospital stay, and health cost, and postoperative inhibition of colonic motility is a major contributor to postoperative ileus. Experimental models for investigating postoperative ileus are needed. In particular, recording of postoperative colonic motility in awake rats has not been described yet. Gastric, small intestinal, and colonic motility were recorded with strain gauge transducers in awake rats, and the effects of anesthesia and abdominal surgery on gastrointestinal motility were investigated. Ether anesthesia increased gastric motility and inhibited small intestinal motility, while enflurane anesthesia had only minor effects on gastrointestinal motility. Abdominal surgery inhibited gastric, small intestinal, and colonic motility, and a detailed analysis of gastrointestinal motility in our postoperative ileus model is given. We established a model to record gastric, small intestinal, and colonic motility in awake rats postoperatively. We could demonstrate that enflurane anesthesia had little effect on gastrointestinal motility, while laparotomy and short manipulation of the cecum produced a prolonged inhibition of gastrointestinal motility. Our model could be used to investigate postoperative ileus, particularly of the colon, in awake rats.

  20. Evaluation of Gastrointestinal Motility in Awake Rats: A Learning Exercise for Undergraduate Biomedical Students

    ERIC Educational Resources Information Center

    Souza, M. A. N.; Souza, M. H. L. P.; Palheta, R. C., Jr.; Cruz, P. R. M.; Medeiros, B. A.; Rola, F. H.; Magalhaes, P. J. C.; Troncon, L. E. A.; Santos, A. A.

    2009-01-01

    Current medical curricula devote scarce time for practical activities on digestive physiology, despite frequent misconceptions about dyspepsia and dysmotility phenomena. Thus, we designed a hands-on activity followed by a small-group discussion on gut motility. Male awake rats were randomly submitted to insulin, control, or hypertonic protocols.…

  1. a-Band Oscillations in Intracellular Membrane Potentials of Dentate Gyrus Neurons in Awake Rodents

    ERIC Educational Resources Information Center

    Anderson, Ross W.; Strowbridge, Ben W.

    2014-01-01

    The hippocampus and dentate gyrus play critical roles in processing declarative memories and spatial information. Dentate granule cells, the first relay in the trisynaptic circuit through the hippocampus, exhibit low spontaneous firing rates even during locomotion. Using intracellular recordings from dentate neurons in awake mice operating a…

  2. Long-Term Two-Photon Imaging in Awake Macaque Monkey.

    PubMed

    Li, Ming; Liu, Fang; Jiang, Hongfei; Lee, Tai Sing; Tang, Shiming

    2017-03-08

    Successful application of two-photon imaging with genetic tools in awake macaque monkeys will enable fundamental advances in our understanding of higher cognitive function at the level of molecular and neuronal circuits. Here we report techniques for long-term two-photon imaging in awake macaque monkeys. Using genetically encoded indicators including GCaMP5 and GCaMP6s delivered by AAV2/1 into the visual cortex, we demonstrate that high-quality two-photon imaging of large neuronal populations can be achieved and maintained in awake monkeys for months. Simultaneous intracellular recording and two-photon calcium imaging confirm that fluorescence activity is linearly proportional to neuronal spiking activity across a wide range of firing rates (10 Hz to 150 Hz). By providing two-photon imaging access to cortical neuronal populations at single-cell or single dendritic spine resolution in awake monkeys, the techniques reported can help bridge the use of modern genetic and molecular tools and the study of higher cognitive function.

  3. Intraoperative Subcortical Electrical Mapping of the Optic Tract in Awake Surgery Using a Virtual Reality Headset.

    PubMed

    Mazerand, Edouard; Le Renard, Marc; Hue, Sophie; Lemée, Jean-Michel; Klinger, Evelyne; Menei, Philippe

    2017-01-01

    Brain mapping during awake craniotomy is a well-known technique to preserve neurological functions, especially the language. It is still challenging to map the optic radiations due to the difficulty to test the visual field intraoperatively. To assess the visual field during awake craniotomy, we developed the Functions' Explorer based on a virtual reality headset (FEX-VRH). The impaired visual field of 10 patients was tested with automated perimetry (the gold standard examination) and the FEX-VRH. The proof-of-concept test was done during the surgery performed on a patient who was blind in his right eye and presenting with a left parietotemporal glioblastoma. The FEX-VRH was used intraoperatively, simultaneously with direct subcortical electrostimulation, allowing identification and preservation of the optic radiations. The FEX-VRH detected 9 of the 10 visual field defects found by automated perimetry. The patient who underwent an awake craniotomy with intraoperative mapping of the optic tract using the FEX-VRH had no permanent postoperative visual field defect. Intraoperative visual field assessment with the FEX-VRH during direct subcortical electrostimulation is a promising approach to mapping the optical radiations and preventing a permanent visual field defect during awake surgery for epilepsy or tumor. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Evaluation of Gastrointestinal Motility in Awake Rats: A Learning Exercise for Undergraduate Biomedical Students

    ERIC Educational Resources Information Center

    Souza, M. A. N.; Souza, M. H. L. P.; Palheta, R. C., Jr.; Cruz, P. R. M.; Medeiros, B. A.; Rola, F. H.; Magalhaes, P. J. C.; Troncon, L. E. A.; Santos, A. A.

    2009-01-01

    Current medical curricula devote scarce time for practical activities on digestive physiology, despite frequent misconceptions about dyspepsia and dysmotility phenomena. Thus, we designed a hands-on activity followed by a small-group discussion on gut motility. Male awake rats were randomly submitted to insulin, control, or hypertonic protocols.…

  5. Being awake intermittently during propofol-induced hypnosis: a study of BIS, explicit and implicit memory.

    PubMed

    Barr, G; Anderson, R E; Owall, A; Jakobsson, J G

    2001-08-01

    Being awake during anaesthesia is a serious complication. An anaesthetic depth monitor must discriminate in real time between wakefulness and unconsciousness. The present study created a period of wakefulness during propofol-induced hypnosis. Bispectral index (BIS), explicit and implicit memories of the awake period were investigated. Ten volunteers were studied. The calculated brain concentration of a target controlled infusion of propofol was increased until loss of response (LOR) to verbal command and then propofol was stopped. When fully awake, volunteers were presented with a picture, sound and smell. Propofol infusion was restarted until LOR and then ceased. BIS and the calculated brain concentration of propofol were recorded every minute. A structured interview was conducted for explicit memories after awakening and for explicit as well as implicit memories the day after. Median BIS-index for the transition between awake and asleep and vice versa differed significantly. It was not possible, however, to establish any threshold value or zone for discriminating between wakefulness and LOR due to the large inter-individual variations in BIS-index. No volunteer could explicitly recall any of the stimuli presented during the period of wakefulness. The BIS-index decreases with increasing sedation but because of the large individual variations, the real-time BIS-index for the individual subject cannot reliably discriminate wakefulness from unconsciousness during propofol infusion. Propofol causes such profound amnesia that lack of postoperative recall does not assure that episodes of awareness have not occurred during propofol-induced hypnosis.

  6. a-Band Oscillations in Intracellular Membrane Potentials of Dentate Gyrus Neurons in Awake Rodents

    ERIC Educational Resources Information Center

    Anderson, Ross W.; Strowbridge, Ben W.

    2014-01-01

    The hippocampus and dentate gyrus play critical roles in processing declarative memories and spatial information. Dentate granule cells, the first relay in the trisynaptic circuit through the hippocampus, exhibit low spontaneous firing rates even during locomotion. Using intracellular recordings from dentate neurons in awake mice operating a…

  7. Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status.

    PubMed

    Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

    2014-01-01

    It is controversial that whether the GABA receptors contribute to the hypnotic action of volatile anesthetics. This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration-awake (MAC-Awake) and emergence mental status. This study included two steps. Firstly, 49 healthy patients, aged 20-40 years scheduled for elective surgeries, were randomly assigned to two groups, a flumazenil group (n=24) and a saline group (n=25). The flumazenil group received 0.006 mg/Kg IV, and the control group received the same volume of saline 20 min before induction. The flumazenil group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command). We used the mask inhalation to measure the MAC-Awake by up-and-down method. The second steps, 60 patients undergoing lower abdomen surgeries were randomly divided into two groups, a experimental group (n=30) and a saline group (n=30). All patients were anesthetized with sevoflurane/sulfentanil. The experimental group received flumazenil at 0.006 mg/Kg IV, and the control group received the same volume of saline at the end of surgery. We recorded the time to awake and extubation. After extubation, the patients' recovery status was scored with the Mini-Mental state examination (MMSE) system in post anesthesia care unit (PACU). The MAC-Awake was 0.65% in the control group and 0.82% in the flumazenil group (p=0.34). After extubation, the recovery time and time to extubation showed no difference between the flumazenil group and the saline group (p>0.05). But the 10 min and 15 min MMSE scores after extubation were better in the flumazenil group than those in the saline group (p<0.05). There was no difference for MMSE scores after 30 min between two groups. We found that an IV flumazenil (0.006 mg/Kg) has

  8. Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status

    PubMed Central

    Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

    2014-01-01

    Objective: It is controversial that whether the GABA receptors contribute to the hypnotic action of volatile anesthetics. This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration–awake (MAC-Awake) and emergence mental status. Methods: This study included two steps. Firstly, 49 healthy patients, aged 20-40 years scheduled for elective surgeries, were randomly assigned to two groups, a flumazenil group (n=24) and a saline group (n=25). The flumazenil group received 0.006 mg/Kg IV, and the control group received the same volume of saline 20 min before induction. The flumazenil group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command). We used the mask inhalation to measure the MAC-Awake by up-and-down method. The second steps, 60 patients undergoing lower abdomen surgeries were randomly divided into two groups, a experimental group (n=30) and a saline group (n=30). All patients were anesthetized with sevoflurane/sulfentanil. The experimental group received flumazenil at 0.006 mg/Kg IV, and the control group received the same volume of saline at the end of surgery. We recorded the time to awake and extubation. After extubation, the patients’ recovery status was scored with the Mini-Mental state examination (MMSE) system in post anesthesia care unit (PACU). Results: The MAC-Awake was 0.65% in the control group and 0.82% in the flumazenil group (p=0.34). After extubation, the recovery time and time to extubation showed no difference between the flumazenil group and the saline group (p>0.05). But the 10 min and 15 min MMSE scores after extubation were better in the flumazenil group than those in the saline group (p<0.05). There was no difference for MMSE scores after 30 min between two groups. Conclusion: We

  9. Comparative potency of sensory-induced brainstem activation to trigger spreading depression and seizures in the cortex of awake rats: Implications for the pathophysiology of migraine aura.

