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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. Wireless neural stimulation in freely behaving small animals.

    PubMed

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

    2009-07-01

    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 microA 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

  3. 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

  4. 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. PMID:26712014

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

    PubMed Central

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

    2016-01-01

    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. PMID:26712014

  6. Firing Rate Homeostasis in Visual Cortex of Freely Behaving Rodents

    PubMed Central

    Hengen, Keith B.; Lambo, Mary E.; Van Hooser, Stephen D.; Katz, Donald B; Turrigiano, Gina G

    2013-01-01

    Summary It has been postulated that homeostatic mechanisms maintain stable circuit function by keeping neuronal firing within a set-point range, but such firing rate homeostasis has never been demonstrated in vivo. Here we use chronic multielectrode recordings to monitor firing rates in visual cortex of freely behaving rats during chronic monocular visual deprivation (MD). Firing rates in V1 were suppressed over the first 2 d of MD, but then rebounded to baseline over the next 2–3 d despite continued MD. This drop and rebound in firing was accompanied by bi-directional changes in mEPSC amplitude measured ex vivo. The rebound in firing was independent of sleep-wake state but was cell-type specific, as putative FS and regular spiking neurons responded to MD with different time-courses. These data establish for the first time that homeostatic mechanisms within the intact CNS act to stabilize neuronal firing rates in the face of sustained sensory perturbations. PMID:24139038

  7. Studying the freely-behaving brain with fMRI

    PubMed Central

    Maguire, Eleanor A.

    2012-01-01

    Given that the brain evolved to function in the real world then it seems reasonable to want to examine how it operates in that context. But of course the world is complex, as are the brain's responses to it, and MRI scanners are inherently restrictive environments. This combination of challenges makes the prospect of studying the freely-behaving brain with fMRI disconcerting to anyone sensible. When designing naturalistic fMRI experiments it is necessary to ensure that the thoughts or behaviours under scrutiny are not unduly perturbed or constrained by the imaging process, while still being amenable to experimental manipulation and control, and result in meaningful and interpretable data. This is difficult to achieve. Here, briefly, and in a highly subjective and selective manner, I consider: why we might want to deploy free-behaviour designs in an fMRI context, how to go about it, review some examples of it in action, and decide finally whether it is worth it (it is). PMID:22245643

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

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

    PubMed Central

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

    2015-01-01

    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

  15. 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

  16. 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

  17. 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. PMID:17946626

  18. TRP channel mediated neuronal activation and ablation in freely behaving zebrafish.

    PubMed

    Chen, Shijia; Chiu, Cindy N; McArthur, Kimberly L; Fetcho, Joseph R; Prober, David A

    2016-02-01

    The zebrafish (Danio rerio) is a useful vertebrate model system in which to study neural circuits and behavior, but tools to modulate neurons in freely behaving animals are limited. As poikilotherms that live in water, zebrafish are amenable to thermal and pharmacological perturbations. We exploit these properties by using transient receptor potential (TRP) channels to activate or ablate specific neuronal populations using the chemical and thermal agonists of heterologously expressed TRPV1, TRPM8 and TRPA1. PMID:26657556

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

    PubMed

    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

  20. 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

  1. Controlled Iontophoresis Coupled with Fast-Scan Cyclic Voltammetry/Electrophysiology in Awake, Freely Moving Animals

    PubMed Central

    2013-01-01

    Simultaneous electrochemical and electrophysiological data were recorded to evaluate the effects of controlled local application of dopaminergic agonists and antagonists in awake rats. Measurements were made with a probe consisting of a carbon-fiber microelectrode fused to three iontophoretic barrels used to introduce the drugs of interest. The probe and the manipulator used to position it in the brain of behaving animals were optimized to improve their performance. The effect of the dopamine autoreceptor on electrically stimulated release was demonstrated. Dopamine inhibited the release of endogenous dopamine whereas raclopride, a D2 antagonist, enhanced it, with similar responses in anesthetized and awake animals. We also examined changes in the firing rate of nucleus accumbens (NAc) neurons in awake animals during and after brief (15 s) iontophoretic ejections of SCH 23390 (D1 receptor antagonist) or raclopride. Changes in response to these antagonists were seen both immediately and on a prolonged time scale. Application of raclopride increased the firing rate in 40% of medium spiny neurons (MSNs), of which half responded immediately. Decreases in firing rate were observed in 46% of MSNs after SCH 23390 application. Only 11% of MSNs responded to both antagonists and one MSN (3%) showed no response to either drug. The same prolonged response in firing rate was seen for electrically stimulated and locally applied dopamine in 75% of MSNs. These results are in agreement with previously reported distributions for dopamine receptor subtypes on MSNs and probe the effects of dopamine on these cell populations. PMID:23480099

  2. 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

  3. 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. PMID:26084901

  4. Decoding of Intentional Actions from Scalp Electroencephalography (EEG) in Freely-behaving Infants

    PubMed Central

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

    2015-01-01

    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 α-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 δ-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. PMID:25570402

  5. 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.

  6. 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

  7. 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

  8. 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. PMID:24587144

  9. 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. PMID:22256112

  10. 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

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

    PubMed

    Alves, Joseph Andrews; Boerner, Barbara Ciralli; Laplagne, Diego Andrés

    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

  12. 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. PMID:25375992

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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. PMID:27378865

  18. 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

  19. 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

  20. 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

  1. Nucleus accumbens neuronal activity in freely behaving rats is modulated following acute and chronic methylphenidate administration.

    PubMed

    Chong, Samuel L; Claussen, Catherine M; Dafny, Nachum

    2012-03-10

    Methylphenidate (MPD) is a psychostimulant that enhances dopaminergic neurotransmission in the central nervous system by using mechanisms similar to cocaine and amphetamine. The mode of action of brain circuitry responsible for an animal's neuronal response to MPD is not fully understood. The nucleus accumbens (NAc) has been implicated in regulating the rewarding effects of psychostimulants. The present study used permanently implanted microelectrodes to investigate the acute and chronic effects of MPD on the firing rates of NAc neuronal units in freely behaving rats. On experimental day 1 (ED1), following a saline injection (control), a 30 min baseline neuronal recording was obtained immediately followed by a 2.5 mg/kg i.p. MPD injection and subsequent 60 min neuronal recording. Daily 2.5 mg/kg MPD injections were given on ED2 through ED6 followed by 3 washout days (ED7 to ED9). On ED10, neuronal recordings were resumed from the same animal after a saline and MPD (rechallenge) injection exactly as obtained on ED1. Sixty-seven NAc neuronal units exhibited similar wave shape, form and amplitude on ED1 and ED10 and their firing rates were used for analysis. MPD administration on ED1 elicited firing rate increases and decreases in 54% of NAc units when compared to their baselines. Six consecutive MPD administrations altered the neuronal baseline firing rates of 85% of NAc units. MPD rechallenge on ED10 elicited significant changes in 63% of NAc units. These alterations in firing rates are hypothesized to be through mechanisms that include D1 and D2-like DA receptor induced cellular adaptation and homeostatic adaptations/deregulation caused by acute and chronic MPD administration. PMID:22248440

  2. Construction of Microdrive Arrays for Chronic Neural Recordings in Awake Behaving Mice

    PubMed Central

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

    2013-01-01

    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. PMID:23851569

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

    PubMed

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

    2013-01-01

    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. PMID:23851569

  4. Optogenetic control of freely behaving adult Drosophila using a red-shifted channelrhodopsin

    PubMed Central

    Inagaki, Hidehiko K.; Jung, Yonil; Hoopfer, Eric D.; Wong, Allan M.; Mishra, Neeli; Lin, John Y.; Tsien, Roger Y.; Anderson, David J.

    2014-01-01

    Optogenetics allows the manipulation of neural activity in freely moving animals with millisecond precision, but its application in Drosophila has been limited. Here we show that a recently described Red activatable Channelrhodopsin (ReaChR) permits control of complex behavior in freely moving adult flies, at wavelengths that are not thought to interfere with normal visual function. This tool affords the opportunity to control neural activity over a broad dynamic range of stimulation intensities. Using time-resolved activation, we show that the neural control of male courtship song can be separated into probabilistic, persistent and deterministic, command-like components. The former, but not the latter, neurons are subject to functional modulation by social experience, supporting the idea that they constitute a locus of state-dependent influence. This separation is not evident using thermogenetic tools, underscoring the importance of temporally precise control of neuronal activation in the functional dissection of neural circuits in Drosophila. PMID:24363022

  5. 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

  6. Coherent 25- to 35-Hz Oscillations in the Sensorimotor Cortex of Awake Behaving Monkeys

    NASA Astrophysics Data System (ADS)

    Murthy, Venkatesh N.; Fetz, Eberhard E.

    1992-06-01

    Synchronous 25- to 35-Hz oscillations were observed in local field potentials and unit activity in sensorimotor cortex of awake rhesus monkeys. The oscillatory episodes occurred often when the monkeys retrieved raisins from a Kluver board or from unseen locations using somatosensory feedback; they occurred less often during performance of repetitive wrist flexion and extension movements. The amplitude, duration, and frequency of oscillations were not directly related to movement parameters in behaviors studied so far. The occurrence of the oscillations was not consistently related to bursts of activity in forearm muscles, but cycle-triggered averages of electromyograms revealed synchronous modulation in flexor and extensor muscles. The phase of the oscillations changed continuously from the surface to the deeper layers of the cortex, reversing their polarity completely at depths exceeding 800 μm. The oscillations could become synchronized over a distance of 14 mm mediolaterally in precentral cortex. Coherent oscillations could also occur at pre- and postcentral sites separated by an estimated tangential intracortical distance of 20 mm. Activity of single units was commonly seen to burst in synchrony with field potential oscillations. These findings suggest that such oscillations may facilitate interactions between cells during exploratory and manipulative movements, requiring attention to sensorimotor integration.

  7. 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

  8. 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

  9. Electrocorticographic activity over sensorimotor cortex and motor function in awake behaving rats

    PubMed Central

    Chen, Xiang Yang; Wolpaw, Jonathan R.

    2015-01-01

    Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electrical analog of the spinal stretch reflex. In 41 awake adult rats, we measured soleus electromyographic (EMG) activity, the soleus H-reflex, and electrocorticographic activity over the contralateral SMC while rats were producing steady-state soleus EMG activity. Principal component analysis of electrocorticographic frequency spectra before H-reflex elicitation consistently revealed three frequency bands: μβ (5–30 Hz), low γ (γ1; 40–85 Hz), and high γ (γ2; 100–200 Hz). Ongoing (i.e., background) soleus EMG amplitude correlated negatively with μβ power and positively with γ1 power. In contrast, H-reflex size correlated positively with μβ power and negatively with γ1 power, but only when background soleus EMG amplitude was included in the linear model. These results support the hypothesis that increased SMC activation (indicated by decrease in μβ power and/or increase in γ1 power) simultaneously potentiates the H-reflex by exciting spinal motoneurons and suppresses it by decreasing the efficacy of the afferent input. They may help guide the development of new rehabilitation methods and of brain-computer interfaces that use SMC activity as a substitute for lost or impaired motor outputs. PMID:25632076

  10. 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

  11. 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

  12. Dysregulation of coordinated neuronal firing patterns in striatum of freely behaving transgenic rats that model Huntington's disease.

    PubMed

    Miller, Benjamin R; Walker, Adam G; Fowler, Stephen C; von Hörsten, Stephan; Riess, Olaf; Johnson, Michael A; Rebec, George V

    2010-01-01

    Altered neuronal activity in the striatum appears to be a key component of Huntington's disease (HD), a fatal, neurodegenerative condition. To assess this hypothesis in freely behaving transgenic rats that model HD (tgHDs), we used chronically implanted micro-wires to record the spontaneous activity of striatal neurons. We found that relative to wild-type controls, HD rats suffer from population-level deficits in striatal activity characterized by a loss of correlated firing and fewer episodes of coincident spike bursting between simultaneously recorded neuronal pairs. These results are in line with our previous report of marked alterations in the pattern of striatal firing in mouse models of HD that vary in background strain, genetic construct, and symptom severity. Thus, loss of coordinated spike activity in striatum appears to be a common feature of HD pathophysiology, regardless of HD model variability. PMID:19818852

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

    PubMed

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

    2016-07-01

    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 dysfunction in the rodent cSCI model will likely aid the search for effective regenerative, pharmacological, and neuroprosthetic treatments for spinal cord injury. PMID:27033345

  14. 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

  15. 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

  16. 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

  17. 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. PMID:22761555

  18. Site-specific postural and locomotor changes evoked in awake, freely moving intact cats by stimulating the brainstem.

