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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 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

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

    PubMed

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

    2011-03-15

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

  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.

  5. 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.

  6. 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.

  7. 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.

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

    PubMed

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

    2015-01-05

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

  9. 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

  10. 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

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

    PubMed

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

    2015-12-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    Ziv, Yaniv; Ghosh, Kunal K

    2015-06-01

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

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    1988-11-01

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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

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

    PubMed Central

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

    2014-01-01

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

  10. 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

  11. 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.

  12. 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

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

    PubMed

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

    2005-08-01

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

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

    2013-07-05

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

  16. 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

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

    PubMed

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

    2011-08-01

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

  18. 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

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

    PubMed

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

    2006-12-15

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

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

    PubMed Central

    Huh, Yeowool; Cho, Jeiwon

    2016-01-01

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

  1. 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

  2. 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

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

    PubMed

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

    2011-01-01

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

  4. 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

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

    PubMed Central

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

    2014-01-01

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

  6. 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

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

    PubMed Central

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

    2004-01-01

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

  8. 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

  9. 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

  10. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2005-01-01

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

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

    PubMed

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

    1989-05-01

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

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

    PubMed

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

    2014-09-01

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

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

    PubMed Central

    Nitz, Douglas A.; McNaughton, Bruce L.

    1999-01-01

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

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

    PubMed

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

    2003-07-23

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

  17. 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.

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

    PubMed

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

    2010-12-15

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

    Weiss, Michael S.; Victor, Jonathan D.

    2013-01-01

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

  1. 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

  2. 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

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

    PubMed

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

    2017-03-16

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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

    Montagne-Clavel, J; Olivéras, J L

    1994-09-19

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

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

    PubMed

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

    2009-10-01

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

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

    PubMed Central

    Hagena, Hardy

    2010-01-01

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

  8. Awake intubation.

    PubMed

    Peiris, Kawshala; Frerk, Chris

    2008-03-01

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

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

    PubMed

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

    2014-12-24

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

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

    PubMed Central

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

    2016-01-01

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

  11. 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

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

    PubMed

    Silva, Afonso C

    2017-03-01

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

  13. Coding odor identity and odor value in awake rodents

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Blaise, J Harry; Bronzino, Joseph D

    2003-08-01

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

  15. 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

  16. 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

  17. 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

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

    PubMed

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

    2015-02-01

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

  19. 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.

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

    PubMed

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

    2017-04-01

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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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

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

    PubMed

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

    2008-07-01

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

  7. 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

  8. Are Girls Behaving like Boys?

    ERIC Educational Resources Information Center

    Arnott, Rosie

    2008-01-01

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

  9. 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.

  10. 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

  11. 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.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2001-04-15

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

  14. 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

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

    PubMed

    Claussen, Catherine M; Dafny, Nachum

    2015-09-01

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

  16. 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.

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

    PubMed

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

    2008-06-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-07-01

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

  20. Pediatric Awake Craniotomy for Brain Lesions.

    PubMed

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

    2016-01-01

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

  1. 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

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

    PubMed

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

    1991-12-15

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

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

    PubMed

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

    2011-01-01

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

  4. Awake animal SPECT: Overview and initial results

    SciTech Connect

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

    2009-02-01

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

  5. Awake Animal Imaging Motion Tracking Software

    SciTech Connect

    Goddard, James

    2010-03-15

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

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

    ERIC Educational Resources Information Center

    Shannon, Patrick

    2011-01-01

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

  7. Hydrodynamics of freely swimming flagellates

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

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

    PubMed

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

    2015-08-12

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

  9. 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

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

    PubMed

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

    2016-03-22

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

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

    PubMed Central

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

    2012-01-01

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

  12. 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].

  13. 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.

  14. 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

  15. Hippocampal awake replay in fear memory retrieval.

    PubMed

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

    2017-04-01

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

  16. Path to AWAKE: Evolution of the concept

    SciTech Connect

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

    2016-01-02

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

  17. Path to AWAKE: Evolution of the concept

    DOE PAGES

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

    2016-01-02

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

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

    PubMed

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

    2015-01-01

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

  19. 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.

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

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

  2. Teachers Behaving Unprofessionally: Stories from Students

    ERIC Educational Resources Information Center

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

    2009-01-01

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

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

    PubMed Central

    Goh, Jinzhong J.; Manahan-Vaughan, Denise

    2012-01-01

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

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

    PubMed

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

    2008-12-01

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

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

    PubMed

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

    2015-08-01

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

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

    PubMed

    Costello, T G

    2014-08-01

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

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

    PubMed

    Ibrahim, George M; Bernstein, Mark

    2012-09-01

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

  9. 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

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

    PubMed

    Nieder, A

    2000-09-15

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

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

    PubMed

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

    2017-02-16

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

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

    PubMed

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

    2017-01-01

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

  13. 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

  14. Inclusions in freely suspended smectic films

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; Harth, Kirsten

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

  15. An inhomogeneous model universe behaving homogeneously

    NASA Astrophysics Data System (ADS)

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

    2008-05-01

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

  16. 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

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

    PubMed

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

    2015-03-11

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Wan Hassan, Wan Mohd Nazaruddin

    2013-10-01

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

  20. 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

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

    PubMed

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

    2004-07-16

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

  2. 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.

  3. 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.

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

    PubMed Central

    Ramkumar, Venkateswaran

    2011-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  6. 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.

  7. 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.

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    Maurya, Sunil Kumar; Gupta, Y. K.

    2011-04-01

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

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

    PubMed

    Rutishauser, Ueli; Kotowicz, Andreas; Laurent, Gilles

    2013-04-30

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    Huh, Yeowool; Cho, Jeiwon

    2015-01-01

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

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

    PubMed

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

    2009-11-15

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

  14. 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

  15. Awake Microlaparoscopy with the Insuflow® Device

    PubMed Central

    2002-01-01

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

  16. 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.

  17. 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

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

    PubMed

    Febo, Marcelo; Ferris, Craig F

    2014-09-11

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

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

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

    PubMed

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

    2015-02-07

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

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

    PubMed

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

    2011-02-01

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

  4. Enclosure for small animals during awake animal imaging

    DOEpatents

    Goddard, Jr., James S

    2013-11-26

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

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

    PubMed

    Sivri, Rukiye Çolak; Bilgiç, Ayhan

    2015-01-01

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

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

    PubMed

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

    2014-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  8. 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.

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

    PubMed

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

    2015-08-01

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

  10. 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

  11. Fuel model selection for BEHAVE in midwestern oak savannas

    USGS Publications Warehouse

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

    2001-01-01

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

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

    PubMed

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

    2002-02-01

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

  13. Submandibular intubation in awake patient of panfacial trauma

    PubMed Central

    Kamra, SK; Khandavilli, HK; Banerjee, P

    2016-01-01

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

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

    PubMed

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

    2017-03-01

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

  15. Production of freely-migrating defects during irradiation

    SciTech Connect

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

    1986-09-01

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

  16. 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.

  17. 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.

  18. Critical Neural Networks in Awake Surgery for Gliomas

    PubMed Central

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

    2016-01-01

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

  19. Realignment strategies for awake-monkey fMRI data.

    PubMed

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

    2011-12-01

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

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

    PubMed

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

    2014-11-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

    Jennings, D B; Szlyk, P C

    1985-02-01

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

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

    PubMed

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

    2016-04-01

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

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

    PubMed

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

    2013-11-15

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

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

    PubMed

    Magnes, Jenny; Susman, Kathleen; Eells, Rebecca

    2012-10-25

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

  6. 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

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

    PubMed

    Roy, Sabyasachi; Wang, Xiaoqin

    2012-01-15

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

  8. 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

  9. Sleep bruxism, awake bruxism and sleep quality among Brazilian dental students: a cross-sectional study.

    PubMed

    Serra-Negra, Júnia Maria; Scarpelli, Ana Carolina; Tirsa-Costa, Débora; Guimarães, Flávia Helena; Pordeus, Isabela Almeida; Paiva, Saul Martins

    2014-01-01

    The aim of the study was to evaluate the association of sleep bruxism, awake bruxism and sleep quality among dental students of the Federal University of Minas Gerais, Belo Horizonte, Brazil. A cross-sectional study was performed including 183 Brazilian dental students aged from 17 to 46 years old. The complete course curriculum consists of 9 semesters. Students enrolled in the first semester, the middle semester and the final semester of the course participated in the survey. The PSQI-BR (the Brazilian version of the Pittsburgh Sleep Questionnaire Index) was used for data collection. The PSQI-BR was distributed during lecture classes. Sleep bruxism and awake bruxism diagnosis was based on self-reported data. Descriptive analysis, Kruskal-Wallis, Mann-Whitney and Poisson regression with robust estimator were the statistical tests used. Sleep bruxism prevalence was 21.5% and awake bruxism prevalence was 36.5%. Sleep duration components were associated with sleep bruxism (PR=1.540; 95% CI: 1.00-2.37) and awake bruxism (PR=1.344; 95% CI: 1,008-1,790). There was an association between awake bruxism and habitual sleep efficiency component (PR=1.323; 95% CI: 1.03-1.70). Sleep disturbance component and awake bruxism were associated (PR=1.533; 95% CI: 1.03-2.27). Poor sleep quality was an important factor among dental students, who reported sleep bruxism as well as among those who presented awake bruxism.

  10. 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.

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

    PubMed

    Berns, Gregory S; Brooks, Andrew; Spivak, Mark

    2013-01-01

    Previously, we demonstrated the possibility of fMRI in two awake and unrestrained dogs. Here, we determined the replicability and heterogeneity of these results in an additional 11 dogs for a total of 13 subjects. Based on an anatomically placed region-of-interest, we compared the caudate response to a hand signal indicating the imminent availability of a food reward to a hand signal indicating no reward. 8 of 13 dogs had a positive differential caudate response to the signal indicating reward. The mean differential caudate response was 0.09%, which was similar to a comparable human study. These results show that canine fMRI is reliable and can be done with minimal stress to the dogs.

  12. Default-mode-like network activation in awake rodents.

    PubMed

    Upadhyay, Jaymin; Baker, Scott J; Chandran, Prasant; Miller, Loan; Lee, Younglim; Marek, Gerard J; Sakoglu, Unal; Chin, Chih-Liang; Luo, Feng; Fox, Gerard B; Day, Mark

    2011-01-01

    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.

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

    PubMed

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

    2003-08-01

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

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

    PubMed Central

    Cristino, Benedetto; Rogliani, Paola; Dauri, Mario

    2015-01-01

    A number of video-assisted thoracoscopic surgery (VATS) procedures are being increasingly performed by awake anesthesia in an attempt of minimizing the surgical- and anesthesia-related traumas. However, so far the usefulness of awake VATS for urgent management of retained haemothorax has been scarcely investigated. Herein we present two patients with retained haemothorax following previous thoracentesis and blunt chest trauma, respectively, who developed acute respiratory failure and underwent successful urgent awake VATS management under local anesthesia through a single trocar access. PMID:26046053

  15. 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

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

    PubMed Central

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

    2014-01-01

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

  17. 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

  18. Eye-movement recording in freely moving animals.

    PubMed

    Rodríguez, F; Salas, C; Vargas, J P; Torres, B

    2001-03-01

    A new method is described for precise recording of eye movements in freely moving animals using Hall-effect devices. This inexpensive system, of small size and low weight, allows the analysis of horizontal and vertical components of saccadic eye movements, optokinetic nystagmus, slow tracking movements, eye vergence, etc., in unrestrained animals. A set of Hall-effect devices mounted in the skull is used to sense variations in the position of high-power miniature magnets fixed to the eye sclera. The output of the Hall-effect devices is amplified by operational amplifiers and collected through an analog-to-digital converter to be displayed on-line in a personal computer and stored for later analysis by specific software. Some examples of simultaneous body- and eye-movement recordings obtained in freely moving goldfish in different experimental situations are presented. This method would be useful in the recording of eye and gaze movements under natural conditions and for behavioural studies in freely moving animals.

  19. Pediatric awake craniotomy for seizure focus resection with dexmedetomidine sedation-a case report.

    PubMed

    Sheshadri, Veena; Chandramouli, B A

    2016-08-01

    Resection of lesions near the eloquent cortex of brain necessitates awake craniotomy to reduce the risk of permanent neurologic deficits during surgery. There are limited reports of anesthetic management of awake craniotomy in pediatric patients. This report is on use of dexmedetomidine sedation for awake craniotomy in a 11-year-old child, without any airway adjuncts throughout the procedure. Dexmedetomidine infusion administered at a dosage of 0.2 to 0.7μg kg(-1) h(-1) provided adequate sedation for the entire procedure. There were no untoward incidents or any interference with electrocorticography, intraoperative stimulation, and functional mapping. Adequate preoperative visits and counseling of patient and parents regarding course and nature of events along with well-planned intraoperative management are of utmost importance in a pediatric age group for successful intraoperative awake craniotomy.

  20. 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.

  1. Chronic multiscale imaging of neuronal activity in the awake common marmoset

    PubMed Central

    Yamada, Yoshiyuki; Matsumoto, Yoshifumi; Okahara, Norio; Mikoshiba, Katsuhiko

    2016-01-01

    We report a methodology to chronically record in vivo brain activity in the awake common marmoset. Over a month, stable imaging revealed macroscopic sensory maps in the somatosensory cortex and their underlying cellular activity with a high signal-to-noise ratio in the awake but not anesthetized state. This methodology is applicable to other brain regions, and will be useful for studying cortical activity and plasticity in marmosets during learning, development, and in neurological disorders. PMID:27786241

  2. Well behaved anisotropic compact star models in general relativity

    NASA Astrophysics Data System (ADS)

    Jasim, M. K.; Maurya, S. K.; Gupta, Y. K.; Dayanandan, B.

    2016-11-01

    Anisotropic compact star models have been constructed by assuming a particular form of a metric function e^{λ}. We solved the Einstein field equations for determining the metric function e^{ν}. For this purpose we have assumed a physically valid expression of radial pressure (pr). The obtained anisotropic compact star model is representing the realistic compact objects such as PSR 1937 +21. We have done an extensive study about physical parameters for anisotropic models and found that these parameters are well behaved throughout inside the star. Along with these we have also determined the equation of state for compact star which gives the radial pressure is purely the function of density i.e. pr=f(ρ).

  3. 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

  4. Dynamic resting state functional connectivity in awake and anesthetized rodents.

    PubMed

    Liang, Zhifeng; Liu, Xiao; Zhang, Nanyin

    2015-01-01

    Since its introduction, resting-state functional magnetic resonance imaging (rsfMRI) has been a powerful tool for investigating functional neural networks in both normal and pathological conditions. When measuring resting-state functional connectivity (RSFC), most rsfMRI approaches do not consider its temporal variations and thus only provide the averaged RSFC over the scan time. Recently, there has been a surge of interest to investigate the dynamic characteristics of RSFC in humans, and promising results have been yielded. However, our knowledge regarding the dynamic RSFC in animals remains sparse. In the present study we utilized the single-volume co-activation method to systematically study the dynamic properties of RSFC within the networks of infralimbic cortex (IL) and primary somatosensory cortex (S1) in both awake and anesthetized rats. Our data showed that both IL and S1 networks could be decomposed into several spatially reproducible but temporally changing co-activation patterns (CAPs), suggesting that dynamic RSFC was indeed a characteristic feature in rodents. In addition, we demonstrated that anesthesia profoundly impacted the dynamic RSFC of neural circuits subserving cognitive and emotional functions but had less effects on sensorimotor systems. Finally, we examined the temporal characteristics of each CAP, and found that individual CAPs exhibited consistent temporal evolution patterns. Together, these results suggest that dynamic RSFC might be a general phenomenon in vertebrate animals. In addition, this study has paved the way for further understanding the alterations of dynamic RSFC in animal models of brain disorders.

  5. Intrinsic connectivity of neural networks in the awake rabbit.

    PubMed

    Schroeder, Matthew P; Weiss, Craig; Procissi, Daniel; Disterhoft, John F; Wang, Lei

    2016-04-01

    The way in which the brain is functionally connected into different networks has emerged as an important research topic in order to understand normal neural processing and signaling. Since some experimental manipulations are difficult or unethical to perform in humans, animal models are better suited to investigate this topic. Rabbits are a species that can undergo MRI scanning in an awake and conscious state with minimal preparation and habituation. In this study, we characterized the intrinsic functional networks of the resting New Zealand White rabbit brain using BOLD fMRI data. Group independent component analysis revealed seven networks similar to those previously found in humans, non-human primates and/or rodents including the hippocampus, default mode, cerebellum, thalamus, and visual, somatosensory, and parietal cortices. For the first time, the intrinsic functional networks of the resting rabbit brain have been elucidated demonstrating the rabbit's applicability as a translational animal model. Without the confounding effects of anesthetics or sedatives, future experiments may employ rabbits to understand changes in neural connectivity and brain functioning as a result of experimental manipulation (e.g., temporary or permanent network disruption, learning-related changes, and drug administration).

  6. Spontaneous cortical activity in awake monkeys composed of neuronal avalanches.

    PubMed

    Petermann, Thomas; Thiagarajan, Tara C; Lebedev, Mikhail A; Nicolelis, Miguel A L; Chialvo, Dante R; Plenz, Dietmar

    2009-09-15

    Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems--tissue cultures, acute slices, and anesthetized rats--show that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studies suggest that networks with this property are poised at a critical state that optimizes input processing, information storage, and transfer, but the relevance of avalanches for fully functional cerebral systems has been controversial. Here we show that ongoing cortical synchronization in awake rhesus monkeys carries the signature of neuronal avalanches. Negative LFP deflections (nLFPs) correlate with neuronal spiking and increase in amplitude with increases in local population spike rate and synchrony. These nLFPs form neuronal avalanches that are scale-invariant in space and time and with respect to the threshold of nLFP detection. This dimension, threshold invariance, describes a fractal organization: smaller nLFPs are embedded in clusters of larger ones without destroying the spatial and temporal scale-invariance of the dynamics. These findings suggest an organization of ongoing cortical synchronization that is scale-invariant in its three fundamental dimensions--time, space, and local neuronal group size. Such scale-invariance has ontogenetic and phylogenetic implications because it allows large increases in network capacity without a fundamental reorganization of the system.

  7. 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

  8. 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

  9. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    PubMed Central

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2–4s temporal resolution, 2mm slice thickness, and 700 micron in-plane resolution while retaining adequate signal-to-noise ratio. 13C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4T yield T1=46±4s and T2=0.55±0.03s. In the rat brain at 4.7T, analysis of the temporal dynamics of the bSSFP image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T2 of roughly 2–4s and a T1 of 43±24s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. PMID:21432901

  10. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates

    PubMed Central

    Adelsberger, Helmuth; Zainos, Antonio; Alvarez, Manuel; Romo, Ranulfo; Konnerth, Arthur

    2014-01-01

    Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit “map” of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber–based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains. PMID:24344287

  11. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates.

    PubMed

    Adelsberger, Helmuth; Zainos, Antonio; Alvarez, Manuel; Romo, Ranulfo; Konnerth, Arthur

    2014-01-07

    Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit "map" of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber-based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains.

  12. 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.

  13. Well-behaved relativistic charged super-dense star models

    NASA Astrophysics Data System (ADS)

    Faruqi, Shahab; Pant, Neeraj

    2012-10-01

    A new class of charged super-dense star models is obtained by using an electric intensity, which involves a parameter, K. The metric describing the model shares its metric potential g 44 with that of Durgapal's fourth solution (J. Phys. A, Math. Gen. 15:2637, 1982). The pressure-free surface is kept at the density ρ b =2×1014 g/cm3 and joins smoothly with the Reissner-Nordstrom solution. The charge analogues are well-behaved for a wide range, 0≤ K≤59, with the optimum value of X=0.264 i.e. the pressure, density, pressure-density ratio and velocity of sound are monotonically decreasing and the electric intensity is monotonically increasing in nature for the given range of the parameter K. The maximum mass and the corresponding radius occupied by the neutral solution are 4.22 M Θ and 20 km, respectively for X=0.264. For the charged solution, the maximum mass and radius are defined by the expressions M≈(0.0059 K+4.22) M Θ and r b ≈-0.021464 K+20 km respectively.

  14. A freely falling magneto-optical trap drop tower experiment

    NASA Astrophysics Data System (ADS)

    Könemann, T.; Brinkmann, W.; Göklü, E.; Lämmerzahl, C.; Dittus, H.; van Zoest, T.; Rasel, E. M.; Ertmer, W.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Vogel, A.; Johannsen, G.; Wildfang, S.; Bongs, K.; Sengstock, K.; Kajari, E.; Nandi, G.; Walser, R.; Schleich, W. P.

    2007-12-01

    We experimentally demonstrate the possibility of preparing ultracold atoms in the environment of weightlessness at the earth-bound short-term microgravity laboratory Drop Tower Bremen, a facility of ZARM - University of Bremen. Our approach is based on a freely falling magneto-optical trap (MOT) drop tower experiment performed within the ATKAT collaboration (“Atom-Catapult”) as a preliminary part of the QUANTUS pilot project (“Quantum Systems in Weightlessness”) pursuing a Bose-Einstein condensate (BEC) in microgravity at the drop tower [1, 2]. Furthermore we give a complete account of the specific drop tower requirements to realize a compact and robust setup for trapping and cooling neutral rubidium 87Rb atoms in microgravity conditions. We also present the results of the first realized freely falling MOT and further accomplished experiments during several drops. The goal of the preliminary ATKAT pilot project is to initiate a basis for extended atom-optical experiments which aim at realizing, observing and investigating ultracold quantum matter in microgravity.

  15. 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.

  16. 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.

  17. Orexin microinjection in the medullary raphe increases heart rate and arterial pressure but does not reduce tail skin blood flow in the awake rat.

    PubMed

    Luong, L N L; Carrive, P

    2012-01-27

    The rostral medullary raphe region is an important target of hypothalamic orexin neurons; however, little is known of the effect of orexin in this key autonomic and somatic premotor region. Here we tested the effect of orexin-A (3 and 30 pmol) microinjected in the medullary raphe, on heart rate (HR), mean arterial pressure (MAP), tail skin blood flow, body temperature, and behavior in freely moving, awake rats. HR, MAP, and body activity were recorded by radio-telemetry. Changes in tail skin blood flow and body temperature, as well as potential interscapular brown adipose tissue thermogenesis were recorded indirectly by infrared thermography of the skin of the tail, lumbosacral back, and interscapular back areas, respectively. Compared with saline, orexin-A (30 pmol) evoked significant and long lasting increases in HR (+99 bpm), MAP (+11 mmHg), and body activity (grooming, not locomotor activity). However, it did not reduce tail skin blood flow more than saline, and there was no significant increase in body temperature. A small, though significant, thermogenic effect was observed in the interscapular region, but this effect is more likely to have originated from activity in neck and shoulder muscles than brown adipose tissue. Thus, orexin projections to the rostral medullary raphe can mediate significant cardiovascular changes, but does not seem to affect tail skin vasomotor tone or brown adipose tissue in the awake rat. This important brainstem relay may contribute to the cardiovascular changes evoked by arousal and various forms of stress that are associated with activation of orexin neurons.

  18. 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

  19. Mapping the connectome in awake surgery for gliomas: an update.

    PubMed

    Duffau, Hugues

    2017-03-06

    The traditional principle underlying oncological neurosurgery is to remove a tumor mass displacing the brain in order to increase survival. Recently, advances in connectomics enabled an improved understanding of cerebral processing, and led to a paradigmatic shift in tumor surgery based upon interactions between neurooncology and cognitive neurosciences. First, glioma is not a focal tumor invaginated within the parenchyma but a diffuse neoplastic disease migrating in the brain. This concept resulted in a new surgical ideology, i.e., to maximally resect the invaded nervous system on the condition that eloquent neural networks are spared. Second, this led to determine what structures are crucial to preserve the quality of life (QoL) versus those that can be compensated by means of neuroplasticity. Because limitations of functional remodelling are mainly represented by the subcortical connectivity, mapping the connectome during surgery is a priority. Neurosurgeons have to switch from an image-guided surgery to a functional mapping-guided resection, namely, from a technological guidance into the operating theater to a philosophy based on the investigation of the dynamics of delocalized neural circuits throughout resection. Indeed, awake mapping with real-time monitoring of sensorimotor, visuospatial, language, executive and behavioral functions allowed an optimization of the onco-functional balance. Third, surgery should not be seen in isolation, but integrated in a global multistep therapeutic management, especially in low- grade gliomas, opening the window to repeat resections thanks to the potential of remapping over years. Such a "cognitive neurooncological surgery" which aims to improve both QoL and survival must become a "connectomal neurosurgery".

  20. 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.

  1. Large-scale brain networks in the awake, truly resting marmoset monkey.

    PubMed

    Belcher, Annabelle M; Yen, Cecil C; Stepp, Haley; Gu, Hong; Lu, Hanbing; Yang, Yihong; Silva, Afonso C; Stein, Elliot A

    2013-10-16

    Resting-state functional MRI is a powerful tool that is increasingly used as a noninvasive method for investigating whole-brain circuitry and holds great potential as a possible diagnostic for disease. Despite this potential, few resting-state studies have used animal models (of which nonhuman primates represent our best opportunity of understanding complex human neuropsychiatric disease), and no work has characterized networks in awake, truly resting animals. Here we present results from a small New World monkey that allows for the characterization of resting-state networks in the awake state. Six adult common marmosets (Callithrix jacchus) were acclimated to light, comfortable restraint using individualized helmets. Following behavioral training, resting BOLD data were acquired during eight consecutive 10 min scans for each conscious subject. Group independent component analysis revealed 12 brain networks that overlap substantially with known anatomically constrained circuits seen in the awake human. Specifically, we found eight sensory and "lower-order" networks (four visual, two somatomotor, one cerebellar, and one caudate-putamen network), and four "higher-order" association networks (one default mode-like network, one orbitofrontal, one frontopolar, and one network resembling the human salience network). In addition to their functional relevance, these network patterns bear great correspondence to those previously described in awake humans. This first-of-its-kind report in an awake New World nonhuman primate provides a platform for mechanistic neurobiological examination for existing disease models established in the marmoset.

  2. Factors determining success of awake and asleep magnetic resonance imaging scans in nonsedated children.

    PubMed

    Vannest, Jennifer; Rajagopal, Akila; Cicchino, Nicole D; Franks-Henry, Julie; Simpson, Sarah M; Lee, Gregory; Altaye, Mekibib; Sroka, Claire; Holland, Scott K

    2014-12-01

    Effective techniques that allow children to complete magnetic resonance imaging (MRI) scans without sedation are high priority for the imaging community. We used behavioral approaches to scan 64 sleeping infants and toddlers younger than 4 years, and 156 awake children aged 2.5 to 18 years, for a neuroimaging research protocol. Infants and their families participated in a desensitization protocol for several days, then scanning was performed at the child's bedtime during natural sleep. For awake young children, a behavioral protocol was used that included tangible reinforcers, exploration of the scanner environment and a brief practice session. Two scan sessions were targeted for awake children. Success rates by participant were quantified in terms of the proportion of requisite scans in each session that were successfully acquired. The average success rate in sleeping infants and toddlers was 0.461. For awake children aged 2.5 to 6 years, success rates for each session were 0.739 and 0.847. For children aged 7 years and older, success rates were over 0.900 for both the sessions. Overall, though success was lower later in a scan session for both sleeping infants and awake young children, our results demonstrate that it is feasible to collect high-quality imaging data using standard imaging sequences in infants and children without sedation.

  3. Can crystals tell us how whole arcs behave?

    NASA Astrophysics Data System (ADS)

    Davidson, J. P.; Ginibre, C.; Tepley, F. J.

    2011-12-01

    Not entirely. But crystals are invaluable archives of information on how individual magma systems behave. We can now tease out information on the evolutionary histories of a magma system by examining core-rim elemental and isotopic profiles in the context of their textures. Magmatic processes can now be distinguished with some confidence; closed system (fractional) crystallisation is characterised by normal zoning, idiomorphic growth and constant radiogenic isotope ratios, whereas open system contamination, on the face of it similar, is accompanied by varying isotope ratios. Recharge events are not only marked by an abrupt change in isotopic and elemental composition, but also a textural fingerprint, typically a resorption surface, reflecting the instantaneous thermal and chemical disequilibrium consequent to recharge. Plagioclase crystals from the El Chichon 1980 eruption are characterised by several internal dissolution surfaces, which correlate with core-to-rim abrupt drops in 87Sr/86Sr. These are interpreted as reflecting recharge by a primitive magma of magma undergoing progressive fractionation and contamination. Given typical reported plagioclase growth rates, the spacing of these dissolution surfaces corresponds to ~600 years, which is the average eruption frequency of El Chichon in recent times. Recharge, recorded in the crystal archives, may then be the trigger for eruption. Plagioclase crystals from Parinacota Volcano, Central Andes, have yielded an extraordinarily detailed archive of information about magma evolution. Different stages of magmatism through time correspond to different crystal records - i.e. during each recognisable stratigraphic stage magmatic processes were distinct. At least two parental mafic magmas are recognised, with evolution involving mixing/ recharge and contamination. The most detailed core-rim records have actually been inverted according to EC-RAFC models to yield information about contaminant, and contamination rate. In

  4. 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

  5. ``Reverse'' Lock-in Regime on a Freely Oscillating Cylinder

    NASA Astrophysics Data System (ADS)

    Atsavapranee, P.; Voorhees, A. V.; Benaroya, H.; Wei, T.

    1998-11-01

    DPIV and flow visualizations were used to characterize the flow in the near wake of a freely oscillating cylinder. A rigid cylinder with a low mass ratio was fixed at one end to a leaf spring and free to oscillate, pendulum-like, at the other end in the cross stream plane. It was found that only a subset of the synchronization range follows the behavior of a ``classical'' lock-in, i.e., when the difference between the natural Strouhal frequency and the natural frequency of the cylinder is small enough, vortex shedding frequency deviates from the linear Strouhal dependence and follows instead the cylinder natural frequency. However, over a range of flow speed in which the response amplitude of the cylinder is significant, it was found that the frequency of oscillation and of vortex shedding follow instead the natural Strouhal frequency, instead of the mechanical natural frequency.

  6. Two-dimensional microrheology of freely suspended liquid crystal films.

    PubMed

    Eremin, A; Baumgarten, S; Harth, K; Stannarius, R; Nguyen, Z H; Goldfain, A; Park, C S; Maclennan, J E; Glaser, M A; Clark, N A

    2011-12-23

    Smectic liquid crystals form freely-suspended, fluid films of highly uniform structure and thickness, making them ideal systems for studies of hydrodynamics in two dimensions. We have measured particle mobility and shear viscosity by direct observation of the gravitational drift of silica spheres and smectic islands included in these fluid membranes. In thick films, we observe a hydrodynamic regime dominated by lateral confinement effects, with the mobility of the inclusion determined predominantly by coupling of the fluid flow to the fixed boundaries of the film. In thin films, the mobility of inclusions is governed primarily by coupling of the fluid to the surrounding air, as predicted by Saffman-Delbrück theory.

  7. 3D Synthetic Aperture PIV of a Freely Swimming Fish

    NASA Astrophysics Data System (ADS)

    Mendelson, Leah; Techet, Alexandra

    2012-11-01

    Fish owe much of their locomotive success to complex body geometries and wake interactions that cannot be fully characterized by planar experimental techniques including 2D PIV. Volumetric methods are valuable to illustrate and quantify these features, thus providing new insights for bioinspired design. In particular, synthetic aperture particle image velocimetry (SAPIV) uses light field imaging algorithms to reconstruct a 3D particle field which can then be analyzed using a 3D cross-correlation. Previous studies have shown that this technique is able to resolve all three velocity components on the same order length scale and to see around partial occlusions, such as a caudal fin, through the use of multiple cameras. To harness these capabilities for biomimetic use, SAPIV is used to depict the three-dimensional velocity field and vortical structures surrounding a freely swimming Giant danio (Devario aequipinnatus) during straight swims and turning maneuvers.