    PubMed

    Vinogradova, Lyudmila V

    2015-10-01

    Migraine and epilepsy are highly co-morbid neurological disorders associated with episodic dysfunction of both cortical and subcortical networks. The study examined the interrelation between cortical spreading depression, the electrophysiological correlate of migraine aura and seizures triggered at cortical and brainstem levels by repeated sound stimulation in rats with acoustic hypersensitivity (reflex audiogenic epilepsy). In awake, freely moving rats with innate audiogenic epilepsy, 25 episodes of running seizure (brainstem seizures) were induced by repeated sound stimulation. Spreading depression and seizures were recorded using implanted cortical electrodes. The first sound-induced brainstem seizures evoked neither spreading depression nor seizures in the cortex. With repetition, brainstem seizures began to be followed by a single cortical spreading depression wave and an epileptiform discharge. Spreading depression was more frequent an early cortical event than seizures: spreading depression appeared after 8.4 ± 1.0 repeated stimulations in 100% rats (n = 24) while cortical seizures were recorded after 12.9 ± 1.2 tests in 46% rats. Brainstem seizure triggered unilateral long-latency spreading depression. Bilateral short-latency cortical spreading depression was recorded only after intense cortical seizures. These data show that episodic brainstem activation is a potent trigger of unilateral cortical spreading depression. Development of intense seizures in the cortex leads to initiation of spreading depression in multiple cortical sites of both hemispheres. © International Headache Society 2014.

  10. Bursting Activity of Substantia Nigra pars Reticulata Neurons in Mouse Parkinsonism in Awake and Anesthetized States

    PubMed Central

    Lobb, CJ; Jaeger, D

    2015-01-01

    Electrophysiological changes in basal ganglia neurons are hypothesized to underlie motor dysfunction in Parkinson’s disease (PD). Previous results in head-restrained MPTP-treated non-human primates have suggested that increased bursting within the basal ganglia and related thalamic and cortical areas may be a hallmark of pathophysiological activity. In this study, we investigated whether there is increased bursting in substantia nigra pars reticulata (SNpr) output neurons in anesthetized and awake, head-restrained unilaterally lesioned 6-OHDA mice when compared to control mice. Confirming previous studies, we show that there are significant changes in the firing rate and pattern in SNpr neuron activity under urethane anesthesia. The regular firing pattern of control urethane-anesthetized SNpr neurons was not present in the 6-OHDA-lesioned group, as the latter neurons instead became phase locked with cortical slow wave activity (SWA). Next, we examined whether such robust electrophysiological changes between groups carried over to the awake state. SNpr neurons from both groups fired at much higher frequencies in the awake state than in the anesthetized state and surprisingly showed only modest changes between awake control and 6-OHDA groups. While there were no differences in firing rate between groups in the awake state, an increase in the coefficient of variation (CV) was observed in the 6-OHDA group. Contrary to the bursting hypothesis, this increased CV was not due to changes in bursting but was instead due to a mild increase in pausing. Together, these results suggest that differences in SNpr activity between control and 6-OHDA lesioned mice may be strongly influenced by changes in network activity during different arousal and behavioral states. PMID:25576395

  11. Characterization of scale-free properties of human electrocorticography in awake and slow wave sleep States.

    PubMed

    Zempel, John M; Politte, David G; Kelsey, Matthew; Verner, Ryan; Nolan, Tracy S; Babajani-Feremi, Abbas; Prior, Fred; Larson-Prior, Linda J

    2012-01-01

    Like many complex dynamic systems, the brain exhibits scale-free dynamics that follow power-law scaling. Broadband power spectral density (PSD) of brain electrical activity exhibits state-dependent power-law scaling with a log frequency exponent that varies across frequency ranges. Widely divergent naturally occurring neural states, awake and slow wave sleep (SWS), were used to evaluate the nature of changes in scale-free indices of brain electrical activity. We demonstrate two analytic approaches to characterizing electrocorticographic (ECoG) data obtained during awake and SWS states. A data-driven approach was used, characterizing all available frequency ranges. Using an equal error state discriminator (EESD), a single frequency range did not best characterize state across data from all six subjects, though the ability to distinguish awake and SWS ECoG data in individual subjects was excellent. Multi-segment piecewise linear fits were used to characterize scale-free slopes across the entire frequency range (0.2-200 Hz). These scale-free slopes differed between awake and SWS states across subjects, particularly at frequencies below 10 Hz and showed little difference at frequencies above 70 Hz. A multivariate maximum likelihood analysis (MMLA) method using the multi-segment slope indices successfully categorized ECoG data in most subjects, though individual variation was seen. In exploring the differences between awake and SWS ECoG data, these analytic techniques show that no change in a single frequency range best characterizes differences between these two divergent biological states. With increasing computational tractability, the use of scale-free slope values to characterize ECoG and EEG data will have practical value in clinical and research studies.

  12. Cardiorespiratory parameters in the awake pigeon and during anaesthesia with isoflurane.

    PubMed

    Botman, Julie; Dugdale, Alex; Gabriel, Fabien; Vandeweerd, Jean-Michel

    2016-01-01

    To determine baseline cardiovascular and respiratory variables in the awake pigeon, and to assess those variables during anaesthesia at the individual minimal anaesthetic concentration (MAC) of isoflurane during spontaneous breathing. Prospective, experimental trial. Seven healthy adult pigeons weighing a mean ± standard deviation (SD) of 438 ± 38 g. Heart rate (HR), heart rhythm, respiratory rate (fR), end-expired carbon dioxide tension (Pe'CO2), indirect systolic arterial pressure (SAP) and cloacal temperature (T) were measured in birds in the awake state (after acclimatization to handling). Two weeks later, the pigeons were anaesthetized with isoflurane in order to determine their MAC and evaluate the same cardiovascular and respiratory variables during a further 40 minutes of isoflurane anaesthesia. In the awake pigeon, mean ± SD HR, SAP, fR, Pe'CO2 and T were, respectively, 155 ± 28 beats minute(-1), 155 ± 21 mmHg, 34 ± 6 breaths minute(-1), 38 ± 8 mmHg (5.1 ± 1.1 kPa) and 41.8 ± 0.5 °C. Mean isoflurane MAC was 1.8 ± 0.4%. During maintenance of anaesthesia at MAC, although no significant decreases between values obtained in the awake and anaesthetized states emerged in HR or respiratory rate, significant decreases in SAP and cloacal temperature and an increase in Pe'CO2 were observed. No arrhythmia was identified in awake pigeons, whereas second- and third-degree atrioventricular blocks occurred under isoflurane. Isoflurane MAC in pigeons appeared to be higher than in other avian species. Isoflurane anaesthesia in pigeons resulted in hypercapnia, hypotension, mild hypothermia and second- and third-degree atrioventricular blocks. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  13. GlideScope vs. C-MAC for Awake Upright Laryngoscopy.

    PubMed

    Drenguis, Andrea Skye; Carlson, Jestin N

    2015-09-01

    Combining video laryngoscopy with awake upright intubation may provide an alternative modality of endotracheal intubation (ETI) that avoids pitfalls associated with traditional ETI. We compared laryngoscopic views and time intervals between the GlideScope (GVL) and C-MAC video laryngoscopes using a face-to-face technique in awake, upright volunteers. We performed a prospective, randomized, crossover study performing awake upright laryngoscopy on healthy volunteers. Under local anesthesia, participants had awake upright laryngoscopy performed by a resident and attending physician, both operating GVL and C-MAC in random order. We recorded times to first view of the glottis and best view of the glottis, percentage of glottic opening (POGO) score, Cormack-Lehane grade, and number of attempts needed to visualize the glottis. We enrolled 26 subjects, 10 male and 16 female (mean age of 31.9 years). GVL had shorter time to first view of the glottis than the CMAC (median 7 s; interquartile range [IQR]: 6.5-18 s vs. 9 s; IQR: 8-13; p = 0.005). However, time to best view of the glottis was similar between devices (GVL 10.25 s; IQR: 8.5-15 s; CMAC 13 s; IQR: 10-16 s; p = 0.238). GVL had higher POGO median scores (61.25; IQR: 45.5-87.5) compared to C-MAC (5; IQR: 2.5-20.5) (p < 0.001) and improved Cormack-Lehane views (median 1.5 views; IQR: 1-2 views) compared to C-MAC (median 2 views; IQR: 2-3 views; p = 0.001). Number of attempts were similar across devices (median 1; IQR, 1-1.5) for both GVL and C-MAC (p = 0.764). GlideScope provides superior views to C-MAC in awake upright laryngoscopy in healthy volunteers. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Hypnosis for Awake Surgery of Low-grade Gliomas: Description of the Method and Psychological Assessment.

    PubMed

    Zemmoura, Ilyess; Fournier, Eric; El-Hage, Wissam; Jolly, Virginie; Destrieux, Christophe; Velut, Stéphane

    2016-01-01

    Awake craniotomy with intraoperative electric stimulation is a reliable method for extensive removal of low-grade gliomas while preserving the functional integrity of eloquent surrounding brain structures. Although fully awake procedures have been proposed, asleep-awake-asleep remains the standard technique. Anesthetic contraindications are the only limitation of this method, which is therefore not reliable for older patients with high-grade gliomas. To describe and assess a novel method for awake craniotomy based on hypnosis. We proposed a novel hypnosedation procedure to patients undergoing awake surgery for low-grade gliomas in our institution between May 2011 and April 2015. Surgical data were retrospectively recorded. The subjective experience of hypnosis was assessed by 3 standardized questionnaires: the Cohen Perceived Stress Scale, the Posttraumatic Stress Disorder Checklist Scale, the Peritraumatic Dissociative Experience Questionnaire, and a fourth questionnaire designed specifically for this study. Twenty-eight questionnaires were retrieved from 43 procedures performed on 37 patients. The Peritraumatic Dissociative Experience Questionnaire revealed a dissociation state in 17 cases. The Perceived Stress Scale was pathological in 8 patients. Two patients in this group stated that they would not accept a second hypnosedation procedure. The Posttraumatic Stress Disorder Checklist Scale revealed 1 case of posttraumatic stress disorder. Burr hole and bone flap procedures were the most frequently reported unpleasant events during opening (15 of 52 events). The main findings of our study are the effectiveness of the technique, which in all cases allowed resection of the tumor up to functional boundaries, and the positive psychological impact of the technique in most of the patients.