    PubMed

    Mori, S; Sakamoto, T; Ohta, Y; Takakusaki, K; Matsuyama, K

    1989-12-25

    Locomotor behaviors evoked by stimulating the hypothalamus and the brainstem were studied in freely moving, awake cats. To do this, stimulating microelectrodes were chronically implanted into the subthalamic locomotor region (SLR) in the lateral hypothalamic area (LHA), the mesencephalic locomotor region (MLR) corresponding to the nucleus cuneiformis, the dorsal tegmental field (DTF) and the ventral tegmental field (VTF) of caudal pons along its midline. After recovery from surgery (2-3 days), open field tests were performed to study stimulus effects upon posture and locomotor movements. The stimuli consisted of pulses of 0.2 ms duration of less than 80 microA delivered at 50 pulses/s for 5-20 s. DTF stimulation resulted in suppression of postural support by the hindlimbs. When the cat was in a standing posture, DTF stimulation simply resulted in a sequential alteration of posture to a squatting and then to a final lying posture. In contrast, VTF stimulation evoked an almost opposite series of postural changes to those induced by DTF stimulation. With VTF stimulation, the cat changed from a lying or a squatting position, and then started to walk during continuation of the stimulation. With MLR stimulation, the cat invariably exhibited fast walking and then running movements. It ran straight forward, avoiding collision with walls or other obstacles, and even tried to jump over a fence placed in front of it. With LHA stimulation, the cat started to walk slowly extending its head forward and looking around repeatedly. It tended to walk with a stoop and stealthy steps along the corners of the room. Induced postural and locomotor changes were always accompanied by behavioral arousal reactions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2611678

  19. 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.

  20. 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

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

    PubMed

    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

  2. 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

  3. 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

  4. Flat-floored Air-lifted Platform: A New Method for Combining Behavior with Microscopy or Electrophysiology on Awake Freely Moving Rodents

    PubMed Central

    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

    2014-01-01

    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. PMID:24998224

  5. 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

    2014-01-01

    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. PMID:24998224

  6. 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. PMID:27121585

  7. 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

    2014-01-01

    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. PMID:25540024

  8. 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

  9. Recording chronically from the same neurons in awake, behaving primates.

    PubMed

    Tolias, Andreas S; Ecker, Alexander S; Siapas, Athanassios G; Hoenselaar, Andreas; Keliris, Georgios A; Logothetis, Nikos K

    2007-12-01

    Understanding the mechanisms of learning requires characterizing how the response properties of individual neurons and interactions across populations of neurons change over time. To study learning in vivo, we need the ability to track an electrophysiological signature that uniquely identifies each recorded neuron for extended periods of time. We have identified such an extracellular signature using a statistical framework that allows quantification of the accuracy by which stable neurons can be identified across successive recording sessions. Our statistical framework uses spike waveform information recorded on a tetrode's four channels to define a measure of similarity between neurons recorded across time. We use this framework to quantitatively demonstrate for the first time the ability to record from the same neurons across multiple consecutive days and weeks. The chronic recording techniques and methods of analyses we report can be used to characterize the changes in brain circuits due to learning. PMID:17942615

  10. In vivo extracellular recording of striatal neurons in the awake rat following unilateral 6-hydroxydopamine lesions.

    PubMed

    Chen, M T; Morales, M; Woodward, D J; Hoffer, B J; Janak, P H

    2001-09-01

    The purpose of this study was to further understand the functional effects of dopaminergic input to the dorsal striatum and to compare the effects of dopaminergic lesions in awake and anesthetized animals. We examined the effects of unilateral 6-hydroxydopamine (6-OHDA) lesions of the ascending dopaminergic bundle on the firing properties of dorsal striatal neurons in the awake freely moving rat using chronically implanted microwire electrode arrays. We recorded extracellular activity of striatal neurons under baseline conditions and following the systemic injection of apomorphine in awake and anesthetized subjects. Firing rates were higher in the hemisphere ipsilateral to the 6-OHDA lesion compared to rates of neurons from the contralateral unlesioned hemisphere. Striatal firing rates from sham and no-surgery control rats were, in general, higher than those from the contralateral unlesioned striatum of experimental subjects. Apomorphine (0.05 mg/kg, sc) normalized the differences in firing rates in lesioned animals by increasing firing of neurons within the contralateral unlesioned side, while simultaneously decreasing firing of neurons within the ipsilateral lesioned side. Mean firing rates were substantially higher in awake animals than in subjects anesthetized with chloral hydrate, perhaps reflecting anesthesia-induced decreases in excitatory input to striatal neurons. Chloral hydrate anesthesia decreased firing rates of neurons in the lesioned, unlesioned, and control striata to a similar degree, although absolute firing rates of neurons from the 6-OHDA-lesioned striata remained elevated over all other groups. Unilateral 6-OHDA lesions also altered the pattern of spike output in the awake animal as indicated by an increase in the number of bursts per minute following dopaminergic deafferentation. This and other burst parameters were altered by apomorphine. Our findings show that effects of dopaminergic deafferentation can be measured in the awake behaving

  11. 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

  12. 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

  13. 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

  14. 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. PMID:26279501

  15. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347

  16. Real-Time Dopamine Measurement in Awake Monkeys

    PubMed Central

    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. PMID:24921937

  17. 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. PMID:24921937

  18. 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

  19. Visually evoked activity in cortical cells imaged in freely moving animals

    PubMed Central

    Sawinski, Juergen; Wallace, Damian J.; Greenberg, David S.; Grossmann, Silvie; Denk, Winfried; Kerr, Jason N. D.

    2009-01-01

    We describe a miniaturized head-mounted multiphoton microscope and its use for recording Ca2+ transients from the somata of layer 2/3 neurons in the visual cortex of awake, freely moving rats. Images contained up to 20 neurons and were stable enough to record continuously for >5 min per trial and 20 trials per imaging session, even as the animal was running at velocities of up to 0.6 m/s. Neuronal Ca2+ transients were readily detected, and responses to various static visual stimuli were observed during free movement on a running track. Neuronal activity was sparse and increased when the animal swept its gaze across a visual stimulus. Neurons showing preferential activation by specific stimuli were observed in freely moving animals. These results demonstrate that the multiphoton fiberscope is suitable for functional imaging in awake and freely moving animals. PMID:19889973

  20. 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.

  1. 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

  2. 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

  3. 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. PMID:26009636

  4. Extracellular Wire Tetrode Recording in Brain of Freely Walking Insects

    PubMed Central

    Guo, Peiyuan; Pollack, Alan J.; Varga, Adrienn G.; Martin, Joshua P.; Ritzmann, Roy E.

    2014-01-01

    Increasing interest in the role of brain activity in insect motor control requires that we be able to monitor neural activity while insects perform natural behavior. We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allowed us to record activity from multiple neurons simultaneously while a tethered cockroach turned or altered walking speed. While a major advance, tethered preparations provide access to limited behaviors and often lack feedback processes that occur in freely moving animals. We now present a modified version of that technique that allows us to record from the central complex of freely moving cockroaches as they walk in an arena and deal with barriers by turning, climbing or tunneling. Coupled with high speed video and cluster cutting, we can now relate brain activity to various parameters of the movement of freely behaving insects. PMID:24747699

  5. Large-scale chronically implantable precision motorized microdrive array for freely behaving animals.

    PubMed

    Yamamoto, Jun; Wilson, Matthew A

    2008-10-01

    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

  6. 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

  7. 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. PMID:26580015

  8. 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

  9. 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. PMID:21704383

  10. Oscillations in the premotor cortex: single-unit activity from awake, behaving monkeys.

    PubMed

    Lebedev, M A; Wise, S P

    2000-01-01

    We examined single-unit activity in the dorsal premotor cortex for evidence of fast neuronal oscillations. Four rhesus monkeys performed a task in which visuospatial instruction stimuli indicated the direction of forelimb movement to be executed on each trial. After an instructed delay period of 1.5-3 s, movements to either the right or left of a central origin were triggered by a second visuospatial stimulus. From a database of 579 single units, 78 units (13%) contained periodic peaks in their autocorrelation histograms (ACHs), with oscillation frequencies typically 20-30 Hz (mean 27 Hz). An additional 26 units (5%) had oscillatory features that were identified in joint interspike-interval (ISI) plots. Three observations, taken together, suggest entrainment by rhythmic drive extrinsic to these neurons: shuffling ISIs attenuated ACH peaks, indicating a dependency on serial-order effects; oscillation frequency did not change during either increases or decreases in firing rate; and joint ISI plots contained features consistent with a rhythmicity interrupted by intervening discharges. In some cells, oscillations occurred for only one of the two directions of movement. During the delay period, such directional selectivity was observed in 37 units (60% of delay-period oscillators). For at least 17 of these units, we could exclude the possibility that oscillatory directional selectivity resulted from the difficulty in detecting oscillations due to low discharge rates (for one of the two movement directions). Directional selectivity in fast oscillations shows that they can reflect specific aspects of an intended action. PMID:10672473

  11. 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

  12. 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.

  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. Freely suspended quantum point contacts

    NASA Astrophysics Data System (ADS)

    Rössler, C.; Herz, M.; Bichler, M.; Ludwig, S.

    2010-05-01

    We present a versatile design of freely suspended quantum point contacts with particular large one-dimensional subband quantization energies of up to Δɛ≈10 meV. The nanoscale bridges embedding a two-dimensional electron system are fabricated from AlGaAs/GaAs heterostructures by electron-beam lithography and etching techniques. Narrow constrictions define quantum point contacts that are capacitively controlled via local in-plane side gates. Employing transport spectroscopy, we investigate the transition from electrostatic subbands to Landau quantization in a perpendicular magnetic field. The large subband quantization energies allow us to utilize a wide magnetic field range and thereby observe a large exchange split spin-gap of the two lowest Landau-levels.

  15. Freely Suspended Liquid Crystalline Films

    NASA Astrophysics Data System (ADS)

    Sonin, A. A.

    2003-05-01

    Freely Suspended Liquid Crystalline Films Andrei A. Sonin Centre d'Etudes Atomiques de Saclay, France and Institute of Crystallography, Russian Academy of Sciences with a Foreword by Professor Noel Clark University of Colorado, USA This book provides a brief introduction to the physics of liquid crystals and to macroscopic physical parameters characterising freely suspended liquid crystalline (FSLC) films, and then reviews the experimental techniques for preparing these films, measuring their thicknesses, and investigating their physical properties and structural aspects. Molecular structures and defects of FSLC films and the problems of film stability, thinning and rupture are discussed in later chapters. Physical phenomena, such as orientational and phase transitions, Frederick's and flexoelectric effects, hydroelectrodynamics, etc., are also analysed. Finally, some applications of FSLC films in industry and in various branches of science are discussed. Specialists working in the physics of liquid crystals and in surface physics will find this book of interest. Industrial firms and their research centres investigating liquid crystals, biological membranes, detergent/surfactant/biomedical areas; and graduates and postgraduates in solid state physics and crystallography will also benefit from this book. The book has an easy-to-read style with just the minimum amount of mathematics necessary to explain important concepts. This is the first book dedicated exclusively to the physics of FSLC in almost a century since their discovery and last twenty years of their active studies. Andrei Sonin, a scientist in the area of FSLC and author of many articles on surface phenomena in liquid crystals, the properties and behaviour of thin liquid crystalline and surfactant films, has a long standing reputation in liquid crystals and surfactant systems and has been particularly active in issues involving surface interactions.

  16. 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

  17. Awake Craniotomy: A New Airway Approach.

    PubMed

    Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

    2016-02-01

    Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique. PMID:26579845

  18. 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.

  19. 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…

  20. 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

    2016-01-01

    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

  1. 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

  2. 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. PMID:27119345

  3. 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].

  4. 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

  5. Human Cortical Excitability Increases with Time Awake

    PubMed Central

    Huber, Reto; Mäki, Hanna; Rosanova, Mario; Casarotto, Silvia; Canali, Paola; Casali, Adenauer G.; Tononi, Giulio

    2013-01-01

    Prolonged wakefulness is associated not only with obvious changes in the way we feel and perform but also with well-known clinical effects, such as increased susceptibility to seizures, to hallucinations, and relief of depressive symptoms. These clinical effects suggest that prolonged wakefulness may be associated with significant changes in the state of cortical circuits. While recent animal experiments have reported a progressive increase of cortical excitability with time awake, no conclusive evidence could be gathered in humans. In this study, we combine transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to monitor cortical excitability in healthy individuals as a function of time awake. We observed that the excitability of the human frontal cortex, measured as the immediate (0–20 ms) EEG reaction to TMS, progressively increases with time awake, from morning to evening and after one night of total sleep deprivation, and that it decreases after recovery sleep. By continuously monitoring vigilance, we also found that this modulation in cortical responsiveness is tonic and not attributable to transient fluctuations of the level of arousal. The present results provide noninvasive electrophysiological evidence that wakefulness is associated with a steady increase in the excitability of human cortical circuits that is rebalanced during sleep. PMID:22314045

  6. 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. PMID:25475698

  7. 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.