  8. 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

  9. 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.

  10. [Non-verbal communication of patients submitted to heart surgery: from awaking after anesthesia to extubation].

    PubMed

    Werlang, Sueli da Cruz; Azzolin, Karina; Moraes, Maria Antonieta; de Souza, Emiliane Nogueira

    2008-12-01

    Preoperative orientation is an essential tool for patient's communication after surgery. This study had the objective of evaluating non-verbal communication of patients submitted to cardiac surgery from the time of awaking from anesthesia until extubation, after having received preoperative orientation by nurses. A quantitative cross-sectional study was developed in a reference hospital of the state of Rio Grande do Sul, Brazil, from March to July 2006. Data were collected in the pre and post operative periods. A questionnaire to evaluate non-verbal communication on awaking from sedation was applied to a sample of 100 patients. Statistical analysis included Student, Wilcoxon, and Mann Whittney tests. Most of the patients responded satisfactorily to non-verbal communication strategies as instructed on the preoperative orientation. Thus, non-verbal communication based on preoperative orientation was helpful during the awaking period.

  11. The history of awake craniotomy for brain tumor and its spread into Asia.

    PubMed

    July, Julius; Manninen, Pirjo; Lai, Jacob; Yao, Zhenhai; Bernstein, Mark

    2009-05-01

    In ancient times, awake craniotomy was used for trepanation to treat seizures and remove a variety of morbid conditions or even to permit the escape of evil air. In modern times, this technique was initially used for removal of epileptic foci with simultaneous application of brain mapping with electrical current. Further developments brought this technique into use for resection of tumors involving functional cortex. Recently, awake craniotomy has been described as an approach for removal of supratentorial tumors nonselectively, regardless of the involvement of eloquent cortex. It has been used in North America since the 1980s, then Europe, and recently has spread into Asia. Its spread to Asia could have significant impact based on the large population of patients and the low resource utilization associated with awake craniotomy.

  12. 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.

  13. The development of one-stop wide-awake dupuytren's fasciectomy service: a retrospective review

    PubMed Central

    Bismil, QMK; Bismil, MSK; Bismil, Annamma; Neathey, Julia; Gadd, Judith; Roberts, Sue; Brewster, Jennifer

    2012-01-01

    Objectives To detail the transition to a totally one-stop wide-awake (OSWA) Dupuytren's contracture surgical service. Design Retrospective review of Dupuytren's component of last 1000 OSWA cases. Setting The UK's first totally one-stop wide-awake orthopaedic service. Participants 270 patients with Dupuytren's contracture out of the last 1000 OSWA cases. Main outcome measures Surgical outcomes, patient satisfaction and cost-effectiveness and efficiency. Results The OSWA Dupuytren's model is safe, efficient and effective; with a low complication rate, extremely high patient satisfaction; and cost-savings to the nhs of £2500 per case treated. The service saved the NHS approximately £675,000 for the 270 cases presented. Conclusions A totally one-stop wide-awake Dupuytren's Contracture service is practicable and feasible alternative to the conventional treatment pathway, with benefits in terms of efficiency and cost-effectiveness. PMID:22908029

  14. 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

  15. 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

  16. Functional MR imaging in the awake monkey: effects of motion on dynamic off-resonance and processing strategies.

    PubMed

    Pfeuffer, Josef; Shmuel, Amir; Keliris, Georgios A; Steudel, Thomas; Merkle, Hellmut; Logothetis, Nikos K

    2007-07-01

    Functional MR imaging of the alert, behaving monkey is being used more and more often to detect activation patterns and guide electrophysiological research investigating the neural basis of behavior. Several labs have reported fMRI data from the awake monkey, but none of them has studied and systematically corrected the effects of monkeys' motion on fMRI time series. In this study, a significant refinement of acquisition and correction strategies is reported that can be used to minimize magnetic susceptibility artifacts induced by respiration and by jaw and body movement. Real-time acquisition of sensor signals (e.g., signals induced by jaw and body movement) and MR navigator data were combined to optimize fMRI signal-correction strategies. Within trials, the artifact-induced off-resonance changes were small and mainly reflected the effects of respiration; between trials, movements caused major changes of global frequency and shim (>20 Hz/cm). Several methods were used to assess the stability of the fMRI series: k-space analysis ('dynamic intensity and off-resonance changes in k-space', dubbed DICK and DORK) and image analysis using a Laplace operator and a center-of-mass metric. The variability between trials made it essential to correct for inter-trial variations. On the other hand, images were sufficiently stable with our approach to perform fMRI evaluations on single trials before averaging of trials. Different motion correction strategies were compared: DORK, McFLIRT (rigid body model with three translations and three rotations) and 2D image alignment based on a center-of-mass detection (in-plane translation). The latter yielded the best results and proved to be fast and robust for intra- and inter-trial alignment. Finally, fMRI in the behaving monkey was tested for spatial and temporal reproducibility on a trial-to-trial basis. Highly activated voxels also displayed good reproducibility between trials. On average, the BOLD amplitude response to a short 3-s

  17. 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

  18. Awake surgery between art and science. Part I: clinical and operative settings.

    PubMed

    Talacchi, Andrea; Santini, Barbara; Casagrande, Francesca; Alessandrini, Franco; Zoccatelli, Giada; Squintani, Giovanna M

    2013-01-01

    Awake surgery requires coordinated teamwork and communication between the surgeon and the anesthesiologist, as he monitors the patient, the neuroradiologist as he interprets the images for intraoperative confirmation, and the neuropsychologist and neurophysiologist as they evaluate in real-time the patient's responses to commands and questions. To improve comparison across published studies on clinical assessment and operative settings in awake surgery, we reviewed the literature, focusing on methodological differences and aims. In complex, interdisciplinary medical care, such differences can affect the outcome and the cost-benefit ratio of the treatment. Standardization of intraoperative mapping and related controversies will be discussed in Part II.

  19. [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.

  20. 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

  1. FREELY DECAYING TURBULENCE IN FORCE-FREE ELECTRODYNAMICS

    SciTech Connect

    Zrake, Jonathan; East, William E.

    2016-02-01

    Freely decaying, relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. Force-free turbulent relaxation is found to exhibit an inverse cascade in all settings and in three dimensions to have a magnetic energy spectrum consistent with the Kolmogorov 5/3 power law. Three-dimensional relaxations also obey the Taylor hypothesis; they settle promptly into the lowest-energy configuration allowed by conservation of the total magnetic helicity. However, in two dimensions, the relaxed state is a force-free equilibrium whose energy greatly exceeds the Taylor minimum and that contains persistent force-free current layers and isolated flux tubes. We explain this behavior in terms of additional topological invariants that exist only in two dimensions, namely the helicity enclosed within each level surface of the magnetic potential function. The speed and completeness of turbulent magnetic free-energy discharge could help account for rapidly variable gamma-ray emission from the Crab Nebula, gamma-ray bursts, blazars, and radio galaxies.

  2. 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.

  3. Dynamics of a freely-falling maple seed

    NASA Astrophysics Data System (ADS)

    Lee, Injae; Choi, Haecheon

    2016-11-01

    We conduct numerical simulations of a freely-falling maple seed using an immersed boundary method in a non-inertial reference frame. A three-dimensional seed model is obtained by scanning a maple seed. The seed reaches a steady autorotation after a transient period, and a stable leading-edge vortex is attached on the surface of the rotating seed, which increases the drag force during autorotation. In addition, two different approaches are considered to obtain scaling laws describing the relation among the seed weight and geometry, and descending and rotating velocities. The first uses the conservations of mass, linear and angular momentum, and energy. In this approach, a model constant to be determined, called axial induction factor, is obtained from the result of present simulation. The second approach employs a classical steady wing theory in which the vortical strength is scaled with the circulation around a wing and the lift force is modeled by the time derivative of vortical impulse. Available data on various seeds well fall on these scaling laws. Supported by NRF-2014M3C1B1033848.

  4. Hippocampal neurochemical and electrophysiological measures from freely moving rats.

    PubMed

    Bronzino, J D; Kehoe, P; Hendriks, R; Vita, L; Golas, B; Vivona, C; Morgane, P J

    1999-01-01

    This paper describes surgical and recording procedures that have been developed which permit the simultaneous monitoring of levels of select neurochemicals (via microdialysis) and measures of dentate-evoked field potentials within the hippocampal formation of freely moving adult rats. To test and evaluate these procedures, they were employed to examine changes in hippocampal neurochemistry and neuronal excitability associated with the establishment and maintenance of hippocampal long-term potentiation (LTP). Measures of hippocampal norepinephrine (NE) and glutamate levels along with measures of the dentate granule cell population spike amplitude (PSA) were obtained before, during, and after tetanization of the medial perforant path using two separate tetanization paradigms. Results obtained using these new procedures in several animals indicated that changes in NE and glutamate levels were strongly correlated with increases in the dentate granule cell PSA measure obtained following tetanization. The results indicate that this newly developed procedure can be effectively used to directly examine the relationship between neurochemical and neurophysiological changes associated with hippocampal neuroplasticity.

  5. Freely available conformer generation methods: how good are they?

    PubMed

    Ebejer, Jean-Paul; Morris, Garrett M; Deane, Charlotte M

    2012-05-25

    Conformer generation has important implications in cheminformatics, particularly in computational drug discovery where the quality of conformer generation software may affect the outcome of a virtual screening exercise. We examine the performance of four freely available small molecule conformer generation tools (Balloon, Confab, Frog2, and RDKit) alongside a commercial tool (MOE). The aim of this study is 3-fold: (i) to identify which tools most accurately reproduce experimentally determined structures; (ii) to examine the diversity of the generated conformational set; and (iii) to benchmark the computational time expended. These aspects were tested using a set of 708 drug-like molecules assembled from the OMEGA validation set and the Astex Diverse Set. These molecules have varying physicochemical properties and at least one known X-ray crystal structure. We found that RDKit and Confab are statistically better than other methods at generating low rmsd conformers to the known structure. RDKit is particularly suited for less flexible molecules while Confab, with its systematic approach, is able to generate conformers which are geometrically closer to the experimentally determined structure for molecules with a large number of rotatable bonds (≥10). In our tests RDKit also resulted as the second fastest method after Frog2. In order to enhance the performance of RDKit, we developed a postprocessing algorithm to build a diverse and representative set of conformers which also contains a close conformer to the known structure. Our analysis indicates that, with postprocessing, RDKit is a valid free alternative to commercial, proprietary software.

  6. 3-D worm tracker for freely moving C. elegans.

    PubMed

    Kwon, Namseop; Pyo, Jaeyeon; Lee, Seung-Jae; Je, Jung Ho

    2013-01-01

    The manner in which the nervous system regulates animal behaviors in natural environments is a fundamental issue in biology. To address this question, C. elegans has been widely used as a model animal for the analysis of various animal behaviors. Previous behavioral assays have been limited to two-dimensional (2-D) environments, confining the worm motion to a planar substrate that does not reflect three-dimensional (3-D) natural environments such as rotting fruits or soil. Here, we develop a 3-D worm tracker (3DWT) for freely moving C. elegans in 3-D environments, based on a stereoscopic configuration. The 3DWT provides us with a quantitative trajectory, including the position and movement direction of the worm in 3-D. The 3DWT is also capable of recording and visualizing postures of the moving worm in 3-D, which are more complex than those in 2-D. Our 3DWT affords new opportunities for understanding the nervous system function that regulates animal behaviors in natural 3-D environments.

  7. 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.

  8. 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

  9. 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…

  10. Long-Term Two-Photon Imaging in Awake Macaque Monkey.

    PubMed

    Li, Ming; Liu, Fang; Jiang, Hongfei; Lee, Tai Sing; Tang, Shiming

    2017-03-08

    Successful application of two-photon imaging with genetic tools in awake macaque monkeys will enable fundamental advances in our understanding of higher cognitive function at the level of molecular and neuronal circuits. Here we report techniques for long-term two-photon imaging in awake macaque monkeys. Using genetically encoded indicators including GCaMP5 and GCaMP6s delivered by AAV2/1 into the visual cortex, we demonstrate that high-quality two-photon imaging of large neuronal populations can be achieved and maintained in awake monkeys for months. Simultaneous intracellular recording and two-photon calcium imaging confirm that fluorescence activity is linearly proportional to neuronal spiking activity across a wide range of firing rates (10 Hz to 150 Hz). By providing two-photon imaging access to cortical neuronal populations at single-cell or single dendritic spine resolution in awake monkeys, the techniques reported can help bridge the use of modern genetic and molecular tools and the study of higher cognitive function.

  11. 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.…

  12. 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)

  13. Effect of flumazenil on sevoflurane requirements for minimum alveolar anesthetic concentration-awake and recovery status

    PubMed Central

    Liang, Peng; Zhou, Cheng; Li, Kai-Yu; Guo, Li-Juan; Liu, Bin; Liu, Jin

    2014-01-01

    Objective: It is controversial that whether the GABA receptors contribute to the hypnotic action of volatile anesthetics. This study was to detect the effect of GABA receptors on the hypnotic action of volatile anesthetics by evaluation of the effect of intravenous flumazenil on sevoflurane minimum alveolar anesthetic concentration–awake (MAC-Awake) and emergence mental status. Methods: This study included two steps. Firstly, 49 healthy patients, aged 20-40 years scheduled for elective surgeries, were randomly assigned to two groups, a flumazenil group (n=24) and a saline group (n=25). The flumazenil group received 0.006 mg/Kg IV, and the control group received the same volume of saline 20 min before induction. The flumazenil group and the control group were compared with regard to MAC-Awake (anesthetic concentration achieving 50% probability of eye opening in response to a verbal command). We used the mask inhalation to measure the MAC-Awake by up-and-down method. The second steps, 60 patients undergoing lower abdomen surgeries were randomly divided into two groups, a experimental group (n=30) and a saline group (n=30). All patients were anesthetized with sevoflurane/sulfentanil. The experimental group received flumazenil at 0.006 mg/Kg IV, and the control group received the same volume of saline at the end of surgery. We recorded the time to awake and extubation. After extubation, the patients’ recovery status was scored with the Mini-Mental state examination (MMSE) system in post anesthesia care unit (PACU). Results: The MAC-Awake was 0.65% in the control group and 0.82% in the flumazenil group (p=0.34). After extubation, the recovery time and time to extubation showed no difference between the flumazenil group and the saline group (p>0.05). But the 10 min and 15 min MMSE scores after extubation were better in the flumazenil group than those in the saline group (p<0.05). There was no difference for MMSE scores after 30 min between two groups. Conclusion: We

  14. Numerical investigation for one bad-behaved flow in a Pelton turbine

    NASA Astrophysics Data System (ADS)

    Wei, X. Z.; Yang, K.; Wang, H. J.; Gong, R. Z.; Li, D. Y.

    2015-01-01

    The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper.

  15. 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

  16. Interplay between viscosity and elasticity in freely expanding liquid sheets

    NASA Astrophysics Data System (ADS)

    Arora, Srishti; Ligoure, Christian; Ramos, Laurence

    2016-12-01

    We investigate the dynamics of freely expanding liquid sheets prepared with fluids with different rheological properties: (i) Viscous fluids with a zero-shear viscosity η0 in the range 1 -1000 mPa s and (ii) viscoelastic fluids whose linear viscoelastic behavior in the frequency range 0.1 -100 rad/s can be accounted for by a Maxwell fluid model, whose characteristic elastic modulus G0, relaxation time τ , and zero-shear viscosity η0=G0τ , can be tuned over several orders of magnitude. The sheets are produced by a drop of fluid impacting a small cylindrical solid target. For viscoelastic fluids, we show that, when τ is shorter than the typical lifetime of the sheet (˜10 ms), the dynamics of the sheet is similar to that of Newtonian viscous liquids with equal zero-shear viscosity. In that case, for little viscous samples (η0≲30 mPa s), the maximal expansion of the sheet dmax is independent of η0, whereas for more viscous samples, dmax decreases as η0 increases. We provide a simple model for the dependence of the maximal expansion of the sheet with the viscosity that accounts well for our experimental data. By contrast, when τ is longer than the typical lifetime of the sheet, the behavior drastically differs. The sheet expansion is strongly enhanced as compared to that of viscous samples with comparable zero-shear viscosity, but is heterogeneous with the occurrence of cracks, revealing the elastic nature of the viscoelastic fluid.

  17. Turbulent Rayleigh-Benard convection with freely moving boundary

    NASA Astrophysics Data System (ADS)

    Zhong, Jin-Qiang

    In thermal convection, coherent flow structures emerge at high Rayleigh numbers as a result of intrinsic hydrodynamic instability and self-organization. They range from small-scale thermal plumes that are produced near both the top and the bottom boundaries to large-scale circulations across the entire convective volume. These flow structures exert viscous forces upon any boundary. Such forces will affect a boundary which is free to deform or change position. In our experiment, we study the dynamics of a free boundary that floats on the upper surface of a convective fluid. This seemingly passive boundary is subjected solely to viscous stress underneath. However, the boundary thermally insulates the fluid, modifying the bulk flow. As a consequence, the interaction between the free boundary and the convective fluid results in rich dynamics including periodic evolution of thr flow structures and predictable motions of the free boundary. Here I present two sets of experiments on thermal convection with freely moving top boundary. The first experiment is conducted in a rectangular geometry. We discover that as the sizes of the free boundary increases, the convection system transits from a nearly-periodic oscillation state into a local trapped state. A phenomenological numerical model explains this dynamcal transition. The second set of experiment is conducted in an annular geometry, where a periodic boundary condition is satisfied for both the flow structures and the free boundary. In a long time scale, persistent rotations of the free boundary along the circular path inside the convection cell are observed. In short time scales, the free boundary rotates in a hopping fashion. Consequently, through temperature distribution measurements, we observe the regular evolutions of the flow patterns in the convective fluid.

  18. Three-dimensional spatial representation in freely swimming fish.

    PubMed

    Burt de Perera, Theresa; Holbrook, Robert I

    2012-08-01

    Research on spatial cognition has focused on how animals encode the horizontal component of space. However, most animals travel vertically within their environments, particularly those that fly or swim. Pelagic fish move with six degrees of freedom and must integrate these components to navigate accurately--how do they do this? Using an assay based on associative learning of the vertical and horizontal components of space within a rotating Y-maze, we found that fish (Astyanax fasciatus) learned and remembered information from both horizontal and vertical axes when they were presented either separately or as an integrated three-dimensional unit. When information from the two components conflicted, the fish used the previously learned vertical information in preference to the horizontal. This not only demonstrates that the horizontal and vertical components are stored separately in the fishes' representation of space (simplifying the problem of 3D navigation), but also suggests that the vertical axis contains particularly salient spatial cues--presumably including hydrostatic pressure. To explore this latter possibility, we developed a physical theoretical model that shows how fish could determine their absolute depth using pressure. We next considered full volumetric spatial cognition. Astyanax were trained to swim towards a reward in a Y-maze that could be rotated, before the arms were removed during probe trials. The subjects were tracked in three dimensions as they swam freely through the surrounding cubic tank. The results revealed that fish are able to accurately encode metric information in a volume, and that the error accrued in the horizontal and vertical axes whilst swimming in probe trials was similar. Together, these experiments demonstrate that unlike in surface-bound rats, the vertical component of the representation of space is vitally important to fishes. We hypothesise that the representation of space in the brain of vertebrates could ultimately be

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

    PubMed

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

    2016-08-01

    An awake craniotomy is a continuously evolving technique used for the resection of brain tumours from the eloquent cortex. We report a 29-year-old male patient who presented to the Khoula Hospital, Muscat, Oman, in 2016 with a two month history of headaches and convulsions due to a space-occupying brain lesion in close proximity with the left motor cortex. An awake craniotomy was conducted using a scalp block, continuous dexmedetomidine infusion and a titrated ultra-low-dose of propofolfentanyl. The patient remained comfortable throughout the procedure and the intraoperative neuropsychological tests, brain mapping and tumour resection were successful. This case report suggests that dexmedetomidine in combination with titrated ultra-low-dose propofolfentanyl are effective options during an awake craniotomy, ensuring optimum sedation, minimal disinhibition and a rapid recovery. To the best of the authors' knowledge, this is the first awake craniotomy conducted successfully in Oman.

  20. Fast Hemodynamic Responses in the Visual Cortex of the Awake Mouse

    PubMed Central

    Pisauro, M. Andrea; Dhruv, Neel T.; Benucci, Andrea

    2013-01-01

    Hemodynamic responses in mice and other species are typically measured under anesthesia. However, anesthesia could influence their relationship to neural activity. To investigate this relationship, we used optical imaging in mouse primary visual cortex (V1). Hemodynamic responses yielded clear maps of retinotopy in both anesthetized and awake mice. However, during wakefulness, responses were four times larger and twice as fast. These differences held whether we induced anesthesia with urethane or isoflurane and whether awake mice were stationary or running on a treadmill. With electrode recordings, we established that the effects of wakefulness reflect changes in neurovascular coupling, not in neural activity. By activating V1 directly via optogenetics, we replicated the effects of wakefulness in terms of timing but not of amplitude. We conclude that neurovascular coupling depends critically on anesthesia and wakefulness: during wakefulness, neural activity is followed by much stronger and quicker hemodynamic responses. PMID:24227743

  1. 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.

  2. [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.

  3. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences.

    PubMed

    Takahashi, Susumu

    2015-10-20

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as 'what' information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only 'where and when' but also 'what' information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process.

  4. Awake nasotracheal intubation using fiberoptic bronchoscope in a pediatric patient with Freeman-Sheldon syndrome.

    PubMed

    Kim, J S; Park, S Y; Min, S K; Kim, J H; Lee, S Y; Moon, B K

    2005-09-01

    The Freeman-Sheldon syndrome is a congenital disease primarily affecting the facial, limb and respiratory muscles that give rise to classical clinical features including typical whistling face and short webbed neck associated with difficult intubation. We present successful awake nasotracheal intubation in a 6-year-old patient with typical clinical features of Freeman-Sheldon syndrome by using fiberoptic bronchoscope on two separate occasions.

  5. Development of a simultaneous optical/PET imaging system for awake mice

    NASA Astrophysics Data System (ADS)

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [11C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [11C]raclopride radioactivity concentration simultaneously. Accumulation of [11C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models.

  6. GHz modulation detection using a streak camera: Suitability of streak cameras in the AWAKE experiment

    NASA Astrophysics Data System (ADS)

    Rieger, K.; Caldwell, A.; Reimann, O.; Muggli, P.

    2017-02-01

    Using frequency mixing, a modulated light pulse of ns duration is created. We show that, with a ps-resolution streak camera that is usually used for single short pulse measurements, we can detect via an FFT detection approach up to 450 GHz modulation in a pulse in a single measurement. This work is performed in the context of the AWAKE plasma wakefield experiment where modulation frequencies in the range of 80-280 GHz are expected.

  7. "Awake Veno-arterial Extracorporeal Membrane Oxygenation" in Pediatric Cardiogenic Shock: A Single-Center Experience.

    PubMed

    Schmidt, F; Jack, T; Sasse, M; Kaussen, T; Bertram, H; Horke, A; Seidemann, K; Beerbaum, P; Koeditz, H

    2015-12-01

    In pediatric patients with acute refractory cardiogenic shock (CS), extracorporeal membrane oxygenation (ECMO) remains an established procedure to maintain adequate organ perfusion. In this context, ECMO can be used as a bridging procedure to recovery, VAD or transplantation. While being supported by ECMO, most centers tend to keep their patients well sedated and supported by invasive ventilation. This may be associated with an increased risk of therapy-related morbidity and mortality. In order to optimize clinical management in pediatric patients with ECMO therapy, we report our strategy of veno-arterial ECMO (VA-ECMO) in extubated awake and conscious patients. We therefore present data of six of our patients with CS, who were treated by ECMO being awake without continuous analgosedation and invasive ventilation. Of these six patients, four were <1 year and two >14 years of age. Median time on ECMO was 17.4 days (range 6.9-94.2 days). Median time extubated, while receiving ECMO support was 9.5 days. Mean time extubated was 78 % of the total time on ECMO. Three patients reached full recovery of cardiac function on "Awake-VA-ECMO," whereas the other three were successfully bridged to destination therapy (VAD, heart transplantation, withdrawal). Four out of our six patients are still alive. Complications related to ECMO therapy (i.e., severe bleeding, site infection or dislocation of cannulas) were not observed. We conclude that "Awake-VA-ECMO" in extubated, spontaneously breathing conscious pediatric patients is feasible and safe for the treatment of acute CS and can be used as a "bridging therapy" to recovery, VAD implantation or transplantation.

  8. Prospective pilot trial of dexmedetomidine sedation for awake diagnostic flexible bronchoscopy.

    PubMed

    Lee, Keat; Orme, Ruari; Williams, Daryl; Segal, Reny

    2010-10-01

    Dexmedetomidine has the favorable properties of sedation, sympatholysis, analgesia, and a low risk of apnea. These properties suggest that dexmedetomidine may be useful in procedural sedation. In view of this, we conducted a pilot trial to determine the feasibility of using dexmedetomidine as a sole agent for providing sedation during awake diagnostic flexible bronchoscopy. Patients presenting for awake diagnostic flexible bronchoscopy consented to participate in a trial of dexmedetomidine sedation for the procedure. In addition to local anesthetic topicalization of the airways, dexmedetomidine was infused at 0.5 μg/kg over 10 minutes followed by an infusion of 0.2 to 0.7 μg/kg/h titrating to a Ramsay Sedation Scale score of 3. Hemodynamic parameters (heart rate, blood pressure), oxygenation status (pulse oximetry), adverse events, use of rescue sedation, and patient and proceduralist satisfaction were recorded during the trial. Five of 9 recruited patients required rescue sedation to allow the procedure to proceed. Dexmedetomidine as a sole agent at an infusion of 0.5 μg/kg over 10 minutes followed by an infusion of 0.2 to 0.7 μg/kg/h is unable to provide adequate sedation for awake diagnostic flexible bronchoscopy without the need for rescue sedation in a large proportion of patients.

  9. Spectrotemporal Response Properties of Core Auditory Cortex Neurons in Awake Monkey

    PubMed Central

    Massoudi, Roohollah; Van Wanrooij, Marc M.; Versnel, Huib; Van Opstal, A. John

    2015-01-01

    So far, most studies of core auditory cortex (AC) have characterized the spectral and temporal tuning properties of cells in non-awake, anesthetized preparations. As experiments in awake animals are scarce, we here used dynamic spectral-temporal broadband ripples to study the properties of the spectrotemporal receptive fields (STRFs) of AC cells in awake monkeys. We show that AC neurons were typically most sensitive to low ripple densities (spectral) and low velocities (temporal), and that most cells were not selective for a particular spectrotemporal sweep direction. A substantial proportion of neurons preferred amplitude-modulated sounds (at zero ripple density) to dynamic ripples (at non-zero densities). The vast majority (>93%) of modulation transfer functions were separable with respect to spectral and temporal modulations, indicating that time and spectrum are independently processed in AC neurons. We also analyzed the linear predictability of AC responses to natural vocalizations on the basis of the STRF. We discuss our findings in the light of results obtained from the monkey midbrain inferior colliculus by comparing the spectrotemporal tuning properties and linear predictability of these two important auditory stages. PMID:25680187

  10. Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse

    PubMed Central

    Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

    2017-01-01

    Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca2+ imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca2+ imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain. PMID:28240275

  11. [Difficult Ventilation Requiring Emergency Endotracheal Intubation during Awake Craniotomy Managed by Laryngeal Mask Airway].

    PubMed

    Matsuda, Asako; Mizota, Toshiyuki; Tanaka, Tomoharu; Segawa, Hajime; Fukuda, Kazuhiko

    2016-04-01

    We report a case of difficult ventilation requiring emergency endotracheal intubation during awake craniotomy managed by laryngeal mask airway (LMA). A 45-year-old woman was scheduled to receive awake craniotomy for brain tumor in the frontal lobe. After anesthetic induction, airway was secured using ProSeal LMA and patient was mechanically ventilated in pressure-control mode. Patient's head was fixed with head-pins at anteflex position, and the operation started. About one hour after the start of the operation, tidal volume suddenly decreased. We immediately started manual ventilation, but the airway resistance was extremely high and we could not adequately ventilate the patient. We administered muscle relaxant for suspected laryngospasm, but ventilatory status did not improve; so we decided to conduct emergency endotracheal intubation. We tried to intubate using Airwayscope or LMA-Fastrach, but they were not effective in our case. Finally trachea was intubated using transnasal fiberoptic bronchoscopy. We discuss airway management during awake craniotomy, focusing on emergency endotracheal intubation during surgery.

  12. Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse.

    PubMed

    Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

    2017-02-27

    Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca(2+) imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca(2+) imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain.

  13. Some effects of vagal blockade on abdominal muscle activation and shortening in awake dogs.

    PubMed Central

    Leevers, A M; Road, J D

    1995-01-01

    1. The mechanisms of abdominal muscle activation are thought to be different during expiratory threshold loading (ETL) compared with hypercapnia. Our objectives in the present study were to determine the effects of removing excitatory vagal feedback on abdominal muscle activation, shortening and pattern of recruitment during ETL and hypercapnia. Six tracheotomized dogs were chronically implanted with sonomicrometer transducers and fine wire EMG electrodes in each of the four abdominal muscles. Muscle length changes and EMG activity were studied in the awake dog during ETL (6 dogs) and CO2 rebreathing (3 dogs), before and after vagal blockade. 2. Following vagal blockade, the change in volume (increase in functional residual capacity, FRC) during ETL was greater and active phasic shortening of all the abdominal muscles was reduced, when shortening was compared with a similar change in lung volume. Similarly, at comparable minute ventilation, abdominal muscle active shortening was also reduced during hypercapnia. The internal muscle layer was recruited preferentially in both control and vagally blocked dogs during both ETL and hypercapnia. 3. The degree of recruitment of the abdominal muscles during ETL and hypercapnia in awake dogs is influenced by vagal feedback, but less so than in anaesthetized dogs. These results illustrate the importance of the vagi and abdominal muscle activation in load compensation. However, vagal reflexes are apparently not contributing to the preferential recruitment of the internal muscle layer. In awake dogs during vagal blockade abdominal muscle recruitment still occurs by extravagal mechanisms. PMID:8568685

  14. Information flow and coherence of EEG during awake, meditation and drowsiness.

    PubMed

    Dissanayaka, Chamila; Ben-Simon, Eti; Gruberger, Michal; Maron-Katz, Adi; Hendler, Talma; Chaparro-Vargas, Ramiro; Cvetkovic, Dean

    2014-01-01

    A comparison of coupling (information flow) and coherence (connectedness) of the brain regions between human awake, meditation and drowsiness states was carried out in this study. The Directed Transfer Function (DTF) method was used to estimate the coupling or brain's flow of information between different regions during each condition. Welch and Minimum Variance Distortionless Response (MVDR) methods were utilised to estimate the coherence between brain areas. Analysis was conducted using the EEG data of 30 subjects (10 awake, 10 drowsiness and 10 meditating) with 6 EEG electrodes. The EEG data was recorded for each subject during 5 minutes baseline and 15 minutes of three specific conditions (awake, meditation or drowsiness). Statistical analysis was carried out which consisted of the Kruskal-Wallis (KW) non-parametric analysis of variance followed by post-hoc tests with Bonferroni alpha-correction. The results of this study revealed that a change in external awareness led to substantial differences in the spectral profile of the brain's information flow as well as it's connectedness.