  15. Whole-cell patch-clamp recordings in freely moving animals.

    PubMed

    Lee, Albert K; Epsztein, Jérôme; Brecht, Michael

    2014-01-01

    The patch-clamp technique and the whole-cell measurements derived from it have greatly advanced our understanding of the coding properties of individual neurons by allowing for a detailed analysis of their excitatory/inhibitory synaptic inputs, intrinsic electrical properties, and morphology. Because such measurements require a high level of mechanical stability they have for a long time been limited to in vitro and anesthetized preparations. Recently, however, a considerable amount of effort has been devoted to extending these techniques to awake restrained/head-fixed preparations allowing for the study of the input-output functions of neurons during behavior. In this chapter we describe a technique extending patch-clamp recordings to awake animals free to explore their environments.

  16. On the symmetrization of rotational spectra for freely rotating linear molecules

    NASA Astrophysics Data System (ADS)

    Borysow, Aleksandra; Moraldi, Massimo

    It is demonstrated that the symmetrization of a quantum mechanical rotational spectrum of freely rotating linear molecules by means of the Egelstaff transformation produces a symmetric spectrum whose first two even moments coincide with the corresponding classical moments.

  17. View of a stone age adze cutting tool floating freely in the flight deck.

    NASA Technical Reports Server (NTRS)

    1992-01-01

    View of a stone age adze cutting tool floating freely in the forward flight deck and framed by the forward and side windows. On the Earth below, the big island of Hawaii can be seen through the window.

  18. Long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals

    PubMed Central

    Grand, Laszlo; Ftomov, Sergiu; Timofeev, Igor

    2012-01-01

    Parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. In this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (LFP, MUA, EOG, EMG) and activity data (accelerometer, video) from freely moving cats. The method is based on the integration of commercially available components into a simple monitoring system and is complete with accelerometers and the needed signal processing tools. LFP activities of freely moving group-housed cats were recorded from multiple intracortical areas and from the hippocampus. EMG, EOG, accelerometer and video were simultaneously acquired with LFP activities 24-h a day for 3 months. These recordings confirm the possibility of using our wireless method for 24-h long-term monitoring of neurophysiological and behavioral data of freely moving experimental animals such as cats, ferrets, rabbits and other large animals. PMID:23099345

  19. Combination of Continuous Dexmedetomidine Infusion with Titrated Ultra-Low-Dose Propofol-Fentanyl for an Awake Craniotomy.

    PubMed

    Das, Samaresh; Al-Mashani, Ali; Suri, Neelam; Salhotra, Neeraj; Chatterjee, Nilay

    2016-08-01

    An awake craniotomy is a continuously evolving technique used for the resection of brain tumours from the eloquent cortex. We report a 29-year-old male patient who presented to the Khoula Hospital, Muscat, Oman, in 2016 with a two month history of headaches and convulsions due to a space-occupying brain lesion in close proximity with the left motor cortex. An awake craniotomy was conducted using a scalp block, continuous dexmedetomidine infusion and a titrated ultra-low-dose of propofolfentanyl. The patient remained comfortable throughout the procedure and the intraoperative neuropsychological tests, brain mapping and tumour resection were successful. This case report suggests that dexmedetomidine in combination with titrated ultra-low-dose propofolfentanyl are effective options during an awake craniotomy, ensuring optimum sedation, minimal disinhibition and a rapid recovery. To the best of the authors' knowledge, this is the first awake craniotomy conducted successfully in Oman.

  20. Localizing and Beamforming Freely-Drifting VLF (Very Low Frequency) Acoustic Sensors

    DTIC Science & Technology

    1988-09-01

    iTmpf rn rnp" 0 l MARINE PHYSICAL LABORATORY SCRIPPS INSTITUTION OF OCEANOGRAPHY San Diego, California 92152 *o 0LOCALIZING AND BEAMFORMING FREELY...and beamforming techniques are illustrated using measurements from a September 1986 Swallow float experiment conducted approximately 50 miles west of...SAN DIEGO Localizing and Beamforming Freely-Drifting VLF Acoustic Sensors A dissertation submitted in partial satisfaction of the requirements for the

  1. A comparison of the Fujita classification of awake and drug-induced sleep endoscopy patients.

    PubMed

    Rabelo, Fabio Augusto Winckler; Küpper, Daniel Salgado; Sander, Heidi Haueisen; Santos Júnior, Vanier dos; Thuler, Eric; Fernandes, Regina Maria França; Valera, Fabiana Cardoso Pereira

    2013-01-01

    Only a few studies have compared the outcomes of patients kept awake during endoscopic examination and subjects submitted to drug-induced sleep endoscopy. This study aimed to compare the endoscopic findings of patients submitted to outpatient endoscopy and endoscopic examination with sedation by propofol based on the Fujita Classification. This cross-sectional cohort study enrolled 34 patients. The subjects underwent ENT examination, nasal endoscopy with Müller's maneuver, and drug-induced sleep endoscopy with propofol. The Fujita Classification was used to compare the two modes of endoscopic examination. The examinations were correlated to patient clinical data such as BMI, age, and OSAS severity. There was no agreement between the two modes of endoscopic examination, whether for the group in general or for the analyzed subgroups. There was no agreement between the endoscopic findings of endoscopic examinations done with the patient awake or in drug-induced sleep.

  2. Whisker barrel cortex delta oscillations and gamma power in the awake mouse are linked to respiration

    PubMed Central

    Ito, J.; Roy, S.; Liu, Y.; Cao, Y.; Fletcher, M.; Lu, L.; Boughter, J.D.; Grün, S.; Heck, D.H.

    2014-01-01

    Current evidence suggests that delta oscillations (0.5–4 Hz) in the brain are generated by intrinsic network mechanisms involving cortical and thalamic circuits. Here we report that delta band oscillation in spike and local field potential (LFP) activity in the whisker barrel cortex of awake mice is phase locked to respiration. Furthermore, LFP oscillations in the gamma frequency band (30–80 Hz) are amplitude modulated in phase with the respiratory rhythm. Removal of the olfactory bulb eliminates respiration-locked delta oscillations and delta-gamma phase-amplitude coupling. Our findings thus suggest respiration-locked olfactory bulb activity as a main driving force behind delta oscillations and gamma power modulation in the whisker barrel cortex in the awake state. PMID:24686563

  3. [Single-port video-assisted thoracic surgery in an awake patient].

    PubMed

    Alonso-García, F J; Navarro-Martínez, J; Gálvez, C; Rivera-Cogollos, M J; Sgattoni, C; Tarí-Bas, I M

    2016-03-01

    Video-assisted thoracic surgery is traditionally carried out with general anaesthesia and endotracheal intubation with double lumen tube. However, in the last few years procedures, such as lobectomies, are being performed with loco-regional anaesthesia, with and without sedation, maintaining the patient awake and with spontaneous breathing, in order to avoid the inherent risks of general anaesthesia, double lumen tube intubation and mechanical ventilation. This surgical approach has also shown to be effective in that it allows a good level of analgesia, maintaining a correct oxygenation and providing a better post-operative recovery. Two case reports are presented in which video-assisted thoracic surgery was used, a lung biopsy and a lung resection, both with epidural anaesthesia and maintaining the patient awake and with spontaneous ventilation, as part of a preliminary evaluation of the anaesthetic technique in this type of surgery.

  4. Brain State Effects on Layer 4 of the Awake Visual Cortex

    PubMed Central

    Zhuang, Jun; Bereshpolova, Yulia; Stoelzel, Carl R.; Huff, Joseph M.; Hei, Xiaojuan; Alonso, Jose-Manuel

    2014-01-01

    Awake mammals can switch between alert and nonalert brain states hundreds of times per day. Here, we study the effects of alertness on two cell classes in layer 4 of primary visual cortex of awake rabbits: presumptive excitatory “simple” cells and presumptive fast-spike inhibitory neurons (suspected inhibitory interneurons). We show that in both cell classes, alertness increases the strength and greatly enhances the reliability of visual responses. In simple cells, alertness also increases the temporal frequency bandwidth, but preserves contrast sensitivity, orientation tuning, and selectivity for direction and spatial frequency. Finally, alertness selectively suppresses the simple cell responses to high-contrast stimuli and stimuli moving orthogonal to the preferred direction, effectively enhancing mid-contrast borders. Using a population coding model, we show that these effects of alertness in simple cells—enhanced reliability, higher gain, and increased suppression in orthogonal orientation—could play a major role at increasing the speed of cortical feature detection. PMID:24623767

  5. Fast Hemodynamic Responses in the Visual Cortex of the Awake Mouse

    PubMed Central

    Pisauro, M. Andrea; Dhruv, Neel T.; Benucci, Andrea

    2013-01-01

    Hemodynamic responses in mice and other species are typically measured under anesthesia. However, anesthesia could influence their relationship to neural activity. To investigate this relationship, we used optical imaging in mouse primary visual cortex (V1). Hemodynamic responses yielded clear maps of retinotopy in both anesthetized and awake mice. However, during wakefulness, responses were four times larger and twice as fast. These differences held whether we induced anesthesia with urethane or isoflurane and whether awake mice were stationary or running on a treadmill. With electrode recordings, we established that the effects of wakefulness reflect changes in neurovascular coupling, not in neural activity. By activating V1 directly via optogenetics, we replicated the effects of wakefulness in terms of timing but not of amplitude. We conclude that neurovascular coupling depends critically on anesthesia and wakefulness: during wakefulness, neural activity is followed by much stronger and quicker hemodynamic responses. PMID:24227743

  6. 5-aminolevulinic acid guidance during awake craniotomy to maximise extent of safe resection of glioblastoma multiforme.

    PubMed

    Corns, Robert; Mukherjee, Soumya; Johansen, Anja; Sivakumar, Gnanamurthy

    2015-07-15

    Overall survival for patients with glioblastoma multiforme (GBM) has been consistently shown to improve when the surgeon achieves a gross total resection of the tumour. It has also been demonstrated that surgical adjuncts such as 5-aminolevulinic acid (5-ALA) fluorescence--which delineates malignant tumour tissue--normal brain tissue margin seen using violet-blue excitation under an operating microscope--helps achieve this. We describe the case of a patient with recurrent left frontal GBM encroaching on Broca's area (eloquent brain). Gross total resection of the tumour was achieved by combining two techniques, awake resection to prevent damage to eloquent brain and 5-ALA fluorescence guidance to maximise the extent of tumour resection.This technique led to gross total resection of all T1-enhancing tumour with the avoidance of neurological deficit. The authors recommend this technique in patients when awake surgery can be tolerated and gross total resection is the aim of surgery.