  8. 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

  9. 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

    2013-11-01

    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. PMID:24102201

  10. Awake hippocampal sharp-wave ripples support spatial memory.

    PubMed

    Jadhav, Shantanu P; Kemere, Caleb; German, P Walter; Frank, Loren M

    2012-06-15

    The hippocampus is critical for spatial learning and memory. Hippocampal neurons in awake animals exhibit place field activity that encodes current location, as well as sharp-wave ripple (SWR) activity during which representations based on past experiences are often replayed. The relationship between these patterns of activity and the memory functions of the hippocampus is poorly understood. We interrupted awake SWRs in animals learning a spatial alternation task. We observed a specific learning and performance deficit that persisted throughout training. This deficit was associated with awake SWR activity, as SWR interruption left place field activity and post-experience SWR reactivation intact. These results provide a link between awake SWRs and hippocampal memory processes, which suggests that awake replay of memory-related information during SWRs supports learning and memory-guided decision-making. PMID:22555434

  11. Preparing to perform an awake fiberoptic intubation.

    PubMed Central

    Walsh, M. E.; Shorten, G. D.

    1998-01-01

    Fiberoptically guided tracheal intubation represents one of the most important advances in airway management to occur in the past thirty years. Perhaps its most important role is in management of the anticipated difficult airway. This is a situation in which the dangers of encountering the life-threatening "can't intubate, can't ventilate" situation can be avoided by placement of an endotracheal tube while the patient is awake. Although skill at the procedure of endoscopy is obviously necessary in this setting, these authors hold that success or failure of the technique frequently depends on the adequacy of preparation. These measures include 1) pre-operative assessment of the patient; 2) careful explanation of what lies in store; 3) "setting the stage"; 4) preparing the equipment to be used; and 5) preparing the patient (antisialogue, sedation, application of topical anesthesia to the upper airway). If these preparatory measures are carried out meticulously, the likelihood of performing a successful and comfortable awake fiberoptic tracheal intubation is greatly increased. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10604785

  12. New methods for localizing and manipulating neuronal dynamics in behaving animals.

    PubMed

    Fee, Michale S; Long, Michael A

    2011-10-01

    Where are the 'prime movers' that control behavior? Which circuits in the brain control the order in which individual motor gestures of a learned behavior are generated, and the speed at which they progress? Here we describe two techniques recently applied to localizing and characterizing the circuitry underlying the generation of vocal sequences in the songbird. The first utilizes small, localized, temperature changes in the brain to perturb the speed of neural dynamics. The second utilizes intracellular manipulation of membrane potential in the freely behaving animal to perturb the dynamics within a single neuron. Both of these techniques are broadly applicable in behaving animals to test hypotheses about the biophysical and circuit dynamics that allow neural circuits to march from one state to the next. PMID:21763124

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

  14. 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

  15. [Long-term potentiation and unit evoked responses in the cingulate cortex of freely moving rats].

    PubMed

    Gorkin, A G; Reymann, K G; Aleksandrov, Iu I

    2002-01-01

    Long-term potentiation (LTP) of synaptic efficacy is considered to be the most probable physiological mechanism of long-term memory. However, lack of understanding of cellular and subcellular mechanisms of LTP induction in freely behaving animals does not correspond to the importance of the problem. It was tested whether the characteristics of potentiation in the cingulate cortex after tetanization of the subiculocingulate tract (SCT) meet the criteria of true LTP (that passes all known stages in its development and lasts for more than a day in freely-behaving animals). Additionally, characteristics of spike responses to SCT stimulation and the effects of application of different glutamate receptor blockers were studied. Without application of GABA receptor blockers, the LTP lasted for more than 24 hours. Application of NMDA glutamate receptor blockers significantly inhibited field potentials evoke by testing stimulation. Short-latency spike responses to SCT stimulation were recorded with low probability that increased with stimulation intensity. The obtained data reveal the possibility to compare the involvement of cingulate neurons in acquisition of adaptive behavior and changes in their spike responses during the LTP development in freely-moving rats. PMID:12528373

  16. 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

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

    PubMed

    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

  18. Sonar location system for freely floating buoys

    NASA Astrophysics Data System (ADS)

    Bird, I. G.

    1983-05-01

    A rf interrogated sonar location system for freely floating buoys is described. The location of an array of up to three buoys may be determined on an almost continuous basis within a radius of 500 m from a shipboard monitoring station. Location accuracy of typically ±0.5 m at 200-m range, low cost, and ease of operation are the major features of the system.

  19. 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

  20. Freely Suspended Smectic Films in Aqueous Environment

    NASA Astrophysics Data System (ADS)

    Peddireddy, Karthik; Bahr, Christian

    2012-02-01

    Smectic liquid crystals easily form thin films which are freely suspended on a solid frame in air. These systems have been thoroughly studied for various purposes such as structural studies of smectic phases, investigating phase transitions in two-dimensional systems, and studying various physical properties of liquid crystals. In the present study, we explore the preparation of freely suspended smectic films in water. A prerequisite is the presence of a surfactant which accumulates at the liquid-crystal/water interface and induces a homeotropic anchoring of the director, so that the smectic layers align parallel to the two film surfaces. The presence of the surfactant might also serve as a handle to tune properties such as the surface tension of the films (which is hardly possible for freely suspended films in air). We study the formation of films in water using different frames and different surfactants, and we focus especially on the thinning behaviour which occurs when the temperature is increased towards the smectic - nematic or smectic - isotropic transition.

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    PubMed Central

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

    2014-01-01

    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. PMID:23536223

  7. 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

  8. [Continuous ECG recording for freely moving patients].

    PubMed

    Shi, Bo; Liu, Shengyang; Chen, Jianfang; Zhang, Genxuan; Tsau, Young

    2013-04-01

    As more and more people are becoming aged in China and many of them tend to suffer from chronic cardiac problems, the long-term dynamic cardiac monitoring for freely moving patients becomes essential. A new design for continuous ECG recording on the freely moving patients at home and/or at work is proposed here. It is miniature in size, using digital technologies of the low gain amplifier, the high resolution analog to digital converter and the real-time digital filter that features > 100dB input signal dynamic range (ISDR), > 100dB common-mode rejection ratio (CMRR), and < 5microV (RMS) internal noise. The device works continuously more than 24 hours with a pair of AAA batteries, and is capable of storing the recorded data into a storage card. The preliminary tests showed that the P-QRS-T waveforms were captured and displayed smoothly in resting, walking, and activities, making the device useful in monitoring and analyzing for the patients on the move. PMID:23858751

  9. 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

  10. Patient experiences during awake mechanical ventilation

    PubMed Central

    Prime, Danille; Arkless, Paul; Fine, Jonathan; Winter, Stephen; Wakefield, Dorothy B.; Scatena, Robyn

    2016-01-01

    Background Sedation practices in an ICU have shifted significantly in the past 20 years toward the use of minimizing sedation in mechanically ventilated patients. While minimizing sedation is clearly in the best interest of patients, data are lacking about how this approach affects patients’ experiences. Methods We interviewed mechanically ventilated patients receiving minimal sedation, over a 6-month period in an ICU, in order to explore their emotional, comfort, and communication experiences. Their responses were compared with the responses of their available family members regarding their attitudes and perceptions of the patients’ experiences. Results Seventy-five percent of the patients agreed or strongly agreed that they experienced pain, and 50% agreed or strongly agreed that they were comfortable. Half of the patients agreed or strongly agreed that they preferred to be kept awake. Five patients (31%) indicated that they were frustrated while 17 relatives (89%) agreed or strongly agreed that the patients were frustrated. When controlling for age and gender of respondents, family members perceived higher levels of patient pain (least square [LS] mean [95% CI]: 4.2 [3.7, 4.7] vs. 3.1 [2.5, 3.8]; p=0.022), frustration (LS mean [95% CI]: 4.2 [3.7, 4.6] vs. 3.2 [2.6, 3.9]; p=0.031), and adequate communication with nurses and doctors (LS mean [95% CI]: 3.9 [3.5, 4.4] vs. 3.1 [2.4, 3.7]; p=0.046) than the patients themselves. Conclusion Patients tolerated minimal sedation without significant frustration while mechanically ventilated despite experiencing discomfort. Patient and family member perceptions of the patient experience may differ, especially in regards to pain and frustration. The use of a communication tool can facilitate understanding of patient experiences and preferences. PMID:26908386

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

    PubMed Central

    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. PMID:26070157

  12. Reverse Translation of Clinical Electrophysiological Biomarkers in Behaving Rodents under Acute and Chronic NMDA Receptor Antagonism

    PubMed Central

    Sullivan, Elyse M; Timi, Patricia; Hong, L Elliot; O'Donnell, Patricio

    2015-01-01

    Electroencephalogram (EEG) stands out as a highly translational tool for psychiatric research, yet rodent and human EEG are not typically obtained in the same way. In this study we developed a tool to record skull EEG in awake-behaving rats in a similar manner to how human EEG are obtained and then used this technique to test whether acute NMDA receptor antagonism alters rodent EEG signals in a similar manner as in humans. Acute MK-801 treatment elevated gamma power and reduced beta band power, which closely mirrored EEG data from healthy volunteers receiving acute ketamine. To explore the mechanisms behind these oscillatory changes, we examined the effects of GABA-A receptor blockade, finding that picrotoxin (PTX) recapitulated the decrease in sound-evoked beta oscillations observed with acute MK-801, but did not produce changes in gamma band power. Chronic treatment with either PTX or MK-801 did not affect frequency-specific oscillatory activity when tested 24 h after the last drug injection, but decreased total broadband oscillatory power. Overall, this study validated a novel platform for recording rodent EEG and demonstrated similar oscillatory changes after acute NMDA receptor antagonism in both humans and rodents, suggesting that skull EEG may be a powerful tool for further translational studies. PMID:25176166

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. EOG responses in anesthetized freely breathing rats.

    PubMed

    Chaput, M A

    2000-12-01

    In mammals, access of odor molecules to the olfactory receptor neurons is controlled by respiratory activity. Thus, anesthetized, freely breathing rats were used to record from the olfactory mucosa in the intact nasal cavity (electroolfactogram or EOG) so as to study global response characteristics to odor stimuli. During alternation of the inspiratory phases of odor sampling and expiratory phases, the response was a succession of individual EOG events synchronized with respiration. These were characterized by a steep decrease that started approximately 100-150 ms after the beginning of inhalation, reached its maximum at the transition between inspiration and expiration and was followed by a slower rise until the next inhalation. They were greater during the first respiratory cycles following odor stimulation onset. Thereafter their amplitudes decreased throughout odor delivery, but a significant EOG signal was still present at the end of short (10 s) and long (60 s) odor presentations. Amplitude increased with odor concentration, but much less than expected from concentration changes. Lastly, for some odors EOG responses persisted well beyond the end of stimulation. These results are in agreement with the respiratory synchronization of mitral cell activities observed during short odor presentations and long duration odor exposures. They underline again the importance of taking into account the respiratory activity in studies on the functioning of the olfactory system. PMID:11114147

  19. Chronic second-by-second measures of l-glutamate in the central nervous system of freely moving rats

    PubMed Central

    Rutherford, Erin C.; Pomerleau, Francois; Huettl, Peter; Strömberg, Ingrid; Gerhardt, Greg A.

    2012-01-01

    l-glutamate (Glu) is the main excitatory neurotransmitter in the central nervous system (CNS) and is associated with motor behavior and sensory perception. While microdialysis methods have been used to record tonic levels of Glu, little is known about the more rapid changes in Glu signals that may be observed in awake rats. We have reported acute recording methods using enzyme-based microelectrode arrays (MEA) with fast response time and low detection levels of Glu in anesthetized animals with minimal interference. The current paper concerns modification of the MEA design to allow for reliable measures in the brain of conscious rats. In this study, we characterized the effects of chronic implantation of the MEA into the brains of rats. We were capable of measuring Glu levels for 7 days without loss of sensitivity. We performed studies of tail-pinch induced stress, which caused a robust biphasic increase in Glu. Histological data show chronic implantation of the MEAs caused minimal injury to the CNS. Taken together, our data show that chronic recordings of tonic and phasic Glu can be carried out in awake rats for up to 17 days in vivo allowing longer term studies of Glu regulation in behaving rats. PMID:17630982

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

    PubMed

    Tomiyama, Yusuke; Fujita, Kosuke; Nishiguchi, Koji M; 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

  1. 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

  2. [Awake intubation using Pentax Airway Scope as an alternative to awake fiberoptic intubation in management of anticipated difficult tracheal intubation in major burn patients].