  15. Effect on breathing of surface ventrolateral medullary cooling in awake, anesthetized and asleep goats.

    PubMed

    Forster, H V; Ohtake, P J; Pan, L G; Lowry, T F

    1997-11-01

    In adult and neonatal goats, we chronically implanted thermodes on the ventrolateral (VLM) medullary surface to create reversible neuronal dysfunction and thereby gain insight into the role of superficial VLM neurons in control of breathing in anesthetized, awake and asleep states. Consistent with data of others, cooling caudal area M and rostral area S caused sustained apnea under anesthesia. However, in the awake and NREM sleep states, cooling at this site caused only a modest reduction in breathing, indicating that neurons at this site are not critical for respiratory rhythm in these states. Moreover, data in the awake state over multiple conditions suggest neurons at this site do not integrate all intracranial and carotid chemoreception. The data suggest though that neurons at this site have a facilitatory-like effect on breathing both unrelated and related to intracranial chemoreception. We believe that this facilitation serves a function similar to the facilitation provided by the carotid chemoreceptors and by sources associated with wakefulness. Accordingly, elimination/attenuation of any one of these three influences (caudal M rostral S VLM, wakefulness, carotid chemoreception) results in a slight decrease in breathing, removal of two of the three results in a greater decrease in breathing, and removal of all three results in sustained apnea.

  16. Whole-cell patch-clamp recordings in freely moving animals.

    PubMed

    Lee, Albert K; Epsztein, Jérôme; Brecht, Michael

    2014-01-01

    The patch-clamp technique and the whole-cell measurements derived from it have greatly advanced our understanding of the coding properties of individual neurons by allowing for a detailed analysis of their excitatory/inhibitory synaptic inputs, intrinsic electrical properties, and morphology. Because such measurements require a high level of mechanical stability they have for a long time been limited to in vitro and anesthetized preparations. Recently, however, a considerable amount of effort has been devoted to extending these techniques to awake restrained/head-fixed preparations allowing for the study of the input-output functions of neurons during behavior. In this chapter we describe a technique extending patch-clamp recordings to awake animals free to explore their environments.

  17. Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

    PubMed Central

    Rossaint, Rolf; Veldeman, Michael

    2016-01-01

    Background Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques. Methods Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI]. Results We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1–3], 8% [95%CI:6–11], 17% [95%CI:12–23] and 2% [95%CI:2–3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36–2.69], 1.01 [95%CI:0.52–1.88] for seizures, 1.66 [95%CI:1.35–3.70] for new neurological dysfunction and 2.17 [95%CI:1.22–3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was

  18. On the symmetrization of rotational spectra for freely rotating linear molecules

    NASA Astrophysics Data System (ADS)

    Borysow, Aleksandra; Moraldi, Massimo

    It is demonstrated that the symmetrization of a quantum mechanical rotational spectrum of freely rotating linear molecules by means of the Egelstaff transformation produces a symmetric spectrum whose first two even moments coincide with the corresponding classical moments.

  19. View of a stone age adze cutting tool floating freely in the flight deck.

    NASA Technical Reports Server (NTRS)

    1992-01-01

    View of a stone age adze cutting tool floating freely in the forward flight deck and framed by the forward and side windows. On the Earth below, the big island of Hawaii can be seen through the window.

  20. Long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals

    PubMed Central

    Grand, Laszlo; Ftomov, Sergiu; Timofeev, Igor

    2012-01-01

    Parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. In this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (LFP, MUA, EOG, EMG) and activity data (accelerometer, video) from freely moving cats. The method is based on the integration of commercially available components into a simple monitoring system and is complete with accelerometers and the needed signal processing tools. LFP activities of freely moving group-housed cats were recorded from multiple intracortical areas and from the hippocampus. EMG, EOG, accelerometer and video were simultaneously acquired with LFP activities 24-h a day for 3 months. These recordings confirm the possibility of using our wireless method for 24-h long-term monitoring of neurophysiological and behavioral data of freely moving experimental animals such as cats, ferrets, rabbits and other large animals. PMID:23099345

  1. NR2B Antagonist CP-101,606 Abolishes Pitch-Mediated Deviance Detection in Awake Rats.

    PubMed

    Sivarao, Digavalli V; Chen, Ping; Yang, Yili; Li, Yu-Wen; Pieschl, Rick; Ahlijanian, Michael K

    2014-01-01

    Schizophrenia patients exhibit a decreased ability to detect change in their auditory environment as measured by auditory event-related potentials (ERP) such as mismatch negativity. This deficit has been linked to abnormal NMDA neurotransmission since, among other observations, non-selective channel blockers of NMDA reliably diminish automatic deviance detection in human subjects as well as in animal models. Recent molecular and functional evidence links NR2B receptor subtype to aberrant NMDA transmission in schizophrenia. However, it is unknown if NR2B receptors participate in pre-attentive deviance detection. We recorded ERP from the vertex of freely behaving rats in response to frequency mismatch protocols. We saw a robust increase in N1 response to deviants compared to standard as well as control stimuli indicating true deviance detection. Moreover, the increased negativity was highly sensitive to deviant probability. Next, we tested the effect of a non-selective NMDA channel blocker (ketamine, 30 mg/kg) and a highly selective NR2B antagonist, CP-101,606 (10 or 30 mg/kg) on deviance detection. Ketamine attenuated deviance mainly by increasing the amplitude of the standard ERP. Amplitude and/or latency of several ERP components were also markedly affected. In contrast, CP-101,606 robustly and dose-dependently inhibited the deviant's N1 amplitude, and as a consequence, completely abolished deviance detection. No other ERPs or components were affected. Thus, we report first evidence that NR2B receptors robustly participate in processes of automatic deviance detection in a rodent model. Lastly, our model demonstrates a path forward to test specific pharmacological hypotheses using translational endpoints relevant to aberrant sensory processing in schizophrenia.

  2. Variety of Well behaved parametric classes of relativistic charged fluid spheres in general relativity

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Rajasekhara, S.

    2011-05-01

    The paper presents a variety of classes of interior solutions of Einstein-Maxwell field equations of general relativity for a static, spherically symmetric distribution of the charged fluid with well behaved nature. These classes of solutions describe perfect fluid balls with positively finite central pressure, positively finite central density; their ratio is less than one and causality condition is obeyed at the center. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing for these solutions. Keeping in view of well behaved nature of these solutions, two new classes of solutions are being studied extensively. Moreover, these classes of solutions give us wide range of constant K for which the solutions are well behaved hence, suitable for modeling of super dense star. For solution (I1) the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3 corresponding to K=1.19 and X=0.20, the maximum mass of the star comes out to be 2.5 M Θ with linear dimension 25.29 Km and central redshift 0.2802. It has been observed that with the increase of charge parameter K, the mass of the star also increases. For n=4,5,6,7, the charged solutions are well behaved with their neutral counterparts however, for n=1,2,3, the charged solution are well behaved but their neutral counterparts are not well behaved.

  3. A class of well behaved charged analogues of Vaidya-Tikekar type super-dense star

    NASA Astrophysics Data System (ADS)

    Gupta, Y. K.; Kumar, Jitendra

    2011-08-01

    In the present article a model of well behaved charged superdense star with surface density 2×1014 gm/cm3 is constructed by considering a static spherically symmetric metric with t=const hypersurfaces as hyperboloid. So far well behaved model described by such metric could not be obtained. Maximum mass of the star is found to be 0.343457 M ⊙ and the corresponding radius is 9.57459 km. The red shift at the centre and on the surface are given as 0.068887 and 0.031726 respectively.

  4. Intraoperative Motor Symptoms during Brain Tumor Resection in the Supplementary Motor Area (SMA) without Positive Mapping during Awake Surgery.

    PubMed

    Nakajima, Riho; Nakada, Mitsutoshi; Miyashita, Katsuyoshi; Kinoshita, Masashi; Okita, Hirokazu; Yahata, Tetsutaro; Hayashi, Yutaka

    2015-01-01

    Awake surgery could be a useful modality for lesions locating in close proximity to the eloquent areas including primary motor cortex and pyramidal tract. In case with supplementary motor area (SMA) lesion, we often encounter with intraoperative motor symptoms during awake surgery even in area without positive mapping. Although the usual recovery of the SMA syndrome has been well documented, rare cases with permanent deficits could be encountered in the clinical setting. It has been difficult to evaluate during surgery whether the intraoperative motor symptoms lead to postoperative permanent deficits. The purpose of this study was to demonstrate the intraoperative motor symptoms could be reversible, further to provide useful information for making decision to continue surgical procedure of tumor resection. Eight consecutive patients (from July 2012 to June 2014, six men and two women, aged 33-63 years) with neoplastic lesions around the SMA underwent an awake surgery. Using a retrospective analysis of intraoperative video records, intraoperative motor symptoms during tumor resection were investigated. In continuous functional monitoring during resection of SMA tumor under awake conditions, the following motor symptoms were observed during resection of the region without positive mapping: delayed motor weakness, delay of movement initiation, slowness of movement, difficulty in dual task response, and coordination disturbance. In seven patients hemiparesis observed immediately after surgery recovered to preoperative level within 6 weeks. During awake surgery for SMA tumors, the above-mentioned motor symptoms could occur in area without positive mapping and might be predictors for reversible SMA syndrome.

  5. BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience.

    PubMed

    Yee, J R; Kenkel, W M; Kulkarni, P; Moore, K; Perkeybile, A M; Toddes, S; Amacker, J A; Carter, C S; Ferris, C F

    2016-09-01

    The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological

  6. The VetMousetrap: a device for computed tomographic imaging of the thorax of awake cats.

    PubMed

    Oliveira, Cintia R; Ranallo, Frank N; Pijanowski, Gerald J; Mitchell, Mark A; O'Brien, Mauria A; McMichael, Maureen; Hartman, Susan K; Matheson, Jodi S; O'Brien, Robert T

    2011-01-01

    The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats.

  7. Asleep-awake-asleep craniotomy: a comparison with general anesthesia for resection of supratentorial tumors.

    PubMed

    Rajan, Shobana; Cata, Juan P; Nada, Eman; Weil, Robert; Pal, Rakhi; Avitsian, Rafi

    2013-08-01

    The anesthetic plan for patients undergoing awake craniotomy, when compared to craniotomy under general anesthesia, is different, in that it requires changes in states of consciousness during the procedure. This retrospective review compares patients undergoing an asleep-awake-asleep technique for craniotomy (group AW: n = 101) to patients undergoing craniotomy under general anesthesia (group AS: n = 77). Episodes of desaturation (AW = 31% versus AS = 1%, p < 0.0001), although temporary, and hypercarbia (AW = 43.75 mmHg versus AS = 32.75 mmHg, p < 0.001) were more common in the AW group. The mean arterial pressure during application of head clamp pins and emergence was significantly lower in AW patients compared to AS patients (pinning 91.47 mmHg versus 102.9 mmHg, p < 0.05 and emergence 84.85 mmHg versus 105 mmHg, p < 0.05). Patients in the AW group required less vasopressors intraoperatively (AW = 43% versus AS = 69%, p < 0.01). Intraoperative fluids were comparable between the two groups. The post anesthesia care unit (PACU) administered significantly fewer intravenous opioids in the AW group. The length of stay in the PACU and hospital was comparable in both groups. Thus, asleep-awake-asleep craniotomies with propofol-dexmedetomidine infusion had less hemodynamic response to pinning and emergence, and less overall narcotic use compared to general anesthesia. Despite a higher incidence of temporary episodes of desaturation and hypoventilation, no adverse clinical consequences were seen.

  8. Chemical composition and physicochemical properties of green banana (Musa acuminata x balbisiana Colla cv. Awak) flour.

    PubMed

    Haslinda, W H; Cheng, L H; Chong, L C; Noor Aziah, A A

    2009-01-01

    Flour was prepared from peeled and unpeeled banana Awak ABB. Samples prepared were subjected to analysis for determination of chemical composition, mineral, dietary fibre, starch and total phenolics content, antioxidant activity and pasting properties. In general, flour prepared from unpeeled banana was found to show enhanced nutrition values with higher contents of mineral, dietary fibre and total phenolics. Hence, flour fortified with peel showed relatively higher antioxidant activity. On the other hand, better pasting properties were shown when banana flour was blended with peel. It was found that a relatively lower pasting temperature, peak viscosity, breakdown, final viscosity and setback were evident in a sample blended with peel.

  9. Evidence of state-dependent interhemispheric relationships in lizard EEG during the awake state.

    PubMed

    Pereda, Ernesto; Gamundi, Antoni; Nicolau, Maria C; De Vera, Luis; González, Julián J

    2002-06-01

    The electroencephalogram (EEG) from both hemispheres of eight Canary lizards Gallotia galloti was registered at 25 degrees C and 35 degrees C during awake state with open eyes (OE) and closed eyes. The possible interdependence between the recorded EEGs was assessed by means of newly developed methods of multivariate nonlinear time-series analysis. The interdependence turned out to be significant and greater for the OE state at both temperatures, although it was of linear type in most of the cases. We conclude that the methods can be successfully applied to study the interdependence between noisy, low-amplitude EEGs.

  10. Acute functional reactivation of the language network during awake intraoperative brain mapping.

    PubMed

    Spena, Giannantonio; Costi, Emanuele; Panciani, Pier Paolo; Roca, Elena; Migliorati, Karol; Fontanella, Marco Maria

    2015-01-01

    Acute brain plasticity during resection of central lesions has been recently described. In the cases reported, perilesional latent networks, useful to preserve the neurological functions, were detected in asymptomatic patients. In this paper, we presented a case of acute functional reactivation (AFR) of the language network in a symptomatic patient. Tumor resection allowed to acutely restore the neurological deficit. Intraoperative direct cortical stimulation (DCS) and functional neuroimaging showed new epicentres of activation of the language network after tumor excision. DCS in awake surgery is mandatory to reveal AFR needful to improve the extent of resection preserving the quality of life.

  11. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats

    PubMed Central

    Tang, Jianbo; Coleman, Jason E.; Dai, Xianjin; Jiang, Huabei

    2016-01-01

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents. PMID:27146026

  12. New class of well behaved exact Solutions for static charged Neutron-star with perfect fluid

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj

    2012-01-01

    The paper presents a class of interior solutions of Einstein-Maxwell field equations in general relativity for a static spherically symmetric distribution of a charged fluid. This class of solutions describes well behaved charged fluid balls. This solution gives us wide range of parameter K (0.53≤ K≤0.95), for which the solution is well behaved hence, suitable for modeling of super dense star. For this solution the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3. Corresponding to K=0.95 with X=-0.15, the maximum mass of the star comes out to be M=1.56 M Θ with radius r b ≈9.22 km and the surface red shift Z b ≈0.124207. It has been observed that under well behaved conditions this class of solutions gives us the mass of super dense object within the range of neutron star. However, its neutral counter part is not well behaved.

  13. Collaborating with Parents for Early School Success: The Achieving-Behaving-Caring Program

    ERIC Educational Resources Information Center

    McConaughy, Stephanie H.; Kay, Pam; Welkowitz, Julie A.; Hewitt, Kim; Fitzgerald, Martha D.

    2007-01-01

    The Achieving-Behaving-Caring (ABC) Program is an evidence-based approach to addressing the needs of elementary students at risk for emotional and behavioral difficulties and promoting successful home-school collaboration. This practical guide demonstrates how classroom teachers and parents can work together to boost individual children's…

  14. A family of well-behaved Karmarkar spacetimes describing interior of relativistic stars

    NASA Astrophysics Data System (ADS)

    Singh, Ksh. Newton; Pant, Neeraj

    2016-10-01

    We present a family of new exact solutions for relativistic anisotropic stellar objects by considering a four-dimensional spacetime embedded in a five-dimensional pseudo Euclidean space, known as Class I solutions. These solutions are well behaved in all respects, satisfy all energy conditions, and the resulting compactness parameter is also within Buchdahl limit. The well-behaved nature of the solutions for a particular star solely depends on the index n. We have discussed the solutions in detail for the neutron star XTE J1739-285 (M=1.51M_⊙, ~R=10.9 km). For this particular star, the solution is well behaved in all respects for 8 ≤ n ≤ 20. However, the solutions with n<8 possess an increasing trend of the sound speed and the solutions belonging to n>20 disobey the causality condition. Further, the well-behaved nature of the solutions for PSR J0348+0432 (2.01M_⊙, ~11 km), EXO 1785-248 (1.3M_⊙, 8.85 km), and Her X-1 (0.85M_⊙, 8.1 km) are specified by the index n with limits 24 ≤ n ≤ 54, 1.5 ≤ n ≤ 4, and 0.8 ≤ n ≤ 2.7, respectively.

  15. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats.

    PubMed

    Tang, Jianbo; Coleman, Jason E; Dai, Xianjin; Jiang, Huabei

    2016-05-05

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents.

  16. A well-behaved class of charged analogue of Durgapal solution

    NASA Astrophysics Data System (ADS)

    Mehta, R. N.; Pant, Neeraj; Mahto, Dipo; Jha, J. S.

    2013-02-01

    We present a well behaved class of charged analogue of M.C. Durgapal (J. Phys. A, Math. Gen. 15:2637, 1982) solution. This solution describes charged fluid balls with positively finite central pressure, positively finite central density; their ratio is less than one and causality condition is obeyed at the centre. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing, however, the electric intensity is monotonically increasing in nature. This solution gives us wide range of parameter for every positive value of n for which the solution is well behaved hence, suitable for modeling of super dense stars. Keeping in view of well behaved nature of this solution, one new class of solution is being studied extensively. Moreover, this class of solution gives us wide range of constant K (0≤ K≤2.2) for which the solution is well behaved hence, suitable for modeling of super dense stars like strange quark stars, neutron stars and pulsars. For this class of solution the mass of a star is maximized with all degree of suitability, compatible with quark stars, neutron stars and pulsars. By assuming the surface density ρ b =2×1014 g/cm3 (like, Brecher and Capocaso, Nature 259:377, 1976), corresponding to K=0 with X=0..235, the resulting well behaved model has the mass M=4.03 M Θ , radius r b =19.53 km and moment of inertia I=1.213×1046 g cm2; for K=1.5 with X=0.235, the resulting well behaved model has the mass M=4.43 M Θ , radius r b =18.04 km and moment of inertia I=1.136×1046 g cm2; for K=2.2 with X=0.235, the resulting well behaved model has the mass M=4.56 M Θ , radius r b =17.30 km and moment of inertia I=1.076×1046 g cm2. These values of masses and moment of inertia are found to be consistent with the crab pulsars.

  17. Case Report: Emergency awake craniotomy for cerebral abscess in a patient with unrepaired cyanotic congenital heart disease

    PubMed Central

    Fassl, Jens; Tobler, Daniel; Zumofen, Daniel; Steiner, Luzius A.; Goettel, Nicolai

    2017-01-01

    We report the case of a 39-year-old male with complex cyanotic congenital heart disease undergoing emergency craniotomy for a cerebral abscess. Maintenance of intraoperative hemodynamic stability and adequate tissue oxygenation during anesthesia may be challenging in patients with cyanotic congenital heart disease. In this case, we decided to perform the surgery as an awake craniotomy after interdisciplinary consensus. We discuss general aspects of anesthetic management during awake craniotomy and specific concerns in the perioperative care of patients with congenital heart disease. PMID:27928498

  18. A Case Report of Onyx Pulmonary Arterial Embolism Contributing to Hypoxemia During Awake Craniotomy for Arteriovenous Malformation Resection.

    PubMed

    Tolly, Brian T; Kosky, Jenna L; Koht, Antoun; Hemmer, Laura B

    2017-02-15

    A healthy 26-year-old man with cerebral arteriovenous malformation underwent staged endovascular embolization with Onyx followed by awake craniotomy for resection. The perioperative course was complicated by tachycardia and severe intraoperative hypoxemia requiring significant oxygen supplementation. Postoperative chest computed tomography (CT) revealed hyperattenuating Onyx embolization material within the pulmonary vasculature, and an electrocardiogram indicated possible right heart strain, supporting clinically significant embolism. With awake arteriovenous malformation resection following adjunctive Onyx embolization becoming increasingly employed for lesions involving the eloquent cortex, anesthesiologists need to be aware of pulmonary migration of Onyx material as a potential contributor to significant perioperative hypoxemia.

  19. A Case Report of Onyx Pulmonary Arterial Embolism Contributing to Hypoxemia During Awake Craniotomy for Arteriovenous Malformation Resection.

    PubMed

    Tolly, Brian T; Kosky, Jenna L; Koht, Antoun; Hemmer, Laura B

    2016-11-02

    A healthy 26-year-old man with cerebral arteriovenous malformation underwent staged endovascular embolization with Onyx followed by awake craniotomy for resection. The perioperative course was complicated by tachycardia and severe intraoperative hypoxemia requiring significant oxygen supplementation. Postoperative chest computed tomography (CT) revealed hyperattenuating Onyx embolization material within the pulmonary vasculature, and an electrocardiogram indicated possible right heart strain, supporting clinically significant embolism. With awake arteriovenous malformation resection following adjunctive Onyx embolization becoming increasingly employed for lesions involving the eloquent cortex, anesthesiologists need to be aware of pulmonary migration of Onyx material as a potential contributor to significant perioperative hypoxemia.

  20. Lower “Awake and Fed Thermogenesis” Predicts Future Weight Gain in Subjects With Abdominal Adiposity

    PubMed Central

    Piaggi, Paolo; Krakoff, Jonathan; Bogardus, Clifton; Thearle, Marie S.

    2013-01-01

    Awake and fed thermogenesis (AFT) is the energy expenditure (EE) of the nonactive fed condition above the minimum metabolic requirement during sleep and is composed of the thermic effect of food and the cost of being awake. AFT was estimated from whole-room 24-h EE measures in 509 healthy subjects (368 Native Americans and 141 whites) while subjects consumed a eucaloric diet. Follow-up data were available for 290 Native Americans (median follow-up time: 6.6 years). AFT accounted for ∼10% of 24-h EE and explained a significant portion of deviations from expected energy requirements. Energy intake was the major determinant of AFT. AFT, normalized as a percentage of intake, was inversely related to age and fasting glucose concentration and showed a nonlinear relationship with waist circumference and BMI. Spline analysis demonstrated that AFT becomes inversely related to BMI at an inflection point of 29 kg/m2. The residual variance of AFT, after accounting for covariates, predicted future weight change only in subjects with a BMI >29 kg/m2. AFT may influence daily energy balance, is reduced in obese individuals, and predicts future weight gain in these subjects. Once central adiposity develops, a blunting of AFT may occur that then contributes to further weight gain. PMID:23974925

  1. Response Patterns of GABAergic Neurons in the Anterior Piriform Cortex of Awake Mice.

    PubMed

    Hu, Rongfeng; Zhang, Juen; Luo, Minmin; Hu, Ji

    2016-06-01

    Local inhibition by γ-amino butyric acid (GABA)-containing neurons is of vital importance for the operation of sensory cortices. However, the physiological response patterns of cortical GABAergic neurons are poorly understood, especially in the awake condition. Here, we utilized the recently developed optical tagging technique to specifically record GABAergic neurons in the anterior piriform cortex (aPC) in awake mice. The identified aPC GABAergic neurons were stimulated with robotic delivery of 32 distinct odorants, which covered a broad range of functional groups. We found that aPC GABAergic neurons could be divided into 4 types based on their response patterns. Type I, type II, and type III neurons displayed broad excitatory responses to test odorants with different dynamics. Type I neurons were constantly activated during odorant stimulation, whereas type II neurons were only transiently activated at the onset of odorant delivery. In addition, type III neurons displayed transient excitatory responses both at the onset and termination of odorant presentation. Interestingly, type IV neurons were broadly inhibited by most of the odorants. Taken together, aPC GABAergic neurons adopt different strategies to affect the cortical circuitry. Our results will allow for better understanding of the role of cortical GABAergic interneurons in sensory information processing.

  2. No short-term effects of digital mobile radio telephone on the awake human electroencephalogram

    SciTech Connect

    Roeschke, J.; Mann, K.

    1997-05-01

    A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3} and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect any difference in the awake EEGs in terms of spectral power density measures.

  3. Representation of dynamic interaural phase difference in auditory cortex of awake rhesus macaques.

    PubMed

    Scott, Brian H; Malone, Brian J; Semple, Malcolm N

    2009-04-01

    Neurons in auditory cortex of awake primates are selective for the spatial location of a sound source, yet the neural representation of the binaural cues that underlie this tuning remains undefined. We examined this representation in 283 single neurons across the low-frequency auditory core in alert macaques, trained to discriminate binaural cues for sound azimuth. In response to binaural beat stimuli, which mimic acoustic motion by modulating the relative phase of a tone at the two ears, these neurons robustly modulate their discharge rate in response to this directional cue. In accordance with prior studies, the preferred interaural phase difference (IPD) of these neurons typically corresponds to azimuthal locations contralateral to the recorded hemisphere. Whereas binaural beats evoke only transient discharges in anesthetized cortex, neurons in awake cortex respond throughout the IPD cycle. In this regard, responses are consistent with observations at earlier stations of the auditory pathway. Discharge rate is a band-pass function of the frequency of IPD modulation in most neurons (73%), but both discharge rate and temporal synchrony are independent of the direction of phase modulation. When subjected to a receiver operator characteristic analysis, the responses of individual neurons are insufficient to account for the perceptual acuity of these macaques in an IPD discrimination task, suggesting the need for neural pooling at the cortical level.

  4. Brain imaging in awake infants by near-infrared optical topography

    NASA Astrophysics Data System (ADS)

    Taga, Gentaro; Asakawa, Kayo; Maki, Atsushi; Konishi, Yukuo; Koizumi, Hideaki

    2003-09-01

    Studies of young infants are critical to understand perceptual, motor, and cognitive processing in humans. However, brain mechanisms involved are poorly understood, because the use of brain-imaging methods such as functional magnetic resonance imaging in awake infants is difficult. In the present study we show functional brain imaging of awake infants viewing visual stimuli by means of multichannel near-infrared spectroscopy, a technique that permits a measurement of cerebral hemoglobin oxygenation in response to brain activation through the intact skull without subject constraint. We found that event-related increases in oxyhemoglobin were evident in localized areas of the occipital cortex of infants aged 2-4 months in response to a brief presentation of a checkerboard pattern reversal while they maintained fixation to attention-grabbing stimuli. The dynamic change in cerebral blood oxygenation was qualitatively similar to that observed in the adult brain. This result introduces near-infrared optical topography as a method for investigating the functional development of the brain in early infancy.

  5. [Perioperative management of an obese patient complicated with sleep apnea syndrome (SAS) undergoing awake craniotomy].

    PubMed

    Komayama, Noriaki; Kamata, Kotoe; Maruyama, Takashi; Nitta, Masayuki; Muragaki, Yoshihiro; Ozaki, Makoto

    2014-10-01

    Both obesity (BMI over 30) and SAS are risks for Supper airway maintenance. We report an obese patient (BMI 33.5) with SAS who underwent awake craniotomy. Weight reduction was instructed 1 month before the operation, and the patient lost enough weight to use intraoperative MRI. Under general anesthesia, surgical pads containing 2% lidocaine with adrenaline were inserted into the nasal cavities. The patient's airway S was secured by i-gel® until dura was opened. A nasal airway was then inserted to confirm the upper airway patency and anesthetics were terminated The patient regained consciousness and started respiration. The i-gel® was removed. The nasal airway was changed to an RAE tracheal tube ; the tube was fixed above the vocal cords under bronchofiberscopic observation. Continuous positive airway pressure (CPAP) via RAE tube was started. Neither coughing nor epistaxis was observed.The RAE tube prevented glossoptosis and did not disturb speech mapping. Emergent endotracheal intubation was easily managed because the tube was close to the glottis. The RAE tube was removed and nasal CP AP was applied overnight Carefully prepared CP AP support via nasal RAE tube was practical in keeping upper airway patency for an obese patient complicated with SAS undergoing awake craniotomy.

  6. DIEP Flap for Breast Reconstruction Using Epidural Anesthesia with the Patient Awake

    PubMed Central

    Camacho, Marco; de la Garza, Jonatan

    2016-01-01

    Background: Many articles have been published about breast reconstruction using the deep inferior epigastric perforator (DIEP) flap; however, few articles have been published in plastic/reconstructive surgery journals describing the difference between anesthetic techniques and recovery in microsurgical patients. Methods: We analyzed 16 patients who underwent DIEP flap for breast reconstruction. Patients were divided into 2 groups: group 1: general anesthesia (n = 9); group 2: epidural block with the patient awake (n = 7). In group 2, the peridural block was done at 2 levels: thoracic (T2–T3) and lumbar (L2–L3). Results: The success rate was 100% with no partial or total loss of the flap. There was no difference between groups in regard to postoperative pain in the first 5 days (Visual Analog Scale). Analgesia used in group 1 was buprenorphine and ketorolac, and in group 2, only ketorolac without opioid derivatives. Immediate postoperative recovery was better in the peridural group than in the group administered general anesthesia (P = 0.0001). Conclusions: DIEP flap with peridural block and the patient awake during surgery is a feasible technique with better recovery in the immediate postoperative period, achieving good analgesia level with minimal intravenous medication. PMID:27579248

  7. A novel tablet computer platform for advanced language mapping during awake craniotomy procedures.

    PubMed

    Morrison, Melanie A; Tam, Fred; Garavaglia, Marco M; Golestanirad, Laleh; Hare, Gregory M T; Cusimano, Michael D; Schweizer, Tom A; Das, Sunit; Graham, Simon J

    2016-04-01

    A computerized platform has been developed to enhance behavioral testing during intraoperative language mapping in awake craniotomy procedures. The system is uniquely compatible with the environmental demands of both the operating room and preoperative functional MRI (fMRI), thus providing standardized testing toward improving spatial agreement between the 2 brain mapping techniques. Details of the platform architecture, its advantages over traditional testing methods, and its use for language mapping are described. Four illustrative cases demonstrate the efficacy of using the testing platform to administer sophisticated language paradigms, and the spatial agreement between intraoperative mapping and preoperative fMRI results. The testing platform substantially improved the ability of the surgeon to detect and characterize language deficits. Use of a written word generation task to assess language production helped confirm areas of speech apraxia and speech arrest that were inadequately characterized or missed with the use of traditional paradigms, respectively. Preoperative fMRI of the analogous writing task was also assistive, displaying excellent spatial agreement with intraoperative mapping in all 4 cases. Sole use of traditional testing paradigms can be limiting during awake craniotomy procedures. Comprehensive assessment of language function will require additional use of more sophisticated and ecologically valid testing paradigms. The platform presented here provides a means to do so.

  8. The linearity and selectivity of neuronal responses in awake visual cortex

    PubMed Central

    Chen, Yao; Anand, Sanjiv; Martinez-Conde, Susana; Macknik, Stephen L.; Bereshpolova, Yulia; Swadlow, Harvey A.; Alonso, Jose-Manuel

    2011-01-01

    Neurons in primary visual cortex (V1) are frequently classified based on their response linearity: the extent in which their visual responses to drifting gratings resemble a linear replica of the stimulus. This classification is supported by the finding that response linearity is bimodally distributed across neurons in area V1 of anesthetized animals. However, recent studies suggest that such bimodal distribution may not reflect two neuronal types but a nonlinear relationship between the membrane potential and the spike output. A main limitation of these previous studies is that they measured response linearity in anesthetized animals, where the distance between the neuronal membrane potential and spike threshold is artificially increased by anesthesia. Here, we measured V1 response linearity in the awake brain and its correlation with the neuronal spontaneous firing rate, which is related to the distance between membrane potential and threshold. Our results demonstrate that response linearity is bimodally distributed in awake V1 but that it is poorly correlated with spontaneous firing rate. In contrast, the spontaneous firing rate is best correlated to the response selectivity and response latency to stimuli. PMID:19761345

  9. Intact skull chronic windows for mesoscopic wide-field imaging in awake mice

    PubMed Central

    Silasi, Gergely; Xiao, Dongsheng; Vanni, Matthieu P.; Chen, Andrew C. N.; Murphy, Timothy H.