  7. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences.

    PubMed

    Takahashi, Susumu

    2015-10-20

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as 'what' information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only 'where and when' but also 'what' information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process.

  8. Behavioral Effects of Acclimatization To Restraint Protocol Used for Awake Animal Imaging

    PubMed Central

    Reed, Michael D.; Pira, Ashley S.; Febo, Marcelo

    2013-01-01

    Functional MRI of awake rats involves acclimatization to restraint to minimize motion. We designed a study to examine the effects of an acclimatization protocol (5 days of restraint, 60 minutes per day) on the emission of 22-kHz ultrasonic vocalizations and performance on a forced swim test (FST). Our results show that USV calls are reduced significantly by day 3, 4 and 5 of acclimatization. Although rats show less climbing activity (and more immobility) in FST on day 5 compared to the 1st day of restraint acclimatization, the difference is gone once animals are given a 2 week hiatus. Overall, we show that animals adapt to the restraint over the five day period, however, restraint may introduce confounding behavioral outcomes that may hinder the interpretation of results derived from awake rat imaging. The present data warrant further testing of the effects of MRI restraint on behavior. PMID:23562621

  9. Behavioral effects of acclimatization to restraint protocol used for awake animal imaging.

    PubMed

    Reed, Michael D; Pira, Ashley S; Febo, Marcelo

    2013-07-15

    Functional MRI in awake rats involves acclimatization to restraint to minimize motion. We designed a study to examine the effects of an acclimatization protocol (5 days of restraint, 60 min per day) on the emission of 22-kHz ultrasonic vocalizations and performance in a forced swim test (FST). Our results showed that USV calls are reduced significantly by days 3, 4 and 5 of acclimatization. Although the rats showed less climbing activity (and more immobility) in FST on day 5 compared to the 1st day of restraint acclimatization, the difference was not detected once the animals were given a 2-week hiatus. Overall, we showed that animals adapt to the restraint over a five-day period; however, restraint may introduce confounding behavioral outcomes that may hinder the interpretation of results derived from awake rat imaging. The present data warrants further testing of the effects of MRI restraint on behavior. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. GHz modulation detection using a streak camera: Suitability of streak cameras in the AWAKE experiment

    NASA Astrophysics Data System (ADS)

    Rieger, K.; Caldwell, A.; Reimann, O.; Muggli, P.

    2017-02-01

    Using frequency mixing, a modulated light pulse of ns duration is created. We show that, with a ps-resolution streak camera that is usually used for single short pulse measurements, we can detect via an FFT detection approach up to 450 GHz modulation in a pulse in a single measurement. This work is performed in the context of the AWAKE plasma wakefield experiment where modulation frequencies in the range of 80-280 GHz are expected.

  11. Ventilatory responses to acute metabolic acidemia in humans awake, sedated, and anesthetized with halothane.

    PubMed

    Knill, R L; Clement, J L

    1985-06-01

    The authors produced metabolic acidemia acutely in human subjects awake, sedated with halothane (0.1 MAC), and anesthetized with halothane (1.0 MAC) by infusing L-arginine hydrochloride, 5-6 mmol X kg-1, over 3 h. Ventilation was recorded at resting arterial hydrogen ion concentration [( H+]a) and at 2-4 isocapnic increments of [H+]a, in each case, while end-tidal oxygen tension (PETO2) was varied between greater than 300 mmHg and 45 mmHg. Total increments of [H+]a in awake, sedated, and anesthetized subjects were 13 +/- 4, 12 +/- 2, and 12 +/- 3 nmol X 1(-1) (means +/- SD). In the awake state, metabolic acidemia increased ventilation (VI) in proportion to [H+]a. The magnitude of response increased with reduced PETO2, such that the response to acidemia and hypoxemia combined was synergistic. The delta VI/delta [H+]a slopes at PETO2 values of greater than 300, 100-120, and 45 mmHg were 0.47 +/- 0.27, 0.85 +/- 0.24, and 3.01 +/- 1.30 1 X min-1 X nmol-1 X 1, respectively (means +/- SD). Halothane sedation reduced the responses to added [H+]a determined at PETO2 values of 100-120 and 45 mmHg, as well as the response to hypoxemia and to the interaction of acidemia and hypoxemia, each to less than half awake values. Halothane anesthesia further impaired the responses to [H+]a and virtually abolished the response to hypoxemia and to acidemia-hypoxemia interaction. A small residual response to added [H+]a during anesthesia could be accounted for by a slight concurrent increase of PaCO2, leaving no response attributable to metabolic [H+]a itself.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. "Awake Veno-arterial Extracorporeal Membrane Oxygenation" in Pediatric Cardiogenic Shock: A Single-Center Experience.

    PubMed

    Schmidt, F; Jack, T; Sasse, M; Kaussen, T; Bertram, H; Horke, A; Seidemann, K; Beerbaum, P; Koeditz, H

    2015-12-01

    In pediatric patients with acute refractory cardiogenic shock (CS), extracorporeal membrane oxygenation (ECMO) remains an established procedure to maintain adequate organ perfusion. In this context, ECMO can be used as a bridging procedure to recovery, VAD or transplantation. While being supported by ECMO, most centers tend to keep their patients well sedated and supported by invasive ventilation. This may be associated with an increased risk of therapy-related morbidity and mortality. In order to optimize clinical management in pediatric patients with ECMO therapy, we report our strategy of veno-arterial ECMO (VA-ECMO) in extubated awake and conscious patients. We therefore present data of six of our patients with CS, who were treated by ECMO being awake without continuous analgosedation and invasive ventilation. Of these six patients, four were <1 year and two >14 years of age. Median time on ECMO was 17.4 days (range 6.9-94.2 days). Median time extubated, while receiving ECMO support was 9.5 days. Mean time extubated was 78 % of the total time on ECMO. Three patients reached full recovery of cardiac function on "Awake-VA-ECMO," whereas the other three were successfully bridged to destination therapy (VAD, heart transplantation, withdrawal). Four out of our six patients are still alive. Complications related to ECMO therapy (i.e., severe bleeding, site infection or dislocation of cannulas) were not observed. We conclude that "Awake-VA-ECMO" in extubated, spontaneously breathing conscious pediatric patients is feasible and safe for the treatment of acute CS and can be used as a "bridging therapy" to recovery, VAD implantation or transplantation.

  13. Awake nasotracheal intubation using fiberoptic bronchoscope in a pediatric patient with Freeman-Sheldon syndrome.

    PubMed

    Kim, J S; Park, S Y; Min, S K; Kim, J H; Lee, S Y; Moon, B K

    2005-09-01

    The Freeman-Sheldon syndrome is a congenital disease primarily affecting the facial, limb and respiratory muscles that give rise to classical clinical features including typical whistling face and short webbed neck associated with difficult intubation. We present successful awake nasotracheal intubation in a 6-year-old patient with typical clinical features of Freeman-Sheldon syndrome by using fiberoptic bronchoscope on two separate occasions.

  14. Development of a simultaneous optical/PET imaging system for awake mice

    NASA Astrophysics Data System (ADS)

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [11C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [11C]raclopride radioactivity concentration simultaneously. Accumulation of [11C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models.

  15. Translation of the glenohumeral joint in patients with anterior instability: awake examination versus examination with the patient under anesthesia.

    PubMed

    Faber, K J; Homa, K; Hawkins, R J

    1999-01-01

    Fifty patients with a clinical diagnosis of traumatic anterior shoulder instability underwent bilateral shoulder translation testing while both awake and under anesthesia. Each patient was examined by 2 surgeons following guidelines developed by the American Shoulder and Elbow Surgeons. A single translation grade was established for anterior, posterior, and inferior directions. A comparison of means was performed with a paired t test. The mean anterior translation grade was significantly higher on the affected side when compared with that of the unaffected side both during awake examination and during examination with the patient under anesthesia (EUA). Ipsilateral comparison revealed significantly greater translation for both affected and unaffected shoulders in anterior, posterior, and inferior directions during EUA than during awake examination. Side-to-side comparison of posterior and inferior translation was similar for both awake examination and EUA. Clinical translation testing was helpful in the diagnosis of anterior shoulder instability. Side-to-side differences were subtle while awake and more apparent during EUA. The usefulness of awake translation testing for traumatic anterior instability was not clearly demonstrated; however, EUA provides helpful information to confirm the direction and degree of instability.

  16. Spectrotemporal Response Properties of Core Auditory Cortex Neurons in Awake Monkey

    PubMed Central

    Massoudi, Roohollah; Van Wanrooij, Marc M.; Versnel, Huib; Van Opstal, A. John

    2015-01-01

    So far, most studies of core auditory cortex (AC) have characterized the spectral and temporal tuning properties of cells in non-awake, anesthetized preparations. As experiments in awake animals are scarce, we here used dynamic spectral-temporal broadband ripples to study the properties of the spectrotemporal receptive fields (STRFs) of AC cells in awake monkeys. We show that AC neurons were typically most sensitive to low ripple densities (spectral) and low velocities (temporal), and that most cells were not selective for a particular spectrotemporal sweep direction. A substantial proportion of neurons preferred amplitude-modulated sounds (at zero ripple density) to dynamic ripples (at non-zero densities). The vast majority (>93%) of modulation transfer functions were separable with respect to spectral and temporal modulations, indicating that time and spectrum are independently processed in AC neurons. We also analyzed the linear predictability of AC responses to natural vocalizations on the basis of the STRF. We discuss our findings in the light of results obtained from the monkey midbrain inferior colliculus by comparing the spectrotemporal tuning properties and linear predictability of these two important auditory stages. PMID:25680187

  17. Information flow and coherence of EEG during awake, meditation and drowsiness.

    PubMed

    Dissanayaka, Chamila; Ben-Simon, Eti; Gruberger, Michal; Maron-Katz, Adi; Hendler, Talma; Chaparro-Vargas, Ramiro; Cvetkovic, Dean

    2014-01-01

    A comparison of coupling (information flow) and coherence (connectedness) of the brain regions between human awake, meditation and drowsiness states was carried out in this study. The Directed Transfer Function (DTF) method was used to estimate the coupling or brain's flow of information between different regions during each condition. Welch and Minimum Variance Distortionless Response (MVDR) methods were utilised to estimate the coherence between brain areas. Analysis was conducted using the EEG data of 30 subjects (10 awake, 10 drowsiness and 10 meditating) with 6 EEG electrodes. The EEG data was recorded for each subject during 5 minutes baseline and 15 minutes of three specific conditions (awake, meditation or drowsiness). Statistical analysis was carried out which consisted of the Kruskal-Wallis (KW) non-parametric analysis of variance followed by post-hoc tests with Bonferroni alpha-correction. The results of this study revealed that a change in external awareness led to substantial differences in the spectral profile of the brain's information flow as well as it's connectedness.