    PubMed

    Fayolle-Pivot, L; Magnin, C; Tissot, S; Bertin-Maghit, M; Allaouchiche, B

    2013-05-01

    Intubating patients with facial burn is difficult to most anesthesiologists. Awake flexible fiberoptic intubation is the gold standard for management of anticipated difficult tracheal intubation. However, serious facial burn and dysmorphic syndrome can make fiberoptic intubation more difficult or impossible. We report the use of awake oral intubation using the Pentax-Airway Scope (AWS) in two major burn patients with facial injury, in whom awake fiberoptic intubation was impossible. As shown in morbidly obese patient and in patients with unstable necks, AWS could be useful to facilitate tracheal intubation in awake, facial burn patients presenting with a potentially difficult airway. Awake AWS intubation seems as a potential alternative to awake fiberoptic intubation. PMID:23453928

  3. Intrinsic Temporal Patterning in the Spontaneous Movement of Awake Neonates.

    ERIC Educational Resources Information Center

    Robertson, Steven S.

    1982-01-01

    The temporal organization of spontaneous movement in healthy, awake neonates was studied on the second or third day after birth. Movement was recorded using time lapse photography and quantified as a function of time. Evidence of intrinsic temporal organization among subjects was found. (MP)

  4. PATTERN REVERSAL VISUAL EVOKED POTENTIALS IN AWAKE RATS

    EPA Science Inventory

    A method for recording pattern reversal evoked potentials (PREPs) from awake restrained rats has been developed. The procedure of Onofrj et al. was modified to eliminate the need for anesthetic, thereby avoiding possible interactions of the anesthetic with other manipulations of ...

  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. PMID:26249245

  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. 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.

  8. Awake Nonhuman Primate Brain PET Imaging with Minimal Head Restraint: Evaluation of GABAA Benzodiazepine Binding with [11C]Flumazenil in Awake and Anesthetized Animals

    PubMed Central

    Sandiego, Christine M.; Jin, Xiao; Mulnix, Tim; Fowles, Krista; Labaree, David; Ropchan, Jim; Huang, Yiyun; Cosgrove, Kelly; Castner, Stacy A.; Williams, Graham V.; Wells, Lisa; Rabiner, Eugenii A.; Carson, Richard E.

    2013-01-01

    Neuroreceptor imaging in the nonhuman primate (NHP) is valuable for translational research approaches in humans. However, the majority of NHP studies are conducted under anesthesia, which affects the interpretability of receptor binding measures. The aims of this study are to develop awake NHP imaging with minimal head restraint and to compare in vivo binding of GABAA-benzodiazepine radiotracer [11C]flumazenil under anesthetized and awake conditions. We hypothesized that [11C]flumazenil binding potential (BPND) would be higher in isoflurane-anesthetized monkeys. Methods The Focus-220 small animal PET scanner was fitted to a mechanical device that raised and tilted the scanner 45° while the awake NHP was tilted back 35° in a custom chair for optimal brain positioning. This required acclimation of the animals to the chair, touch-screen tasks, i.v. catheter insertion, and tilting. For PET studies, the bolus plus constant infusion (B/I) method was used for [11C]flumazenil administration. Two rhesus monkeys were scanned under the awake (n=6 scans) and isoflurane-anesthetized (n=4 scans) conditions. The Vicra infrared camera was used to track head motion during PET scans. Under the awake condition, emission and head motion-tracking data were acquired for 40-75 min post-injection. Anesthetized monkeys were scanned for 90 min. Cortisol measurements were acquired during awake and anesthetized scans. Equilibrium analysis was used for both the anesthetized (n=4) and awake (n=5) datasets to compute mean BPND images in NHP template space, using the pons as a reference region. Percent change per min (%Δ/min) in radioactivity concentration was calculated in high and low binding regions to assess the quality of equilibrium. Results The monkeys acclimated to procedures in the NHP chair necessary to perform awake PET imaging. Image quality was comparable between awake and anesthetized conditions. The relationship between awake and anesthetized values was BPND(awake)=0.94BPND

  9. 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.

  10. Avoidance and management of trigeminocardiac reflex complicating awake-craniotomy.

    PubMed

    Prabhu, Vikram C; Bamber, Norman I; Shea, John F; Jellish, W Scott

    2008-12-01

    The trigeminocardiac reflex occurs from manipulation or stimulation of peripheral branches or the central component of the trigeminal nerve and consists of bradycardia, hypotension, apnea, and increased gastric motility. The efferent limb of the response is mediated by the vagus nerve. This 65-year-old Caucasian male suffered an episode of bradycardia progressing to transient asystole during the course of an awake-craniotomy procedure for tumor resection. The cardiac rhythm changes resolved with administration of intravenous atropine, removal of the precipitating stimulus, and application of topical anesthetic on the dura of the middle cranial fossa. The trigeminocardiac response may complicate the course of a craniotomy and may place an awake, unintubated patient at increased risk for morbidity. The reflex may be prevented by anesthetizing the dura innervated by the trigeminal nerve via injection or topical application of local anesthetic. If encountered, removal of the stimulus, airway protection, and administration of vagolytic medications are measures that need to be considered. PMID:18845385

  11. Enclosure for small animals during awake animal imaging

    SciTech Connect

    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.

  12. Sonographically guided superior laryngeal nerve block during awake fiberoptic intubation.

    PubMed

    Sawka, Andrew; Tang, Raymond; Vaghadia, Himat

    2015-04-15

    We report 5 patients who underwent ultrasound-guided superior laryngeal nerve block before awake intubation and general anesthesia. We used a 8- to 15-MHz hockey stick-shaped ultrasound transducer (HST15-8/20 linear probe, Ultrasonix) to visualize the superior laryngeal nerve. A 3.8-cm 25-G needle was inserted in real time and directed toward the superior laryngeal nerve followed by circumferential placement of local anesthetic. All 5 patients tolerated subsequent awake fiberoptic intubation with either minimal or no sedation. Sonographically guided superior laryngeal nerve block may be useful in patients where identification of landmarks in the neck is difficult as a result of patient anatomy. PMID:25867195

  13. 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

  14. 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. PMID:25352088

  15. Presurgical Rehearsals for Patients Considering "Awake" Deep Brain Stimulation.

    PubMed

    Falconer, Ramsey A; Rogers, Sean L; Brewer, Cristie M; Piscitani, Franco; Shenai, Mahesh B

    2016-01-01

    Simulated surgical environments are rapidly gaining adoption in training students, residents, and members of specialized surgical teams. However, minimal attention has been given to the use of simulated surgical environments to educate patients on surgical processes, particularly procedures that require the active participation of the patient. "Awake" neurosurgery provides a unique situation in which patients openly participate in their operation. We describe a case report, in which a 62-year-old male was referred for "awake" deep brain stimulation implantation, in relation to medically refractory Parkinson's disease. The patient had significant concerns regarding anxiety and claustrophobia, and toleration of the "awake" procedure. Consequently, we designed a simulated OR environment and process, to recreate the physical experience of the procedure, with minimal cost or risk. This experience was crucial in determining the care plan, as after this experience, the patient opted for an "asleep" alternative. Thus, in certain settings, presurgical rehearsals may have a dramatic impact in the overall course of care. PMID:27532036

  16. Freely tunable broadband polarization rotator for terahertz waves.

    PubMed

    Fan, Ren-Hao; Zhou, Yu; Ren, Xiao-Ping; Peng, Ru-Wen; Jiang, Shang-Chi; Xu, Di-Hu; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

    2015-02-18

    A freely tunable polarization rotator for broadband terahertz waves is demonstrated using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized terahertz wave to any desired direction with nearly perfect conversion efficiency. This low-cost, high-efficiency, and freely tunable device has potential applications as material analysis, wireless communication, and THz imaging. PMID:25545177

  17. 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.

  18. 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. PMID:10719268

  19. 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

  20. Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: functional imaging in freely behaving rodent pups

    PubMed Central

    Bock, Jörg; Riedel, Anett; Braun, Katharina

    2012-01-01

    The trumpet-tailed rat or degu (Octodon degus) is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behavior. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method) in 8-day-old male degu pups the following stress conditions were compared: (A) pups together with parents and siblings (control), (B) separation of the litter from the parents, (C) individual separation from parents and siblings, and (D) individual separation and presentation of maternal calls. Condition (B) significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens (NAcc), and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C), where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D) maternal vocalizations “reactivated” brain activity in the cingulate and precentral medial cortex, NAcc, and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex (IL) and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other conditions. PMID:22590453

  1. 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

    2016-01-01

    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 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. PMID:27441501

  2. 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. PMID:26001580

  3. Preparation of an Awake Mouse for Recording Neural Responses and Injecting Tracers

    PubMed Central

    Muniak, Michael A.; Mayko, Zachary M.; Ryugo, David K.; Portfors, Christine V.

    2012-01-01

    It is well known that anesthesia alters neural response properties in various regions of the brain.13. In the auditory system, fundamental response properties of brainstem neurons including threshold, frequency specificity, and inhibitory sidebands are altered in significant ways under anesthesia1-2. These observations prompted physiologists to seek ways to record from single neurons without the contaminating effects of anesthesia. One result was a decerebrate preparation, where the brainstem was completely transected at the level of the midbrain4. The drawbacks of this preparation are a formidable surgery, the elimination of descending projections from the forebrain, and an inability to use sensory stimulation to examine structures above the midbrain. A different strategy has been to implant electrode arrays chronically to record from single neurons and multiunit clusters while the animal is awake and/or behaving5,6. These techniques however are not compatible with injecting tracer dyes after first electrophysiologically characterizing a brain structure. To avoid altering neural response properties with anesthetics while recording electrophysiological response properties from single neurons, we have adapted a head restraint technique long used in bats7-9 to mouse10-12. Using this method, we are able to conduct electrophysiological recordings over several days in the unanesthetized mouse. At the end of the recording sessions, we can then inject a dye to reconstruct electrode positions and recording sites or inject a tracer so that pathways to and from the recording loci can be determined. This method allows for well isolated single neuron recordings over multiple days without the use anesthetics. PMID:22781848

  4. Wearable scanning photoacoustic brain imaging in behaving rats.

    PubMed

    Tang, Jianbo; Dai, Xianjin; Jiang, Huabei

    2016-06-01

    A wearable scanning photoacoustic imaging (wPAI) system is presented for noninvasive brain study in behaving rats. This miniaturized wPAI system consists of four pico linear servos and a single transducer-based PAI probe. It has a dimension of 50 mm × 35 mm × 40 mm, and a weight of 26 g excluding cablings. Phantom evaluation shows that wPAI achieves a lateral resolution of ∼0.5 mm and an axial resolution of ∼0.1 mm at a depth of up to 11 mm. Its imaging ability is also tested in a behaving rat, and the results indicate that wPAI is able to image blood vessels at a depth of up to 5 mm with intact scalp and skull. With its noninvasive, deep penetration, and functional imaging ability in behaving animals, wPAI can be used for behavior, cognition, and preclinical brain disease studies. PMID:26777064

  5. Robust Reproducible Resting State Networks in the Awake Rodent Brain

    PubMed Central

    Becerra, Lino; Pendse, Gautam; Chang, Pei-Ching; Bishop, James; Borsook, David

    2011-01-01

    Resting state networks (RSNs) have been studied extensively with functional MRI in humans in health and disease to reflect brain function in the un-stimulated state as well as reveal how the brain is altered with disease. Rodent models of disease have been used comprehensively to understand the biology of the disease as well as in the development of new therapies. RSN reported studies in rodents, however, are few, and most studies are performed with anesthetized rodents that might alter networks and differ from their non-anesthetized state. Acquiring RSN data in the awake rodent avoids the issues of anesthesia effects on brain function. Using high field fMRI we determined RSNs in awake rats using an independent component analysis (ICA) approach, however, ICA analysis can produce a large number of components, some with biological relevance (networks). We further have applied a novel method to determine networks that are robust and reproducible among all the components found with ICA. This analysis indicates that 7 networks are robust and reproducible in the rat and their putative role is discussed. PMID:22028788

  6. 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. PMID:26573650

  7. 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

  8. 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.

  9. Improvements in intrinsic feature pose measurement for awake animal imaging

    SciTech Connect

    J.S. Goddard, J.S. Baba, S.J. Lee, A.G. Weisenberger, A. Stolin, J. McKisson, M.F. Smith

    2011-06-01

    Development has continued with intrinsic feature optical motion tracking for awake animal imaging to measure 3D position and orientation (pose) for motion compensated reconstruction. Prior imaging results have been directed towards head motion measurement for SPECT brain studies in awake unrestrained mice. This work improves on those results in extracting and tracking intrinsic features from multiple camera images and computing pose changes from the tracked features over time. Previously, most motion tracking for 3D imaging has been limited to measuring extrinsic features such as retro-reflective markers applied to an animal's head. While this approach has been proven to be accurate, the use of external markers is undesirable for several reasons. The intrinsic feature approach has been further developed from previous work to provide full pose measurements for a live mouse scan. Surface feature extraction, matching, and pose change calculation with point tracking and accuracy results are described. Experimental pose calculation and 3D reconstruction results from live images are presented.