    2016-01-01

    Background Craniotomy-based window implants are commonly used for microscopic imaging, in head-fixed rodents, however their field of view is typically small and incompatible with mesoscopic functional mapping of cortex. New Method We describe a reproducible and simple procedure for chronic through-bone wide-field imaging in awake head-fixed mice providing stable optical access for chronic imaging over large areas of the cortex for months. Results The preparation is produced by applying clear-drying dental cement to the intact mouse skull, followed by a glass coverslip to create a partially transparent imaging surface. Surgery time takes about 30 minutes. A single set-screw provides a stable means of attachment for mesoscale assessment without obscuring the cortical field of view. Comparison with Existing Methods We demonstrate the utility of this method by showing seed-pixel functional connectivity maps generated from spontaneous cortical activity of GCAMP6 signals in both awake and anesthetized mice. Conclusions We propose that the intact skull preparation described here may be used for most longitudinal studies that do not require micron scale resolution and where cortical neural or vascular signals are recorded with intrinsic sensors. PMID:27102043

  10. Disrupting neural activity related to awake-state sharp wave-ripple complexes prevents hippocampal learning.

    PubMed

    Nokia, Miriam S; Mikkonen, Jarno E; Penttonen, Markku; Wikgren, Jan

    2012-01-01

    Oscillations in hippocampal local-field potentials (LFPs) reflect the crucial involvement of the hippocampus in memory trace formation: theta (4-8 Hz) oscillations and ripples (~200 Hz) occurring during sharp waves are thought to mediate encoding and consolidation, respectively. During sharp wave-ripple complexes (SPW-Rs), hippocampal cell firing closely follows the pattern that took place during the initial experience, most likely reflecting replay of that event. Disrupting hippocampal ripples using electrical stimulation either during training in awake animals or during sleep after training retards spatial learning. Here, adult rabbits were trained in trace eyeblink conditioning, a hippocampus-dependent associative learning task. A bright light was presented to the animals during the inter-trial interval (ITI), when awake, either during SPW-Rs or irrespective of their neural state. Learning was particularly poor when the light was presented following SPW-Rs. While the light did not disrupt the ripple itself, it elicited a theta-band oscillation, a state that does not usually coincide with SPW-Rs. Thus, it seems that consolidation depends on neuronal activity within and beyond the hippocampus taking place immediately after, but by no means limited to, hippocampal SPW-Rs.

  11. Association of Awake Bruxism with Khat, Coffee, Tobacco, and Stress among Jazan University Students

    PubMed Central

    Quadri, Mir Faeq Ali; Mahnashi, Ali; Al Almutahhir, Ayman; Tubayqi, Hamzah; Hakami, Abdullah; Arishi, Mohamed; Alamir, Abdulwahab

    2015-01-01

    Objective. The objective is to assess the prevalence of bruxism among the university students and to check its association with their khat chewing habit. Materials and Methods. A cross-sectional descriptive study is designed using cluster random sampling. Pretested questionnaire was administered by a trained interviewer to assess awake bruxism and the use of variables like khat, coffee, tobacco, and stress. Chi-square test at 5% significance was used for assessing the association. Logistic regression was also performed after adjusting for covariates. Results. A high response rate (95%) was obtained as the distribution and collection of questionnaire was within an hour interval. 85% (63%, males; 22%, females) experienced an episode of bruxism at least one time in the past six months. Regression analysis revealed an association of stress (P = 0.00; OR = 5.902, 95% CI 2.614–13.325) and khat use (P = 0.05; OR = 1.629, 95% CI 0.360–7.368) with bruxism. Interestingly, it is observed that the one who chew khat experienced 3.56 times (95% CI; 2.62–11.22) less pain when compared to the nonusers. Conclusion. This study is the first of its kind to assess the association of bruxism with khat chewing. High amount of stress and khat use can be considered as important risk indicators for awake bruxism. PMID:26491448

  12. Association of Awake Bruxism with Khat, Coffee, Tobacco, and Stress among Jazan University Students.

    PubMed

    Quadri, Mir Faeq Ali; Mahnashi, Ali; Al Almutahhir, Ayman; Tubayqi, Hamzah; Hakami, Abdullah; Arishi, Mohamed; Alamir, Abdulwahab

    2015-01-01

    Objective. The objective is to assess the prevalence of bruxism among the university students and to check its association with their khat chewing habit. Materials and Methods. A cross-sectional descriptive study is designed using cluster random sampling. Pretested questionnaire was administered by a trained interviewer to assess awake bruxism and the use of variables like khat, coffee, tobacco, and stress. Chi-square test at 5% significance was used for assessing the association. Logistic regression was also performed after adjusting for covariates. Results. A high response rate (95%) was obtained as the distribution and collection of questionnaire was within an hour interval. 85% (63%, males; 22%, females) experienced an episode of bruxism at least one time in the past six months. Regression analysis revealed an association of stress (P = 0.00; OR = 5.902, 95% CI 2.614-13.325) and khat use (P = 0.05; OR = 1.629, 95% CI 0.360-7.368) with bruxism. Interestingly, it is observed that the one who chew khat experienced 3.56 times (95% CI; 2.62-11.22) less pain when compared to the nonusers. Conclusion. This study is the first of its kind to assess the association of bruxism with khat chewing. High amount of stress and khat use can be considered as important risk indicators for awake bruxism.

  13. Status of the proton and electron transfer lines for the AWAKE Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Schmidt, J. S.; Bauche, J.; Biskup, B.; Bracco, C.; Doebert, S.; Goddard, B.; Gschwendtner, E.; Jensen, L. K.; Jones, O. R.; Mazzoni, S.; Meddahi, M.; Pepitone, K.; Petrenko, A.; Velotti, F. M.; Vorozhtsov, A.

    2016-09-01

    The AWAKE project at CERN is planned to study proton driven plasma wakefield acceleration with an externally injected electron beam. Therefore two transfer lines are being designed in order to provide the proton beam from the SPS and the electron beam from an RF gun to the plasma cell. The commissioning of the proton line will take place in 2016 for the first phase of the experiment, which is focused on the self-modulation of a 12 cm long proton bunch in the plasma. The electron line will be added for the second phase of AWAKE in 2017, when the wakefield will be probed with an electron beam of 10-20 MeV/c. The challenge for these transfer lines lies in the parallel operation of the proton, electron and laser beam used to ionize the plasma and seed the self-modulation. These beams, of different characteristics, need to be synchronized and positioned for optimized injection conditions into the wakefield. This task requires great flexibility in the transfer line optics. The status of these designs will be presented in this paper.

  14. Indirect self-modulation instability measurement concept for the AWAKE proton beam

    NASA Astrophysics Data System (ADS)

    Turner, M.; Petrenko, A.; Biskup, B.; Burger, S.; Gschwendtner, E.; Lotov, K. V.; Mazzoni, S.; Vincke, H.

    2016-09-01

    AWAKE, the Advanced Proton-Driven Plasma Wakefield Acceleration Experiment, is a proof-of-principle R&D experiment at CERN using a 400 GeV / c proton beam from the CERN SPS (longitudinal beam size σz = 12 cm) which will be sent into a 10 m long plasma section with a nominal density of ≈ 7 ×1014 atoms /cm3 (plasma wavelength λp = 1.2 mm). In this paper we show that by measuring the time integrated transverse profile of the proton bunch at two locations downstream of the AWAKE plasma, information about the occurrence of the self-modulation instability (SMI) can be inferred. In particular we show that measuring defocused protons with an angle of 1 mrad corresponds to having electric fields in the order of GV/m and fully developed self-modulation of the proton bunch. Additionally, by measuring the defocused beam edge of the self-modulated bunch, information about the growth rate of the instability can be extracted. If hosing instability occurs, it could be detected by measuring a non-uniform defocused beam shape with changing radius. Using a 1 mm thick Chromox scintillation screen for imaging of the self-modulated proton bunch, an edge resolution of 0.6 mm and hence an SMI saturation point resolution of 1.2 m can be achieved.

  15. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences

    PubMed Central

    Takahashi, Susumu

    2015-01-01

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as ‘what’ information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only ‘where and when’ but also ‘what’ information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process. DOI: http://dx.doi.org/10.7554/eLife.08105.001 PMID:26481131

  16. Influence of hemorrhage on adrenal secretion, blood glucose and serum insulin in the awake pig.

    PubMed Central

    Carey, L C; Curtin, R; Sapira, J D

    1976-01-01

    A study was performed to quantitate the adrenal medullary and cortical response to hemorrhage in awake animals bled at different rates and to relate these responses to simultaneous changes in blood glucose and serum insulin. A series of awake pigs were bled either slowly or rapidly of 30% of their calculated blood volume. Infusions of exogenous epinephrine were performed in an additional series of unbled animals and infusions of epinephrine plus hydrocortisone were similarly performed in an additonal series. Increase in blood glucose and epinephrine secretion rate following hemorrhage were found to be significantly dependent upon the rate of initial hemorrhage. Cortisol secretion was found to rise significantly during and following hemorrhage in both rapidly and slowly bled animals. Serum insulin levels remained at baseline levels during shock, despite the presence of significant hyperglycemia. In unbled animals infused with epinephrine at rates comparable to those measured in shock, elevations in blood glucose were markedly lower, shifting to the right of the dose-response curve during hemorrhage. Simultaneous infusions of cortisol and epinephrine resulted in a dose-response curve which did not differ significantly from that following infusion of epinephrine alone. Images Fig. 2. PMID:1247317

  17. Technical and Conceptual Considerations for Performing and Interpreting Functional MRI Studies in Awake Rats

    PubMed Central

    Febo, Marcelo

    2011-01-01

    Functional neuroimaging studies in rodents have the potential to provide insight into neurodevelopmental and psychiatric conditions. The strength of the technique lies in its non-invasive nature that can permit longitudinal functional studies in the same animal over its adult life. The relatively good spatial and temporal resolution and the ever-growing database on the biological and biophysical basis of the blood oxygen level dependent (BOLD) signal make it a unique technique in preclinical neuroscience research. Our laboratory has used imaging to investigate brain activation in awake rats following cocaine administration and during the presentation of lactation-associated sensory stimuli. Factors that deserve attention when planning functional magnetic resonance imaging studies in rats include technical issues, animal physiology and interpretability of the resulting data. The present review discusses the pros and cons of animal imaging with a particular focus on the technical aspects of studies with awake rats. Overall, the benefits of the technique outweigh its limitations and the rapidly evolving methods will open the way for more laboratories to employ the technique in neuroscience research. PMID:21808625

  18. The Development of Nociceptive Network Activity in the Somatosensory Cortex of Freely Moving Rat Pups

    PubMed Central

    Chang, P.; Fabrizi, L.; Olhede, S.; Fitzgerald, M.

    2016-01-01

    Cortical perception of noxious stimulation is an essential component of pain experience but it is not known how cortical nociceptive activity emerges during brain development. Here we use continuous telemetric electrocorticogram (ECoG) recording from the primary somatosensory cortex (S1) of awake active rat pups to map functional nociceptive processing in the developing brain over the first 4 weeks of life. Cross-sectional and longitudinal recordings show that baseline S1 ECoG energy increases steadily with age, with a distinctive beta component replaced by a distinctive theta component in week 3. Event-related potentials were evoked by brief noxious hindpaw skin stimulation at all ages tested, confirming the presence of functional nociceptive spinothalamic inputs in S1. However, hindpaw incision, which increases pain sensitivity at all ages, did not increase S1 ECoG energy until week 3. A significant increase in gamma (20–50 Hz) energy occurred in the presence of skin incision at week 3 accompanied by a longer-lasting increase in theta (4–8 Hz) energy at week 4. Continuous ECoG recording demonstrates specific postnatal functional stages in the maturation of S1 cortical nociception. Somatosensory cortical coding of an ongoing pain “state” in awake rat pups becomes apparent between 2 and 4 weeks of age. PMID:27797835

  19. Controlling ill-behaved flows with active queue management in DiffServ networks

    NASA Astrophysics Data System (ADS)

    Shu, Yantai; Gao, Deyun; Yang, Oliver W. W.; Qi, Lantao

    2003-08-01

    In this paper, we propose a new active queue management mechanism called the RIO-SD (RED IN and OUT with Selective Dropping) to control ill-behaved flows in DiffServ networks. Under this scheme, core routers are not required to maintain per-flow state, and the ill-behaved flows can be identified based on the drop history of the "OUT-profile" virtual queue. Control is effected by placing two pre-filters in front of the "IN-profile" and "OUT-profile" virtual queues respectively. Simulation results indicate that our approach can also improve the performance of other normal flows. Our work demonstrates that our algorithm is robust and simple to use.

  20. Motion quantification during multi-photon functional imaging in behaving animals

    PubMed Central

    Kong, Lingjie; Little, Justin P.; Cui, Meng

    2016-01-01

    Functional imaging in behaving animals is essential to understanding brain function. However, artifacts resulting from animal motion, including locomotion, can severely corrupt functional measurements. To dampen tissue motion, we designed a new optical window with minimal optical aberrations. Using the newly developed high-speed continuous volumetric imaging system based on an optical phase-locked ultrasound lens, we quantified motion of the cerebral cortex and hippocampal surface during two-photon functional imaging in behaving mice. We find that the out-of-plane motion is generally greater than the axial dimension of the point-spread-function during mouse locomotion, which indicates that high-speed continuous volumetric imaging is necessary to minimize motion artifacts. PMID:27699129

  1. New class of regular and well behaved exact solutions in general relativity

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Mehta, R. N.; Pant, Mamta Joshi

    2010-12-01

    We present a new class of spherically symmetric regular and well behaved solutions of the general relativistic field equations in isotropic coordinates. These solutions describe perfect fluid balls with positively finite central pressure and positively finite central density; their ratio is less than one and causality condition is obeyed at the centre. The solutions of this class, the outmarch of pressure, density pressure-density ratio and the ratio of sound speed to light is monotonically decreasing. Keeping in view of well behaved nature in terms of central red shift and surface red shift and by assuming the surface density ρ b =2×1014 g/cm3, we constructed a Neutral star model for k=2, resulting into maximum mass ≈6.36 M Θ, linear dimension ≈48.08 km, surface red shift ≈1.132 and central red shift ≈17.1314.

  2. Speaking Freely

    ERIC Educational Resources Information Center

    Watson, Jamal Eric

    2012-01-01

    Ask Princeton University's Dr. Cornel West about his views on Black History Month, and somehow the conversation ends up with a sharp critique of the Obama administration. This article profiles West who pulls no punches when it comes to his advocacy for impoverished Americans. For more than three decades, the 58-year-old philosopher has combined…

  3. Bioreactivity: Studies on a Simple Brain Stem Reflex in Behaving Animals

    DTIC Science & Technology

    1990-01-04

    activity of LC-NE neurons in behaving cats changes in direct relation to behavioral state ( sleep -wake-arousal). They are silent in REM sleep ...state, with the hypothesis that serotonin would increase during periods of arousal, and decrease during sleep , thus paralleling the changes that we...decrease during sleep periods. We measured extracellular serotonin and simultaneously monitored behavioral state using a set of polygraphic criteria. As

  4. A class of well behaved charged superdense star models of embedding class one

    NASA Astrophysics Data System (ADS)

    Gupta, Y. K.; Kumar, Jitendra

    2011-12-01

    A class of well behaved charged superdense star models of embedding class one is obtained by taking perfect fluid to be interior matter. In the process we come across the models for white dwarf, quark and neutron stars. Maximum mass of the star of this class is found to be 6.716998 M Θ with its radius is 18.92112 Km. In the absence of charge the models reduce to Schwarzchild's interior model with constant density.

  5. Spontaneous and repetitive cardiac slowdown in the freely moving spiny lobster, Panulirus japonicus.

    PubMed

    Yazawa, T; Katsuyama, T

    2001-12-01

    The fluctuation of heartbeat interval was investigated to assess cardio-regulatory nervous function in freely moving spiny lobsters. This was performed by time series analysis of the heartbeat interval recorded from restrained animals, freely moving animals, and isolated hearts. The heart rate of freely moving animals exhibited on/off switching: i.e., an elevated and maintained rate was repetitively interrupted by periods of decreased rate. Each period was initiated by a sudden decrease in rate and was terminated by an exponential return to normal activity. In order to explain this characteristic change in heart rate, we have constructed a neurotransmitter release-reuptake model for such bi-stable activity of cardio-regulatory nerves. The model was successful in reproducing the characteristic observed fluctuation. In freely moving animals, the brain seems to regulate the heart through the inhibitory nerve in an "on/off" manner. In the hearts of restrained animals and isolated hearts, the heart rate exhibited white-noise like fluctuation. This implies that stress impairs the normal bi-stable regulatory mode.

  6. Concentration of frequencies of trapped waves in problems on freely floating bodies

    SciTech Connect

    Nazarov, Sergei A

    2012-09-30

    It is shown that by choosing the shape of two identical bodies floating freely in a channel with symmetric cross-section it is possible to form any pre-assigned number of linearly independent trapped waves (localized solutions). Bibliography: 27 titles.

  7. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A) Meets the applicable requirements of Part B of the Act that apply to States. (B) Meets the requirements... receive funds under Part B of the Act must include, in its application for assistance— (i)...

  8. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A) Meets the applicable requirements of Part B of the Act that apply to States. (B) Meets the requirements... receive funds under Part B of the Act must include, in its application for assistance— (i)...

  9. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A) Meets the applicable requirements of Part B of the Act that apply to States. (B) Meets the requirements... receive funds under Part B of the Act must include, in its application for assistance— (i)...

  10. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A) Meets the applicable requirements of Part B of the Act that apply to States. (B) Meets the requirements... receive funds under Part B of the Act must include, in its application for assistance— (i)...

  11. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A) Meets the applicable requirements of Part B of the Act that apply to States. (B) Meets the requirements... receive funds under Part B of the Act must include, in its application for assistance— (i)...

  12. Optical spatial phase retarder/modulator by a rotating freely suspended LC film

    NASA Astrophysics Data System (ADS)

    Saghaei, Tayebeh; Feiz, Mohammad-Sadegh; Amjadi, Ahmad

    2016-12-01

    This study presents a new method to develop a thin controllable retarder/modulator with spatial axial symmetry by rotating a freely suspended of 4-Cyano-4-n-pentylbiphenyl (5CB) and N-(4-methoxybenzylidene)-4-butylaniline (MBBA) liquid crystal films using mechanical method or as a liquid film motor.

  13. Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

    PubMed

    Waaramaa, Teija; Palo, Pertti; Kankare, Elina

    2015-12-01

    Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions.

  14. Well behaved parametric class of relativistic charged fluid ball in general relativity

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj

    2011-04-01

    The paper presents a class of interior solutions of Einstein-Maxwell field equations of general relativity for a static, spherically symmetric distribution of the charged fluid. This class of solutions describes well behaved charged fluid balls. The class of solutions gives us wide range of parameter K (0≤ K≤42) for which the solution is well behaved hence, suitable for modeling of super dense star. For this solution the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3. Corresponding to K=2 and X=0.30, the maximum mass of the star comes out to be 4.96 M Θ with linear dimension 34.16 km and central redshift and surface redshift 2.1033 and 0.683 respectively. In absence of the charge we are left behind with the well behaved fourth model of Durgapal (J. Phys., A, Math. Gen. 15:2637, 1982).

  15. A new well behaved exact solution in general relativity for perfect fluid

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Fuloria, Pratibha; Tewari, B. C.

    2012-08-01

    We present a new spherically symmetric solution of the general relativistic field equations in isotropic coordinates. The solution is having positive finite central pressure and positive finite central density. The ratio of pressure and density is less than one and casualty condition is obeyed at the centre. Further, the outmarch of pressure, density and pressure-density ratio, and the ratio of sound speed to light is monotonically decreasing. The solution is well behaved for all the values of u lying in the range 0< u≤.186. The central red shift and surface red shift are positive and monotonically decreasing. Further, we have constructed a neutron star model with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3. The maximum mass of the Neutron star comes out to be M=1.591 M Θ with radius R b ≈12.685 km. The most striking feature of the solution is that the solution not only well behaved but also having one of the simplest expressions so far known well behaved solutions. Moreover, the good matching of our results for Vela pulsars show the robustness of our model.

  16. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    EPA Science Inventory

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  17. Association of Masseter Muscle Activities during Awake and Sleep Periods with Self-Reported Anxiety, Depression, and Somatic Symptoms

    PubMed Central

    Khawaja, Shehryar N; Iwasaki, Laura R; Dunford, Robert; Nickel, Jeffrey C; McCall, Willard; Crow, Heidi C; Gonzalez, Yoly

    2015-01-01

    Aim and background The objective of this study was to determine if duty factors (DF) of low-magnitude MMA during awake and sleep periods were associated with self-reports of anxiety, depression, and somatic symptoms, and if so, whether or not any associations were modified by gender or the presence of pain. Limited information is currently available in the literature regarding the association of low-magnitude masseter muscle activities (MMA) in habitual environmental settings and the presence of psychological symptoms. Materials and methods Sixty-eight consenting participants were classified using the Diagnostic Criteria for Temporomandibular Disorders examination and validated self-reporting psychological symptom evaluation questionnaires. Each subject also had masseter electromyography recordings during standardized biting tasks in 2 laboratory sessions to calibrate the in-field MMA collected during 3 awake and 3 sleep periods. Results During awake periods, subjects with self-reported depression and somatic symptoms had statistically high odds of having higher DF of low-magnitude MMA (defined by ≥ 75th percentile of sample). The association between high DF of low-magnitude MMA and self-reported depression symptoms was significantly augmented among male participants, whereas, the association between high DF of low-magnitude MMA and self-reported somatic symptoms was significantly increased among female participants without pain. Conclusion These pilot data support associations of low-magnitude masseter muscle activities with self-reported depression and somatic symptoms during awake periods. PMID:26709387

  18. Maturation of upstream and downstream esophageal reflexes in human premature neonates: the role of sleep and awake states.

    PubMed

    Jadcherla, Sudarshan R; Chan, Chin Yee; Fernandez, Soledad; Splaingard, Mark

    2013-11-01

    We tested the hypothesis that the sensory-motor characteristics of aerodigestive reflexes are dependent on stimulus type and volumes, sleep or awake states, and maturation. Thirteen neonates were studied at 33.6 ± 0.5 wk (time 1) and 37.3 ± 0.5 wk (time 2) postmenstrual age using multimodal provocative esophageal manometry concurrent with video polysomnography. Effects of graded volumes (399 infusions at time 1, 430 infusions at time 2) of midesophageal stimulation with air, water, and apple juice on the sensory thresholds and recruitment frequency of upper esophageal sphincter (UES), esophageal body, and lower esophageal sphincter (LES) reflexes were investigated during sleep and awake states. Sensory thresholds for aerodigestive reflexes between maturational stages were similar. Increased frequency recruitment of UES contractile reflex, LES relaxation reflex, and peristaltic reflexes were noted at time 2 (all, P < 0.05). Graded stimulus-response relationships were evident at time 1 and time 2 during awake and sleep states (P < 0.05). Secondary peristalsis vs. esophago-deglutition response proportions during sleep at time 1 vs. time 2 (P = 0.001) and awake vs. sleep at time 2 (P = 0.02) were distinct. We concluded that sensory-motor effects of esophageal mechanosensitivity, osmosensitivity, and chemosensitivity are advanced in sleep with maturation. Sleep further modulates the frequency recruitment and the type of aerodigestive reflexes.

  19. Upper airway dynamics during negative expiratory pressure in apneic and non-apneic awake snorers

    PubMed Central

    Ferretti, A; Giampiccolo, P; Redolfi, S; Mondini, S; Cirignotta, F; Cavalli, A; Tantucci, C

    2006-01-01

    Background The ability of negative expiratory pressure (NEP) technique to differentiate between awake snorers with and without obstructive sleep apnea-hypopnea (OSAH) was investigated. Methods Forty-eight subjects with sleep disordered breathing (SDB) and 7 healthy subjects, as non-snorer controls, underwent the NEP application of -5 and -7 cmH2O in the seated and supine position during wakefulness, after performing a sleep study. The upper airway collapsibility was assessed by computing the volume exhaled during the first 0.5 sec. (V,NEP0.5) and 1 sec. (V,NEP1) following the NEP start. Results Patients with severe (AHI ≥ 30) (n = 19) and mild-to-moderate (AHI <30 and >5) (n = 15) OSAH had lower V,NEP0.5 (340 ± 88 ml) as compared to snorers (AHI ≤ 5) (n = 14) (427 ± 101 ml; p < 0.01) and controls (n = 7) (492 ± 69 ml; p < 0.001) in the supine position with NEP -5 cmH2O. Less significant differences among the different groups were observed for V,NEP0.5 in the seated position with NEP -5 cmH2O and in both positions with NEP -7 cmH2O (only OSAH patients vs controls, p < 0.001). Similar results were obtained for V,NEP1 in either position by using both NEP -5 cmH2O and -7 cmH2O. In spite of this, a substantial overlapping of V,NEP0.5 and V,NEP1 between snorers and OSAH patients did not allow to identify a reliable diagnostic cut-off level. An inverse correlation with AHI was found for V,NEP0.5 in the supine position with NEP -5 cmH2O (rs = -0.46, p < 0.05) in severe OSAH patients. Conclusion The awake OSAH patients exhibit values of V,NEP0.5 and V,NEP1 lesser than those of awake snorers. The NEP technique, however, appears to have a limited usefulness as clinical tool for routine screening of the OSAH patients during wakefulness. PMID:16573817

  20. A Comparison of Visual Response Properties in the Lateral Geniculate Nucleus and Primary Visual Cortex of Awake and Anesthetized Mice.

    PubMed

    Durand, Séverine; Iyer, Ramakrishnan; Mizuseki, Kenji; de Vries, Saskia; Mihalas, Stefan; Reid, R Clay

    2016-11-30

    The cerebral cortex of the mouse has become one of the most important systems for studying information processing and the neural correlates of behavior. Multiple studies have examined the first stages of visual cortical processing: primary visual cortex (V1) and its thalamic inputs from the dorsal lateral geniculate nucleus (dLGN), but more rarely in the lateral posterior nucleus (LP) in mice. Multiple single-unit surveys of dLGN and V1, both with electrophysiology and two-photon calcium imaging, have described receptive fields in anesthetized animals. Increasingly, awake animals are being used in physiological studies, so it is important to compare neuronal responses between awake and anesthetized state. We have performed a comprehensive survey of spatial and temporal response properties in V1, dLGN, and lateral posterior nucleus of both anesthetized and awake animals, using a common set of stimuli: drifting sine-wave gratings spanning a broad range of spatial and temporal parameters, and sparse noise stimuli consisting of flashed light and dark squares. Most qualitative receptive field parameters were found to be unchanged between the two states, such as most aspects of spatial processing, but there were significant differences in several parameters, most notably in temporal processing. Compared with anesthetized animals, the temporal frequency that evoked the peak response was shifted toward higher values in the dLGN of awake mice and responses were more sustained. Further, the peak response to a flashed stimulus was earlier in all three areas. Overall, however, receptive field properties in the anesthetized animal remain a good model for those in the awake animal.

  1. The Dutch Linguistic Intraoperative Protocol: a valid linguistic approach to awake brain surgery.

    PubMed

    De Witte, E; Satoer, D; Robert, E; Colle, H; Verheyen, S; Visch-Brink, E; Mariën, P

    2015-01-01

    Intraoperative direct electrical stimulation (DES) is increasingly used in patients operated on for tumours in eloquent areas. Although a positive impact of DES on postoperative linguistic outcome is generally advocated, information about the neurolinguistic methods applied in awake surgery is scarce. We developed for the first time a standardised Dutch linguistic test battery (measuring phonology, semantics, syntax) to reliably identify the critical language zones in detail. A normative study was carried out in a control group of 250 native Dutch-speaking healthy adults. In addition, the clinical application of the Dutch Linguistic Intraoperative Protocol (DuLIP) was demonstrated by means of anatomo-functional models and five case studies. A set of DuLIP tests was selected for each patient depending on the tumour location and degree of linguistic impairment. DuLIP is a valid test battery for pre-, intraoperative and postoperative language testing and facilitates intraoperative mapping of eloquent language regions that are variably located.

  2. Millisecond Coupling of Local Field Potentials to Synaptic Currents in the Awake Visual Cortex

    PubMed Central

    Haider, Bilal; Schulz, David P.A.; Häusser, Michael; Carandini, Matteo

    2016-01-01

    Summary The cortical local field potential (LFP) is a common measure of population activity, but its relationship to synaptic activity in individual neurons is not fully established. This relationship has been typically studied during anesthesia and is obscured by shared slow fluctuations. Here, we used patch-clamp recordings in visual cortex of anesthetized and awake mice to measure intracellular activity; we then applied a simple method to reveal its coupling to the simultaneously recorded LFP. LFP predicted membrane potential as accurately as synaptic currents, indicating a major role for synaptic currents in the relationship between cortical LFP and intracellular activity. During anesthesia, cortical LFP predicted excitation far better than inhibition; during wakefulness, it predicted them equally well, and visual stimulation further enhanced predictions of inhibition. These findings reveal a central role for synaptic currents, and especially inhibition, in the relationship between the subthreshold activity of individual neurons and the cortical LFP during wakefulness. PMID:27021173

  3. Spontaneous high-gamma band activity reflects functional organization of auditory cortex in the awake macaque.

    PubMed

    Fukushima, Makoto; Saunders, Richard C; Leopold, David A; Mishkin, Mortimer; Averbeck, Bruno B

    2012-06-07

    In the absence of sensory stimuli, spontaneous activity in the brain has been shown to exhibit organization at multiple spatiotemporal scales. In the macaque auditory cortex, responses to acoustic stimuli are tonotopically organized within multiple, adjacent frequency maps aligned in a caudorostral direction on the supratemporal plane (STP) of the lateral sulcus. Here, we used chronic microelectrocorticography to investigate the correspondence between sensory maps and spontaneous neural fluctuations in the auditory cortex. We first mapped tonotopic organization across 96 electrodes spanning approximately two centimeters along the primary and higher auditory cortex. In separate sessions, we then observed that spontaneous activity at the same sites exhibited spatial covariation that reflected the tonotopic map of the STP. This observation demonstrates a close relationship between functional organization and spontaneous neural activity in the sensory cortex of the awake monkey.

  4. Effect of khat on uteroplacental blood flow in awake, chronically catheterized, late-pregnant guinea pigs.

    PubMed

    Jansson, T; Kristiansson, B; Qirbi, A

    1988-01-01

    In order to investigate effects of khat chewing on uteroplacental blood flow, eight awake, chronically catheterized guinea pigs were fed 2.2 g khat leaves/kg in late pregnancy and regional blood flows were measured with the microsphere technique. Seven animals fed with aspen leaves in the same amounts served as controls. The mean concentration of (+)-norpseudoephedrine in urine 3 h after the end of the feeding was 4.6 micrograms/ml in the khat-fed group with no detectable amounts in the controls. Placental blood flow was reduced by 10% 75 min and by 24% 180 min after khat feeding. Since the khat dose used gave urinary concentrations of (+)-norpseudoephedrine of the same magnitude as those reported in khat chewing women, khat chewing in pregnancy may reduce placental blood flow and impair fetal growth.