  18. Physiotherapy for Patients on Awake Extracorporeal Membrane Oxygenation: A Systematic Review.

    PubMed

    Polastri, Massimiliano; Loforte, Antonino; Dell'Amore, Andrea; Nava, Stefano

    2016-12-01

    Extracorporeal membrane oxygenation (ECMO) is used as temporary life support in subjects with potentially reversible respiratory/cardiac failure. The principal purpose of this review was to assess the characteristics and potential advantages of physiotherapeutic interventions in subjects on awake ECMO support. Seven databases were interrogated: we searched titles, abstracts and keywords using the Medical Subject Headings terms 'extracorporeal membrane oxygenation' and 'rehabilitation' linked with the Boolean operator 'AND'. In total, 216 citations were retrieved. Nine citations satisfied our inclusion criteria and were subjected to full-text analysis. The numbers of patients enrolled in the included studies (most of which were case series) were low (n = 52). We found no prospective studies or randomized controlled trials. Overall, subjects on awake ECMO usually received a combination of passive and active physiotherapy, and most achieved an acceptable degree of autonomy after treatment. Emerging research in the field affords preliminary evidence supporting the safety of early mobilization and ambulation in patients on awake veno-venous ECMO support. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse.

    PubMed

    Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

    2017-02-27

    Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca(2+) imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca(2+) imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain.

  20. Awake craniotomy vs surgery under general anesthesia for resection of supratentorial lesions.

    PubMed

    Sacko, Oumar; Lauwers-Cances, Valérie; Brauge, David; Sesay, Musa; Brenner, Adam; Roux, Franck-Emmanuel

    2011-05-01

    The use of an awake craniotomy in the treatment of supratentorial lesions is a challenge for both patients and staff in the operation theater. To assess the safety and effectiveness of an awake craniotomy with brain mapping in comparison with a craniotomy performed under general anesthesia. We prospectively compared 2 groups of patients who underwent surgery for supratentorial lesions: those in whom an awake craniotomy with intraoperative brain mapping was used (AC group, n = 214) and those in whom surgery was performed under general anesthesia (GA group, n = 361, including 72 patients with lesions in eloquent areas). The AC group included lesions in close proximity to the eloquent cortex that were surgically treated on an elective basis. Globally, the 2 groups were comparable in terms of sex, age, American Society of Anesthesiologists score, pathology, size of lesions, quality of resection, duration of surgery, and neurological outcome, and different in tumor location and preoperative neurological deficits (higher in the AC group). However, specific data analysis of patients with lesions in eloquent areas revealed a significantly better neurological outcome and quality of resection (P < .001) in the AC group than the subgroup of GA patients with lesions in eloquent areas. Surgery was uneventful in AC patients and they were discharged home sooner. AC with brain mapping is safe and allows maximal removal of lesions close to functional areas with low neurological complication rates. It provides an excellent alternative to craniotomy under GA.

  1. Expression of anion exchanger 3 influences respiratory rate in awake and isoflurane anesthetized mice.

    PubMed

    Meier, S; Hübner, C A; Groeben, H; Peters, J; Bingmann, D; Wiemann, M

    2007-11-01

    The anion exchanger 3 (AE3) is involved in neuronal pH regulation of which may include chemosensitive neurons. Here we examined the effect of AE3 expression on respiratory rate (RR) in vivo. AE3 knockout (KO, n=5) and wild type (WT, n=6) mice were subjected to body plethysmography, both while awake and during isoflurane anesthesia. RR was significantly lower in awake AE3 KO (162+/-7SE min(-1)) than in WT mice (212+/-20 min(-1), P=0.036). The same was found during isoflurane anesthesia at 0.5 MAC (KO: 123+/-9 min(-1), WT: 168+/-15 min(-1), P=0.026) and 1.0 MAC (KO: 51+/-6 min(-1), WT: 94+/-6 min(-1), P=0.001). Hypercapnia (5% CO2) increased RR in awake and decreased RR in nesthetized (1.0 MAC) mice, whereby relative changes were larger in AE3 KO mice. Recovery from isoflurane anesthesia in respect to RR regaining baseline values was more pronounced in AE3 KO. Results show that AE3 expression profoundly influences control of breathing in mice.

  2. [Difficult Ventilation Requiring Emergency Endotracheal Intubation during Awake Craniotomy Managed by Laryngeal Mask Airway].

    PubMed

    Matsuda, Asako; Mizota, Toshiyuki; Tanaka, Tomoharu; Segawa, Hajime; Fukuda, Kazuhiko

    2016-04-01

    We report a case of difficult ventilation requiring emergency endotracheal intubation during awake craniotomy managed by laryngeal mask airway (LMA). A 45-year-old woman was scheduled to receive awake craniotomy for brain tumor in the frontal lobe. After anesthetic induction, airway was secured using ProSeal LMA and patient was mechanically ventilated in pressure-control mode. Patient's head was fixed with head-pins at anteflex position, and the operation started. About one hour after the start of the operation, tidal volume suddenly decreased. We immediately started manual ventilation, but the airway resistance was extremely high and we could not adequately ventilate the patient. We administered muscle relaxant for suspected laryngospasm, but ventilatory status did not improve; so we decided to conduct emergency endotracheal intubation. We tried to intubate using Airwayscope or LMA-Fastrach, but they were not effective in our case. Finally trachea was intubated using transnasal fiberoptic bronchoscopy. We discuss airway management during awake craniotomy, focusing on emergency endotracheal intubation during surgery.

  3. Direct Medial Entorhinal Cortex Input to Hippocampal CA1 Is Crucial for Extended Quiet Awake Replay.

    PubMed

    Yamamoto, Jun; Tonegawa, Susumu

    2017-09-27

    Hippocampal replays have been demonstrated to play a crucial role in memory. Chains of ripples (ripple bursts) in CA1 have been reported to co-occur with long-range place cell sequence replays during the quiet awake state, but roles of neural inputs to CA1 in ripple bursts and replays are unknown. Here we show that ripple bursts in CA1 and medial entorhinal cortex (MEC) are temporally associated. An inhibition of MECIII input to CA1 during quiet awake reduced ripple bursts in CA1 and restricted the spatial coverage of replays to a shorter distance corresponding to single ripple events. The reduction did not occur with MECIII input inhibition during slow-wave sleep. Inhibition of CA3 activity suppressed ripples and replays in CA1 regardless of behavioral state. Thus, MECIII input to CA1 is crucial for ripple bursts and long-range replays specifically in quiet awake, whereas CA3 input is essential for both, regardless of behavioral state. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse

    PubMed Central

    Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

    2017-01-01

    Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca2+ imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca2+ imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain. PMID:28240275

  5. Prospective pilot trial of dexmedetomidine sedation for awake diagnostic flexible bronchoscopy.

    PubMed

    Lee, Keat; Orme, Ruari; Williams, Daryl; Segal, Reny

    2010-10-01

    Dexmedetomidine has the favorable properties of sedation, sympatholysis, analgesia, and a low risk of apnea. These properties suggest that dexmedetomidine may be useful in procedural sedation. In view of this, we conducted a pilot trial to determine the feasibility of using dexmedetomidine as a sole agent for providing sedation during awake diagnostic flexible bronchoscopy. Patients presenting for awake diagnostic flexible bronchoscopy consented to participate in a trial of dexmedetomidine sedation for the procedure. In addition to local anesthetic topicalization of the airways, dexmedetomidine was infused at 0.5 μg/kg over 10 minutes followed by an infusion of 0.2 to 0.7 μg/kg/h titrating to a Ramsay Sedation Scale score of 3. Hemodynamic parameters (heart rate, blood pressure), oxygenation status (pulse oximetry), adverse events, use of rescue sedation, and patient and proceduralist satisfaction were recorded during the trial. Five of 9 recruited patients required rescue sedation to allow the procedure to proceed. Dexmedetomidine as a sole agent at an infusion of 0.5 μg/kg over 10 minutes followed by an infusion of 0.2 to 0.7 μg/kg/h is unable to provide adequate sedation for awake diagnostic flexible bronchoscopy without the need for rescue sedation in a large proportion of patients.

  6. Effect on breathing of surface ventrolateral medullary cooling in awake, anesthetized and asleep goats.

    PubMed

    Forster, H V; Ohtake, P J; Pan, L G; Lowry, T F

    1997-11-01

    In adult and neonatal goats, we chronically implanted thermodes on the ventrolateral (VLM) medullary surface to create reversible neuronal dysfunction and thereby gain insight into the role of superficial VLM neurons in control of breathing in anesthetized, awake and asleep states. Consistent with data of others, cooling caudal area M and rostral area S caused sustained apnea under anesthesia. However, in the awake and NREM sleep states, cooling at this site caused only a modest reduction in breathing, indicating that neurons at this site are not critical for respiratory rhythm in these states. Moreover, data in the awake state over multiple conditions suggest neurons at this site do not integrate all intracranial and carotid chemoreception. The data suggest though that neurons at this site have a facilitatory-like effect on breathing both unrelated and related to intracranial chemoreception. We believe that this facilitation serves a function similar to the facilitation provided by the carotid chemoreceptors and by sources associated with wakefulness. Accordingly, elimination/attenuation of any one of these three influences (caudal M rostral S VLM, wakefulness, carotid chemoreception) results in a slight decrease in breathing, removal of two of the three results in a greater decrease in breathing, and removal of all three results in sustained apnea.