  10. Robust reproducible resting state networks in the awake rodent brain.

    PubMed

    Becerra, Lino; Pendse, Gautam; Chang, Pei-Ching; Bishop, James; Borsook, David

    2011-01-01

    Resting state networks (RSNs) have been studied extensively with functional MRI in humans in health and disease to reflect brain function in the un-stimulated state as well as reveal how the brain is altered with disease. Rodent models of disease have been used comprehensively to understand the biology of the disease as well as in the development of new therapies. RSN reported studies in rodents, however, are few, and most studies are performed with anesthetized rodents that might alter networks and differ from their non-anesthetized state. Acquiring RSN data in the awake rodent avoids the issues of anesthesia effects on brain function. Using high field fMRI we determined RSNs in awake rats using an independent component analysis (ICA) approach, however, ICA analysis can produce a large number of components, some with biological relevance (networks). We further have applied a novel method to determine networks that are robust and reproducible among all the components found with ICA. This analysis indicates that 7 networks are robust and reproducible in the rat and their putative role is discussed. PMID:22028788

  11. Improvements in Intrinsic Feature Pose Measurement for Awake Animal Imaging

    SciTech Connect

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

    2010-01-01

    Development has continued with intrinsic feature optical motion tracking for awake animal imaging to measure 3D position and orientation (pose) for motion compensated reconstruction. Prior imaging results have been directed towards head motion measurement for SPECT brain studies in awake unrestrained mice. This work improves on those results in extracting and tracking intrinsic features from multiple camera images and computing pose changes from the tracked features over time. Previously, most motion tracking for 3D imaging has been limited to measuring extrinsic features such as retro-reflective markers applied to an animal s head. While this approach has been proven to be accurate, the use of external markers is undesirable for several reasons. The intrinsic feature approach has been further developed from previous work to provide full pose measurements for a live mouse scan. Surface feature extraction, matching, and pose change calculation with point tracking and accuracy results are described. Experimental pose calculation and 3D reconstruction results from live images are presented.

  12. 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

  13. 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

  14. Mini-coil for magnetic stimulation in the behaving primate.

    PubMed

    Tischler, Hadass; Wolfus, Shuki; Friedman, Alexander; Perel, Eli; Pashut, Tamar; Lavidor, Michal; Korngreen, Alon; Yeshurun, Yosef; Bar-Gad, Izhar

    2011-01-15

    Transcranial magnetic stimulation (TMS) is rapidly becoming a leading method in both cognitive neuroscience and clinical neurology. However, the cellular and network level effects of stimulation are still unclear and their study relies heavily on indirect physiological measurements in humans. Direct electrophysiological studies of the effect of magnetic stimulation on neuronal activity in behaving animals are severely limited by both the size of the stimulating coils, which affect large regions of the animal brain, and the large artifacts generated on the recording electrodes. We present a novel mini-coil which is specifically aimed at studying the neurophysiological mechanism of magnetic stimulation in behaving primates. The mini-coil fits into a chronic recording chamber and provides focal activation of brain areas while enabling simultaneous extracellular multi-electrode recordings. We present a comparison of this coil to a commercial coil based on the theoretical and recorded magnetic fields and induced electric fields they generate. Subsequently, we present the signal recorded in the behaving primate during stimulation and demonstrate the ability to extract the spike trains of multiple single units from each of the electrodes with minimal periods affected by the stimulus artifact (median period <2.5 ms). The directly recorded effect of the magnetic stimulation on cortical neurons is in line with peripheral recordings obtained in humans. This novel mini-coil is a key part of the infrastructure for studying the neurophysiological basis of magnetic stimulation, thereby enabling the development and testing of better magnetic stimulation tools and protocols for both neuroscientists and clinicians. PMID:20974177

  15. Quantum-Behaved Particle Swarm Optimization with Chaotic Search

    NASA Astrophysics Data System (ADS)

    Yang, Kaiqiao; Nomura, Hirosato

    The chaotic search is introduced into Quantum-behaved Particle Swarm Optimization (QPSO) to increase the diversity of the swarm in the latter period of the search, so as to help the system escape from local optima. Taking full advantages of the characteristics of ergodicity and randomicity of chaotic variables, the chaotic search is carried out in the neighborhoods of the particles which are trapped into local optima. The experimental results on test functions show that QPSO with chaotic search outperforms the Particle Swarm Optimization (PSO) and QPSO.

  16. 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.

  17. Urgent awake thoracoscopic treatment of retained haemothorax associated with respiratory failure.

    PubMed

    Pompeo, Eugenio; Cristino, Benedetto; Rogliani, Paola; Dauri, Mario

    2015-05-01

    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

  18. 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.

  19. 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

    2014-04-01

    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. PMID:24631345

  20. 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

  1. 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

  2. Flyception: imaging brain activity in freely walking fruit flies.

    PubMed

    Grover, Dhruv; Katsuki, Takeo; Greenspan, Ralph J

    2016-07-01

    Genetically encoded calcium sensors have enabled monitoring of neural activity in vivo using optical imaging techniques. Linking neural activity to complex behavior remains challenging, however, as most imaging systems require tethering the animal, which can impact the animal's behavioral repertoire. Here, we report a method for monitoring the brain activity of untethered, freely walking Drosophila melanogaster during sensorially and socially evoked behaviors to facilitate the study of neural mechanisms that underlie naturalistic behaviors. PMID:27183441

  3. Soot Formation in Freely-Propagating Laminar Premixed Flames

    NASA Technical Reports Server (NTRS)

    Lin, K.-C.; Hassan, M. I.; Faeth, G. M.

    1997-01-01

    Soot formation within hydrocarbon-fueled flames is an important unresolved problem of combustion science. Thus, the present study is considering soot formation in freely-propagating laminar premixed flames, exploiting the microgravity environment to simplify measurements at the high-pressure conditions of interest for many practical applications. The findings of the investigation are relevant to reducing emissions of soot and continuum radiation from combustion processes, to improving terrestrial and spacecraft fire safety, and to developing methods of computational combustion, among others. Laminar premixed flames are attractive for studying soot formation because they are simple one-dimensional flows that are computationally tractable for detailed numerical simulations. Nevertheless, studying soot-containing burner-stabilized laminar premixed flames is problematical: spatial resolution and residence times are limited at the pressures of interest for practical applications, flame structure is sensitive to minor burner construction details so that experimental reproducibility is not very good, consistent burner behavior over the lengthy test programs needed to measure soot formation properties is hard to achieve, and burners have poor durability. Fortunately, many of these problems are mitigated for soot-containing, freely-propagating laminar premixed flames. The present investigation seeks to extend work in this laboratory for various soot processes in flames by observing soot formation in freely-propagating laminar premixed flames. Measurements are being made at both Normal Gravity (NG) and MicroGravity (MG), using a short-drop free-fall facility to provide MG conditions.

  4. 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. PMID:20851571

  5. 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. PMID:27290976

  6. Responses from parabrachial gustatory neurons in behaving rats.

    PubMed

    Nishijo, H; Norgren, R

    1990-04-01

    1. The responses of a total of 70 single neurons were recorded from the parabrachial nuclei (PBN) in awake rats. In 59 neurons, sapid stimuli (0.5 ml) elicited significant taste responses. Of these 59 neurons, 10 also had significant responses to water. The mean spontaneous rate of the taste neurons was 13.4 +/- 6.9 (SD) spikes/s. Of the remaining 11 neurons, 9 responded significantly only to water; 2 had no significant responses to the standard fluid stimuli. 2. Based on the magnitude of their response to our four standard stimuli, the taste neurons were classified as follows: 42 NaCl-best, 14 sucrose-best, 2 citric acid-best, and 1 QHCl-best. Of these, 25 responded only to one of four sapid stimuli; 20 of these specific cells responded only to NaCl. All the remaining 34 neurons responded to two or more of the four sapid stimuli, with NaCl and sucrose responsiveness dominant. For the 59 taste neurons, the mean entropy for the absolute value of the responses was 0.68; for the excitatory activity alone, it was 0.58. 3. The mean responses to NaCl and sucrose concentration series increased monotonically. Except at the lowest concentration, responses to citric acid also increased monotonically, but with a lower slope. Mean responses to QHCl, however, remained stable or even decreased with increasing concentration. Thus the power functions for the NaCl and sucrose intensity-response series were higher than those of citric acid and QHCl. 4. A hierarchical cluster analysis of 59 parabrachial neurons suggested four different categories: NaCl-best, sucrose-best, citric acid-best, and QHCl-best. These categories were less evident in the two-dimensional space produced by multidimensional analysis, because the positions of NaCl- and sucrose-best neurons formed a continuum in which neural response profiles change successively from sucrose-specific to NaCl-specific. 5. The results were consistent with previous anatomic and neurophysiological data suggesting convergence in the

  7. Pentax-AWS videolaryngoscope for awake nasal intubation in patients with unstable necks.

    PubMed

    Asai, T

    2010-01-01

    In patients with unstable necks and at risk of pulmonary aspiration, awake fibreoptic intubation is often appropriate. However, stabilization of the neck can make fibreoptic intubation more difficult. I report the use of awake nasal intubation using the Pentax-Aiway Scope (AWS) in three patients with restricted neck movement, in whom awake fibreoptic intubation had failed. Case 1: a 59-yr-old man, at risk of aspiration, required an emergency cervical laminectomy. Awake fibreoptic intubation was attempted while a Halo vest was being applied, but it was impossible to see the glottis, mainly due to pharyngeal and laryngeal oedema. The Pentax-AWS was easily inserted orally, and nasotracheal intubation was achieved within 20 s. Case 2: an 85-yr-old woman with neck injury required emergency surgical stabilization. A retropharyngeal haematoma prevented a fibreoptic bronchoscope from being advanced beyond the epiglottis. Nasotracheal intubation using the Pentax-AWS (with the aid of a gum elastic bougie) was achieved within 1 min. Case 3: a 22-yr-old man, with partial spinal cord damage, was undergoing cervical laminoplasty. He was at risk of aspiration and had an oedematous larynx. Although it was possible to insert a fibreoptic bronchoscope into the trachea while the neck was stabilized with a Halo vest, it was impossible to advance a tube over the fibrescope. Awake nasotracheal intubation using the Pentax-AWS was achieved within 15 s. The Pentax-AWS may be useful for nasotracheal intubation in awake patients with restricted necks. PMID:19923133

  8. 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

  9. 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

  10. 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

    2014-01-01

    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

  11. Velocity measurements around a freely swimming fish using PIV

    NASA Astrophysics Data System (ADS)

    Kamran Siddiqui, M. H.

    2007-01-01

    Two-dimensional velocity fields around a freely swimming goldfish in a vertical plane have been measured using the particle image velocimetry (PIV) technique. A novel scheme has been developed to detect the fish body in each PIV image. The scheme is capable of detecting the bodies of fish and other aquatic animals with multicolour skin and different patterns. In this scheme, the body portions brighter and darker than the background are extracted separately and then combined together to construct the entire body. The velocity fields show that the fins and tail produce jets. Vortices are also observed in the wake region.

  12. Hypothesis: solid tumours behave as systemic metabolic dictators.

    PubMed

    Lee, Yang-Ming; Chang, Wei-Chun; Ma, Wen-Lung

    2016-06-01

    Current knowledge regarding mechanisms of carcinogenesis in human beings centres around the accumulation of genetic instability, amplified cellular signalling, disturbed cellular energy metabolism and microenvironmental regulation governed by complicated cell-cell interactions. In this article, we provide an alternative view of cancer biology. We propose that cancer behaves as a systemic dictator that interacts with tissues throughout the body to control their metabolism and eventually homeostasis. The mechanism of development of this endocrine organ-like tumour (EOLT) tissue might be the driving force for cancer progression. Here, we review the literature that led to the development of this hypothesis. The EOLT phenotype can be defined as a tumour that alters systemic homeostasis. The literature indicates that the EOLT phenotype is present throughout cancer progression. The feedback mechanism that governs the interaction between tumours and various organs is unknown. We believe that investigating the mechanism of EOLT development may advance the current knowledge of regulation within the tumour macroenvironment and consequently lead to new diagnostic methods and therapy. PMID:26843513

  13. 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

  14. 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

  15. 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

  16. Brainstem areas activated by intermittent apnea in awake unrestrained rats.

    PubMed

    Ferreira, C B; Schoorlemmer, G H; Rossi, M V; Takakura, A C; Barna, B F; Moreira, T S; Cravo, S L