  5. Prevalence of sleep bruxism and awake bruxism in different chronotype profiles: Hypothesis of an association.

    PubMed

    Serra-Negra, J M; Lobbezoo, F; Martins, C C; Stellini, E; Manfredini, D

    2017-04-01

    Sleep (SB) and awake bruxism (AB) recognize a multifactorial etiology and have a relationship with several psychological factors. Psychological disorders have recently been associated also with the chronotype, which is the propensity for an individual to be especially active at a particular time during a 24-h period. Based on the chronotype, the two extreme profiles are morningness and eveningness individuals. Due to the relationship that both the chronotype and bruxism have with psychological factors and the fact that performing tasks not compatible with chronotype can trigger stress, this review presents the hypothesis that the prevalence of SB and AB can differ with the various chronotype profiles. New perspectives for the study of bruxism etiology may emerge from investigations on the topic.

  6. Statistical modeling and analysis of laser-evoked potentials of electrocorticogram recordings from awake humans.

    PubMed

    Chen, Zhe; Ohara, Shinji; Cao, Jianting; Vialatte, François; Lenz, Fred A; Cichocki, Andrzej

    2007-01-01

    This article is devoted to statistical modeling and analysis of electrocorticogram (ECoG) signals induced by painful cutaneous laser stimuli, which were recorded from implanted electrodes in awake humans. Specifically, with statistical tools of factor analysis and independent component analysis, the pain-induced laser-evoked potentials (LEPs) were extracted and investigated under different controlled conditions. With the help of wavelet analysis, quantitative and qualitative analyses were conducted regarding the LEPs' attributes of power, amplitude, and latency, in both averaging and single-trial experiments. Statistical hypothesis tests were also applied in various experimental setups. Experimental results reported herein also confirm previous findings in the neurophysiology literature. In addition, single-trial analysis has also revealed many new observations that might be interesting to the neuroscientists or clinical neurophysiologists. These promising results show convincing validation that advanced signal processing and statistical analysis may open new avenues for future studies of such ECoG or other relevant biomedical recordings.

  7. Pleural liquid clearance rate measured in awake sheep by the volume of dilution method

    SciTech Connect

    Broaddus, V.C.; Wiener-Kronish, J.P.; Berthiaume, Y.; Staub, N.C.

    1986-03-01

    The authors reported 24h clearance of mock pleural effusions measured terminally in sheep. To measure effusion volume at different times in the same sheep, they injected /sup 111/In-transferrin and measured its dilution. In 5 sheep with effusions of known sizes, the method was accurate to +/-10%. In 5 awake sheep, the authors injected 10 ml/kg of a 1% protein solution via a non-penetrating rib capsule. At 6h, the authors measured the volume by the dilution method and at 24h by direct recovery. The clearance rate in each animal was constant at 2.9-6.0%/h (average 4.8 +/- 1.3%/h). This new method gives a reliable two point clearance rate and requires fewer animals.

  8. Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state.

    PubMed

    Bellay, Timothy; Klaus, Andreas; Seshadri, Saurav; Plenz, Dietmar

    2015-07-07

    Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output. Here, we study spontaneous firing in pyramidal neurons (PNs) from rat superficial cortical layers in vivo and in vitro using 2-photon imaging. As the animal transitions from the anesthetized to awake state, spontaneous single neuron firing increases in irregularity and assembles into scale-invariant avalanches at the group level. In vitro spike avalanches emerged naturally yet required balanced excitation and inhibition. This demonstrates that neuronal avalanches are linked to the global physiological state of wakefulness and that cortical resting activity organizes as avalanches from firing of local PN groups to global population activity.

  9. Chronic cellular imaging of entire cortical columns in awake mice using microprisms

    PubMed Central

    Andermann, Mark L.; Gilfoy, Nathan B.; Goldey, Glenn J.; Sachdev, Robert N.S.; Wölfel, Markus; McCormick, David A.; Reid, R. Clay; Levene, Michael J.

    2013-01-01

    Summary Two-photon imaging of cortical neurons in vivo has provided unique insights into the structure, function, and plasticity of cortical networks, but this method does not currently allow simultaneous imaging of neurons in the superficial and deepest cortical layers. Here, we describe a simple modification that enables simultaneous, long-term imaging of all cortical layers. Using a chronically implanted glass microprism in barrel cortex, we could image the same fluorescently labeled deeplayer pyramidal neurons across their entire somatodendritic axis for several months. We could also image visually evoked and endogenous calcium activity in hundreds of cell bodies or long-range axon terminals, across all six layers in visual cortex of awake mice. Electrophysiology and calcium imaging of evoked and endogenous activity near the prism face were consistent across days and comparable with previous observations. These experiments extend the reach of in vivo two-photon imaging to chronic, simultaneous monitoring of entire cortical columns. PMID:24139817

  10. Replicability and Heterogeneity of Awake Unrestrained Canine fMRI Responses

    PubMed Central

    Berns, Gregory S.; Brooks, Andrew; Spivak, Mark

    2013-01-01

    Previously, we demonstrated the possibility of fMRI in two awake and unrestrained dogs. Here, we determined the replicability and heterogeneity of these results in an additional 11 dogs for a total of 13 subjects. Based on an anatomically placed region-of-interest, we compared the caudate response to a hand signal indicating the imminent availability of a food reward to a hand signal indicating no reward. 8 of 13 dogs had a positive differential caudate response to the signal indicating reward. The mean differential caudate response was 0.09%, which was similar to a comparable human study. These results show that canine fMRI is reliable and can be done with minimal stress to the dogs. PMID:24324719

  11. Long-term optical imaging of intrinsic signals in anesthetized and awake monkeys

    NASA Astrophysics Data System (ADS)

    Roe, Anna W.

    2007-04-01

    Some exciting new efforts to use intrinsic signal optical imaging methods for long-term studies in anesthetized and awake monkeys are reviewed. The development of such methodologies opens the door for studying behavioral states such as attention, motivation, memory, emotion, and other higher-order cognitive functions. Long-term imaging is also ideal for studying changes in the brain that accompany development, plasticity, and learning. Although intrinsic imaging lacks the temporal resolution offered by dyes, it is a high spatial resolution imaging method that does not require application of any external agents to the brain. The bulk of procedures described here have been developed in the monkey but can be applied to the study of surface structures in any in vivo preparation.

  12. Variable responses of regional renal oxygenation and perfusion to vasoactive agents in awake sheep.

    PubMed

    Calzavacca, Paolo; Evans, Roger G; Bailey, Michael; Bellomo, Rinaldo; May, Clive N

    2015-11-15

    Vasoactive agents are used in critical care to optimize circulatory function, but their effects on renal tissue oxygenation in the absence of anesthesia remain largely unknown. Therefore, we assessed the effects of multiple vasoactive agents on regional kidney oxygenation in awake sheep. Sheep were surgically instrumented with pulmonary and renal artery flow probes, and combination fiber-optic probes, in the renal cortex and medulla, comprising a fluorescence optode to measure tissue Po2 and a laser-Doppler probe to assess tissue perfusion. Carotid arterial and renal venous cannulas enabled measurement of arterial pressure and total renal oxygen delivery and consumption. Norepinephrine (0.1 or 0.8 μg·kg(-1)·min(-1)) dose-dependently reduced cortical and medullary laser Doppler flux (LDF) and Po2 without significantly altering renal blood flow (RBF), or renal oxygen delivery or consumption. Angiotensin II (9.8 ± 2.1 μg/h) reduced RBF by 21%, renal oxygen delivery by 28%, oxygen consumption by 18%, and medullary Po2 by 38%, but did not significantly alter cortical Po2 or cortical or medullary LDF. Arginine vasopressin (3.3 ± 0.5 μg/h) caused similar decreases in RBF and renal oxygen delivery, but did not significantly alter renal oxygen consumption or cortical or medullary LDF or Po2. Captopril had no observable effects on cortical or medullary LDF or Po2, at a dose that increased renal oxygen delivery by 24%, but did not significantly alter renal oxygen consumption. We conclude that vasoactive agents have diverse effects on regional kidney oxygenation in awake sheep that are not predictable from their effects on LDF, RBF, or total renal oxygen delivery and consumption.

  13. Continuous thoracic epidural anesthesia induces segmental sympathetic block in the awake rat.

    PubMed

    Freise, Hendrik; Anthonsen, Sören; Fischer, Lars G; Van Aken, Hugo K; Sielenkämper, Andreas W

    2005-01-01

    Thoracic epidural anesthesia (TEA) is used increasingly in critical care, especially for cardiac and intestinal sympathetic block. In this study we evaluated cardiorespiratory function and sympathetic activity in a new model of continuous TEA in awake rats. Thirteen rats received epidural saline control (CON) or bupivacaine 0.5% epidural infusion (EPI) at 15 microl/h for 2 h on day 1 and day 3. Mean arterial blood pressure, heart rate, respiration rate, arterial PCO2, and motor score were recorded at baseline and after 30, 60, 90, and 120 min. Skin temperature was measured at front paws, high-thoracic, mid-thoracic, and low-thoracic, hind paws, and the proximal and distal tail. Changes in sympathetic activity were assessed by skin temperature changes from baseline (DeltaT). In the EPI group, hemodynamics and respiration remained unchanged and only mild motor deficits occurred. DeltaT in thoracic segments was higher in the EPI than in the CON group (P <0.001 at all times at high-thoracic, mid-thoracic, and low-thoracic segments). Skin temperature decreased in the distal tail in the EPI group, e.g., after 90 min DeltaT=-0.86 +/- 0.25 degrees C (EPI) versus 0.4 +/- 0.12 degrees C (CON) (P <0.05 at 60, 90, and 120 min). DeltaT on day 3 was comparable to day 1. TEA induced stable segmental sympathetic block without cardiorespiratory and motor side effects in awake rats. This new technique may be applied in prolonged models of critical illness.

  14. Motion compensation using origin ensembles in awake small animal positron emission tomography

    NASA Astrophysics Data System (ADS)

    Gillam, John E.; Angelis, Georgios I.; Kyme, Andre Z.; Meikle, Steven R.

    2017-02-01

    In emission tomographic imaging, the stochastic origin ensembles algorithm provides unique information regarding the detected counts given the measured data. Precision in both voxel and region-wise parameters may be determined for a single data set based on the posterior distribution of the count density allowing uncertainty estimates to be allocated to quantitative measures. Uncertainty estimates are of particular importance in awake animal neurological and behavioral studies for which head motion, unique for each acquired data set, perturbs the measured data. Motion compensation can be conducted when rigid head pose is measured during the scan. However, errors in pose measurements used for compensation can degrade the data and hence quantitative outcomes. In this investigation motion compensation and detector resolution models were incorporated into the basic origin ensembles algorithm and an efficient approach to computation was developed. The approach was validated against maximum liklihood—expectation maximisation and tested using simulated data. The resultant algorithm was then used to analyse quantitative uncertainty in regional activity estimates arising from changes in pose measurement precision. Finally, the posterior covariance acquired from a single data set was used to describe correlations between regions of interest providing information about pose measurement precision that may be useful in system analysis and design. The investigation demonstrates the use of origin ensembles as a powerful framework for evaluating statistical uncertainty of voxel and regional estimates. While in this investigation rigid motion was considered in the context of awake animal PET, the extension to arbitrary motion may provide clinical utility where respiratory or cardiac motion perturb the measured data.

  15. Cardiovascular Alterations during the Interictal Period in Awake and Pithed Amygdala-Kindled Rats.

    PubMed

    Ruiz-Salinas, Inna; Rocha, Luisa; Marichal-Cancino, Bruno A; Villalón, Carlos M

    2016-08-01

    Epileptic seizures are often accompanied by increased sympathetic cardiovascular activity (even interictally), but it remains unknown whether this increased activity is of central and/or peripheral origin. Hence, this study investigated the cardiovascular alterations produced by amygdala kindling in awake and pithed Wistar rats. Blood pressure (BP) and heart rate (HR) were initially recorded by tail cuff plethysmography in awake control, sham-operated and amygdala-kindled rats before and 24 hr after the kindling process. The after-discharge threshold (ADT) was measured under different conditions to correlate brain excitability with BP and HR in kindled rats. Twenty-four hours after the last kindling seizure, (i) HR, systolic and diastolic BP were increased and (ii) only higher HR values correlated with lower ADT values. Forty-eight hr after the last kindled seizure, all rats were pithed and prepared for analysing the tachycardic, vasopressor and vasodepressor responses by (i) stimulation of the sympathetic or sensory vasodepressor CGRPergic out-flows (stimulus-response curves, S-R curves) and (ii) intravenous injections of noradrenaline or α-CGRP (dose-response curves, D-R curves). Interestingly, (i) the tachycardic S-R and D-R curves were attenuated, whilst the CGRPergic S-R and D-R curves were potentiated in kindled rats, and (ii) the vasopressor noradrenergic S-R and D-R curves were not significantly different in all groups. Therefore, the kindling process may be associated with overstimulation in the central sympathetic and sensory out-flows interictally, producing (i) peripheral attenuation of cardiac sympathetic out-flow and β-adrenoceptor activity and (ii) peripheral potentiation of vasodepressor sensory CGRPergic out-flow and CGRP receptor activity.

  16. Epilepsy and hippocampal neurodegeneration induced by glutamate decarboxylase inhibitors in awake rats.

    PubMed

    Salazar, Patricia; Tapia, Ricardo

    2015-10-01

    Glutamic acid decarboxylase (GAD), the enzyme responsible for GABA synthesis, requires pyridoxal phosphate (PLP) as a cofactor. Thiosemicarbazide (TSC) and γ-glutamyl-hydrazone (PLPGH) inhibit the free PLP-dependent isoform (GAD65) activity after systemic administration, leading to epilepsy in mice and in young, but not in adult rats. However, the competitive GAD inhibitor 3-mercaptopropionic acid (MPA) induces convulsions in both immature and adult rats. In the present study we tested comparatively the epileptogenic and neurotoxic effects of PLPGH, TSC and MPA, administered by microdialysis in the hippocampus of adult awake rats. Cortical EEG and motor behavior were analyzed during the next 2h, and aspartate, glutamate and GABA were measured by HPLC in the microdialysis-collected fractions. Twenty-four hours after drug administration rats were fixed for histological analysis of the hippocampus. PLPGH or TSC did not affect the motor behavior, EEG or cellular morphology, although the extracellular concentration of GABA was decreased. In contrast, MPA produced intense wet-dog shakes, EEG epileptiform discharges, a >75% reduction of extracellular GABA levels and remarkable neurodegeneration of the CA1 region, with >80% neuronal loss. The systemic administration of the NMDA glutamate receptor antagonist MK-801 30 min before MPA did not prevent the MPA-induced epilepsy but significantly protected against its neurotoxic effect, reducing neuronal loss to <30%. We conclude that in adult awake rats, drugs acting on PLP availability have only a weak effect on GABA neurotransmission, whereas direct GAD inhibition produced by MPA induces hyperexcitation leading to epilepsy and hippocampal neurodegeneration. Because this degeneration was prevented by the blockade of NMDA receptors, we conclude that it is due to glutamate-mediated excitotoxicity consequent to disinhibition of the hippocampal excitatory circuits.

  17. Neural oscillation, network, eloquent cortex and epileptogenic zone revealed by magnetoencephalography and awake craniotomy

    PubMed Central

    Idris, Zamzuri; Kandasamy, Regunath; Reza, Faruque; Abdullah, Jafri M.

    2014-01-01

    Background: Magnetoencephalography (MEG) is a method of functional neuroimaging. The concomitant use of MEG and electrocorticography has been found to be useful in elucidating neural oscillation and network, and to localize epileptogenic zone and functional cortex. We describe our early experience using MEG in neurosurgical patients, emphasizing on its impact on patient management as well as the enrichment of our knowledge in neurosciences. Materials and Methods: A total of 10 subjects were included; five patients had intraaxial tumors, one with an extraaxial tumor and brain compression, two with arteriovenous malformations, one with cerebral peduncle hemorrhage and one with sensorimotor cortical dysplasia. All patients underwent evoked and spontaneous MEG recordings. MEG data was processed at band-pass filtering frequency of between 0.1 and 300 Hz with a sampling rate of 1 kHz. MEG source localization was performed using either overdetermined equivalent current dipoles or underdetermined inversed solution. Neuromag collection of events software was used to study brain network and epileptogenic zone. The studied data were analyzed for neural oscillation in three patients; brain network and clinical manifestation in five patients; and for the location of epileptogenic zone and eloquent cortex in two patients. Results: We elucidated neural oscillation in three patients. One demonstrated oscillatory phenomenon on stimulation of the motor-cortex during awake surgery, and two had improvement in neural oscillatory parameters after surgery. Brain networks corresponding to clinico-anatomical relationships were depicted in five patients, and two networks were illustrated here. Finally, we demonstrated epilepsy cases in which MEG data was found to be useful in localizing the epileptogenic zones and functional cortices. Conclusion: The application of MEG while enhancing our knowledge in neurosciences also has a useful role in epilepsy and awake surgery. PMID:25685205

  18. Age of language acquisition and cortical language organization in multilingual patients undergoing awake brain mapping.

    PubMed

    Fernández-Coello, Alejandro; Havas, Viktória; Juncadella, Montserrat; Sierpowska, Joanna; Rodríguez-Fornells, Antoni; Gabarrós, Andreu

    2016-08-19

    OBJECTIVE Most knowledge regarding the anatomical organization of multilingualism is based on aphasiology and functional imaging studies. However, the results have still to be validated by the gold standard approach, namely electrical stimulation mapping (ESM) during awake neurosurgical procedures. In this ESM study the authors describe language representation in a highly specific group of 13 multilingual individuals, focusing on how age of acquisition may influence the cortical organization of language. METHODS Thirteen patients who had a high degree of proficiency in multiple languages and were harboring lesions within the dominant, left hemisphere underwent ESM while being operated on under awake conditions. Demographic and language data were recorded in relation to age of language acquisition (for native languages and early- and late-acquired languages), neuropsychological pre- and postoperative language testing, the number and location of language sites, and overlapping distribution in terms of language acquisition time. Lesion growth patterns and histopathological characteristics, location, and size were also recorded. The distribution of language sites was analyzed with respect to age of acquisition and overlap. RESULTS The functional language-related sites were distributed in the frontal (55%), temporal (29%), and parietal lobes (16%). The total number of native language sites was 47. Early-acquired languages (including native languages) were represented in 97 sites (55 overlapped) and late-acquired languages in 70 sites (45 overlapped). The overlapping distribution was 20% for early-early, 71% for early-late, and 9% for late-late. The average lesion size (maximum diameter) was 3.3 cm. There were 5 fast-growing and 7 slow-growing lesions. CONCLUSIONS Cortical language distribution in multilingual patients is not homogeneous, and it is influenced by age of acquisition. Early-acquired languages have a greater cortical representation than languages acquired

  19. A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys

    PubMed Central

    Economides, John R.; Jocson, Cristina M.; Parker, John M.; Horton, Jonathan C.

    2011-01-01

    Neurophysiological recording in alert monkeys requires the creation of a permanent aperture in the skull for repeated insertion of microelectrodes. Most laboratories use polymethyl methacrylate to attach a recording chamber over the skull opening. Here, we describe a titanium chamber that fastens to the skull with screws, using no polymethyl methacrylate. The gap between the base of the chamber and the skull is filled with hydroxyapatite, forming a watertight gasket. As the chamber base osseointegates with the skull, the hydroxyapatite is replaced with bone. Rather than having a finite lifetime, the recording chamber becomes more firmly anchored the longer it is in place. It has a small footprint, low profile, and needs little maintenance to control infection. Toilette consists of occasional application of betadine to clean the scalp margin, followed by application of neomycin, polymyxin, and bacitracin ointment. Antibiotic is also placed inside the chamber to suppress bacterial proliferation. Thickening of the dura within the chamber can be prevented by regular application of mitocycin C and/or bevacizumab, an antibody against vascular endothelial growth factor. By conducting an e-mail survey, this protocol for chamber maintenance was compared with procedures used in 37 other vision research laboratories. Refinement of appliances and techniques used for recordings in awake monkeys promises to increase the pace of scientific discovery and to benefit animal welfare. PMID:21676928

  20. Single neurons with both form/color differential responses and saccade-related responses in the nonretinotopic pulvinar of the behaving macaque monkey.

    PubMed

    Benevento, L A; Port, J D

    1995-01-01

    The nonretinotopic portion of the macaque pulvinar complex is interconnected with the occipitoparietal and occipitotemporal transcortical visual systems where information about the location and motion of a visual object or its form and color are modulated by eye movements and attention. We recorded from single cells in and about the border of the dorsal portion of the lateral pulvinar and the adjacent medial pulvinar of awake behaving Macaca mulatta in order to determine how the properties of these two functionally dichotomous cortical systems were represented. We found a class of pulvinar neurons that responded differentially to ten different patterns or broadband wavelengths (colors). Thirty-four percent of cells tested responded to the presentation of at least one of the pattern or color stimuli. These cells often discharged to several of the patterns or colors, but responded best to only one or two of them, and 86% were found to have statistically significant pattern and/or color preferences. Pattern/color preferential cells had an average latency of 79.1 +/- 46.0 ms (range 31-186 ms), responding well before most inferotemporal cortical cell responses. Visually guided and memory-guided saccade tasks showed that 58% of pattern/color preferential cells also had saccade-related properties, e.g. directional presaccadic and postsaccadic discharges, and inhibition of activity during the saccade. In the pulvinar, the mean presacadic response latency was earlier, and the mean postsaccadic response latency was later, than those reported for parietal cortex. We also discovered that the strength of response to patterns or colors changed depending upon the behavioral setting. In comparison to trials in which the monkey fixated dead ahead during passive presentations of pattern and color stimuli, 92% of the cells showed attenuated responses to the same passive presentation of patterns and colors during fixation when these trials were interleaved with trials which also

  1. An investigation of the challenges in reconstructing PET images of a freely moving animal.

    PubMed

    Akhtar, Mahmood; Kyme, Andre; Zhou, Victor; Fulton, Roger; Meikle, Steven

    2013-12-01

    Imaging the brain of a freely moving small animal using positron emission tomography (PET) while simultaneously observing its behaviour is an important goal for neuroscience. While we have successfully demonstrated the use of line-of-response (LOR) rebinning to correct the head motion of confined animals, a large proportion of events may need to be discarded because they either 'miss' the detector array after transformation or fall out of the acceptance range of a sinogram. The proportion of events that would have been measured had motion not occurred, so-called 'lost events', is expected to be even larger for freely moving animals. Moreover, the data acquisition in the case of a freely moving animal is further complicated by a complex attenuation field. The aims of this study were (a) to characterise the severity of the 'lostevents' problem for the freely moving animal scenario, and(b) to investigate the relative impact of attenuation correction errors on quantitative accuracy of reconstructed images. A phantom study was performed to simulate the uncorrelated motion of a target and non-target sourcevolume. A small animal PET scanner was used to acquirelist-mode data for different sets of phantom positions. The list-mode data were processed using the standard LOR rebinning approach, and multiple frame variants of this designed to reduce discarded events. We found that LOR rebinning caused up to 86 % 'lost events', and artifacts that we attribute to incomplete projections, when applied to a freely moving target. This fraction was reduced by up to 18 % using the variant approaches, resulting in slightly reduced image artifacts. The effect of the non-target compartment on attenuation correction of the target volume was surprisingly small. However, for certain poses where the target and non-target volumes are aligned transaxially in the field-of-view, the attenuation problem becomes more complex and sophisticated correction methods will be required. We conclude that

  2. An extra band within the human 9qh+ region that behaves like the surrounding constitutive heterochromatin.

    PubMed Central

    Fernández, J L; Pereira, S; Campos, A; Gosálvez, J; Goyanes, V

    1994-01-01

    An extra variant G band in a human 9qh+ region was analysed in normally condensed and 5-azacytidine undercondensed chromosomes. Fluorescence in situ hybridisation showed that specific, classical, alphoid and beta satellite DNA was not present. Nevertheless, this extra band behaves like the surrounding heterochromatin because (1) its chromatin fibres showed condensation inhibition after 5-azacytidine treatment, as confirmed by electron microscopy, and (2) it was not affected by in situ digestion with the restriction endonucleases AluI and Sau3A. These results suggest that this variant band may correspond to euchromatin that has become inactivated by a position effect. Images PMID:7529317

  3. A study on the effect of multisensory stimulation in behaving rats.

    PubMed

    Semprini, Marianna; Boi, Fabio; Tucci, Valter; Vato, Alessandro

    2016-08-01

    This study explored the psychophysical effects of intracortical microstimulation (ICMS) coupled to auditory stimulation during a behavioral detection task in rats. ICMS directed to the sensory areas of the cortex can be instrumental in facilitating operant conditioning behavior. Moreover, multisensory stimulation promotes learning by enabling the subject to access multiple information channels. However, the extent to which multisensory information can be used as a cue to make decisions has not been fully understood. This study addressed the exploration of the parameters of multisensory stimulation delivered to behaving rats in an operant conditioning task. Preliminary data indicate that animal decisions can be shaped by online changing the stimulation parameters.

  4. Freely Evolving Process and Statistics in the Two-Dimensional Granular Turbulence

    NASA Astrophysics Data System (ADS)

    Isobe, Masaharu

    2002-08-01

    We studied the macroscopic statistical properties on the freely evolving quasi-inelastic hard disk (granular) system by performing large-scale (more than a million particles) event-driven molecular dynamics systematically and found that remarkably analogous to an enstrophy cascade process in decaying two-dimensional fluid turbulence. There are four typcial stages in the freely evolving inelastic hard disk system, which are homogeneous, shearing (vortex), clustering and final state. In the shearing stage, the self-organized macroscopic coherent vortices become dominant and the enstrophy decays power-low behavior. In the clustering stage, the energy spectra are close to the expectation of Kraichnan-Batchelor theory and the squared two particle separation strictly obeys Richardson law. These results indicate that the cooperative behavior of quasi-inelastic hard disks system has a same universal class as the macroscopic Navier-Stokes fluid turbulence in the study of dissipative structure.

  5. External optical imaging of freely moving mice with green fluorescent protein-expressing metastatic tumors

    NASA Astrophysics Data System (ADS)

    Yang, Meng; Baranov, Eugene; Shimada, Hiroshi; Moossa, A. R.; Hoffman, Robert M.

    2000-04-01

    We report here a new approach to genetically engineering tumors to become fluorescence such that they can be imaged externally in freely-moving animals. We describe here external high-resolution real-time fluorescent optical imaging of metastatic tumors in live mice. Stable high-level green flourescent protein (GFP)-expressing human and rodent cell lines enable tumors and metastasis is formed from them to be externally imaged from freely-moving mice. Real-time tumor and metastatic growth were quantitated from whole-body real-time imaging in GFP-expressing melanoma and colon carcinoma models. This GFP optical imaging system is highly appropriate for high throughput in vivo drug screening.

  6. Between soap bubbles and vesicles: The dynamics of freely floating smectic bubbles

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    The dynamics of droplets and bubbles, particularly on microscopic scales, are of considerable importance in biological, environmental, and technical contexts. We introduce freely floating bubbles of smectic liquid crystals and report their unique dynamic properties. Smectic bubbles can be used as simple models for dynamic studies of fluid membranes. In equilibrium, they form minimal surfaces like soap films. However, shape transformations of closed smectic membranes that change the surface area involve the formation and motion of molecular layer dislocations. These processes are slow compared to the capillary wave dynamics, therefore the effective surface tension is zero like in vesicles. Freely floating smectic bubbles are prepared from collapsing catenoid films and their dynamics is studied with optical high-speed imaging. Experiments are performed under normal gravity and in microgravity during parabolic flights. Supported by DLR within grant OASIS-Co.

  7. Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas.

    PubMed

    Kolvin, Itamar; Livne, Eli; Meerson, Baruch

    2010-08-01

    We show that, in dimension higher than one, heat diffusion and viscosity cannot arrest thermal collapse in a freely evolving dilute granular gas, even in the absence of gravity. Thermal collapse involves a finite-time blowup of the gas density. It was predicted earlier in ideal, Euler hydrodynamics of dilute granular gases in the absence of gravity, and in nonideal, Navier-Stokes granular hydrodynamics in the presence of gravity. We determine, analytically and numerically, the dynamic scaling laws that characterize the gas flow close to collapse. We also investigate bifurcations of a freely evolving dilute granular gas in circular and wedge-shaped containers. Our results imply that, in general, thermal collapse can only be arrested when the gas density becomes comparable with the close-packing density of grains. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows.

  8. Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2

    PubMed Central

    2012-01-01

    We fabricate freely suspended nanosheets of molybdenum disulphide (MoS2) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS2 using an atomic force microscope. The Young's modulus and the initial pre-tension of the nanosheets are determined by performing a nanoscopic version of a bending test experiment. MoS2 sheets show high elasticity and an extremely high Young's modulus (0.30 TPa, 50% larger than steel). These results make them a potential alternative to graphene in applications requiring flexible semiconductor materials. PACS, 73.61.Le, other inorganic semiconductors, 68.65.Ac, multilayers, 62.20.de, elastic moduli, 81.40.Jj, elasticity and anelasticity, stress-strain relations. PMID:22533903

  9. Dual-modal (OIS/LSCI) imager of cerebral cortex in freely moving animals

    NASA Astrophysics Data System (ADS)

    Lu, Hongyang; Miao, Peng; Liu, Qi; Li, Yao; Tong, Shanbao

    2012-03-01

    Optical intrinsic signals (OIS) and laser speckle contrast imaging (LSCI) have been used for years in the study of the cerebral blood flow (CBF) and hemodynamic responses to the neural activity under functional stimulation. So far, most in vivo rodent experiments are based on the anesthesia model when the animals are in unconscious and restrained conditions. The influences of anesthesia on the neural activity have been documented in literature. In this study, we designed a miniature head-mounted dual-modal imager in freely moving animals that could monitor in real time the coupling of local oxygen consumption and blood perfusion of CBF by integrating different imaging modalities of OIS and LSCI. The system facilitates the study the cortical hemodynamics and neural-hemodynamic coupling in real time in freely moving animals.

  10. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage.

  11. Experimental measurement of the flow field around a freely swimming microorganism

    NASA Astrophysics Data System (ADS)

    Polin, Marco; Drescher, Knut; Goldstein, Raymond; Michel, Nicolas; Tuval, Idan

    2010-03-01

    Despite their small size, the fluid flows produced by billions of microscopic swimmers in nature can have dramatic macroscopic effects (e.g. biogenic mixing in the ocean). Understanding the flow structure of a single swimming microorganism is essential to explain and model these macroscopic phenomena. Here we report the first detailed measurement of the flow field around an isolated, freely swimming microorganism, the spherical alga Volvox, and discuss the implications of this measurement for other species.

  12. Hybrid Metameterials Enable Fast Electrical Modulation Of Freely Propagating Terahertz Waves

    SciTech Connect

    Chen, Hou-tong; O' Hara, John F; Taylor, Antoinette J

    2008-01-01

    We demonstrate fast electrical modulation of freely propagating THz waves at room temperature using hybrid metamaterial devices. the devices are planar metamaterials fabricated on doped semiconducor epitaxial layers, which form hybrid metamaterial - Schottky diode structures. With an applied ac voltage bias, we show modulation of THz radiation at inferred frequencies over 2 MHz. The modulation speed is limited by the device depletion capacitance which may be reduced for even faster operation.

  13. Differences in cutaneous sensory response properties of single somatosensory cortical neurons in awake and halothane anesthetized rats.