  7. Some effects of vagal blockade on abdominal muscle activation and shortening in awake dogs.

    PubMed Central

    Leevers, A M; Road, J D

    1995-01-01

    1. The mechanisms of abdominal muscle activation are thought to be different during expiratory threshold loading (ETL) compared with hypercapnia. Our objectives in the present study were to determine the effects of removing excitatory vagal feedback on abdominal muscle activation, shortening and pattern of recruitment during ETL and hypercapnia. Six tracheotomized dogs were chronically implanted with sonomicrometer transducers and fine wire EMG electrodes in each of the four abdominal muscles. Muscle length changes and EMG activity were studied in the awake dog during ETL (6 dogs) and CO2 rebreathing (3 dogs), before and after vagal blockade. 2. Following vagal blockade, the change in volume (increase in functional residual capacity, FRC) during ETL was greater and active phasic shortening of all the abdominal muscles was reduced, when shortening was compared with a similar change in lung volume. Similarly, at comparable minute ventilation, abdominal muscle active shortening was also reduced during hypercapnia. The internal muscle layer was recruited preferentially in both control and vagally blocked dogs during both ETL and hypercapnia. 3. The degree of recruitment of the abdominal muscles during ETL and hypercapnia in awake dogs is influenced by vagal feedback, but less so than in anaesthetized dogs. These results illustrate the importance of the vagi and abdominal muscle activation in load compensation. However, vagal reflexes are apparently not contributing to the preferential recruitment of the internal muscle layer. In awake dogs during vagal blockade abdominal muscle recruitment still occurs by extravagal mechanisms. PMID:8568685

  8. Variety of Well behaved parametric classes of relativistic charged fluid spheres in general relativity

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Rajasekhara, S.

    2011-05-01

    The paper presents a variety of classes of interior solutions of Einstein-Maxwell field equations of general relativity for a static, spherically symmetric distribution of the charged fluid with well behaved nature. These classes of solutions describe perfect fluid balls with positively finite central pressure, positively finite central density; their ratio is less than one and causality condition is obeyed at the center. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing for these solutions. Keeping in view of well behaved nature of these solutions, two new classes of solutions are being studied extensively. Moreover, these classes of solutions give us wide range of constant K for which the solutions are well behaved hence, suitable for modeling of super dense star. For solution (I1) the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3 corresponding to K=1.19 and X=0.20, the maximum mass of the star comes out to be 2.5 M Θ with linear dimension 25.29 Km and central redshift 0.2802. It has been observed that with the increase of charge parameter K, the mass of the star also increases. For n=4,5,6,7, the charged solutions are well behaved with their neutral counterparts however, for n=1,2,3, the charged solution are well behaved but their neutral counterparts are not well behaved.

  9. A class of well behaved charged analogues of Vaidya-Tikekar type super-dense star

    NASA Astrophysics Data System (ADS)

    Gupta, Y. K.; Kumar, Jitendra

    2011-08-01

    In the present article a model of well behaved charged superdense star with surface density 2×1014 gm/cm3 is constructed by considering a static spherically symmetric metric with t=const hypersurfaces as hyperboloid. So far well behaved model described by such metric could not be obtained. Maximum mass of the star is found to be 0.343457 M ⊙ and the corresponding radius is 9.57459 km. The red shift at the centre and on the surface are given as 0.068887 and 0.031726 respectively.

  10. A silicon-based microelectrode array with a microdrive for monitoring brainstem regions of freely moving rats.

    PubMed

    Márton, G; Baracskay, P; Cseri, B; Plósz, B; Juhász, G; Fekete, Z; Pongrácz, A

    2016-04-01

    Exploring neural activity behind synchronization and time locking in brain circuits is one of the most important tasks in neuroscience. Our goal was to design and characterize a microelectrode array (MEA) system specifically for obtaining in vivo extracellular recordings from three deep-brain areas of freely moving rats, simultaneously. The target areas, the deep mesencephalic reticular-, pedunculopontine tegmental-and pontine reticular nuclei are related to the regulation of sleep-wake cycles. The three targeted nuclei are collinear, therefore a single-shank MEA was designed in order to contact them. The silicon-based device was equipped with 3 × 4 recording sites, located according to the geometry of the brain regions. Furthermore, a microdrive was developed to allow fine actuation and post-implantation relocation of the probe. The probe was attached to a rigid printed circuit board, which was fastened to the microdrive. A flexible cable was designed in order to provide not only electronic connection between the probe and the amplifier system, but sufficient freedom for the movements of the probe as well. The microdrive was stable enough to allow precise electrode targeting into the tissue via a single track. The microelectrodes on the probe were suitable for recording neural activity from the three targeted brainstem areas. The system offers a robust solution to provide long-term interface between an array of precisely defined microelectrodes and deep-brain areas of a behaving rodent. The microdrive allowed us to fine-tune the probe location and easily scan through the regions of interest.

  11. Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

    PubMed Central

    Rossaint, Rolf; Veldeman, Michael

    2016-01-01

    Background Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques. Methods Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI]. Results We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1–3], 8% [95%CI:6–11], 17% [95%CI:12–23] and 2% [95%CI:2–3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36–2.69], 1.01 [95%CI:0.52–1.88] for seizures, 1.66 [95%CI:1.35–3.70] for new neurological dysfunction and 2.17 [95%CI:1.22–3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was

  12. Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis.

    PubMed

    Stevanovic, Ana; Rossaint, Rolf; Veldeman, Michael; Bilotta, Federico; Coburn, Mark

    2016-01-01

    Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques. Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI]. We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1-3], 8% [95%CI:6-11], 17% [95%CI:12-23] and 2% [95%CI:2-3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36-2.69], 1.01 [95%CI:0.52-1.88] for seizures, 1.66 [95%CI:1.35-3.70] for new neurological dysfunction and 2.17 [95%CI:1.22-3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was abolished in a sensitivity analysis of only

  13. NR2B Antagonist CP-101,606 Abolishes Pitch-Mediated Deviance Detection in Awake Rats.

    PubMed

    Sivarao, Digavalli V; Chen, Ping; Yang, Yili; Li, Yu-Wen; Pieschl, Rick; Ahlijanian, Michael K

    2014-01-01

    Schizophrenia patients exhibit a decreased ability to detect change in their auditory environment as measured by auditory event-related potentials (ERP) such as mismatch negativity. This deficit has been linked to abnormal NMDA neurotransmission since, among other observations, non-selective channel blockers of NMDA reliably diminish automatic deviance detection in human subjects as well as in animal models. Recent molecular and functional evidence links NR2B receptor subtype to aberrant NMDA transmission in schizophrenia. However, it is unknown if NR2B receptors participate in pre-attentive deviance detection. We recorded ERP from the vertex of freely behaving rats in response to frequency mismatch protocols. We saw a robust increase in N1 response to deviants compared to standard as well as control stimuli indicating true deviance detection. Moreover, the increased negativity was highly sensitive to deviant probability. Next, we tested the effect of a non-selective NMDA channel blocker (ketamine, 30 mg/kg) and a highly selective NR2B antagonist, CP-101,606 (10 or 30 mg/kg) on deviance detection. Ketamine attenuated deviance mainly by increasing the amplitude of the standard ERP. Amplitude and/or latency of several ERP components were also markedly affected. In contrast, CP-101,606 robustly and dose-dependently inhibited the deviant's N1 amplitude, and as a consequence, completely abolished deviance detection. No other ERPs or components were affected. Thus, we report first evidence that NR2B receptors robustly participate in processes of automatic deviance detection in a rodent model. Lastly, our model demonstrates a path forward to test specific pharmacological hypotheses using translational endpoints relevant to aberrant sensory processing in schizophrenia.

  14. BEHAVE: fire behavior prediction and fuel modeling system--FUEL subsystem

    Treesearch

    Robert E. Burgan; Richard C. Rothermel

    1984-01-01

    This manual documents the fuel modeling procedures of BEHAVE--a state-of-the-art wildland fire behavior prediction system. Described are procedures for collecting fuel data, using the data with the program, and testing and adjusting the fuel model.

  15. Collaborating with Parents for Early School Success: The Achieving-Behaving-Caring Program

    ERIC Educational Resources Information Center

    McConaughy, Stephanie H.; Kay, Pam; Welkowitz, Julie A.; Hewitt, Kim; Fitzgerald, Martha D.

    2007-01-01

    The Achieving-Behaving-Caring (ABC) Program is an evidence-based approach to addressing the needs of elementary students at risk for emotional and behavioral difficulties and promoting successful home-school collaboration. This practical guide demonstrates how classroom teachers and parents can work together to boost individual children's…

  16. Modeling moisture content of fine dead wildland fuels: Input to the BEHAVE fire prediction system

    Treesearch

    Richard C. Rothermel; Ralph A. Wilson; Glen A. Morris; Stephen S. Sackett

    1986-01-01

    Describes a model for predicting moisture content of fine fuels for use with the BEHAVE fire behavior and fuel modeling system. The model is intended to meet the need for more accurate predictions of fine fuel moisture, particularly in northern conifer stands and on days following rain. The model is based on the Canadian Fine Fuel Moisture Code (FFMC), modified to...

  17. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats.

    PubMed

    Tang, Jianbo; Coleman, Jason E; Dai, Xianjin; Jiang, Huabei

    2016-05-05

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents.

  18. A family of well-behaved Karmarkar spacetimes describing interior of relativistic stars

    NASA Astrophysics Data System (ADS)

    Singh, Ksh. Newton; Pant, Neeraj

    2016-10-01

    We present a family of new exact solutions for relativistic anisotropic stellar objects by considering a four-dimensional spacetime embedded in a five-dimensional pseudo Euclidean space, known as Class I solutions. These solutions are well behaved in all respects, satisfy all energy conditions, and the resulting compactness parameter is also within Buchdahl limit. The well-behaved nature of the solutions for a particular star solely depends on the index n. We have discussed the solutions in detail for the neutron star XTE J1739-285 (M=1.51M_⊙, ~R=10.9 km). For this particular star, the solution is well behaved in all respects for 8 ≤ n ≤ 20. However, the solutions with n<8 possess an increasing trend of the sound speed and the solutions belonging to n>20 disobey the causality condition. Further, the well-behaved nature of the solutions for PSR J0348+0432 (2.01M_⊙, ~11 km), EXO 1785-248 (1.3M_⊙, 8.85 km), and Her X-1 (0.85M_⊙, 8.1 km) are specified by the index n with limits 24 ≤ n ≤ 54, 1.5 ≤ n ≤ 4, and 0.8 ≤ n ≤ 2.7, respectively.

  19. BehavePlus fire modeling system, version 5.0: Design and Features

    Treesearch

    Faith Ann Heinsch; Patricia L. Andrews

    2010-01-01

    The BehavePlus fire modeling system is a computer program that is based on mathematical models that describe wildland fire behavior and effects and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a host of fire management applications, including projecting the behavior of an ongoing fire, planning...