    2015-06-25

    We investigated the role of the autonomic nervous system to cardiovascular responses to obstructive apnea in awake, unrestrained rats, and measured expression of Fos induced by apnea in the brainstem. We implanted a tracheal balloon contained in a rigid tube to allow the induction of apnea without inducing pain in the trachea. During bouts of 15s of apnea, heart rate fell from 371±8 to 161±11bpm (mean±SEM, n=15, p<0.01) and arterial pressure increased from 115±2 to 131±4mmHg (p<0.01). Bradycardia was due to parasympathetic activity because it was blocked by the muscarinic antagonist, methylatropine. The pressor response was due to vasoconstriction caused by sympathetic activation because it was blocked by the α1 antagonist, prazosin. Apnea induced Fos expression in several brainstem areas involved in cardiorespiratory control such as the nucleus of the solitary tract (NTS), ventrolateral medulla (VLM), and pons. Ligation of the carotid body artery reduced apnea-induced bradycardia, blocked heart rate responses to i.v. injection of cyanide, reduced Fos expression in the caudal NTS, and increased Fos expression in the rostral VLM. In conclusion, apnea activates neurons in regions that process signals from baroreceptors, chemoreceptors, pulmonary receptors, and regions responsible for autonomic and respiratory activity both in the presence and absence of carotid chemoreceptors. PMID:25862588

  17. Neural representation of face familiarity in an awake chimpanzee.

    PubMed

    Fukushima, Hirokata; Hirata, Satoshi; Matsuda, Goh; Ueno, Ari; Fuwa, Kohki; Sugama, Keiko; Kusunoki, Kiyo; Hiraki, Kazuo; Tomonaga, Masaki; Hasegawa, Toshikazu

    2013-01-01

    Evaluating the familiarity of faces is critical for social animals as it is the basis of individual recognition. In the present study, we examined how face familiarity is reflected in neural activities in our closest living relative, the chimpanzee. Skin-surface event-related brain potentials (ERPs) were measured while a fully awake chimpanzee observed photographs of familiar and unfamiliar chimpanzee faces (Experiment 1) and human faces (Experiment 2). The ERPs evoked by chimpanzee faces differentiated unfamiliar individuals from familiar ones around midline areas centered on vertex sites at approximately 200 ms after the stimulus onset. In addition, the ERP response to the image of the subject's own face did not significantly diverge from those evoked by familiar chimpanzees, suggesting that the subject's brain at a minimum remembered the image of her own face. The ERPs evoked by human faces were not influenced by the familiarity of target individuals. These results indicate that chimpanzee neural representations are more sensitive to the familiarity of conspecific than allospecific faces. PMID:24392287

  18. Effect of nitroglycerin on myocardial collateral conductance in awake dogs

    SciTech Connect

    Brazzamano, S.; Rembert, J.C.; Greenfield, J.C. Jr. )

    1988-04-01

    Conductance of the coronary collateral circulation during the course of two abrupt circumflex coronary occlusions was measured in awake dogs {approximately} 2 wk after collateral vessels were stimulated to develop. The pressure gradient from the central aorta to the distal circumflex coronary artery was measured, and myocardial blood flow was determined by 9-{mu}m radioactive microspheres at 30 s and 4 min after coronary occlusions. Collateral conductance was calculated as mean collateral blood flow divided by the mean aorta-coronary pressure gradient. Before nitroglycerin, collateral conductance increased in all eight dogs from 30 s to 4 min. After nitroglycerin administration, the conductance at 30 s increased from the prenitroglycerin control value to 0.014 {+-} 0.012 ml{center dot}min{sup {minus}1}{center dot}g{sup {minus}1}{center dot}mmHg{sup {minus}1}. The mean change in conductance from 30 s to 4 min postnitroglycerin was significantly less than during prenitroglycerin. These data indicate that an increase in conductance during coronary occlusion occurs even in the immature collateral circulation. This effect presumably takes place in the arterial smooth muscle at the origin of the collateral vasculature.

  19. Optogenetic Control of Targeted Peripheral Axons in Freely Moving Animals

    PubMed Central

    Iyer, Shrivats M.; Deisseroth, Karl; Delp, Scott L.

    2013-01-01

    Optogenetic control of the peripheral nervous system (PNS) would enable novel studies of motor control, somatosensory transduction, and pain processing. Such control requires the development of methods to deliver opsins and light to targeted sub-populations of neurons within peripheral nerves. We report here methods to deliver opsins and light to targeted peripheral neurons and robust optogenetic modulation of motor neuron activity in freely moving, non-transgenic mammals. We show that intramuscular injection of adeno-associated virus serotype 6 enables expression of channelrhodopsin (ChR2) in motor neurons innervating the injected muscle. Illumination of nerves containing mixed populations of axons from these targeted neurons and from neurons innervating other muscles produces ChR2-mediated optogenetic activation restricted to the injected muscle. We demonstrate that an implanted optical nerve cuff is well-tolerated, delivers light to the sciatic nerve, and optically stimulates muscle in freely moving rats. These methods can be broadly applied to study PNS disorders and lay the groundwork for future therapeutic application of optogenetics. PMID:23991144

  20. 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.

  1. Nonlinear fluctuation effects in dynamics of freely suspended films

    NASA Astrophysics Data System (ADS)

    Kats, E. I.; Lebedev, V. V.

    2015-03-01

    Long-scale dynamic fluctuation phenomena in freely suspended films is analyzed. We consider isotropic films that, say, can be pulled from bulk smectic-A liquid crystals. The key feature of such objects is possibility of bending deformations of the film. The bending (also known as flexular) mode turns out to be anomalously weakly attenuated. In the harmonic approximation there is no viscous-like damping of the bending mode, proportional to q2 (q is the wave vector of the mode), since it is forbidden by the rotational symmetry. Therefore, the bending mode is strongly affected by nonlinear dynamic fluctuation effects. We calculate the dominant fluctuation contributions to the damping of the bending mode due to its coupling to the inplane viscous mode, which restores the viscous-like q2 damping of the bending mode. Our calculations are performed in the framework of the perturbation theory where the coupling of the modes is assumed to be small, then the bending mode damping is relatively weak. We discuss our results in the context of existing experiments and numeric simulations of the freely suspended films and propose possible experimental observations of our predictions.

  2. 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.

  3. Striatal hyperthermia associated with arousal: intracranial thermorecordings in behaving rats.

    PubMed

    Kiyatkin, E A; Wise, R A

    2001-11-01

    Humans and experimental animals show strong increases in body temperature in response to a variety of stimuli presumed to have stress as their common denominator. To assess the brain's role in this 'emotional' hyperthermia, temperatures were continuously recorded in dorsal and ventral striatum and in deep temporal muscle of freely moving rats exposed to different arousing and mild stress stimuli (placement in the test cage, 20-s sound stimulation, i.v. saline injection, 3-min social interaction with conspecific, and 3-min tail-pinch). The stimuli caused brain hyperthermia of differing degrees but similar pattern, in both the dorsal and ventral striatum. Ventral striatum had approximately 0.4 degrees C higher basal temperature than dorsal striatum, each of these brain temperatures was higher than that in deep temporal muscle. Maximal increases in brain temperature ( approximately 0.8-1.2 degrees C for 20-40 min) occurred upon placement in the test cages, during tail-pinch and during social interaction, all of which were accompanied by behavioral activation. These increases developed with short onset latencies (up to 5-15 s) and always preceded increases in muscle temperature. Significant but smaller increases in brain temperature ( approximately 0.2 degrees C for 4-6 min) were detected after sound stimulation and i.v. saline injection that induced minimal changes in behavior and no change in muscle temperature. Thus, it appears that brain hyperthermia can be triggered by quite different arousing or stressful stimuli that disturb an organism's homeostasis and demand adaptive responding. Although the exact mechanisms of local heat production in brain tissue remain to be confirmed, neuronal activation appears to be the primary triggering force behind changes in brain temperature that are sufficient to affect body temperature. Because most neural processes are temperature-dependent, change in local temperature may result in dramatic modulation of the efficiency of

  4. 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

  5. Gustatory responses of neurons in the nucleus of the solitary tract of behaving rats.

    PubMed

    Nakamura, K; Norgren, R

    1991-10-01

    1. The activity of 117 single neurons was recorded in the rostral nucleus of the solitary tract (NST) and tested with each of four standard chemical stimuli [sucrose, NaCl, citric acid, and quinine HCl (QHCl)] and distilled water in awake, behaving rats. In 101 of these neurons, at least one sapid stimulus elicited a significant taste response. The mean spontaneous rate of the taste neurons was 4.1 +/- 5.8 (SD) spike/s. The mean response magnitudes were as follows: sucrose, 10.6 +/- 11.7; NaCl, 8.6 +/- 14.6; citric acid, 6.2 +/- 7.8; and QHCl, 2.4 +/- 6.6 spikes/s. 2. On the basis of their largest response, 42 taste neurons were classified as sucrose-best, 25 as NaCl-best, 30 as citric acid-best, and 4 as QHCl-best. The mean spontaneous rates for these categories were 4.9 +/- 6.2 for sucrose-best cells, 5.8 +/- 7.4 for NaCl-best, 1.6 +/- 2.0 for citric acid-best, and 5.8 +/- 6.0 spikes/s for QHCl-best. The spontaneous rate of the citric acid-best neurons was significantly lower than that of the other categories. 3. At the standard concentrations, 45 taste cells (44.6%) responded significantly to only one of the gustatory stimuli. Of the 30 acid-best neurons, 23 (76.7%) responded only to citric acid. For sucrose-best cells, specific sensitivity was less common (18/42, 42.9%), and for NaCl-best neurons, it was relatively uncommon (3/25, 12%). One of the 4 QHCl-best neurons was specific. In a concentration series, more than one-half of the 19 specific neurons tested responded to only one chemical at any strength. 4. The mean entropy for the excitatory responses of all gustatory neurons was 0.60. Citric acid-best cells showed the least breadth of responsiveness (0.49), sucrose-best cells were somewhat broader (0.56), but NaCl-best and QHCl-best cells were considerably less selective (0.77 and 0.79, respectively). Inhibition was observed infrequently and never reached the criterion for significance. 5. In the hierarchical cluster analysis, the four largest clusters

  6. 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. PMID:19295387

  7. Effects of memantine on hippocampal long-term potentiation, gamma activity, and sensorimotor gating in freely moving rats.

    PubMed

    Ma, Jingyi; Mufti, Asfandyar; Stan Leung, L

    2015-09-01

    Memantine, an uncompetitive N-methyl-D-aspartate receptor antagonist, is used for treatment of patients with Alzheimer's disease. The mechanisms of memantine in relieving cognitive and behavioral symptoms are unclear, and this study attempts to elucidate its action on network and synaptic functions of the hippocampus. The effects of memantine on electrographic activity and hippocampal long-term potentiation (LTP) were investigated in freely moving rats. Basal dendritic excitation on hippocampal CA1 pyramidal cells showed a robust LTP after theta-frequency primed bursts, and the LTP was higher after 5-10 mg/kg intraperitoneal (ip) memantine pretreatment, as compared with saline pretreatment. Injection of scopolamine (5 mg/kg ip) before memantine failed to block the LTP-enhancing effect of memantine. Memantine as compared with saline pretreatment did not affect the LTP after an afterdischarge induced by high-frequency (200-Hz) train stimulation. Memantine (5 or 10 mg/kg ip) significantly enhanced gamma oscillations in the hippocampal local field potentials of 40-100 Hz during walking and awake immobility. Memantine at 10 mg/kg ip, but not at 5 mg/kg ip, increased prepulse inhibition of the acoustic startle response, while both 5 and 10 mg/kg ip memantine enhanced the acoustic startle response as compared with saline-injected rats. These electrophysiological and behavioral effects of memantine are unique among N-methyl-D-aspartate receptor antagonists but are consistent with memantine's effects in improving cognitive and sensorimotor functions of Alzheimer's patients. PMID:26119223

  8. Respiratory plasticity in the behaving rat following chronic intermittent hypoxia.

    PubMed

    Edge, Deirdre; Skelly, J Richard; Bradford, Aidan; O'Halloran, Ken D

    2010-01-01

    Chronic intermittent hypoxia (CIH), a feature of obstructive sleep apnoea (OSA) has been shown to have myriad effects on the respiratory control system. The effects on breathing are of great clinical significance for the sleep apnoea patient. We sought to determine the effect of CIH on normoxic ventilation. Both male and female adult Wistar rats were studied due to the evident sex difference in the prevalence of OSA. A role for oxidative stress in respiratory modifications was also explored. Adult male (n = 30) and female (n = 16) rats were exposed to alternating periods of N(2) and O(2) for 90 s each, bringing the ambient oxygen concentration to 5% at nadir (CIH) group. Sham groups were subject to cycles of air/air under identical experimental conditions. A subset of male rats (8 controls, 8 CIH) had free access to water containing 1 mM Tempol (SOD-mimetic) at all times. Treatments were carried out for 8 hours a day for 9 days. Following treatment, normoxic ventilation was assessed by whole body plethysmography in sleeping animals. Baseline normoxic ventilation was increased in both male and female treated rats but this did not achieve statistical significance. However, ventilatory drive (V(T)/Ti) was significantly increased in male rats. Chronic treatment with Tempol abolished this effect. Conversely, CIH had no significant effect on VT/Ti in female rats. Our results indicate subtle effects of intermittent hypoxia on breathing in conscious behaving rats. We speculate the increased ventilatory drive following CIH represents a form a neural plasticity - a ROS dependent phenomenon - with sexual dimorphism. PMID:20217363

  9. Chronic multiunit recordings in behaving animals: advantages and limitations.

    PubMed

    Supèr, Hans; Roelfsema, Pieter R

    2005-01-01

    By simultaneous recording from neural responses at many different loci at the same time, we can understand the interaction between neurons, and thereby gain insight into the network properties of neural processing, instead of the functioning of individual neurons. Here we will discuss a method for recording in behaving animals that uses chronically implanted micro-electrodes that allow one to track neural responses over a long period of time. In a majority of cases, multiunit activity, which is the aggregate spiking activity of a number of neurons in the vicinity of an electrode tip, is recorded through these electrodes, and occasionally single neurons can be isolated. Here we compare the properties of multiunit responses to the responses of single neurons in the primary visual cortex. We also discuss the advantages and disadvantages of the multiunit signal as opposed to a signal of single neurons. We demonstrate that multiunit recording provides a reliable and useful technique in cases where the neurons at the electrodes have similar response properties. Multiunit recording is therefore especially valuable when task variables have an effect that is consistent across the population of neurons. In the primary visual cortex, this is the case for figure-ground segregation and visual attention. Multiunit recording also has clear advantages for cross-correlation analysis. We show that the cross-correlation function between multiunit signals gives a reliable estimate of the average single-unit cross-correlation function. By the use of multiunit recording, it becomes much easier to detect relatively weak interactions between neurons at different cortical locations. PMID:15581712

  10. 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.