    PubMed

    Chapin, J K; Waterhouse, B D; Woodward, D J

    1981-01-01

    The major aim of this study was to investigate the effect of halothane anesthesia on different latency components of cutaneous sensory responses of single units in the primary somatosensory (SI) cortex of rats. Quantitative studies of computer generated post-stimulus time histograms were used to determine whether the increase in "nonspecific" properties often observed in the SI cortices of awake animals were attributable to a generally increased sensory responsiveness of these cells or to a selective increase of certain "nonspecific" components of their sensory response. Sensory "specificity" was investigated here by measuring the size of cutaneous receptive fields of single cells and testing their ability to follow high stimulus frequencies. Histograms generated by repetitive touch stimulation of the forepaw in awake animals were divisible into the following different latency components: (1) a short latency excitatory response which was often divisible into two peaks (E1a and E1b), and occasionally (2) a post-excitatory inhibitory phase (I1) and/or (3) a long latency excitatory peak (E2). In anesthetized animals spontaneous discharge rates were lower and the proportion of cells exhibiting either pure inhibition or post-excitatory inhibition was increased. By contrast, the longer latency excitatory components (E1b and E2) were weaker and were seen much less frequently than in the awake situation. In nine cells tested in the awake state and then again in the anesthetized state the magnitude, receptive field size, and ability to follow high frequencies of the E1a peak was slightly reduced. The E1b and E2 peaks seen in the awake state, on the other hand, were completely abolished by anesthesia. In awake animals the E1b and E2 phases exhibited relatively "nonspecific" physiological properties. This was indicated by the facts that: (1) the cutaneous receptive fields of the E1a peak were slightly smaller than those of the E1b peaks and much smaller than those of the E2

  14. Surgical benefits of combined awake craniotomy and intraoperative magnetic resonance imaging for gliomas associated with eloquent areas.

    PubMed

    Motomura, Kazuya; Natsume, Atsushi; Iijima, Kentaro; Kuramitsu, Shunichiro; Fujii, Masazumi; Yamamoto, Takashi; Maesawa, Satoshi; Sugiura, Junko; Wakabayashi, Toshihiko

    2017-01-06

    OBJECTIVE Maximum extent of resection (EOR) for lower-grade and high-grade gliomas can increase survival rates of patients. However, these infiltrative gliomas are often observed near or within eloquent regions of the brain. Awake surgery is of known benefit for the treatment of gliomas associated with eloquent regions in that brain function can be preserved. On the other hand, intraoperative MRI (iMRI) has been successfully used to maximize the resection of tumors, which can detect small amounts of residual tumors. Therefore, the authors assessed the value of combining awake craniotomy and iMRI for the resection of brain tumors in eloquent areas of the brain. METHODS The authors retrospectively reviewed the records of 33 consecutive patients with glial tumors in the eloquent brain areas who underwent awake surgery using iMRI. Volumetric analysis of MRI studies was performed. The pre-, intra-, and postoperative tumor volumes were measured in all cases using MRI studies obtained before, during, and after tumor resection. RESULTS Intraoperative MRI was performed to check for the presence of residual tumor during awake surgery in a total of 25 patients. Initial iMRI confirmed no further tumor resection in 9 patients (36%) because all observable tumors had already been removed. In contrast, intraoperative confirmation of residual tumor during awake surgery led to further tumor resection in 16 cases (64%) and eventually an EOR of more than 90% in 8 of 16 cases (50%). Furthermore, EOR benefiting from iMRI by more than 15% was found in 7 of 16 cases (43.8%). Interestingly, the increase in EOR as a result of iMRI for tumors associated mainly with the insular lobe was significantly greater, at 15.1%, than it was for the other tumors, which was 8.0% (p = 0.001). CONCLUSIONS This study revealed that combining awake surgery with iMRI was associated with a favorable surgical outcome for intrinsic brain tumors associated with eloquent areas. In particular, these benefits were

  15. Phasic boosting of medial perforant path-evoked granule cell output time-locked to spontaneous dentate EEG spikes in awake rats.

    PubMed

    Bramham, C R

    1998-06-01

    Dentate spikes (DSs) are positive-going field potential transients that occur intermittently in the hilar region of the dentate gyrus during alert wakefulness and slow-wave sleep. The function of dentate spikes is unknown; they have been suggested to be triggered by perforant path input and are associated with firing of hilar interneurons and inhibition of CA3 pyramidal cells. Here we investigated the effect of DSs on medial perforant path (MPP)-granule cell-evoked transmission in freely moving rats. The MPP was stimulated selectively in the angular bundle while evoked field potentials and the EEG were recorded with a vertical multielectrode array in the dentate gyrus. DSs were identified readily on the basis of their characteristic voltage-versus-depth profile, amplitude, duration, and state dependency. Using on-line detection of the DS peak, the timing of MPP stimulation relative to single DSs was controlled. DS-triggered evoked responses were compared with conventional, manually evoked responses in still-alert wakefulness (awake immobility) and, in some cases, slow-wave sleep. Input-output curves were obtained with stimulation on the positive DS peak (0 delay) and at delays of 50, 100, and 500 ms. Stimulation on the peak DS was associated with a significant increase in the population spike amplitude, a reduction in population spike latency, and a decrease in the field excitatory postsynaptic potential (fEPSP) slope, relative to manual stimulation. Granule cell excitability was enhanced markedly during DSs, as indicated by a mean 93% increase in the population spike amplitude and a leftward shift in the fEPSP-spike relation. Maximum effects occurred at the DS peak, and lasted between 50 and 100 ms. Paired-pulse inhibition of the population spike was unaffected, indicating intact recurrent inhibition during DSs. The results demonstrate enhancement of perforant path-evoked granule cell output time-locked to DSs. DSs therefore may function to intermittently boost

  16. Single-molecule force spectroscopy of membrane proteins from membranes freely spanning across nanoscopic pores.

    PubMed

    Petrosyan, Rafayel; Bippes, Christian A; Walheim, Stefan; Harder, Daniel; Fotiadis, Dimitrios; Schimmel, Thomas; Alsteens, David; Müller, Daniel J

    2015-05-13

    Single-molecule force spectroscopy (SMFS) provides detailed insight into the mechanical (un)folding pathways and structural stability of membrane proteins. So far, SMFS could only be applied to membrane proteins embedded in native or synthetic membranes adsorbed to solid supports. This adsorption causes experimental limitations and raises the question to what extent the support influences the results obtained by SMFS. Therefore, we introduce here SMFS from native purple membrane freely spanning across nanopores. We show that correct analysis of the SMFS data requires extending the worm-like chain model, which describes the mechanical stretching of a polypeptide, by the cubic extension model, which describes the bending of a purple membrane exposed to mechanical stress. This new experimental and theoretical approach allows to characterize the stepwise (un)folding of the membrane protein bacteriorhodopsin and to assign the stability of single and grouped secondary structures. The (un)folding and stability of bacteriorhodopsin shows no significant difference between freely spanning and directly supported purple membranes. Importantly, the novel experimental SMFS setup opens an avenue to characterize any protein from freely spanning cellular or synthetic membranes.

  17. Methane oxidation in freely and poorly drained grassland soils and effects of cattle urine application.

    PubMed

    Li, Zheng; Kelliher, Francis M

    2007-01-01

    A sink for atmospheric methane (CH4) is microbial oxidation in soils. We report CH4 oxidation rates in freely and poorly drained soils on an intensively managed dairy farm. Following cattle urine application to half the plots (650 kg of nitrogen [N] ha(-1)) 31 chamber measurements were made over 100 d during autumn and winter. In the control plots, the freely and poorly drained soils' integrated CH4 oxidation rates averaged 1.8+/-0.2 and 0.6+/-0.1 kg CH4 ha(-1) yr(-1), respectively. In the poorly drained soil, the highest CH4 oxidation rates occurred when water-filled pore space (WFPS)<56% and CH4 oxidation rate declined by ninefold to near zero as WFPS increased from 56 to 68%. Urine application induced the freely and poorly drained soils' CH4 oxidation rates to decline for up to 2 mo by 0.7+/-0.2 and 0.4+/-0.1 kg CH4 ha(-1) yr(-1), respectively. The two soils' responses were thus not significantly different. After urine application, soil pore space CH4 concentration profiles suggested a simultaneous inhibition of bacteria that were CH4 oxidizers and stimulation of CH4 producers.

  18. Similar Odor Discrimination Behavior in Head-Restrained and Freely Moving Mice

    PubMed Central

    Abraham, Nixon M.; Guerin, Delphine; Bhaukaurally, Khaleel; Carleton, Alan

    2012-01-01

    A major challenge in neuroscience is relating neuronal activity to animal behavior. In olfaction limited techniques are available for these correlation studies in freely moving animals. To solve this problem, we developed an olfactory behavioral assay in head-restrained mice where we can monitor behavioral responses with high temporal precision. Mice were trained on a go/no-go operant conditioning paradigm to discriminate simple monomolecular odorants, as well as complex odorants such as binary mixtures of monomolecular odorants or natural odorants. Mice learned to discriminate both simple and complex odors in a few hundred trials with high accuracy. We then compared the discrimination performance of head-restrained mice to the performance observed in freely moving mice. Discrimination accuracies were comparable in both behavioral paradigms. In addition, discrimination times were measured while the animals performed well. In both tasks, mice discriminated simple odors in a few hundred milliseconds and took additional time to discriminate the complex mixtures. In conclusion, mice showed similar and efficient discrimination behavior while head-restrained compared with freely moving mice. Therefore, the head-restrained paradigm offers a relevant approach to monitor neuronal activity while animals are actively engaged in olfactory discrimination behaviors. PMID:23272168

  19. Nanoscopic Terraces, Mesas, and Ridges in Freely Standing Thin Films Sculpted by Supramolecular Oscillatory Surface Forces.

    PubMed

    Zhang, Yiran; Yilixiati, Subinuer; Pearsall, Collin; Sharma, Vivek

    2016-04-26

    Freely standing thin liquid films containing supramolecular structures including micelles, nanoparticles, polyelectrolyte-surfactant complexes, and smectic liquid crystals undergo drainage via stratification. The layer-by-layer removal of these supramolecular structures manifests as stepwise thinning over time and a coexistence of domains and nanostructures of discretely different thickness. The layering of supramolecular structures in confined thin films contributes additional non-DLVO, supramolecular oscillatory surface forces to disjoining pressure, thus influencing both drainage kinetics and stability of thin films. Understanding and characterizing the spontaneous creation and evolution of nanoscopic topography of stratifying, freely standing thin liquid films have been long-standing challenges due to the absence of experimental techniques with the requisite spatial (thickness <10 nm) and temporal resolution (<1 ms). Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed herein, we visualize and characterize size, shape, and evolution kinetics of nanoscopic mesas, terraces, and ridges. The exquisite thickness maps created using IDIOM protocols provide much needed and unprecedented insights into the role of supramolecular oscillatory surface forces in driving growth of such nanostructures as well as in controlling properties and stability of freely standing thin films and, more generally, of colloidal dispersions like foams.

  20. Belonging, believing, bonding, and behaving: the relationship between religion and business ownership at the country level.

    PubMed

    Hoogendoorn, Brigitte; Rietveld, Cornelius A; van Stel, André

    2016-01-01

    This cross-country study adopts a competing theories approach in which both a value perspective and a social capital perspective are used to understand the relation between religion and a country's business ownership rate. We distinguish among four dimensions of religion: belonging to a religious denomination, believing certain religious propositions, bonding to religious practices, and behaving in a religious manner. An empirical analysis of data from 30 OECD countries with multiple data points per country covering the period 1984-2010 suggests a positive relationship between religion and business ownership based on those dimensions that reflect the internal aspects of religiosity (i.e., believing and behaving). We do not observe a significant association for those dimensions that reflect more external aspects of religion (i.e., belonging and bonding). These results suggest that the social capital perspective prevails the value perspective, at least when internal aspects of religiosity are concerned. More generally, our study demonstrates the importance of distinguishing between different dimensions of religion when investigating the link between religion and entrepreneurship.

  1. A Novel Quantum-Behaved Bat Algorithm with Mean Best Position Directed for Numerical Optimization.

    PubMed

    Zhu, Binglian; Zhu, Wenyong; Liu, Zijuan; Duan, Qingyan; Cao, Long

    2016-01-01

    This paper proposes a novel quantum-behaved bat algorithm with the direction of mean best position (QMBA). In QMBA, the position of each bat is mainly updated by the current optimal solution in the early stage of searching and in the late search it also depends on the mean best position which can enhance the convergence speed of the algorithm. During the process of searching, quantum behavior of bats is introduced which is beneficial to jump out of local optimal solution and make the quantum-behaved bats not easily fall into local optimal solution, and it has better ability to adapt complex environment. Meanwhile, QMBA makes good use of statistical information of best position which bats had experienced to generate better quality solutions. This approach not only inherits the characteristic of quick convergence, simplicity, and easy implementation of original bat algorithm, but also increases the diversity of population and improves the accuracy of solution. Twenty-four benchmark test functions are tested and compared with other variant bat algorithms for numerical optimization the simulation results show that this approach is simple and efficient and can achieve a more accurate solution.

  2. An Improved Quantum-Behaved Particle Swarm Optimization Algorithm with Elitist Breeding for Unconstrained Optimization.

    PubMed

    Yang, Zhen-Lun; Wu, Angus; Min, Hua-Qing

    2015-01-01

    An improved quantum-behaved particle swarm optimization with elitist breeding (EB-QPSO) for unconstrained optimization is presented and empirically studied in this paper. In EB-QPSO, the novel elitist breeding strategy acts on the elitists of the swarm to escape from the likely local optima and guide the swarm to perform more efficient search. During the iterative optimization process of EB-QPSO, when criteria met, the personal best of each particle and the global best of the swarm are used to generate new diverse individuals through the transposon operators. The new generated individuals with better fitness are selected to be the new personal best particles and global best particle to guide the swarm for further solution exploration. A comprehensive simulation study is conducted on a set of twelve benchmark functions. Compared with five state-of-the-art quantum-behaved particle swarm optimization algorithms, the proposed EB-QPSO performs more competitively in all of the benchmark functions in terms of better global search capability and faster convergence rate.

  3. Path planning for UAV based on quantum-behaved particle swarm optimization

    NASA Astrophysics Data System (ADS)

    Fu, Yangguang; Ding, Mingyue; Zhou, Chengping; Cai, Chao; Sun, Yangguang

    2009-10-01

    Based on quantum-behaved particle swarm optimization (QPSO), a novel path planner for unmanned aerial vehicle (UAV) is employed to generate a safe and flyable path. The standard particle swarm optimization (PSO) and quantum-behaved particle swarm optimization (QPSO) are presented and compared through a UAV path planning application. Every particle in swarm represents a potential path in search space. For the purpose of pruning the search space, constraints are incorporated into the pre-specified cost function, which is used to evaluate whether a particle is good or not. As the system iterated, each particle is pulled toward its local attractor, which is located between the personal best position (pbest) and the global best position (gbest) based on the interaction of particles' individual searches and group's public search. For the sake of simplicity, we only consider planning the projection of path on the plane and assume threats are static instead of moving. Simulation results demonstrated the effectiveness and feasibility of the proposed approach.

  4. Large-scale recording of neurons by movable silicon probes in behaving rodents.

    PubMed

    Vandecasteele, Marie; M, S; Royer, Sébastien; Belluscio, Mariano; Berényi, Antal; Diba, Kamran; Fujisawa, Shigeyoshi; Grosmark, Andres; Mao, Dun; Mizuseki, Kenji; Patel, Jagdish; Stark, Eran; Sullivan, David; Watson, Brendon; Buzsáki, György

    2012-03-04

    A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of neurons and circuits requires methods with the spatial selectivity and temporal resolution appropriate for mechanistic analysis of neural ensembles in the behaving animal, i.e. recording of representatively large samples of isolated single neurons. Ensemble monitoring of neuronal activity has progressed remarkably in the past decade in both small and large-brained animals, including human subjects. Multiple-site recording with silicon-based devices are particularly effective because of their scalability, small volume and geometric design. Here, we describe methods for recording multiple single neurons and local field potential in behaving rodents, using commercially available micro-machined silicon probes with custom-made accessory components. There are two basic options for interfacing silicon probes to preamplifiers: printed circuit boards and flexible cables. Probe supplying companies (http://www.neuronexustech.com/; http://www.sbmicrosystems.com/; http://www.acreo.se/) usually provide the bonding service and deliver probes bonded to printed circuit boards or flexible cables. Here, we describe the implantation of a 4-shank, 32-site probe attached to flexible polyimide cable, and mounted on a movable microdrive. Each step of the probe preparation, microdrive construction and surgery is illustrated so that the end user can easily replicate the process.

  5. Quantum-behaved particle swarm optimization with collaborative attractors for nonlinear numerical problems

    NASA Astrophysics Data System (ADS)

    Liu, Tianyu; Jiao, Licheng; Ma, Wenping; Shang, Ronghua

    2017-03-01

    In this paper, an improved quantum-behaved particle swarm optimization (CL-QPSO), which adopts a new collaborative learning strategy to generate local attractors for particles, is proposed to solve nonlinear numerical problems. Local attractors, which directly determine the convergence behavior of particles, play an important role in quantum-behaved particle swarm optimization (QPSO). In order to get a promising and efficient local attractor for each particle, a collaborative learning strategy is introduced to generate local attractors in the proposed algorithm. Collaborative learning strategy consists of two operators, namely orthogonal operator and comparison operator. For each particle, orthogonal operator is used to discover the useful information that lies in its personal and global best positions, while comparison operator is used to enhance the particle's ability of jumping out of local optima. By using a probability parameter, the two operators cooperate with each other to generate local attractors for particles. A comprehensive comparison of CL-QPSO with some state-of-the-art evolutionary algorithms on nonlinear numeric optimization functions demonstrates the effectiveness of the proposed algorithm.

  6. A Novel Quantum-Behaved Bat Algorithm with Mean Best Position Directed for Numerical Optimization

    PubMed Central

    Zhu, Wenyong; Liu, Zijuan; Duan, Qingyan; Cao, Long

    2016-01-01

    This paper proposes a novel quantum-behaved bat algorithm with the direction of mean best position (QMBA). In QMBA, the position of each bat is mainly updated by the current optimal solution in the early stage of searching and in the late search it also depends on the mean best position which can enhance the convergence speed of the algorithm. During the process of searching, quantum behavior of bats is introduced which is beneficial to jump out of local optimal solution and make the quantum-behaved bats not easily fall into local optimal solution, and it has better ability to adapt complex environment. Meanwhile, QMBA makes good use of statistical information of best position which bats had experienced to generate better quality solutions. This approach not only inherits the characteristic of quick convergence, simplicity, and easy implementation of original bat algorithm, but also increases the diversity of population and improves the accuracy of solution. Twenty-four benchmark test functions are tested and compared with other variant bat algorithms for numerical optimization the simulation results show that this approach is simple and efficient and can achieve a more accurate solution. PMID:27293424

  7. Well behaved class of charge analogue of Heintzmann's relativistic exact solution

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Mehta, R. N.; Pant, Mamta (Joshi)

    2011-04-01

    We present a well behaved class of Charge Analogue of Heintzmann (Z. Phys. 228:489, 1969) solution. This solution describes charge fluid balls with positively finite central pressure and positively finite central density ; their ratio is less than one and causality condition is obeyed at the centre. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing, however, the electric intensity is monotonically increasing in nature. The solution gives us wide range of constant K (1.25≤ K≤15) for which the solution is well behaved and therefore, suitable for modeling of super dense star. For this solution the mass of a star is maximized with all degrees of suitability and by assuming the surface density ρ b =2×1014 g/cm3. Corresponding to K=1.25 and X=0.42, the maximum mass of the star comes out to be 3.64 M Θ with linear dimension 24.31 km and central redshift 1.5316. The charge analogue of Heint-solution has simple algebraic expressions. In order to study the behavior of physical parameters from centre to boundary we use the analytic method with the help of the developed theorem. However, the charge analogue of exact solutions, so far obtained, the numerical methods have been used to study the behavior of physical parameters from centre to boundary.

  8. Examining transactional influences between reading achievement and antisocially-behaving friends.

    PubMed

    Hart, Sara A; Mikolajewski, Amy J; Johnson, Wendy; Schatschneider, Christopher; Taylor, Jeanette

    2014-12-01

    The association between poorer academic outcomes and having antisocial friends is reliably demonstrated yet not well understood. Genetically sensitive designs uniquely allow for measuring genetic vulnerabilities and/or environmental risk in the association of antisocial friend behavior and poor school achievement, allowing for a better understanding of the nature of the association. This study included 233 pairs of twins from the Florida Twin Project on Reading. First, the role of antisocial friends as an environmental moderator of reading comprehension was examined. Antisocial friends significantly moderated the nonshared environmental variance in reading comprehension, with increased variation at lower levels of association with antisocial friends, with niche-picking indicated. Second, the role of reading comprehension as an environmental moderator of antisocial friends was examined. Reading comprehension significantly moderated the nonshared environmental variance in associating with antisocial friends, with increased variance at lower levels of reading comprehension and indication that common genetic influences contributed to higher reading achievement and better-behaved friends. In total, these results suggested reciprocal influences between reading achievement and antisocially-behaving friends. The impact of antisocial friends appeared to be limited in the extent to which they can undermine reading achievement, and high reading achievement appeared to support less association with antisocial friends.

  9. Examining transactional influences between reading achievement and antisocially-behaving friends

    PubMed Central

    Hart, Sara A.; Mikolajewski, Amy J.; Johnson, Wendy; Schatschneider, Christopher; Taylor, Jeanette

    2014-01-01

    The association between poorer academic outcomes and having antisocial friends is reliably demonstrated yet not well understood. Genetically sensitive designs uniquely allow for measuring genetic vulnerabilities and/or environmental risk in the association of antisocial friend behavior and poor school achievement, allowing for a better understanding of the nature of the association. This study included 233 pairs of twins from the Florida Twin Project on Reading. First, the role of antisocial friends as an environmental moderator of reading comprehension was examined. Antisocial friends significantly moderated the nonshared environmental variance in reading comprehension, with increased variation at lower levels of association with antisocial friends, with niche-picking indicated. Second, the role of reading comprehension as an environmental moderator of antisocial friends was examined. Reading comprehension significantly moderated the nonshared environmental variance in associating with antisocial friends, with increased variance at lower levels of reading comprehension and indication that common genetic influences contributed to higher reading achievement and better-behaved friends. In total, these results suggested reciprocal influences between reading achievement and antisocially-behaving friends. The impact of antisocial friends appeared to be limited in the extent to which they can undermine reading achievement, and high reading achievement appeared to support less association with antisocial friends. PMID:25242836

  10. Discharge correlates of hippocampal complex spike neurons in behaving rats passively displaced on a mobile robot.

    PubMed

    Gavrilov, V V; Wiener, S I; Berthoz, A

    1998-01-01

    This study investigated location-, movement-, and directional-selectivity of action potential discharges of hippocampal neurons in awake rats subjected to passive displacements in order to estimate vestibular contributions to this activity. Water-deprived rats were habituated to being restrained in a sling mounted on a moving robot. The extracellular activity of single complex-spike cells in area CA1 of the hippocampus was recorded with glass micropipettes in the rats during passive translations, rotations, and immobility. The robot made a standardized series of trajectories starting from each of four corners of a square enclosure surrounded by black curtains. A drop of water was delivered to the rat each time the robot arrived at one designated corner of the arena. The activities of 29 neurons were investigated in 45 recording sessions (16 of which were in total darkness) in four rats. Hippocampal neurons recorded in 31 sessions (9 sessions in the dark) had significant location-selective increases or decreases in firing rate as the rat was passively displaced or immobile within the experimental arena. In 20 sessions (6 in the dark) direction-selective discharges were found when the rat was in the corners. In six sessions, cells discharged selectively during movement initiation or termination. These data suggest that information essential for path integration is present in the hippocampus and that inertial cues could play a vital role in hippocampal spatial functions. These results resemble those of O'Mara et al. ([1994] J Neurosci 14:6511) using the same protocol in macaques, suggesting similarities in hippocampal processing and function.

  11. Collection, storage, and electrophoretic analysis of nanoliter microdialysis samples collected from awake animals in vivo

    PubMed Central

    Wang, Meng; Hershey, Neil D.; Mabrouk, Omar S.

    2011-01-01

    Microdialysis sampling is an important tool for chemical monitoring in living systems. Temporal resolution is an important figure of merit that is determined by sampling frequency, assay sensitivity, and dispersion of chemical zones during transport from sampling device to fraction collector or analytical system. Temporal resolution has recently been improved by segmenting flow into plugs, so that nanoliter fractions are collected at intervals of 0.1–2 s, thus eliminating temporal distortion associated with dispersion in continuous flow. Such systems, however, have yet to be used with behaving subjects. Furthermore, long-term storage of nanoliter samples created by segmented flow has not been reported. In this work, we have addressed these challenges. A microdialysis probe was integrated to a plug generator that could be stably mounted onto behaving animals. Long-term storage of dialysate plugs was achieved by collecting plugs into high-purity perfluoroalkoxy tubes, placing the tube into hexane and then freezing at −80°C. Slow warming with even temperatures prevented plug coalescence during sample thawing. As a demonstration of the system, plugs were collected from the striatum of behaving rats using a 0.5-mm-long microdialysis probe. Resulting plugs were analyzed 1–4 days later by chip-based electrophoresis. To improve throughput of plug analysis over previous work, the speed of electrophoretic separation was increased by using forced air cooling and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate as a separation buffer additive, allowing resolution of six neuroactive amino acids in 30 s. Concentration changes induced by K+ microinjections were monitored with 10 s temporal resolution. The improvements reported in this work make it possible to apply segmented flow microdialysis to the study of behaving animals and enable experiments where the analytical system cannot be placed close to the animal. PMID:21465093

  12. Simultaneous multisite recordings of neural ensemble responses in the motor cortex of behaving rats to peripheral noxious heat and chemical stimuli.

    PubMed

    Wang, Chang-Ming; Yang, Lei; Lu, Dan; Lu, Yun-Fei; Chen, Xue-Feng; Yu, Yao-Qing; Li, Zhen; Zhang, Fu-Kang; Li, Hua; Chen, Jun

    2011-09-30

    Chronic motor cortex (MCx) stimulation (MCS) is an effective approach for patients with chronic, intractable neuropathic pain. However, the underlying neural mechanisms are less known. Combining an in vivo simultaneous multisite recording technique with a video-based behavioral tracker, simultaneous neuronal ensemble activities of the MCx and behavioral responses to noxious heat stimuli applied to bilateral hindpaw pads under naïve and inflammatory pain state were studied in freely behaving rats receiving prior implantation of microwire multielectrode array (2 × 4). Totally, 81 active units were sorted and separated from 40 microwire electrodes pre-implanted in the MCx of 5 rats. Under naïve state, 41% (33/81) units were responsive to contralateral, while 27% (22/81) were responsive to ipsilateral heat stimuli. However, the proportion of heat-responsive units under inflammatory pain state induced by subcutaneous bee venom (BV) injection was significantly increased when compared with saline control (BV vs. saline: 60% vs. 48% for contralateral and 51% vs. 37% for ipsilateral, P < 0.05, n = 81 units) as a consequence of recruitment of some previously heat non-responsive to heat sensitive units. Moreover, under the BV-inflamed condition, the discharge rate of the MCx neurons was significantly increased. The time course of increased spontaneous neuronal ensemble activities (n = 81) was in parallel with that of pain-related behaviors following BV injection. It is concluded that there are pain-related neurons in the MCx that can be functionally changed by peripheral inflammatory pain condition.

  13. Biofeedback for treatment of awake and sleep bruxism in adults: systematic review protocol

    PubMed Central

    2014-01-01

    Background Bruxism is a disorder of jaw-muscle activity characterised by repetitive clenching or grinding of the teeth which results in discomfort and damage to dentition. The two clinical manifestations of the condition (sleep and awake bruxism) are thought to have unrelated aetiologies but are palliated using similar techniques. The lack of a definitive treatment has prompted renewed interest in biofeedback, a behaviour change method that uses electronic detection to provide a stimulus whenever bruxism occurs. This systematic review aims to provide a comprehensive overview of the state of research into biofeedback for bruxism; to assess the efficacy and acceptability of biofeedback therapy in management of awake bruxism and, separately, sleep bruxism in adults; and to compare findings between the two variants. Methods A systematic review of published literature examining biofeedback as an intervention directed at controlling primary bruxism in adults. We will search electronic databases and the grey literature using a predefined search strategy to identify randomised and non-randomised studies, technical reports and patents. Searches will not be restricted by language or date and will be expanded through contact with authors and experts, and by following up reference lists and citations. Two authors, working independently, will conduct screening of search results, study selection, data extraction and quality assessment and a third will resolve any disagreements. The primary outcomes of acceptability and effectiveness will be assessed using only randomised studies, segregated by bruxism subtype. A meta-analysis of these data will be conducted only if pre-defined conditions for quality and heterogeneity are met, otherwise the data will be summarized in narrative form. Data from non-randomised studies will be used to augment a narrative synthesis of the state of technical developments and any safety-related issues. PROSPERO registration number: CRD42013006880

  14. Gender differences in associations of diurnal blood pressure variation, awake physical activity, and sleep quality with negative affect: the work site blood pressure study.

    PubMed

    Kario, K; Schwartz, J E; Davidson, K W; Pickering, T G

    2001-11-01

    This study reports on the associations among depression, anxiety, awake physical activity, sleep quality (assessed by nocturnal physical activity), and diurnal blood pressure (BP) variation in a nonpsychiatric sample (The Work Site Blood Pressure Study). We conducted ambulatory BP (ABP) monitoring and actigraphy in 231 working men and women. Depression and anxiety were measured by the Brief Symptom Inventory. There were gender-specific associations between depression or anxiety and ABP parameters. In men, depression was associated positively with the sleep/awake systolic BP (SBP) ratio (r=0.24, P=0.006). After controlling for age, body mass index, and awake and sleep activity, depression remained significantly associated with the sleep/awake SBP ratio (r=0.25, P=0.005) and was also significantly related to sleep SBP (r=0.21, P=0.02). Anxiety, which was related to depression (r=0.73, P<0.0001), had a similar but slightly weaker pattern of associations with ABP and activity. These associations were not found in women, but there were associations of anxiety with awake SBP (r=0.24, P=0.01) and pulse rate (r=0.27, P=0.006). In conclusion, depression is associated with disrupted diurnal BP variation independent of ambulatory physical activity in working men, whereas anxiety is associated with awake SBP and pulse rate in women.

  15. Markerless rat head motion tracking using structured light for brain PET imaging of unrestrained awake small animals

    NASA Astrophysics Data System (ADS)

    Miranda, Alan; Staelens, Steven; Stroobants, Sigrid; Verhaeghe, Jeroen

    2017-03-01

    Preclinical positron emission tomography (PET) imaging in small animals is generally performed under anesthesia to immobilize the animal during scanning. More recently, for rat brain PET studies, methods to perform scans of unrestrained awake rats are being developed in order to avoid the unwanted effects of anesthesia on the brain response. Here, we investigate the use of a projected structure stereo camera to track the motion of the rat head during the PET scan. The motion information is then used to correct the PET data. The stereo camera calculates a 3D point cloud representation of the scene and the tracking is performed by point cloud matching using the iterative closest point algorithm. The main advantage of the proposed motion tracking is that no intervention, e.g. for marker attachment, is needed. A manually moved microDerenzo phantom experiment and 3 awake rat [18F]FDG experiments were performed to evaluate the proposed tracking method. The tracking accuracy was 0.33 mm rms. After motion correction image reconstruction, the microDerenzo phantom was recovered albeit with some loss of resolution. The reconstructed FWHM of the 2.5 and 3 mm rods increased with 0.94 and 0.51 mm respectively in comparison with the motion-free case. In the rat experiments, the average tracking success rate was 64.7%. The correlation of relative brain regional [18F]FDG uptake between the anesthesia and awake scan reconstructions was increased from on average 0.291 (not significant) before correction to 0.909 (p  <  0.0001) after motion correction. Markerless motion tracking using structured light can be successfully used for tracking of the rat head for motion correction in awake rat PET scans.