  20. Bioreactivity: Studies on a Simple Brain Stem Reflex in Behaving Animals

    DTIC Science & Technology

    1990-01-04

    examining NE neurons in the locus coeruleus (LC) of behaving cats under physiologically and/or ecologically relevant conditions. This work is now...virtually completed except for one study on LC neuronal activity during the feline defense reaction. These studies may be summarized by saying that the

  1. New class of well behaved exact Solutions for static charged Neutron-star with perfect fluid

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj

    2012-01-01

    The paper presents a class of interior solutions of Einstein-Maxwell field equations in general relativity for a static spherically symmetric distribution of a charged fluid. This class of solutions describes well behaved charged fluid balls. This solution gives us wide range of parameter K (0.53≤ K≤0.95), for which the solution is well behaved hence, suitable for modeling of super dense star. For this solution the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3. Corresponding to K=0.95 with X=-0.15, the maximum mass of the star comes out to be M=1.56 M Θ with radius r b ≈9.22 km and the surface red shift Z b ≈0.124207. It has been observed that under well behaved conditions this class of solutions gives us the mass of super dense object within the range of neutron star. However, its neutral counter part is not well behaved.

  2. BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

    Treesearch

    Patricia L. Andrews

    1986-01-01

    Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

  3. BEHAVE: fire behavior prediction and fuel modeling system - BURN subsystem, Part 2

    Treesearch

    Patricia L. Andrews; Carolyn H. Chase

    1989-01-01

    This is the third publication describing the BEHAVE system of computer programs for predicting behavior of wildland fires. This publication adds the following predictive capabilities: distance firebrands are lofted ahead of a wind-driven surface fire, probabilities of firebrands igniting spot fires, scorch height of trees, and percentage of tree mortality. The system...

  4. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats

    PubMed Central

    Tang, Jianbo; Coleman, Jason E.; Dai, Xianjin; Jiang, Huabei

    2016-01-01

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents. PMID:27146026

  5. BehavePlus fire modeling system, version 4.0: User's Guide

    Treesearch

    Patricia L. Andrews; Collin D. Bevins; Robert C. Seli

    2005-01-01

    The BehavePlus fire modeling system is a program for personal computers that is a collection of mathematical models that describe fire and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a multitude of fire management applications including projecting the behavior of an ongoing fire, planning...

  6. An Investigation of the Family Characteristics of Bullies, Victims, and Positively Behaving Adolescents

    ERIC Educational Resources Information Center

    Cenkseven Onder, Fulya; Yurtal, Filiz

    2008-01-01

    The present study investigated the family characteristics of bullies, victims, and positively behaving adolescents. The study was conducted in three elementary schools in Adana central province with students who were attending 6th-7th, and 8th grades. A who-is-who form prepared by the researchers was used for the determination of the family…

  7. A well-behaved class of charged analogue of Durgapal solution

    NASA Astrophysics Data System (ADS)

    Mehta, R. N.; Pant, Neeraj; Mahto, Dipo; Jha, J. S.

    2013-02-01

    We present a well behaved class of charged analogue of M.C. Durgapal (J. Phys. A, Math. Gen. 15:2637, 1982) solution. This solution describes charged fluid balls with positively finite central pressure, positively finite central density; their ratio is less than one and causality condition is obeyed at the centre. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing, however, the electric intensity is monotonically increasing in nature. This solution gives us wide range of parameter for every positive value of n for which the solution is well behaved hence, suitable for modeling of super dense stars. Keeping in view of well behaved nature of this solution, one new class of solution is being studied extensively. Moreover, this class of solution gives us wide range of constant K (0≤ K≤2.2) for which the solution is well behaved hence, suitable for modeling of super dense stars like strange quark stars, neutron stars and pulsars. For this class of solution the mass of a star is maximized with all degree of suitability, compatible with quark stars, neutron stars and pulsars. By assuming the surface density ρ b =2×1014 g/cm3 (like, Brecher and Capocaso, Nature 259:377, 1976), corresponding to K=0 with X=0..235, the resulting well behaved model has the mass M=4.03 M Θ , radius r b =19.53 km and moment of inertia I=1.213×1046 g cm2; for K=1.5 with X=0.235, the resulting well behaved model has the mass M=4.43 M Θ , radius r b =18.04 km and moment of inertia I=1.136×1046 g cm2; for K=2.2 with X=0.235, the resulting well behaved model has the mass M=4.56 M Θ , radius r b =17.30 km and moment of inertia I=1.076×1046 g cm2. These values of masses and moment of inertia are found to be consistent with the crab pulsars.

  8. The effect of adenosine triphosphate on sevoflurane requirements for minimum alveolar anesthetic concentration and minimum alveolar anesthetic concentration-awake.

    PubMed

    Suzuki, A; Katoh, T; Ikeda, K

    1998-01-01

    We evaluated the effects of i.v. adenosine triphosphate (ATP) on sevoflurane minimum alveolar anesthetic concentration (MAC) and MAC-Awake. The study group included healthy patients 20-60 yr of age. The study groups for MAC-Awake determination included 49 patients who were scheduled for elective surgery. The study groups for MAC determination included 53 patients scheduled for elective surgery involving a skin incision. These patients were randomly assigned to two groups, an ATP group and a control group. The ATP group received 100 micrograms.kg-1.min-1 ATP i.v., and the control group received no medication. The ATP group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) and MAC (anesthetic concentration achieving 50% probability of no movement in response to skin incision). The MAC-Awake was 0.7% +/- 0.1% in the control group (mean +/- SD) and 0.7% +/- 0.1% in the ATP group. MAC was 1.9% +/- 0.1% in the control group and 2.1% +/- 0.2% in the ATP group. The differences in MAC and MAC-Awake between the two groups were not statistically significant. We conclude that ATP infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane MAC and MAC-Awake. We found that an i.v. adenosine triphosphate infusion (100 micrograms.kg-1.min-1) has no effect on sevoflurane minimum alveolar anesthetic concentration (anesthetic concentration achieving 50% probability of no movement in response to skin incision) and minimum alveolar anesthetic concentration-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command) in humans.

  9. Awake surgery for hemispheric low-grade gliomas: oncological, functional and methodological differences between pediatric and adult populations.

    PubMed

    Trevisi, Gianluca; Roujeau, Thomas; Duffau, Hugues

    2016-10-01

    Brain mapping through a direct cortical and subcortical electrical stimulation during an awake craniotomy has gained an increasing popularity as a powerful tool to prevent neurological deficit while increasing extent of resection of hemispheric diffuse low-grade gliomas in adults. However, few case reports or very limited series of awake surgery in children are currently available in the literature. In this paper, we review the oncological and functional differences between pediatric and adult populations, and the methodological specificities that may limit the use of awake mapping in pediatric low-grade glioma surgery. This could be explained by the fact that pediatric low-grade gliomas have a different epidemiology and biologic behavior in comparison to adults, with pilocytic astrocytomas (WHO grade I glioma) as the most frequent histotype, and with WHO grade II gliomas less prone to anaplastic transformation than their adult counterparts. In addition, aside from the issue of poor collaboration of younger children under 10 years of age, some anatomical and functional peculiarities of children developing brain (cortical and subcortical myelination, maturation of neural networks and of specialized cortical areas) can influence direct electrical stimulation methodology and sensitivity, limiting its use in children. Therefore, even though awake procedure with cortical and axonal stimulation mapping can be adapted in a specific subgroup of children with a diffuse glioma from the age of 10 years, only few pediatric patients are nonetheless candidates for awake brain surgery.

  10. Intraoperative Motor Symptoms during Brain Tumor Resection in the Supplementary Motor Area (SMA) without Positive Mapping during Awake Surgery.

    PubMed

    Nakajima, Riho; Nakada, Mitsutoshi; Miyashita, Katsuyoshi; Kinoshita, Masashi; Okita, Hirokazu; Yahata, Tetsutaro; Hayashi, Yutaka

    2015-01-01

    Awake surgery could be a useful modality for lesions locating in close proximity to the eloquent areas including primary motor cortex and pyramidal tract. In case with supplementary motor area (SMA) lesion, we often encounter with intraoperative motor symptoms during awake surgery even in area without positive mapping. Although the usual recovery of the SMA syndrome has been well documented, rare cases with permanent deficits could be encountered in the clinical setting. It has been difficult to evaluate during surgery whether the intraoperative motor symptoms lead to postoperative permanent deficits. The purpose of this study was to demonstrate the intraoperative motor symptoms could be reversible, further to provide useful information for making decision to continue surgical procedure of tumor resection. Eight consecutive patients (from July 2012 to June 2014, six men and two women, aged 33-63 years) with neoplastic lesions around the SMA underwent an awake surgery. Using a retrospective analysis of intraoperative video records, intraoperative motor symptoms during tumor resection were investigated. In continuous functional monitoring during resection of SMA tumor under awake conditions, the following motor symptoms were observed during resection of the region without positive mapping: delayed motor weakness, delay of movement initiation, slowness of movement, difficulty in dual task response, and coordination disturbance. In seven patients hemiparesis observed immediately after surgery recovered to preoperative level within 6 weeks. During awake surgery for SMA tumors, the above-mentioned motor symptoms could occur in area without positive mapping and might be predictors for reversible SMA syndrome.