  11. Adjustable frequency selectivity of auditory forebrain neurons recorded in a freely moving songbird via radiotelemetry.

    PubMed

    Nieder, A; Klump, G M

    1999-01-01

    One of the hearing system's basic properties that determines the detection of signals is its frequency selectivity. In the natural environment, a songbird may achieve an improved detection ability if the neuronal filters of its auditory system could be sharpened to adapt to the spectrum of the background noise. To address this issue, we studied 35 multi-unit clusters in the input layer of the primary auditory forebrain of nine European starlings (Sturnus vulgaris). Microelectrodes were chronically implanted in this songbird's cortex analogue and the neuronal activity was transmitted from unrestrained birds via a miniature FM transmitter. Frequency tuning curves (FTCs) and inhibitory sidebands were determined by presenting a matrix of frequency-level combinations of pure tones. From each FTC, the characteristic frequency (CF) and several parameters describing the neurons' filter characteristics were derived and compared to the same recording site's filter function while simultaneously stimulating with a continuous CF tone 20 dB above the response threshold. Our results show a significant improvement of frequency selectivity during two-tone stimulation, indicating that spectral filtering in the starling's auditory forebrain depends on the acoustic background in which a signal is presented. Moreover, frequency selectivity was found to be a function of the time over which the stimulus persisted, since FTCs were much sharper and inhibitory sidebands were largely expanded several milliseconds after response onset. Neuronal filter bandwidths during two-tone stimulation in the auditory forebrain are in good agreement with psychoacoustically measured critical bandwidths in the same species. Radiotelemetry proved to be a powerful tool in studying neuronal activity in freely behaving birds. PMID:9925015

  12. Awake brain tumor resection during pregnancy: Decision making and technical nuances.

    PubMed

    Meng, Lingzhong; Han, Seunggu J; Rollins, Mark D; Gelb, Adrian W; Chang, Edward F

    2016-02-01

    The co-occurrence of primary brain tumor and pregnancy poses unique challenges to the treating physician. If a rapidly growing lesion causes life-threatening mass effect, craniotomy for tumor debulking becomes urgent. The choice between awake craniotomy versus general anesthesia becomes complicated if the tumor is encroaching on eloquent brain because considerations pertinent to both patient safety and oncological outcome, in addition to fetal wellbeing, are involved. A 31-year-old female at 30 weeks gestation with twins presented to our hospital seeking awake craniotomy to resect a 7 × 6 × 5 cm left frontoparietal brain tumor with 7 mm left-to-right subfalcine herniation on imaging that led to word finding difficulty, dysfluency, right upper extremity paralysis, and right lower extremity weakness. She had twice undergone tumor debulking under general anesthesia during the same pregnancy at an outside hospital at 16 weeks and 28 weeks gestation. There were considerations both for and against awake brain tumor resection over surgery under general anesthesia. The decision-making process and the technical nuances related to awake brain tumor resection in this neurologically impaired patient are discussed. Awake craniotomy benefits the patient who harbors a tumor that encroaches on the eloquent brain by allowing a greater extent of resection while preserving the language and sensorimotor function. It can be successfully done in pregnant patients who are neurologically impaired. The patient should be motivated and well informed of the details of the process. A multidisciplinary and collaborative effort is also crucial. PMID:26498092

  13. 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

  14. 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

  15. Plug flow in a viscous freely-suspended film

    NASA Astrophysics Data System (ADS)

    Dalnoki-Veress, Kari; Ilton, Mark; Couchman, Miles; Salez, Thomas; Benzaquen, Michael; Fowler, Paul; Raphael, Elie

    The flow of viscous polymer liquids supported by a solid substrate has been well characterized by a variety of experimental techniques. Previous studies found that the velocity profile within a flowing liquid film depends strongly on the friction at the liquid-substrate interface. For the case of low interfacial friction, liquid molecules can slide along the solid substrate. This is the ``slip'' boundary condition. Here we probe flow in a system with no interfacial friction: a viscous polymer film suspended at its edges. Using AFM, we measure the capillary-driven relaxation of freestanding polymer films with an initially stepped film thickness profile. The time evolution of the profile is consistent with plug flow. A freely-suspended viscous polymer film provides a physical realization of an idealized infinite slip boundary condition. Interestingly, in such a context, the profile evolution satisfies a diffusion-like equation, thus allowing for the use of a broad mathematical and physical toolbox by analogy.

  16. Two-Dimensional Microrheology of Freely Suspended Liquid Crystal Films

    NASA Astrophysics Data System (ADS)

    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.

    2011-12-01

    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.

  17. Meal-contingent intestinal lymph sampling from awake, unrestrained rats.

    PubMed

    Arnold, Myrtha; Dai, Yunting; Tso, Patrick; Langhans, Wolfgang

    2012-06-15

    Standard procedures for intestinal lymph collection involve continuous, quantitative drainage of the lymph fluid in anesthetized or restrained animals that are often euthanized within 48 h. We here describe a novel technique for the nonocclusive cannulation of the major intestinal lymph duct in rats that allows for repetitive in vivo sampling of intestinal lymph from unrestrained, awake, and ad libitum-fed animals. The distinctive feature of this novel technique is that a 5- to 7-mm long piece of Vialon tubing (OD/ID: 0.8/0.7 mm) with a small hole in its wall is first implanted into the major intestinal lymph duct for stabilization. The tapered tip (OD: ≈0.1 mm) of the catheter is then inserted into the hole of the tubing and fixed in place with a polyamid suture and a drop of tissue glue. In our hands, catheters implanted this way remain patent for up to 6 wk after surgery. In an initial experiment we collected lymph from six adult rats before (0) and 15, 30, 45, 60, 75, 90, 120, and 180 min (120 μl, each) after the onset of isocaloric (12.5 kcal) low-fat (LF) or high-fat (HF) test meals and measured active glucagon-like peptide-1 (GLP-1). Intestinal lymphatic GLP-1 concentration increased (P < 0.05) from ≈4 pmol/l (0 min) to a peak of 33 ± 6 (means ± SE) or 22 ± 4 pmol/l at 15 (HF) or 30 min (LF) after meal onset and gradually returned to baseline levels by 180 min. With this new technique fewer animals are required to generate physiologically relevant data for various aspects of gastrointestinal physiology that involve the lymphatic system. Furthermore, the advantage of this system is that the animal can act as its own control when the effect of different experimental protocols is tested. PMID:22513747

  18. 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

  19. 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

  20. 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.

  1. [Awake intubation with landiolol and dexmedetomidine in a patient with anxiety neurosis].

    PubMed

    Nagamine, Tatsunari; Komasawa, Nobuyasu; Fujitate, Yasutaka; Kuzukawa, Yosuke; Kitano, Manabu; Minami, Toshiaki

    2014-08-01

    We report a successful case of awake intubation in a patient with anxiety neurosis via continuous administration of landiolol and dexmedetomidine. A 52-year-old woman weighing 46.8 kg with anxiety neurosis experienced postoperative bleeding after left-side thyroidectomy and was scheduled for emergent hemostasis under general anesthesia Due to swelling of the neck, we anticipated a difficult airway and decided to perform awake intubation. She showed extreme insecurity and shivering, and initially did not agree to the procedure. To calm her anxiety and panic, we continuously administered 10 microg x kg(-1). min(-1) landiolol and 1.0 microg x kg(-1) hr(-1) dexmedetomidine. After 10 minutes, her shivering disappeared, and she agreed to undergo awake intubation, which was performed with the Pentax-AWS Airwayscope and thin Intlock blade. The patient bucked slightly during intubation but hemodynamic changes were minimal. PMID:25199332

  2. 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

  3. [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. PMID:26466500

  4. 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

  5. Hydrodynamics of Inclusions in Freely Suspended Liquid Crystal Films

    NASA Astrophysics Data System (ADS)

    Qi, Zhiyuan

    Hydrodynamic interaction of pairs of circular inclusions in two-dimensional (2D), fluid smectic membranes suspended in air has been studied systematically. By analyzing their Brownian motion, it is found that the radial mutual mobilities of identical inclusions are independent of their size but that the angular coupling becomes strongly size-dependent when their radius exceeds a characteristic hydrodynamic length. These observations are described well for arbitrary inclusion separations by a model that generalizes the Levine/MacKintosh theory of point-force response functions and uses a boundary-element approach to calculate the mobility matrix for inclusions of finite extent. Beyond that, 2D flow fields generated by a rigid, oscillating post inserted in the film have been measured by analyzing the motion of tracer particles and provide a detailed understanding of the hydrodynamic behavior in the film/gas system. The Brownian diffusion of micron-scale inclusions in freely suspended smectic A liquid crystal films a few nanometers thick and several millimeters in diameter depends strongly on the air surrounding the film. Near atmospheric pressure, the three-dimensionally coupled film/gas system is well described by Hughes/Pailthorpe/White hydrodynamic theory but at lower pressure, the diffusion coefficient increases substantially, tending in high vacuum toward the two-dimensional limit where it is determined by film size. In the absence of air, the films are found to be a nearly ideal physical realization of a two-dimensional, incompressible Newtonian fluid.

  6. 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.

  7. Acoustic tracking of a freely drifting sonobuoy field

    NASA Astrophysics Data System (ADS)

    Dosso, Stan E.; Collison, Nicole E. B.

    2002-05-01

    This paper develops an acoustic inversion algorithm to track a field of freely drifting sonobuoys using travel-time measurements from a series of nonsimultaneous impulsive sources deployed around the field. In this scenario, the time interval between sources can be sufficiently long that significant independent movement of the individual sonobuoys occurs. In addition, the source transmission instants are unknown, and the source positions and initial sonobuoy positions are known only approximately. The formulation developed here solves for the track of each sonobuoy (parametrized by the sonobuoy positions at the time of each source transmission), allowing arbitrary, independent sonobuoy motion between transmissions, as well as for the source positions and transmission instants. This leads to a strongly underdetermined inverse problem. However, regularized inversion provides meaningful solutions by incorporating a priori information consisting of prior estimates (with uncertainties) for the source positions and initial sonobuoy positions, and a physical model for preferred sonobuoy motion. Several models for sonobuoy motion are evaluated, with the best results obtained by minimizing the second spatial derivative of the tracks to obtain the minimum-curvature or smoothest track, subject to fitting the acoustic data to a statistically appropriate level.

  8. Freely propagating open premixed turbulent flames stabilized by swirl

    SciTech Connect

    Chan, C.K.; Lau, K.S.; Chin, W.K.; Cheng, R.K.

    1991-12-01

    A novel means has been developed for using weak swirl to stabilize freely propagating open premixed turbulent flames (swirl numbers between 0.05 to 0.3). By injecting a small amount of air tangentially into the co-flow of a concentric burner, stationary flames can be maintained above the burner exit for a large range of mixture, turbulence and flow conditions. The absence of physical surfaces in the vicinity of the flame provides free access to laser diagnostics. Laser Doppler anemometry and laser Mie scattering measurements of four flames with and without incident turbulence show that their features are typical of wrinkled laminar flames. The most distinct characteristics is that flame stabilization does not rely on flow recirculation. Centrifugal force induced by swirl causes flow divergence, and the flame is maintained at where the local mass flux balances the burning rate. The flame speeds can be estimated based on the centerline velocity vector, which is locally normal to the flame brush. This flame geometry is the closest approximation to the 1-D planar flame for determining fundamental properties to advance turbulent combustion theories. 18 refs.

  9. 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.