  16. Significance of time awake for predicting pilots' fatigue on short-haul flights: implications for flight duty time regulations.

    PubMed

    Vejvoda, Martin; Elmenhorst, Eva-Maria; Pennig, Sibylle; Plath, Gernot; Maass, Hartmut; Tritschler, Kristjof; Basner, Mathias; Aeschbach, Daniel

    2014-10-01

    European regulations restrict the duration of the maximum daily flight duty period for pilots as a function of the duty start time and the number of scheduled flights. However, late duty end times that may include long times awake are not specifically regulated. In this study, fatigue levels in pilots finishing their duty late at night (00:00-01:59 hour) were analysed and compared with pilots starting their duty early (05:00-06:59 hour). Fatigue levels of 40 commercial short-haul pilots were studied during a total of 188 flight duty periods, of which 87 started early and 22 finished late. Pilots used a small handheld computer to maintain a duty and sleep log, and to indicate fatigue levels immediately after each flight. Sleep logs were checked with actigraphy. Pilots on late-finishing flight duty periods were more fatigued at the end of their duty than pilots on early-starting flight duty periods, despite the fact that preceding sleep duration was longer by 1.1 h. Linear mixed-model regression identified time awake as a preeminent factor predicting fatigue. Workload had a minor effect. Pilots on late-finishing flight duty periods were awake longer by an average of 5.5 h (6.6 versus 1.1 h) before commencing their duty than pilots who started early in the morning. Late-finishing flights were associated with long times awake at a time when the circadian system stops promoting alertness, and an increased, previously underestimated fatigue risk. Based on these findings, flight duty limitations should consider not only duty start time, but also the time of the final landing.

  17. Only a whisper away. A philosophical view of the awake patient's situation during regional anaesthetics and surgery.

    PubMed

    Karlsson, Ann-Christin; Ekebergh, Margaretha; Larsson Mauléon, Annika; Almerud Österberg, Sofia

    2012-10-01

    In this study the awake patient's intraoperative situation and experiences during regional anaesthetics and surgery are reflected upon by using the work of the French philosopher Maurice Merleau-Ponty. Merleau-Ponty's phenomenological idea of the body as being at the centre of the world highlights the patient's embodied position and bestows significance onto the body as a whole, as a lived body. A case, based on the findings from a previous interview study, is presented as a contextual starting point where a patient goes from having a familiar body recognized as her own to having a partially anaesthetized body experienced as an unknown object. The intraoperative caring space is described in this context as the mutual ground where the awake patient and the nurse anaesthetist (NA) can interact to create meaning. The NA can act as the patient's bodily extension to bridge the gap between the patient's experiences and the situation. This calls for the NA's proximity and genuine presence in order to meet and understand the patient's awake experiences. Learning from the patient's situatedness gives information that is valuable for NAs to share with patients who are less experienced with this contextual situation. The challenge for the NA is not to perform routine-based care, but to acknowledge every patient's lifeworld and uniqueness thus enabling the patient to move easily along the mind-body-world continuum. The core of intraoperative care is to provide support and promote well-being of awake patients in the intraoperative environment. The use of a philosophical perspective is relevant for nurses who work in an intraoperative setting where patients undergo regional anaesthetics. This study shows how nursing research using phenomenological philosophy can help uncover new meanings known only to the patients living the experience.

  18. The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note

    PubMed Central

    Conner, Andrew K; Glenn, Chad; Burks, Joshua D; McCoy, Tressie; Bonney, Phillip A; Chema, Ahmed A; Case, Justin L; Brunner, Scott; Sughrue, Michael

    2016-01-01

    The success of awake craniotomies relies on the patient’s performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities. PMID:28003947

  19. Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses

    PubMed Central

    Low, Lucie A.; Bauer, Lucy C.; Pitcher, Mark H.; Bushnell, M. Catherine

    2016-01-01

    Abstract With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the “nociceptive” central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli. PMID:27058679

  20. Interhemispheric transfalcine approach and awake cortical mapping for resection of peri-atrial gliomas associated with the central lobule.

    PubMed

    Malekpour, Mahdi; Cohen-Gadol, Aaron A

    2015-02-01

    Medial posterior frontal and parietal gliomas extending to the peri-atrial region are difficult to reach surgically because of the working angle required to expose the lateral aspect of the tumor and the proximity of the tumor to the sensorimotor lobule; retraction of the sensorimotor cortex may lead to morbidity. The interhemispheric transfalcine approach is favorable and safe for resection of medial hemispheric tumors adjacent to the falx cerebri, but the literature on this approach is scarce. Awake cortical mapping using this operative route for tumors associated with the sensorimotor cortex has not been previously reported to our knowledge. We present the first case of a right medial posterior frontoparietal oligoastrocytoma that was resected through the interhemispheric transfalcine approach using awake cortical and subcortical mapping. Through a contralateral frontoparietal craniotomy, we excised a section of the falx and exposed the contralateral medial hemisphere. Cortical stimulation allowed localization of the supplementary motor cortex, and suprathreshold stimulation mapping excluded the primary motor cortex corresponding to the leg area. Gross total tumor resection was accomplished without any intraoperative or postoperative deficits. Awake cortical mapping using the contralateral transfalcine approach allows a "cross-court" operative route to map functional cortices and resect peri-atrial low-grade gliomas. This technique can minimize the otherwise necessary retraction on the ipsilateral hemisphere through an ipsilateral craniotomy.

  1. [Incidence and causes of early end in awake surgery for language mapping not directly related to eloquence].

    PubMed

    Villalba, Gloria; Pacreu, Susana; Fernández-Candil, Juan Luis; León, Alba; Serrano, Laura; Conesa, Gerardo

    2016-01-01

    The incidence and causes that may lead to an early end (unfinished cortical/subcortical mapping) of awake surgery for language mapping are little known. A study was conducted on 41 patients with brain glioma located in the language area that had awake surgery under conscious sedation. Surgery was ended early in 6 patients. The causes were: tonic-clonic seizure (1), lack of cooperation due to fatigue/sleep (4), whether or not word articulation was involved, a decreased level of consciousness for ammonia encephalopathy that required endotracheal intubation (1). There are causes that could be expected and in some cases avoided. Tumour size, preoperative aphasia, valproate treatment, and type of anaesthesia used are variables to consider to avoid failure in awake surgery for language mapping. With these results, the following measures are proposed: l) If the tumour is large, perform surgery in two times to avoid fatigue, 2) if patient has a preoperative aphasia, do not use sedation during surgery to ensure that sleepiness does not cause worse word articulation, 3) if the patient is on valproate treatment, it is necessary to rule out the pre-operative symptoms that are not due to ammonia encephalopathy.

  2. The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note.

    PubMed

    Conner, Andrew K; Glenn, Chad; Burks, Joshua D; McCoy, Tressie; Bonney, Phillip A; Chema, Ahmed A; Case, Justin L; Brunner, Scott; Baker, Cordell; Sughrue, Michael

    2016-11-17

    The success of awake craniotomies relies on the patient's performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities.

  3. Diagnostic work up for language testing in patients undergoing awake craniotomy for brain lesions in language areas.

    PubMed

    Bilotta, Federico; Stazi, Elisabetta; Titi, Luca; Lalli, Diana; Delfini, Roberto; Santoro, Antonio; Rosa, Giovanni

    2014-06-01

    Awake craniotomy is the technique of choice in patients with brain tumours adjacent to primary and accessory language areas (Broca's and Wernicke's areas). Language testing should be aimed to detect preoperative deficits, to promptly identify the occurrence of new intraoperative impairments and to establish the course of postoperative language status. Aim of this case series is to describe our experience with a dedicated language testing work up to evaluate patients with or at risk for language disturbances undergoing awake craniotomy for brain tumour resection. Pre- and intra operative testing was accomplished with 8 tests. Intraoperative evaluation was accomplished when patients were fully cooperative (Ramsey < 3). Postoperative evaluation was scheduled at early (within 21 days) and long-term follow-up (3-6 months). Twenty consecutive patients were prospectively recruited. Preoperative language testings were normal in 9 patients (45%), showed mild to moderate language deficit in 8 (40%) and severe language deficit or aphasic disorders in 3 (15%). Broca's area was identified in 15 patients, in all cases by counting arrest during stimulation and in 12 cases by naming arrest. In this article we describe our experience using a language testing work up to evaluate - pre, intra and postoperatively - patients undergoing awake craniotomy for brain tumour resection with preoperative language disturbances or at risk for postoperative language deficits. This approach allows a systematic evaluation and recording of language function status and can be accomplished even when a neuropsychologist or speech therapist are not involved in the operation crew.

  4. Preliminary research on abnormal brain detection by wavelet-energy and quantum- behaved PSO.

    PubMed

    Zhang, Yudong; Ji, Genlin; Yang, Jiquan; Wang, Shuihua; Dong, Zhengchao; Phillips, Preetha; Sun, Ping

    2016-04-29

    It is important to detect abnormal brains accurately and early. The wavelet-energy (WE) was a successful feature descriptor that achieved excellent performance in various applications; hence, we proposed a WE based new approach for automated abnormal detection, and reported its preliminary results in this study. The kernel support vector machine (KSVM) was used as the classifier, and quantum-behaved particle swarm optimization (QPSO) was introduced to optimize the weights of the SVM. The results based on a 5 × 5-fold cross validation showed the performance of the proposed WE + QPSO-KSVM was superior to ``DWT + PCA + BP-NN'', ``DWT + PCA + RBF-NN'', ``DWT + PCA + PSO-KSVM'', ``WE + BPNN'', ``WE +$ KSVM'', and ``DWT $+$ PCA $+$ GA-KSVM'' w.r.t. sensitivity, specificity, and accuracy. The work provides a novel means to detect abnormal brains with excellent performance.

  5. A class of regular and well behaved relativistic super-dense star models

    NASA Astrophysics Data System (ADS)

    Gupta, Y. K.; Maurya, Sunil Kumar

    2011-03-01

    We obtain a new class of charged super-dense star models after prescribing particular forms of the metric potential g 44 and electric intensity. The metric describing the superdense stars joins smoothly with the Reissner-Nordstrom metric at the pressure free boundary. The interior of the stars possess there energy density, pressure, pressure-density ratio and velocity of sound to be monotonically decreasing towards the pressure free interface. In view of the surface density 2×1014 g/cm3, the heaviest star occupies a mass 5.6996 M ⊙ with its radius 17.0960 km. The red shift at the centre and boundary are found to be 3.5120 and 1.1268 respectively. In absence of the charge we are left behind with the regular and well behaved fifth model of Durgapal (J. Phys. A 15:2637, 1982).

  6. Iridium versus Iridium: Nanocluster and Monometallic Catalysts Carrying the Same Ligand Behave Differently.

    PubMed

    Cano, Israel; Martínez-Prieto, Luis M; Chaudret, Bruno; van Leeuwen, Piet W N M

    2017-01-26

    A specific secondary phosphine oxide (SPO) ligand (tert-butyl(phenyl)phosphine oxide) was employed to generate two iridium catalysts, an Ir-SPO complex and IrNPs (iridium nanoparticles) ligated with SPO ligands, which were compared mutually and with several supported iridium catalysts with the aim to establish the differences in their catalytic properties. The Ir-SPO-based catalysts showed totally different activities and selectivities in the hydrogenation of various substituted aldehydes, in which H2 is likely cleaved by a metal-ligand cooperation, that is, the SPO ligand and a neighboring metal centre operate in tandem to activate the hydrogen molecule. In addition, the supported IrNPs behave very differently from both Ir-SPO catalysts. This study exemplifies perfectly the advantages and disadvantages related to the use of the main types of catalysts, and thus the dissimilarities between them.

  7. A quantum-behaved evolutionary algorithm based on the Bloch spherical search

    NASA Astrophysics Data System (ADS)

    Li, Panchi

    2014-04-01

    In order to enhance the optimization ability of the quantum evolutionary algorithms, a new quantum-behaved evolutionary algorithm is proposed. In this algorithm, the search mechanism is established based on the Bloch sphere. First, the individuals are expressed by qubits described on the Bloch sphere, then the rotation axis is established by Pauli matrixes, and the evolution search is realized by rotating qubits on the Bloch sphere about the rotating axis. In order to avoid premature convergence, the mutation of individuals is achieved by the Hadamard gates. Such rotation can make the current qubit approximate the target qubit along with the great circle on the Bloch sphere, which can accelerate optimization process. Taking the function extreme value optimization as an example, the experimental results show that the proposed algorithm is obviously superior to other similar algorithms.

  8. Serotonergic agonists behave as partial agonists at the dopamine D2 receptor.

    PubMed

    Rinken, A; Ferré, S; Terasmaa, A; Owman, C; Fuxe, K

    1999-02-25

    RAT dopamine D2short receptors expressed in CHO cells were characterized by activation of [35S]GTPgammaS binding. There were no significant differences between the maximal effects seen in activation of [35S]GTPgammaS binding caused by dopaminergic agonists, but the effects of 5-HT, 8OH-DPAT and 5-methoxytryptamine amounted to 47 +/- 7%, 43 +/- 5% and 70 +/- 7% of the dopamine effect, respectively. The dopaminergic antagonist (+)butaclamol inhibited activations of both types of ligands with equal potency (pA2 = 8.9 +/- 0.1), indicating that only one type of receptor is involved. In competition with [3H]raclopride binding, dopaminergic agonists showed 53 +/- 2% of the binding sites in the GTP-dependent high-affinity state, whereas 5-HT showed only 20 +/- 3%. Taken together, the results indicate that serotonergic agonists behave as typical partial agonists for D2 receptors with potential antiparkinsonian activity.

  9. Hypoxia-induced vasodilation and effects of regional phentolamine in awake patients with sleep apnea.

    PubMed

    Moradkhan, Raman; Spitnale, Brett; McQuillan, Patrick; Hogeman, Cynthia; Gray, Kristen S; Leuenberger, Urs A

    2010-05-01

    Obstructive sleep apnea (OSA) is associated with increased sympathetic nerve activity, endothelial dysfunction, and premature cardiovascular disease. To determine whether hypoxia is associated with impaired skeletal muscle vasodilation, we compared femoral artery blood flow (ultrasound) and muscle sympathetic nerve activity (peroneal microneurography) during exposure to acute systemic hypoxia (fraction of inspired oxygen 0.1) in awake patients with OSA (n=10) and controls (n=8). To assess the role of elevated sympathetic nerve activity, in a separate group of patients with OSA (n=10) and controls (n=10) we measured brachial artery blood flow during hypoxia before and after regional alpha-adrenergic block with phentolamine. Despite elevated sympathetic activity, in OSA the vascular responses to hypoxia in the leg did not differ significantly from those in controls [P=not significant (NS)]. Following regional phentolamine, in both groups the hypoxia-induced increase in brachial blood flow was markedly enhanced (OSA pre vs. post, 84+/-13 vs. 201+/-34 ml/min, P<0.002; controls pre vs. post 62+/-8 vs. 140+/-26 ml/min, P<0.01). At end hypoxia after phentolamine, the increase of brachial blood flow above baseline was similar (OSA vs. controls +61+/-16 vs. +48+/-6%; P=NS). We conclude that despite high sympathetic vasoconstrictor tone and prominent sympathetic responses to acute hypoxia, hypoxia-induced limb vasodilation is preserved in OSA.

  10. Validation of a Modified Algometer to Measure Mechanical Nociceptive Thresholds in Awake Dogs

    PubMed Central

    Chen, Hui Cheng; Goh, Yong Meng; Abubakar, Adamu Abdul; Fakurazi, Sharida

    2015-01-01

    This study was conducted to validate the use of a modified algometer device to measure mechanical nociceptive thresholds in six dogs. Dogs were administered morphine intravenously (IV) at 1 mg/kg or saline at equivolume in a crossover design with one-week washout period. Mechanical nociceptive thresholds were determined before, after the administration of treatments at 5 minutes, and hourly for 8 hours. Thresholds were recorded at the carpal pad, metacarpal foot pad, tibia, femur, and abdomen. Heart rates, body temperature, and respiration were recorded at similar time points. Thresholds increased significantly (P < 0.05) from baseline values for up to 3 hours at tibia and abdomen, 4 hours at metacarpal pad, and 5 hours at the carpal pad and femur. Hypothermia, bradycardia, and change in respiration were observed in all dogs after morphine injection. Saline did not alter any threshold levels during the eight-hour study period, indicating no evidence of tolerance, learned avoidance, or local hyperaesthesia. The device and methods of testing were well tolerated by all the dogs. Results suggest that the modified algometer and method of application are useful to measure nociceptive mechanical thresholds in awake dogs. PMID:26075236

  11. Respiratory effects of sectioning the carotid sinus glossopharyngeal and abdominal vagal nerves in the awake rat.

    PubMed Central

    Martin-Body, R L; Robson, G J; Sinclair, J D

    1985-01-01

    Normoxic and hypoxic respiration has been measured in awake rats after denervation procedures designed to eliminate the regulatory input from the carotid bodies, from all chemosensory tissue supplied by the glossopharyngeal nerve (n. IX), and from abdominal chemoreceptors. Studies were made 1 day after section of the carotid sinus nerve (c.s.n.), n. IX (at a level including c.s.n.), the abdominal vagus (n. Xa) and combinations of these nerves. Results were compared with those found in normal controls. C.s.n. section led to hypoventilation in both normoxia and hypoxia, reductions in respiratory frequency being consistent and substantial, and reductions in tidal volume varying with the degree of hypoxia. By comparison, section of n. IX produced significantly greater reductions of both normoxic and hypoxic ventilation. Section of n. Xa produced no significant change in normoxic ventilation but in hypoxia produced a significant small reduction in ventilation, mostly from an effect on tidal volume. Denervation of all the associated chemosensory tissue by combined section of n. IX and n. Xa demonstrated a summation of effects but left two distinct residual responses, one to mild hypoxia, and one to severe hypoxia, both associated mainly with increases of tidal volume. The experiments demonstrate that glomus tissues at different sites in the rat produce significant and distinct contributions to respiratory regulation. Denervation of all known receptors shows that significant ventilatory responses to hypoxia are still produced, either by unrevealed peripheral chemoreceptors, or by central neural mechanisms. PMID:3989730

  12. Auditory response properties of neurons in the putamen and globus pallidus of awake cats.

    PubMed

    Zhong, Renjia; Qin, Ling; Sato, Yu

    2014-05-01

    Several decades of research have provided evidence that the basal ganglia are closely involved in motor processes. Recent clinical, electrophysiological, behavioral data have revealed that the basal ganglia also receive afferent input from the auditory system, but the detailed auditory response characteristics have not yet reported. The present study aimed to reveal the acoustic response properties of neurons in parts of the basal ganglia. We recorded single-unit activities from the putamen (PU) and globus pallidus (GP) of awake cats passively listening to pure tones, click trains, and natural sounds. Our major findings were: 1) responses in both PU and GP neurons were elicited by pure-tone stimuli, whereas PU neurons had lower intensity thresholds, shorter response latencies, shorter excitatory duration, and larger response magnitudes than GP neurons. 2) Some GP neurons showed a suppressive response lasting throughout the stimulus period. 3) Both PU and GP did not follow periodically repeated click stimuli well, and most neurons only showed a phasic response at the stimulus onset and offset. 4) In response to natural sounds, PU also showed a stronger magnitude and shorter duration of excitatory response than GP. The selectivity for natural sounds was low in both nuclei. 5) Nonbiological environmental sounds more efficiently evoked responses in PU and GP than the vocalizations of conspecifics and other species. Our results provide insights into how acoustic signals are processed in the basal ganglia and revealed the distinction of PU and GP in sensory representation.

  13. PET measured evoked cerebral blood flow responses in an awake monkey

    SciTech Connect

    Perlmutter, J.S.; Lich, L.L.; Margenau, W.; Buchholz, S. )

    1991-03-01

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments.

  14. Characterization of flexible ECoG electrode arrays for chronic recording in awake rats

    PubMed Central

    Yeager, John D.; Phillips, Derrick J.; Rector, David M.; Bahr, David F.

    2008-01-01

    We developed a 64 channel flexible polyimide ECoG electrode array and characterized its performance for long term implantation, chronic cortical recording and high resolution mapping of surface evoked potentials in awake rats. To achieve the longest possible recording periods, the flexibility of the electrode array, adhesion between the metals and carrier substrate, and biocompatibility was critical for maintaining the signal integrity. Experimental testing of thin film adhesion was applied to a gold – polyimide system in order to characterize relative interfacial fracture energies for several different adhesion layers, yielding an increase in overall device reliability. We tested several different adhesion techniques including: gold alone without an adhesion layer, titanium-tungsten, tantalum and chromium. We found the titanium-tungsten to be a suitable adhesion layer considering the biocompatibility requirements as well as stability and delamination resistance. While chromium and tantalum produced stronger gold adhesion, concerns over biocompatibility of these materials require further testing. We implanted the polyimide ECoG electrode arrays through a slit made in the skull of rats and recorded cortical surface evoked responses. The arrays performed reliably over a period of at least 100 days and signals compared well with traditional screw electrodes, with better high frequency response characteristics. Since the ultimate goal of chronically implanted electrode arrays is for neural prosthetic devices that need to last many decades, other adhesion layers that would prove safe for implantation may be tested in the same way in order to improve the device reliability. PMID:18640155

  15. Spatial structure of neuronal receptive field in awake monkey secondary visual cortex (V2)

    PubMed Central

    Liu, Lu; She, Liang; Chen, Ming; Liu, Tianyi; Lu, Haidong D.; Dan, Yang; Poo, Mu-ming

    2016-01-01

    Visual processing depends critically on the receptive field (RF) properties of visual neurons. However, comprehensive characterization of RFs beyond the primary visual cortex (V1) remains a challenge. Here we report fine RF structures in secondary visual cortex (V2) of awake macaque monkeys, identified through a projection pursuit regression analysis of neuronal responses to natural images. We found that V2 RFs could be broadly classified as V1-like (typical Gabor-shaped subunits), ultralong (subunits with high aspect ratios), or complex-shaped (subunits with multiple oriented components). Furthermore, single-unit recordings from functional domains identified by intrinsic optical imaging showed that neurons with ultralong RFs were primarily localized within pale stripes, whereas neurons with complex-shaped RFs were more concentrated in thin stripes. Thus, by combining single-unit recording with optical imaging and a computational approach, we identified RF subunits underlying spatial feature selectivity of V2 neurons and demonstrated the functional organization of these RF properties. PMID:26839410

  16. Real-time Awake Animal Motion Tracking System for SPECT Imaging

    SciTech Connect

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

    2008-01-01

    Enhancements have been made in the development of a real-time optical pose measurement and tracking system that provides 3D position and orientation data for a single photon emission computed tomography (SPECT) imaging system for awake, unanesthetized, unrestrained small animals. Three optical cameras with infrared (IR) illumination view the head movements of an animal enclosed in a transparent burrow. Markers placed on the head provide landmark points for image segmentation. Strobed IR LED s are synchronized to the cameras and illuminate the markers to prevent motion blur for each set of images. The system using the three cameras automatically segments the markers, detects missing data, rejects false reflections, performs trinocular marker correspondence, and calculates the 3D pose of the animal s head. Improvements have been made in methods for segmentation, tracking, and 3D calculation to give higher speed and more accurate measurements during a scan. The optical hardware has been installed within a Siemens MicroCAT II small animal scanner at Johns Hopkins without requiring functional changes to the scanner operation. The system has undergone testing using both phantoms and live mice and has been characterized in terms of speed, accuracy, robustness, and reliability. Experimental data showing these motion tracking results are given.

  17. Epinephrine converts long-term potentiation from transient to durable form in awake rats.

    PubMed

    Korol, D L; Gold, P E

    2008-01-01

    Neuroendocrine responses to an emotional or arousing experience modulate memory for the event. Extensive evidence suggests that epinephrine plays an important role in the regulation of memory formation by emotions and arousal. Some forms of synaptic plasticity are similarly responsive to modulation by stress and arousal. The present experiment examined the effects of epinephrine on induction and maintenance of long-term potentiation (LTP) in awake rats. Rats were prepared with bilaterally implanted electrodes for recording evoked field potentials in dentate granule cells following perforant pathway stimulation. LTP was induced with high-frequency stimulation parameters that resulted in modest early potentiation of the EPSP that decayed within 20 min. Epinephrine enhanced the magnitude of early LTP induction and also extended the durability of LTP from minutes to at least several days. Epinephrine did not alter baseline responses or modulate pre-LTP input-output curves. The enhancement of LTP by epinephrine was dose-dependent, following an inverted-U dose-response curve similar to that seen in memory enhancement experiments, suggesting considerable convergence of epinephrine modulation of memory and LTP. In extending substantially the maintenance of LTP after induction, the present finding offer potential means to study the neurobiology of rapid forgetting seen in aged rodents and other animals and the neurobiology of the impaired forgetting seen in post-traumatic stress disorder.

  18. A regenerative microchannel device for recording multiple single-unit action potentials in awake, ambulatory animals.

    PubMed

    Srinivasan, Akhil; Tipton, John; Tahilramani, Mayank; Kharbouch, Adel; Gaupp, Eric; Song, Chao; Venkataraman, Poornima; Falcone, Jessica; Lacour, Stéphanie P; Stanley, Garrett B; English, Arthur W; Bellamkonda, Ravi V

    2016-02-01

    Despite significant advances in robotics, commercially advanced prosthetics provide only a small fraction of the functionality of the amputated limb that they are meant to replace. Peripheral nerve interfacing could provide a rich controlling link between the body and these advanced prosthetics in order to increase their overall utility. Here, we report on the development of a fully integrated regenerative microchannel interface with 30 microelectrodes and signal extraction capabilities enabling evaluation in an awake and ambulatory rat animal model. In vitro functional testing validated the capability of the microelectrodes to record neural signals similar in size and nature to those that occur in vivo. In vitro dorsal root ganglia cultures revealed striking cytocompatibility of the microchannel interface. Finally, in vivo, the microchannel interface was successfully used to record a multitude of single-unit action potentials through 63% of the integrated microelectrodes at the early time point of 3 weeks. This marks a significant advance in microchannel interfacing, demonstrating the capability of microchannels to be used for peripheral nerve interfacing.

  19. Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state

    PubMed Central

    Bellay, Timothy; Klaus, Andreas; Seshadri, Saurav; Plenz, Dietmar

    2015-01-01

    Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output. Here, we study spontaneous firing in pyramidal neurons (PNs) from rat superficial cortical layers in vivo and in vitro using 2-photon imaging. As the animal transitions from the anesthetized to awake state, spontaneous single neuron firing increases in irregularity and assembles into scale-invariant avalanches at the group level. In vitro spike avalanches emerged naturally yet required balanced excitation and inhibition. This demonstrates that neuronal avalanches are linked to the global physiological state of wakefulness and that cortical resting activity organizes as avalanches from firing of local PN groups to global population activity. DOI: http://dx.doi.org/10.7554/eLife.07224.001 PMID:26151674

  20. Characterization of flexible ECoG electrode arrays for chronic recording in awake rats.

    PubMed

    Yeager, John D; Phillips, Derrick J; Rector, David M; Bahr, David F

    2008-08-30

    We developed a 64-channel flexible polyimide ECoG electrode array and characterized its performance for long-term implantation, chronic cortical recording and high resolution mapping of surface-evoked potentials in awake rats. To achieve the longest possible recording periods, the flexibility of the electrode array, adhesion between the metals and carrier substrate, and biocompatibility were critical for maintaining the signal integrity. Experimental testing of thin film adhesion was applied to a gold-polyimide system in order to characterize relative interfacial fracture energies for several different adhesion layers, yielding an increase in overall device reliability. We tested several different adhesion techniques including the following: gold alone without an adhesion layer, titanium-tungsten, tantalum and chromium. We found titanium-tungsten to be a suitable adhesion layer considering the biocompatibility requirements as well as stability and delamination resistance. While chromium and tantalum produced stronger gold adhesion, concerns over biocompatibility of these materials require further testing. We implanted the polyimide ECoG electrode arrays through a slit made in the skull of rats and recorded cortical surface evoked responses. The arrays performed reliably over a period of at least 100 days and signals compared well with traditional screw electrodes, with better high frequency response characteristics. Since the ultimate goal of chronically implanted electrode arrays is for neural prosthetic devices that need to last many decades, other adhesion layers that would prove safe for implantation may be tested in the same way in order to improve the device reliability.

  1. From "awake" to "monitored anesthesia care" thoracic surgery: A 15 year evolution.

    PubMed

    Mineo, Tommaso C; Tacconi, Federico

    2014-01-01

    Although general anesthesia still represents the standard when performing thoracic surgery, the interest toward alternative methods is increasing. These have evolved from the employ of just local or regional analgesia techniques in completely alert patients (awake thoracic surgery), to more complex protocols entailing conscious sedation and spontaneous ventilation. The main rationale of these methods is to prevent serious complications related to general anesthesia and selective ventilation, such as tracheobronchial injury, acute lung injury, and cardiovascular events. Trends toward shorter hospitalization and reduced overall costs have also been indicated in preliminary reports. Monitored anesthesia care in thoracic surgery can be successfully employed to manage diverse oncologic conditions, such as malignant pleural effusion, peripheral lung nodules, and mediastinal tumors. Main non-oncologic indications include pneumothorax, emphysema, pleural infections, and interstitial lung disease. Furthermore, as the familiarity with this surgical practice has increased, major operations are now being performed this way. Despite the absence of randomized controlled trials, there is preliminary evidence that monitored anesthesia care protocols in thoracic surgery may be beneficial in high-risk patients, with non-inferior efficacy when compared to standard operations under general anesthesia. Monitored anesthesia care in thoracic surgery should enter the armamentarium of modern thoracic surgeons, and adequate training should be scheduled in accredited residency programs.

  2. Effects of hypercapnia on variability of normal respiratory behavior in awake cats.

    PubMed

    Szlyk, P C; Jennings, D B

    1987-03-01

    Resting quiet awake cats breathing air in a steady state have a range of respiratory behavior, and this encompasses nonpurring and purring (D. B. Jennings and P. C. Szlyk, Can. J. Physiol. Pharmacol. 63: 148-154, 1985). On a given study day, individual cats usually breathed in a limited part of their potential respiratory range. Respiratory pattern, such as average breath frequency (f) and average tidal volume (VT) utilized for a given level of ventilation (V), could be predicted when cats breathed air; as well, inspiratory (TI) and expiratory (TE) times were specific for a given breath f. Inhalation of 2% and 4% CO2 in air caused an average increase in ventilation of 16 and 100%, respectively but breath-to-breath variability of V, f, and VT persisted at each fractional concentration of inspired CO2 (FICO2). The range of different V utilized breath to breath when breathing 2% CO2 overlapped with V during air control studies. Substantial overlap with control V also occurred in three of six cats when breathing 4% CO2. The most consistent effect of progressive hypercapnia was to increase VT and decrease f at a given level of V; increase in V during hypercapnia was accounted for by an increase in mean inspiratory flow (VT/TI). Hypercapnia also caused the fraction of breathing cycle devoted to inspiration (TI/TT) to increase at low f but not at high f.