  11. Contribution of Inhibition to Stimulus Selectivity in Primary Auditory Cortex of Awake Primates

    PubMed Central

    Sadagopan, Srivatsun

    2010-01-01

    Recent studies have demonstrated the high selectivity of neurons in primary auditory cortex (A1) and a highly sparse representation of sounds by the population of A1 neurons in awake animals. However, the underlying receptive field structures that confer high selectivity on A1 neurons are poorly understood. The sharp tuning of A1 neurons' excitatory receptive fields (RFs) provides a partial explanation of the above properties. However, it remains unclear how inhibitory components of RFs contribute to the selectivity of A1 neurons observed in awake animals. To examine the role of the inhibition in sharpening stimulus selectivity, we have quantitatively analyzed stimulus-induced suppressive effects over populations of single neurons in frequency, amplitude, and time in A1 of awake marmosets. In addition to the well documented short-latency side-band suppression elicited by masking tones around the best frequency (BF) of a neuron, we uncovered long-latency suppressions caused by single-tone stimulation. Such long-latency suppressions also included monotonically increasing suppression with sound level both on-BF and off-BF, and persistent suppression lasting up to 100 ms after stimulus offset in a substantial proportion of A1 neurons. The extent of the suppression depended on the shape of a neuron's frequency-response area (“O” or “V” shaped). These findings suggest that the excitatory RF of A1 neurons is cocooned by wide-ranging inhibition that contributes to the high selectivity in A1 neurons' responses to complex stimuli. Population sparseness of the tone-responsive A1 neuron population may also be a consequence of this pervasive inhibition. PMID:20505098

  12. Electrical stimulation of the midbrain increases heart rate and arterial blood pressure in awake humans

    PubMed Central

    Thornton, Judith M; Aziz, Tipu; Schlugman, David; Paterson, David J

    2002-01-01

    Electrical stimulation of the hypothalamus, basal ganglia or pedunculopontine nucleus in decorticate animals results in locomotion and a cardiorespiratory response resembling that seen during exercise. This has led to the hypothesis that parallel activation of cardiorespiratory and locomotor systems from the midbrain could form part of the ‘central command’ mechanism of exercise. However, the degree to which subcortical structures play a role in cardiovascular activation in awake humans has not been established. We studied the effects on heart rate (HR) and mean arterial blood pressure (MAP) of electrically stimulating the thalamus and basal ganglia in awake humans undergoing neurosurgery for movement disorders (n = 13 Parkinson's disease, n = 1 myoclonic dystonia, n = 1 spasmodic torticollis). HR and MAP increased during high frequency (> 90 Hz) electrical stimulation of the thalamus (HR 5 ± 3 beats min−1, P = 0.002, MAP 4 ± 3 mmHg, P = 0.05, n = 9), subthalamic nucleus (HR 5 ± 3 beats min−1, P = 0.002, MAP 5 ± 3 mmHg, P = 0.006, n = 8) or substantia nigra (HR 6 ± 3 beats min−1, P = 0.001, MAP 5 ± 2 mmHg, P = 0.005, n = 8). This was accompanied by the facilitation of movement, but without the movement itself. Stimulation of the internal globus pallidus did not increase cardiovascular variables but did facilitate movement. Low frequency (< 20 Hz) stimulation of any site did not affect cardiovascular variables or movement. Electrical stimulation of the midbrain in awake humans can cause a modest increase in cardiovascular variables that is not dependent on movement feedback from exercising muscles. The relationship between this type of response and that occurring during actual exercise is unclear, but it indicates that subcortical command could be involved in ‘parallel activation’ of the locomotor and cardiovascular systems and thus contribute to the neurocircuitry of ‘central command’. PMID:11882692

  13. BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience.

    PubMed

    Yee, J R; Kenkel, W M; Kulkarni, P; Moore, K; Perkeybile, A M; Toddes, S; Amacker, J A; Carter, C S; Ferris, C F

    2016-09-01

    The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological

  14. The Cost of Brain Surgery: Awake vs Asleep Craniotomy for Perirolandic Region Tumors.

    PubMed

    Eseonu, Chikezie I; Rincon-Torroella, Jordina; ReFaey, Karim; Quiñones-Hinojosa, Alfredo

    2017-08-01

    Cost effectiveness has become an important factor in the health care system, requiring surgeons to improve efficacy of procedures while reducing costs. An awake craniotomy (AC) with direct cortical stimulation (DCS) presents one method to resect eloquent region tumors; however, some authors assert that this procedure is an expensive alternative to surgery under general anesthesia (GA) with neuromonitoring. To evaluate the cost effectiveness and clinical outcomes between AC and GA patients. Retrospective analysis of a cohort of 17 patients with perirolandic gliomas who underwent an AC with DCS were case-control matched with 23 patients with perirolandic gliomas who underwent surgery under GA with neuromonitoring (ie, motor-evoked potentials, somatosensory-evoked potentials, phase reversal). Inpatient costs, quality-adjusted life years (QALY), extent of resection, and neurological outcome were compared between the groups. Total inpatient expense per patient was $34 804 in the AC group and $46 798 in the GA group ( P = .046). QALY score for the AC group was 0.97 and 0.47 for the GA group ( P = .041). The incremental cost per QALY for the AC group was $82 720 less than the GA group. Postoperative Karnofsky performance status was 91.8 in the AC group and 81.3 in the GA group (P = .047). Length of hospitalization was 4.12 days in the AC group and 7.61 days in the GA group ( P = .049). The total inpatient costs for awake craniotomies were lower than surgery under GA. This study suggests better cost effectiveness and neurological outcome with awake craniotomies for perirolandic gliomas.

  15. Continuous physical examination during subcortical resection in awake craniotomy patients: Its usefulness and surgical outcome.

    PubMed

    Bunyaratavej, Krishnapundha; Sangtongjaraskul, Sunisa; Lerdsirisopon, Surunchana; Tuchinda, Lawan

    2016-08-01

    To evaluate the value of physical examination as a monitoring tool during subcortical resection in awake craniotomy patients and surgical outcomes. Authors reviewed medical records of patients underwent awake craniotomy with continuous physical examination for pathology adjacent to the eloquent area. Between January 2006 and August 2015, there were 37 patients underwent awake craniotomy with continuous physical examination. Pathology was located in the left cerebral hemisphere in 28 patients (75.7%). Thirty patients (81.1%) had neuroepithelial tumors. Degree of resections were defined as total, subtotal, and partial in 16 (43.2%), 11 (29.7%) and 10 (27.0%) patients, respectively. Median follow up duration was 14 months. The reasons for termination of subcortical resection were divided into 3 groups as follows: 1) by anatomical landmark with the aid of neuronavigation in 20 patients (54%), 2) by reaching subcortical stimulation threshold in 8 patients (21.6%), and 3) by abnormal physical examination in 9 patients (24.3%). Among these 3 groups, there were statistically significant differences in the intraoperative (p=0.002) and early postoperative neurological deficit (p=0.005) with the lowest deficit in neuronavigation group. However, there were no differences in neurological outcome at later follow up (3-months p=0.103; 6-months p=0.285). There were no differences in the degree of resection among the groups. Continuous physical examination has shown to be of value as an additional layer of monitoring of subcortical white matter during resection and combining several methods may help increase the efficacy of mapping and monitoring of subcortical functions. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Overnight duty impairs behaviour, awake activity and sleep in medical doctors.

    PubMed

    Dru, Michel; Bruge, Philippe; Benoit, Odile; Mason, Nicholas P; Combes, Xavier; Margenet, Alain; Dhonneur, Gilles; Marty, Jean

    2007-08-01

    The impact of prolonged work cycles among senior doctors remains disputed. We evaluated the effects of overnight duty on awake activity and sleep quality in senior doctors in emergency medical specialties. Thirty-six healthy doctors were monitored during a 2-week period including three separate 84 h on-call cycles. An on-call cycle consisted of the night and the day before night duty; the night duty itself and the subsequent 2 days and nights after night duty. The first day after night duty could either be worked or not. Actigraphy was used to measure physical activity and to evaluate sleep duration and quality. A standardized questionnaire was used to assess daytime performance and night sleep quality. Night actigraphy demonstrated that on-call work induced a significant reduction in sleep duration that was not recovered during the subsequent two nights. Sleep during the night duty itself was fragmented and of poor quality. Awake activity was significantly impaired on the day after night duty. Although subjectively night sleep quality did not differ between the nights before and after night duty, all subjective daytime parameters were impaired the day after night duty, and mood, fatigue and concentration remained altered on the second day. Working the day after night duty impaired objective measurements of daytime activity and sleep quality during the subsequent two nights. On-call night work in acute specialties induces sleep debt associated with prolonged impairment of awake activity, sleep quality and performance. Not working the following day after an on-call night allows partial recovery of sleep quality to begin.

  17. Asleep-awake-asleep craniotomy: a comparison with general anesthesia for resection of supratentorial tumors.

    PubMed

    Rajan, Shobana; Cata, Juan P; Nada, Eman; Weil, Robert; Pal, Rakhi; Avitsian, Rafi

    2013-08-01

    The anesthetic plan for patients undergoing awake craniotomy, when compared to craniotomy under general anesthesia, is different, in that it requires changes in states of consciousness during the procedure. This retrospective review compares patients undergoing an asleep-awake-asleep technique for craniotomy (group AW: n = 101) to patients undergoing craniotomy under general anesthesia (group AS: n = 77). Episodes of desaturation (AW = 31% versus AS = 1%, p < 0.0001), although temporary, and hypercarbia (AW = 43.75 mmHg versus AS = 32.75 mmHg, p < 0.001) were more common in the AW group. The mean arterial pressure during application of head clamp pins and emergence was significantly lower in AW patients compared to AS patients (pinning 91.47 mmHg versus 102.9 mmHg, p < 0.05 and emergence 84.85 mmHg versus 105 mmHg, p < 0.05). Patients in the AW group required less vasopressors intraoperatively (AW = 43% versus AS = 69%, p < 0.01). Intraoperative fluids were comparable between the two groups. The post anesthesia care unit (PACU) administered significantly fewer intravenous opioids in the AW group. The length of stay in the PACU and hospital was comparable in both groups. Thus, asleep-awake-asleep craniotomies with propofol-dexmedetomidine infusion had less hemodynamic response to pinning and emergence, and less overall narcotic use compared to general anesthesia. Despite a higher incidence of temporary episodes of desaturation and hypoventilation, no adverse clinical consequences were seen.

  18. The VetMousetrap: a device for computed tomographic imaging of the thorax of awake cats.

    PubMed

    Oliveira, Cintia R; Ranallo, Frank N; Pijanowski, Gerald J; Mitchell, Mark A; O'Brien, Mauria A; McMichael, Maureen; Hartman, Susan K; Matheson, Jodi S; O'Brien, Robert T

    2011-01-01

    The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.

  19. Chemical composition and physicochemical properties of green banana (Musa acuminata x balbisiana Colla cv. Awak) flour.

    PubMed

    Haslinda, W H; Cheng, L H; Chong, L C; Noor Aziah, A A

    2009-01-01

    Flour was prepared from peeled and unpeeled banana Awak ABB. Samples prepared were subjected to analysis for determination of chemical composition, mineral, dietary fibre, starch and total phenolics content, antioxidant activity and pasting properties. In general, flour prepared from unpeeled banana was found to show enhanced nutrition values with higher contents of mineral, dietary fibre and total phenolics. Hence, flour fortified with peel showed relatively higher antioxidant activity. On the other hand, better pasting properties were shown when banana flour was blended with peel. It was found that a relatively lower pasting temperature, peak viscosity, breakdown, final viscosity and setback were evident in a sample blended with peel.

  20. <