  10. 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. PMID:25609786

  11. 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

  12. Acoustic tracking of a freely drifting sonobuoy field.

    PubMed

    Dosso, Stan E; Collison, Nicole E B

    2002-05-01

    This paper develops an acoustic inversion algorithm to track a field of freely drifting sonobuoys using travel-time measurements from a series of nonsimultaneous impulsive sources deployed around the field. In this scenario, the time interval between sources can be sufficiently long that significant independent movement of the individual sonobuoys occurs. In addition, the source transmission instants are unknown, and the source positions and initial sonobuoy positions are known only approximately. The formulation developed here solves for the track of each sonobuoy (parametrized by the sonobuoy positions at the time of each source transmission), allowing arbitrary, independent sonobuoy motion between transmissions, as well as for the source positions and transmission instants. This leads to a strongly underdetermined inverse problem. However, regularized inversion provides meaningful solutions by incorporating a priori information consisting of prior estimates (with uncertainties) for the source positions and initial sonobuoy positions, and a physical model for preferred sonobuoy motion. Several models for sonobuoy motion are evaluated, with the best results obtained by minimizing the second spatial derivative of the tracks to obtain the minimum-curvature or smoothest track, subject to fitting the acoustic data to a statistically appropriate level. PMID:12051436

  13. Locomotor patterns in freely moving crayfish (Procambarus clarkii)

    PubMed

    Jamon; Clarac

    1995-01-01

    Freely walking crayfish, Procambarus clarkii, were studied using a video analysis procedure adapted especially for use with crayfish. The animals were placed in a tank and their homing behaviour was filmed as they returned in a straight line to their shelter. Various sequences were studied at the two following levels. First, the trajectory of each pair of legs (from leg 2 to leg 5) during the step cycle (power stroke and return stroke) was studied to measure stride length and to analyse in detail changes in acceleration. Each leg was found to contribute in a specific manner to locomotion. Second, ipsi- and contralateral leg coordination was investigated. Ipsilateral coordination was found to involve a metachronal organization from front to back in all the walking sequences recorded, whereas contralateral coordination involved, in addition to the weak alternate coupling commonly observed in treadmill walking, another coordination pattern where the legs on each side (legs 3 and 4) are in phase. The results obtained in these free-walking sequences are discussed and compared with those obtained previously, in particular in treadmill situations. PMID:9318428

  14. 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.

  15. 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)

  16. "Awake" extracorporeal membrane oxygenation (ECMO): pathophysiology, technical considerations, and clinical pioneering.

    PubMed

    Langer, Thomas; Santini, Alessandro; Bottino, Nicola; Crotti, Stefania; Batchinsky, Andriy I; Pesenti, Antonio; Gattinoni, Luciano

    2016-01-01

    Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been classically employed as a rescue therapy for patients with respiratory failure not treatable with conventional mechanical ventilation alone. In recent years, however, the timing of ECMO initiation has been readdressed and ECMO is often started earlier in the time course of respiratory failure. Furthermore, some centers are starting to use ECMO as a first line of treatment, i.e., as an alternative to invasive mechanical ventilation in awake, non-intubated, spontaneously breathing patients with respiratory failure ("awake" ECMO). There is a strong rationale for this type of respiratory support as it avoids several side effects related to sedation, intubation, and mechanical ventilation. However, the complexity of the patient-ECMO interactions, the difficulties related to respiratory monitoring, and the management of an awake patient on extracorporeal support together pose a major challenge for the intensive care unit staff. Here, we review the use of vv-ECMO in awake, spontaneously breathing patients with respiratory failure, highlighting the pros and cons of this approach, analyzing the pathophysiology of patient-ECMO interactions, detailing some of the technical aspects, and summarizing the initial clinical experience gained over the past years. PMID:27357690

  17. 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.…

  18. 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…

  19. Awake nasotracheal fiberoptic intubation and self-positioning followed by anesthesia induction in prone patients

    PubMed Central

    Heng, Lei; Wang, Ming-Yu; Sun, Hou-Liang; Zhu, Shan-Shan

    2016-01-01

    Abstract Anesthesia followed by placement in the prone position takes time and may result in complications. This study aimed to evaluate the feasibility of awake nasotracheal fiberoptic intubation and self-positioning followed by anesthesia induction in prone-positioned patients under general anesthesia. Sixty-two patients (ASA physical status I–II) scheduled for awake nasotracheal fiberoptic intubation and prone self-positioning before surgery under general anesthesia were selected. Patient preparation began with detailed preoperative counseling regarding the procedure. Premedication with sedative and antisialagogue was followed by airway anesthesia with topical lidocaine; then, awake nasotracheal fiberoptic intubation was carried out. The patients then positioned themselves comfortably before induction of general anesthesia. The changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), incidence of coughing or gagging, and rate pressure product (RPP) were assessed. Statistical analysis was performed with repeated-measures one-way analysis of variance. Fifty-eight of the 62 patients completed prone self-positioning smoothly. Compared with values before intubation, SBP, DBP, HR, and RPP were slightly increased after intubation, although the difference was not statistically significant (P > 0.05). One patient had moderate coughing and 1 patient had gagging during prone self-positioning, which were tolerable. These findings indicated that awake nasotracheal fiberoptic intubation and self-positioning followed by induction of anesthesia is safe and feasible alternative to routine prone positioning after induction of general anesthesia. PMID:27512858

  20. 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

  1. Taste responses of cortical neurons in freely ingesting rats.

    PubMed

    Yamamoto, T; Matsuo, R; Kiyomitsu, Y; Kitamura, R

    1989-06-01

    1. Activities of 35 taste-responsive neurons in the cortical gustatory area were recorded with chronically implanted fine wires in freely ingesting Wistar rats. Quantitative analyses were performed on responses to distilled water, food solution, and four taste stimuli: sucrose, NaCl, HCl, and quinine hydrochloride. 2. Taste-responsive neurons were classified into type-1 and type-2 groups according to the response patterns to licking of the six taste stimuli. Type-1 neurons (n = 29) responded in excitatory or inhibitory directions to one or more of the taste stimuli. Type-2 neurons (n = 6) showed responses in different directions depending upon palatability of the liquids to rats: neurons showing excitatory (or inhibitory) responses to palatable stimuli exhibited inhibitory (or excitatory) responses to unpalatable stimuli. 3. Correlation coefficients of responses to pairs of stimuli across neurons suggested that palatable stimuli (water, food solution, sucrose, and NaCl) and unpalatable stimuli (HCl and quinine) elicited reciprocal (excitatory vs. inhibitory) responses in type-2 neurons, whereas type-1 neurons showed positively correlated responses to specific combinations of stimuli such as food solution and NaCl, sucrose and HCl, NaCl and quinine, and HCl and quinine. 4. A tendency toward equalization of effectiveness in eliciting responses among the four basic taste stimuli was detected on the cortex. The ratios of mean evoked responses in 29 type-1 neurons in comparison with spontaneous rate (4.4 spikes/s) were 1.7, 1.9, 1.8, and 1.9 for sucrose, NaCl, HCl, and quinine, respectively. 5. The breadth of responsiveness to the four basic taste stimuli was quantified by means of the entropy measure introduced by Smith and Travers (33). The mean entropy value was 0.540 for 29 type-1 neurons, which was similar to 0.588 previously reported for rat chorda tympani fibers, suggesting that breadth of tuning is not more narrowly tuned in a higher level of the gustatory

  2. Curve walking in freely moving crayfish (Procambarus clarkii)

    PubMed

    Domenici; Jamon; Clarac

    1998-05-01

    The curve walking of freely moving crayfish trained to walk along a curved path during homing behaviour was investigated using a video-analysis system. The leg kinematics and leg phase relationships, as well as the relationship between stepping patterns and body axis rotation measured relative to external references, were studied.

    The anterior and posterior extreme positions of the power stroke (AEP and PEP, respectively) and step amplitudes were analysed. As in a previous study on crayfish curve walking on a treadmill, PEPs were more posterior in outer legs (the legs on the outside of the turn) than in the inner legs. As a result, outer legs showed larger step amplitudes than inner legs. Leg kinematics varied within each walking sequence. AEP leg angles (the angles between the body and leg axes at the AEP) tended to decrease over time for inner legs and increase for outer legs. This leg angle drift was present mainly in the anterior legs and it suggests that these legs did not completely compensate for the body rotation after each step. In addition, leg angle asymmetries in a direction opposite to that of leg angle drift were observed at the start of each curve-walking sequence, suggesting that the extensive training (3 weeks) may have allowed crayfish to anticipate the leg angle drift.

    The rotational component of curve walking showed a discontinuous pattern, with the animal's body axis turning towards the inside of the curve only periodically. Analysis of cross-correlation functions showed that the angular acceleration of the body axis in the direction of the turn occurred during the power strokes of inner legs 2 and 5 and outer leg 4. While the tripod formed by these three legs showed in-phase relationships, the legs of the corresponding contralateral tripod (outer legs 2 and 5 and inner leg 4) were not in phase. We hypothesize that inner legs 2 and 5 and outer leg 4 act synergically causing the inward body rotation observed in curve-walking crayfish and

  3. Rapid EEG desynchronization and EMG activation induced by intravenous cocaine in freely moving rats: a peripheral, nondopamine neural triggering.

    PubMed

    Kiyatkin, Eugene A; Smirnov, Michael S

    2010-02-01

    Many important physiological, behavioral, and psychoemotional effects of intravenous (IV) cocaine (COC) are too fast and transient compared with pharmacokinetic predictions, suggesting a possible involvement of peripheral neural mechanisms in their triggering. In the present study, we examined changes in cortical electroencephalogram (EEG) and neck electromyogram (EMG) induced in freely moving rats by IV COC administration at low, reinforcing doses (0.25-1.0 mg/kg) and compared them with those induced by an auditory stimulus and IV COC methiodide, which cannot cross the blood-brain barrier. We found that COC induces rapid, strong, and prolonged EEG desynchronization, associated with decrease in alpha and increase in beta and gamma activities, and EMG activation and that both begin within 2-6 s following the start of a 10-s injection; immediate components of this effect were dose independent. The rapid COC-induced changes in EEG and EMG resembled those induced by an auditory stimulus; the latter effects had shorter onset latencies and durations and were fully blocked during urethane anesthesia. Although urethane anesthesia completely blocked COC-induced EMG activation and rapid components of EEG response, COC still induced EEG desynchronization that was much weaker, greatly delayed (approximately 60 s), and associated with tonic decreases in delta and increases in alpha, beta, and gamma activities. Surprisingly, IV saline delivered during slow-wave sleep (but not quite wakefulness) also induced a transient EEG desynchronization but without changes in EMG activity; these effects were also fully blocked during anesthesia. Peripherally acting COC methiodide fully mimicked rapid EEG and EMG effects of regular COC, but the effects at an equimolar dose were less prolonged than those with regular COC. These data suggest that in awake animals IV COC, like somato-sensory stimuli, induces cortical activation and a subsequent motor response via its action on peripheral neural

  4. 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. PMID:27606116

  5. Combination of Continuous Dexmedetomidine Infusion with Titrated Ultra-Low-Dose Propofol-Fentanyl for an Awake Craniotomy

    PubMed Central

    Das, Samaresh; Al-Mashani, Ali; Suri, Neelam; Salhotra, Neeraj; Chatterjee, Nilay

    2016-01-01

    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. PMID:27606116

  6. Retrospective evaluation of airway management with blind awake intubation in temporomandibular joint ankylosis patients: A review of 48 cases

    PubMed Central

    Sankar, Duraiswamy; Krishnan, Radhika; Veerabahu, Muthusubramanian; Vikraman, Bhaskara Pandian; Nathan, J. A.

    2016-01-01

    Aim: The aim was to determine the morbidity or mortality associated with the blind awake intubation technique in temporomandibular ankylosis patients. Settings and Design: A total of 48 cases with radiographically and clinically confirmed cases of temporomandibular joint (TMJ) ankylosis were included in the study for evaluation of anesthetic management and its complications. Materials and Methods: Airway assessment was done with standard proforma including Look externally, evaluate 3-3-2 rule, Mallampati classification, Obstruction, Neck mobility (LEMON) score assessment in all TMJ ankylosis patients. The intubation was carried out with the standard departmental anesthetic protocol in all the patients. The preoperative difficulty assessment and postoperative outcome were recorded. Results: Blind awake intubation was done in 92% of cases, 6% of cases were intubated by fiberoptic awake intubation, and 2% patient required surgical airway. Ninety-eight percent of the patients were cooperative during the awake intubation. The frequent complications encountered during the blind awake intubation were epistaxis and sore throat. Conclusion: In an anesthetic setup, where fiberoptic intubation is not available, blind awake intubation could be considered in the anesthetic management algorithm. PMID:27563608

  7. [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. PMID:26298720

  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. PMID:23562621

  10. 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

    2015-01-01

    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. PMID:26177997