  3. Thyroarytenoid muscle activity during hypocapnic central apneas in awake nonsedated lambs.

    PubMed

    Kianicka, I; Leroux, J F; Praud, J P

    1994-03-01

    In this study, we examined whether the glottis is open or closed during central apnea and the effect of arterial PO2 (PaO2) on this control. We hyperventilated nine 11- to 30-day-old awake nonsedated lambs via a tracheostomy for 1 min to induce central apnea. Four gas mixtures (8, 15, 21, and 30% O2) were used. At the end of the hyperventilation period, the lambs were allowed to breathe spontaneously through intact upper airways. Using a pneumotachograph attached to a face mask, we measured airflow, and we continuously recorded electromyographic (EMG) activity of the thyroarytenoid (TA), the main glottic adductor muscle. We also studied the lateral cricoarytenoid muscle (LCA, laryngeal adductor), the posterior cricoarytenoid muscle (PCA, laryngeal abductor), the cricothyroid muscle (CT), and the diaphragm. We found that hyperventilation consistently induced hypocapnic central apnea in all nine lambs in hyperoxic conditions [30% inspiratory fraction of O2 (FIO2)], in eight of nine lambs in normoxia or mild hypoxia (15 and 21% FIO2), and in four of seven lambs in hypoxia (8% FIO2). During baseline room air breathing, there was no glottic adductor muscle expiratory EMG activity or expiratory airflow braking. Continuous TA EMG activity began early during hyperventilation and continued throughout the central apnea, regardless of PaO2. The first subsequent breathing efforts were marked by expiratory flow braking and expiratory activity of the TA. The LCA and the TA demonstrated the same EMG activity pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Efficacy of "Awake ECMO" for critical respiratory failure after pediatric open-heart surgery.

    PubMed

    Higashida, Akihiko; Hoashi, Takaya; Kagisaki, Koji; Shimada, Masatoshi; Takahashi, Yuzo; Hayashi, Teruyuki; Ichikawa, Hajime

    2016-06-01

    A 4-year-old boy with atrioventricular discordance, double-outlet right ventricle, pulmonary stenosis, and mitral regurgitation, was undergoing anatomical repair consisting of Senning, Rastelli, Damus-Kaye-Stansel procedures, and a mitral valve repair, complained of post-operative excessive airway tract secretion, which ultimately developed into acute respiratory distress syndrome (ARDS) 28 days after the operation. The cause of the ARDS was thought to be frequent manual positive pressure recruitment and prolonged inhalation of pure oxygen. At 45 days after the operation, hypercapnia and respiratory acidosis turned out to be irreversible, and therefore, veno-arterial extracorporeal membrane oxygenation (ECMO) was established utilizing the Endumo(®)4000 system. Pulmonic interstitial inflammation gradually improved while resting the lung under ECMO support; however, effective ventilation volume decreased critically because a massive pulmonary hemorrhage occurred at 2 and 9 days after the initiation of ECMO. To maximize the effectiveness of respiratory physical therapy, "Awake ECMO" was started and tidal volume dramatically increased with a regained cough reflex. Five days later, he was successfully weaned off from ECMO, and discharged 7 months after the operation without any neurological and physiological sequelae.

  5. Effects of lesions of the caudal cerebellar vermis on cardiovascular regulation in awake cats

    NASA Technical Reports Server (NTRS)

    Holmes, M. J.; Cotter, L. A.; Arendt, H. E.; Cass, S. P.; Yates, B. J.

    2002-01-01

    The vestibular system is known to participate in cardiovascular regulation during movement and postural alterations. The present study considered whether lesions of two regions of the posterior cerebellar vermis (the nodulus and uvula) that provide inputs to vestibular nucleus regions that affect control of blood pressure would alter cardiovascular responses during changes in posture. Blood pressure and heart rate were monitored in awake cats during nose-up tilts up to 60 degrees in amplitude before and following aspiration lesions of the nodulus or uvula; in most animals, cardiovascular responses were also recorded following the subsequent removal of vestibular inputs. Lesions of the nodulus or uvula did not affect baseline blood pressure or heart rate, although cardiovascular responses during nose-up tilts were altered. Increases in heart rate that typically occurred during 60 degrees nose-up tilt were attenuated in all three animals with lesions affecting both dorsal and ventral portions of the uvula; in contrast, the heart rate responses were augmented in the two animals with lesions mainly confined to the nodulus. Furthermore, following subsequent removal of vestibular inputs, uvulectomized animals, but not those with nodulus lesions, experienced more severe orthostatic hypotension than has previously been reported in cerebellum-intact animals with bilateral labyrinthectomies. These data suggest that the cerebellar nodulus and uvula modulate vestibulo-cardiovascular responses, although the two regions play different roles in cardiovascular regulation.

  6. A family of well behaved charge analogues of Durgapal's perfect fluid exact solution in general relativity

    NASA Astrophysics Data System (ADS)

    Murad, Mohammad Hassan; Fatema, Saba

    2013-02-01

    This paper presents a new family of interior solutions of Einstein-Maxwell field equations in general relativity for a static spherically symmetric distribution of a charged perfect fluid with a particular form of charge distribution. This solution gives us wide range of parameter, K, for which the solution is well behaved hence, suitable for modeling of superdense star. For this solution the gravitational mass of a star is maximized with all degree of suitability by assuming the surface density equal to normal nuclear density, ρ nm=2.5×1017 kg m-3. By this model we obtain the mass of the Crab pulsar, M Crab, 1.36 M ⊙ and radius 13.21 km, constraining the moment of inertia > 1.61×1038 kg m2 for the conservative estimate of Crab nebula mass 2 M ⊙. And M Crab=1.96 M ⊙ with radius R Crab=14.38 km constraining the moment of inertia > 3.04×1038 kg m2 for the newest estimate of Crab nebula mass, 4.6 M ⊙. These results are quite well in agreement with the possible values of mass and radius of Crab pulsar. Besides this, our model yields moments of inertia for PSR J0737-3039A and PSR J0737-3039B, I A =1.4285×1038 kg m2 and I B =1.3647×1038 kg m2 respectively. It has been observed that under well behaved conditions this class of solutions gives us the overall maximum gravitational mass of super dense object, M G(max)=4.7487 M ⊙ with radius R_{M_{max}}=15.24 km, surface redshift 0.9878, charge 7.47×1020 C, and central density 4.31 ρ nm.

  7. A new well behaved class of charge analogue of Adler's relativistic exact solution

    NASA Astrophysics Data System (ADS)

    Murad, Mohammad Hassan

    2013-01-01

    The paper presents a new class of parametric interior solutions of Einstein-Maxwell field equations in general relativity for a static spherically symmetric distribution of a charged perfect fluid with a particular form of electric field intensity. This solution gives us wide range of parameter, K (0.69≤ K≤7.1), for which the solution is well behaved hence, suitable for modeling of superdense star. For this solution the gravitational mass of a superdense object is maximized with all degree of suitability by assuming the surface density of the star equal to the normal nuclear density ρ nm=2.5×1017kg m-3. By this model we obtain the mass of the Crab pulsar M Crab=1.401 M ⊙ and the radius, R Crab=12.98 km constraining the moment of inertia I NS,38>1.61 for the conservative estimate of Crab nebula mass 2 M ⊙ and M Crab=2.0156 M ⊙ with radius, R Crab=14.07 km constraining the moment of inertia I NS,38>3.04 for the newest estimate of Crab nebula mass 4.6 M ⊙ which are quite well in agreement with the possible values of mass and radius of Crab pulsar. Besides this, our model yields the moments of inertia for PSR J0737-3039A and PSR J0737-3039B are I A,38=1.4624 and I B,38=1.2689 respectively. It has been observed that under well behaved conditions this class of parametric solution gives us the maximum gravitational mass of causal superdense object 2.8020 M ⊙ with radius 14.49 km, surface redshift z R =0.4319, charge Q=4.67×1020 C, and central density ρ c =2.68 ρ nm.

  8. Flood Inundation Modelling Under Uncertainty Using Globally and Freely Available Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Yan, K.; Di Baldassarre, G.; Giustarini, L.; Solomatine, D. P.

    2012-04-01

    The extreme consequences of recent catastrophic events have highlighted that flood risk prevention still needs to be improved to reduce human losses and economic damages, which have considerably increased worldwide in recent years. Flood risk management and long term floodplain planning are vital for living with floods, which is the currently proposed approach to cope with floods. To support the decision making processes, a significant issue is the availability of data to build appropriate and reliable models, from which the needed information could be obtained. The desirable data for model building, calibration and validation are often not sufficient or available. A unique opportunity is offered nowadays by globally available data which can be freely downloaded from internet. This might open new opportunities for filling the gap between available and needed data, in order to build reliable models and potentially lead to the development of global inundation models to produce floodplain maps for the entire globe. However, there remains the question of what is the real potential of those global remote sensing data, characterized by different accuracy, for global inundation monitoring and how to integrate them with inundation models. This research aims at contributing to understand whether the current globally and freely available remote sensing data (e.g. SRTM, SAR) can be actually used to appropriately support inundation modelling. In this study, the SRTM DEM is used for hydraulic model building, while ENVISAT-ASAR satellite imagery is used for model validation. To test the usefulness of these globally and freely available data, a model based on the high resolution LiDAR DEM and ground data (high water marks) is used as benchmark. The work is carried out on a data-rich test site: the River Alzette in the north of Luxembourg City. Uncertainties are estimated for both SRTM and LiDAR based models. Probabilistic flood inundation maps are produced under the framework of

  9. Comparing the Planform Morphologies of a Freely Meandering Channel and the Bedrock- Controlled South River, VA.

    NASA Astrophysics Data System (ADS)

    Narinesingh, P.; Pizzuto, J.

    2008-12-01

    The planforms of the lithologically controlled South River, VA, and the freely meandering Teklanika River, AK were investigated using two statistical methods as well as fractal and spectral analyses. The lithologic controls along the South River include riverbanks consisting of pre-Holocene terraces and alluvial fans, and highly resistant bedrock that frequently crops out both in the bed and along the banks. A statistical analysis of bends composed of single arcs shows that the average radius of curvature is six times greater and the average bend length is 25 percent smaller for the South River relative to the meandering river, indicating that lithologically controlled bends are less curved and shorter than freely-formed meander bends. Fractal analysis reveals that the meandering river displays a smaller range in length scales than the South River, which exhibits a wider range in length scales that reflect a wider distribution of bend sizes. The method of Lancaster and Bras, (2002), which identifies bends of different complexity, indicates that the meandering river displays bends composed of single arcs, complex arcs and multiple complex arcs. Unlike the freely meandering Teklanika River, the lithologically controlled South River does not display bends composed of multiple complex arcs, though bends composed of single and complex arcs are common. Spectral analysis reveals that the meandering river's pattern is composed of a relatively narrow range of dominant wavelengths with the most prominent wavelength being the longest, while the lithologically controlled river displays dominant wavelengths over a relatively wide range and the most prominent wavelength is not the longest. This analysis demonstrates that lithological controls increase the range of bend lengths, increase radii of curvature, simplify bend shapes, and increase the distribution of wavelengths of sinuous rivers.

  10. Freely accessible water does not decrease consumption of ethanol liquid diets.

    PubMed

    de Fiebre, NancyEllen C; de Fiebre, Christopher M

    2003-02-01

    In experimental studies, liquid ethanol diets are usually given as the sole source of nutrition and fluid. Two series of experiments were conducted to examine the effect of freely accessible water on the consumption of ethanol liquid diets in male Long-Evans rats. The consumption of diets and subsequent learning ability of rats were first examined in animals given twice-daily saline injections. One group received diet with no access to water for 12 weeks and was subsequently given free access to water with diets for an additional 12 weeks. A second group was given diet and water ad libitum for 24 weeks. Control animals received an isocaloric sucrose-containing diet (with or without ad libitum access to water). Subsequently, rats were tested for active avoidance learning. In the first 12 weeks, animals with ad libitum access to water drank more diet than did water-restricted animals, and previously water-restricted animals increased their diet consumption when access to water was freely available. All water-restricted animals, in both ethanol- and sucrose-treated groups, showed deficits in active avoidance learning, whereas only ethanol-treated animals in groups with ad libitum access to water showed learning deficits. In the second series of experiments, the effect of saline injections on diet consumption, both in the presence and absence of water, was examined. Although saline injections were associated with decreased diet consumption, there was no effect of free access to water. No differences in blood ethanol concentration were seen among groups. Findings obtained from both series of studies demonstrate that consumption of a Sustacal-based liquid ethanol diet does not decrease if access to water is freely available.

  11. Optical 90-deg hybrid of birefringent crystals for freely propagating laser beams

    NASA Astrophysics Data System (ADS)

    Wan, Lingyu; Zhi, Yanan; Zhou, Yu; Liu, Liren

    2010-12-01

    An optical 90-deg hybrid of birefringent crystals for freely propagating laser beams is presented. It consists principally of a quarter-wave plate, two pairs of birefringent crystal plates, and a polarization analyzer. The splitting and recombination of the signal and local-oscillator beams are achieved through the birefringence of the crystals, and a 90-deg phase shift is introduced between orthogonally polarized beam components by use of a quarter-wave plate. The optical hybrid has a self-compensating light path, and its correct function is demonstrated in a self-heterodyne measurement setup.

  12. Trapped modes around freely floating bodies in a two-layer fluid channel

    PubMed Central

    Cal, Filipe S.; Dias, Gonçalo A. S.; Videman, Juha H.

    2014-01-01

    Unlike the trapping of time-harmonic water waves by fixed obstacles, the oscillation of freely floating structures gives rise to a complex nonlinear spectral problem. Still, through a convenient elimination scheme the system simplifies to a linear spectral problem for a self-adjoint operator in a Hilbert space. Under symmetry assumptions on the geometry of the fluid domain, we present conditions guaranteeing the existence of trapped modes in a two-layer fluid channel. Numerous examples of floating bodies supporting trapped modes are given. PMID:25294970

  13. PROGRAM DROP: A computer program for prediction of evaporation from freely falling multicomponent drops

    SciTech Connect

    Gavin, P.M.

    1996-12-01

    PROGRAM DROP consists of a series of FORTRAN routine which together are used to model the evaporation of a freely falling, multicomponent drop composed of an arbitrary number of volatile species and a single nonvolatile, inert component. The physics underlying the model are clearly identified, and the model`s relationship to previous work in the literature is described. Test cases are used to illustrate the viability of the model and to highlight its potential usefulness in the accurate prediction of multicomponent droplet vaporization in a variety of applications.

  14. OptoZIF Drive: a 3D printed implant and assembly tool package for neural recording and optical stimulation in freely moving mice

    NASA Astrophysics Data System (ADS)

    Freedman, David S.; Schroeder, Joseph B.; Telian, Gregory I.; Zhang, Zhengyang; Sunil, Smrithi; Ritt, Jason T.

    2016-12-01

    Objective. Behavioral neuroscience studies in freely moving rodents require small, light-weight implants to facilitate neural recording and stimulation. Our goal was to develop an integrated package of 3D printed parts and assembly aids for labs to rapidly fabricate, with minimal training, an implant that combines individually positionable microelectrodes, an optical fiber, zero insertion force (ZIF-clip) headstage connection, and secondary recording electrodes, e.g. for electromyography (EMG). Approach. Starting from previous implant designs that position recording electrodes using a control screw, we developed an implant where the main drive body, protective shell, and non-metal components of the microdrives are 3D printed in parallel. We compared alternative shapes and orientations of circuit boards for electrode connection to the headstage, in terms of their size, weight, and ease of wire insertion. We iteratively refined assembly methods, and integrated additional assembly aids into the 3D printed casing. Main results. We demonstrate the effectiveness of the OptoZIF Drive by performing real time optogenetic feedback in behaving mice. A novel feature of the OptoZIF Drive is its vertical circuit board, which facilities direct ZIF-clip connection. This feature requires angled insertion of an optical fiber that still can exit the drive from the center of a ring of recording electrodes. We designed an innovative 2-part protective shell that can be installed during the implant surgery to facilitate making additional connections to the circuit board. We use this feature to show that facial EMG in mice can be used as a control signal to lock stimulation to the animal’s motion, with stable EMG signal over several months. To decrease assembly time, reduce assembly errors, and improve repeatability, we fabricate assembly aids including a drive holder, a drill guide, an implant fixture for microelectode ‘pinning’, and a gold plating fixture. Significance. The

  15. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    SciTech Connect

    Rahmanseresht, Sheema; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S.; Milas, Peker

    2015-05-11

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  16. Continuous Force Decoding from Local Field Potentials of the Primary Motor Cortex in Freely Moving Rats

    PubMed Central

    Khorasani, Abed; Heydari Beni, Nargess; Shalchyan, Vahid; Daliri, Mohammad Reza

    2016-01-01

    Local field potential (LFP) signals recorded by intracortical microelectrodes implanted in primary motor cortex can be used as a high informative input for decoding of motor functions. Recent studies show that different kinematic parameters such as position and velocity can be inferred from multiple LFP signals as precisely as spiking activities, however, continuous decoding of the force magnitude from the LFP signals in freely moving animals has remained an open problem. Here, we trained three rats to press a force sensor for getting a drop of water as a reward. A 16-channel micro-wire array was implanted in the primary motor cortex of each trained rat, and obtained LFP signals were used for decoding of the continuous values recorded by the force sensor. Average coefficient of correlation and the coefficient of determination between decoded and actual force signals were r = 0.66 and R2 = 0.42, respectively. We found that LFP signal on gamma frequency bands (30–120 Hz) had the most contribution in the trained decoding model. This study suggests the feasibility of using low number of LFP channels for the continuous force decoding in freely moving animals resembling BMI systems in real life applications. PMID:27767063

  17. Wireless inertial measurement of head kinematics in freely-moving rats

    PubMed Central

    Pasquet, Matthieu O.; Tihy, Matthieu; Gourgeon, Aurélie; Pompili, Marco N.; Godsil, Bill P.; Léna, Clément; Dugué, Guillaume P.

    2016-01-01

    While miniature inertial sensors offer a promising means for precisely detecting, quantifying and classifying animal behaviors, versatile inertial sensing devices adapted for small, freely-moving laboratory animals are still lacking. We developed a standalone and cost-effective platform for performing high-rate wireless inertial measurements of head movements in rats. Our system is designed to enable real-time bidirectional communication between the headborne inertial sensing device and third party systems, which can be used for precise data timestamping and low-latency motion-triggered applications. We illustrate the usefulness of our system in diverse experimental situations. We show that our system can be used for precisely quantifying motor responses evoked by external stimuli, for characterizing head kinematics during normal behavior and for monitoring head posture under normal and pathological conditions obtained using unilateral vestibular lesions. We also introduce and validate a novel method for automatically quantifying behavioral freezing during Pavlovian fear conditioning experiments, which offers superior performance in terms of precision, temporal resolution and efficiency. Thus, this system precisely acquires movement information in freely-moving animals, and can enable objective and quantitative behavioral scoring methods in a wide variety of experimental situations. PMID:27767085

  18. A novel miniature telemetric system for recording EEG activity in freely moving rats.

    PubMed

    Lapray, Damien; Bergeler, Jürgen; Dupont, Erwan; Thews, Oliver; Luhmann, Heiko J

    2008-02-15

    Telemetric recording systems offer the advantage to monitor physiological parameters in freely moving animals without any restrictions in their explorative behaviour. We present a novel, inexpensive, portable and reusable telemetric system to record the electroencephalogram (EEG) from adult freely moving rats under various experimental conditions. Our system consists of an implantable transmitter which communicates at a sampling rate of 500 Hz bi-directional with a receiver via radio transmission (in EU: 868.35 MHz; in USA: 916.5 MHz) over a distance of up to 3m. The switching time between receiving and transmitting signals is 20 mus and the data transmission rate amounts to 115.2 kbps. The receiver is connected to a laptop via an USB connection and the data are displayed and saved by a software developed by the authors. This system allows the simultaneous recording and storage of a video signal for direct comparison of the animal's EEG with its behaviour. EEG recordings could be obtained over 4-5 weeks and under various experimental conditions (i.e. from rats swimming in water). The current system is optimized for recording electrical activity from the animal's brain, but can be easily modified to record other physiological parameters.

  19. Dynamics of freely moving plates connected by a shallow liquid bridge

    NASA Astrophysics Data System (ADS)

    Gat, Amir; Navaz, Homayun; Gharib, Morteza

    2011-09-01

    We study the dynamics of freely moving plates connected by a shallow liquid bridge via analytic and experimental methods. The gap between the plates is used as a small parameter within a lubrication approximation, reducing the problem to an Abel equation of the second kind. Analysis of the governing differential equation yields two novel physical phenomena: (1) An impulse-like peak in the force applied by the liquid bridge on the plates, obtained from a uniform asymptotic solution for small capillary numbers. (2) Both linear and non-linear oscillations of the system for the case of surfaces with low wettability, obtained from small perturbations of the system around the equilibrium point. An experimental setup examining the motion of freely moving plates was constructed, yielding experimental data which compared favorably with the analytic results and specifically displayed the predicted oscillations and impulse-like peak of the applied force. The application of the current analysis to the manipulation of solid bodies and possible future research directions are discussed.

  20. Dynamics of freely moving plates connected by a shallow liquid bridge

    NASA Astrophysics Data System (ADS)

    Gat, Amir; Navaz, Homayun; Gharib, Morteza

    2011-11-01

    We study the dynamics of freely moving solid bodies connected by a shallow liquid bridge via analytic and experimental methods. The gap between the solid bodies is used as a small parameter within a lubrication approximation, reducing the problem to an Abel equation of the second kind. Analysis of the governing differential equation yields two novel physical phenomena: (1) An impulse-like peak in the force applied by the liquid bridge on the solid bodies, obtained from a uniform asymptotic solution for small Capillary numbers. (2) Both linear and non-linear oscillations of the system for the case of surfaces with low wettability, obtained from small perturbations of the system around the equilibrium point. An experimental setup examining the motion of freely moving solid bodies was constructed, yielding experimental data which compared favorably with the analytic results and specifically displayed the predicted oscillations and impulse-like peak of the applied force. The application of the current analysis to the micro-manipulation of solid bodies and possible future research directions are discussed. This project was supported by the Defense Threat Reduction Agency (DTRA), Award Number: 330233-A.

  1. Walking freely in the energy and temperature space by the modified replica exchange molecular dynamics method.

    PubMed

    Chen, Changjun; Huang, Yanzhao

    2016-06-30

    Replica Exchange Molecular Dynamics (REMD) method is a powerful sampling tool in molecular simulations. Recently, we made a modification to the standard REMD method. It places some inactive replicas at different temperatures as well as the active replicas. The method completely decouples the number of the active replicas and the number of the temperature levels. In this article, we make a further modification to our previous method. It uses the inactive replicas in a different way. The inactive replicas first sample in their own knowledge-based energy databases and then participate in the replica exchange operations in the REMD simulation. In fact, this method is a hybrid between the standard REMD method and the simulated tempering method. Using different active replicas, one can freely control the calculation quantity and the convergence speed of the simulation. To illustrate the performance of the method, we apply it to some small models. The distribution functions of the replicas in the energy space and temperature space show that the modified REMD method in this work can let the replicas walk freely in both of the two spaces. With the same number of the active replicas, the free energy surface in the simulation converges faster than the standard REMD. © 2016 Wiley Periodicals, Inc.

  2. Simultaneous optogenetic manipulation and calcium imaging in freely moving C. elegans.

    PubMed

    Shipley, Frederick B; Clark, Christopher M; Alkema, Mark J; Leifer, Andrew M

    2014-01-01

    Understanding how an organism's nervous system transforms sensory input into behavioral outputs requires recording and manipulating its neural activity during unrestrained behavior. Here we present an instrument to simultaneously monitor and manipulate neural activity while observing behavior in a freely moving animal, the nematode Caenorhabditis elegans. Neural activity is recorded optically from cells expressing a calcium indicator, GCaMP3. Neural activity is manipulated optically by illuminating targeted neurons expressing the optogenetic protein Channelrhodopsin. Real-time computer vision software tracks the animal's behavior and identifies the location of targeted neurons in the nematode as it crawls. Patterned illumination from a DMD is used to selectively illuminate subsets of neurons for either calcium imaging or optogenetic stimulation. Real-time computer vision software constantly updates the illumination pattern in response to the worm's movement and thereby allows for independent optical recording or activation of different neurons in the worm as it moves freely. We use the instrument to directly observe the relationship between sensory neuron activation, interneuron dynamics and locomotion in the worm's mechanosensory circuit. We record and compare calcium transients in the backward locomotion command interneurons AVA, in response to optical activation of the anterior mechanosensory neurons ALM, AVM or both.

  3. Wireless inertial measurement of head kinematics in freely-moving rats.

    PubMed

    Pasquet, Matthieu O; Tihy, Matthieu; Gourgeon, Aurélie; Pompili, Marco N; Godsil, Bill P; Léna, Clément; Dugué, Guillaume P

    2016-10-21

    While miniature inertial sensors offer a promising means for precisely detecting, quantifying and classifying animal behaviors, versatile inertial sensing devices adapted for small, freely-moving laboratory animals are still lacking. We developed a standalone and cost-effective platform for performing high-rate wireless inertial measurements of head movements in rats. Our system is designed to enable real-time bidirectional communication between the headborne inertial sensing device and third party systems, which can be used for precise data timestamping and low-latency motion-triggered applications. We illustrate the usefulness of our system in diverse experimental situations. We show that our system can be used for precisely quantifying motor responses evoked by external stimuli, for characterizing head kinematics during normal behavior and for monitoring head posture under normal and pathological conditions obtained using unilateral vestibular lesions. We also introduce and validate a novel method for automatically quantifying behavioral freezing during Pavlovian fear conditioning experiments, which offers superior performance in terms of precision, temporal resolution and efficiency. Thus, this system precisely acquires movement information in freely-moving animals, and can enable objective and quantitative behavioral scoring methods in a wide variety of experimental situations.

  4. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    NASA Astrophysics Data System (ADS)

    Rahmanseresht, Sheema; Milas, Peker; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S.

    2015-05-01

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  5. Passive sampling methods for contaminated sediments: scientific rationale supporting use of freely dissolved concentrations.

    PubMed

    Mayer, Philipp; Parkerton, Thomas F; Adams, Rachel G; Cargill, John G; Gan, Jay; Gouin, Todd; Gschwend, Philip M; Hawthorne, Steven B; Helm, Paul; Witt, Gesine; You, Jing; Escher, Beate I

    2014-04-01

    Passive sampling methods (PSMs) allow the quantification of the freely dissolved concentration (Cfree ) of an organic contaminant even in complex matrices such as sediments. Cfree is directly related to a contaminant's chemical activity, which drives spontaneous processes including diffusive uptake into benthic organisms and exchange with the overlying water column. Consequently, Cfree provides a more relevant dose metric than total sediment concentration. Recent developments in PSMs have significantly improved our ability to reliably measure even very low levels of Cfree . Application of PSMs in sediments is preferably conducted in the equilibrium regime, where freely dissolved concentrations in the sediment are well-linked to the measured concentration in the sampler via analyte-specific partition ratios. The equilibrium condition can then be assured by measuring a time series or a single time point using passive samplers with different surface to volume ratios. Sampling in the kinetic regime is also possible and generally involves the application of performance reference compounds for the calibration. Based on previous research on hydrophobic organic contaminants, it is concluded that Cfree allows a direct assessment of 1) contaminant exchange and equilibrium status between sediment and overlying water, 2) benthic bioaccumulation, and 3) potential toxicity to benthic organisms. Thus, the use of PSMs to measure Cfree provides an improved basis for the mechanistic understanding of fate and transport processes in sediments and has the potential to significantly improve risk assessment and management of contaminated sediments.

  6. Virally mediated optogenetic excitation and inhibition of pain in freely moving non-transgenic mice

    PubMed Central

    Iyer, Shrivats Mohan; Montgomery, Kate L.; Towne, Chris; Lee, Soo Yeun; Ramakrishnan, Charu; Deisseroth, Karl; Delp, Scott L.

    2014-01-01

    Primary nociceptors are the first neurons involved in the complex processing system that regulates normal and pathological pain1. Our ability to excite and inhibit these neurons has been limited by pharmacological and electrical stimulation constraints; non-invasive excitation and inhibition of these neurons in freely moving non-transgenic animals has not been possible. Here we use an optogenetic2 strategy to bidirectionally control nociceptors of non-transgenic mice. Intra-sciatic nerve injection of adeno-associated viruses encoding an excitatory opsin enabled light-inducible stimulation of acute pain, place aversion, and optogenetically mediated reductions in withdrawal thresholds to mechanical and thermal stimuli. In contrast, viral delivery of an inhibitory opsin enabled light-inducible inhibition of acute pain perception, and reversed mechanical allodynia and thermal hyperalgesia in a model of neuropathic pain. Light was delivered transdermally enabling these behaviors to be induced in freely moving animals. This approach may have utility in basic and translational pain research, and enable rapid drug screening and testing of newly engineered opsins. PMID:24531797

  7. Statistics of the electrosensory input in the freely swimming weakly electric fish Apteronotus leptorhynchus.

    PubMed

    Fotowat, Haleh; Harrison, Reid R; Krahe, Rüdiger

    2013-08-21

    The neural computations underlying sensory-guided behaviors can best be understood in view of the sensory stimuli to be processed under natural conditions. This input is often actively shaped by the movements of the animal and its sensory receptors. Little is known about natural sensory scene statistics taking into account the concomitant movement of sensory receptors in freely moving animals. South American weakly electric fish use a self-generated quasi-sinusoidal electric field for electrolocation and electrocommunication. Thousands of cutaneous electroreceptors detect changes in the transdermal potential (TDP) as the fish interact with conspecifics and the environment. Despite substantial knowledge about the circuitry and physiology of the electrosensory system, the statistical properties of the electrosensory input evoked by natural swimming movements have never been measured directly. Using underwater wireless telemetry, we recorded the TDP of Apteronotus leptorhynchus as they swam freely by themselves and during interaction with a conspecific. Swimming movements caused low-frequency TDP amplitude modulations (AMs). Interacting with a conspecific caused additional AMs around the difference frequency of their electric fields, with the amplitude of the AMs (envelope) varying at low frequencies due to mutual movements. Both AMs and envelopes showed a power-law relationship with frequency, indicating spectral scale invariance. Combining a computational model of the electric field with video tracking of movements, we show that specific swimming patterns cause characteristic spatiotemporal sensory input correlations that contain information that may be used by the brain to guide behavior.

  8. Excitation and Inhibition Compete to Control Spiking during Hippocampal Ripples: Intracellular Study in Behaving Mice

    PubMed Central

    English, Daniel F.; Peyrache, Adrien; Stark, Eran; Roux, Lisa; Vallentin, Daniela; Long, Michael A.

    2014-01-01

    High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation of the rhythm and the recruitment of spikes from pyramidal neurons are still poorly understood. Using intracellular, sharp electrode recordings in freely moving, drug-free mice, we observed consistent large depolarizations in CA1 pyramidal cells during sharp wave ripples, which are associated with ripple frequency fluctuation of the membrane potential (“intracellular ripple”). Despite consistent depolarization, often exceeding pre-ripple spike threshold values, current pulse-induced spikes were strongly suppressed, indicating that spiking was under the control of concurrent shunting inhibition. Ripple events were followed by a prominent afterhyperpolarization and spike suppression. Action potentials during and outside ripples were orthodromic, arguing against ectopic spike generation, which has been postulated by computational models of ripple generation. These findings indicate that dendritic excitation of pyramidal neurons during ripples is countered by shunting of the membrane and postripple silence is mediated by hyperpolarizing inhibition. PMID:25471587

  9. Interactions between hippocampus and medial septum during sharp waves and theta oscillation in the behaving rat.

    PubMed

    Dragoi, G; Carpi, D; Recce, M; Csicsvari, J; Buzsáki, G

    1999-07-15

    The medial septal region and the hippocampus are connected reciprocally via GABAergic neurons, but the physiological role of this loop is still not well understood. In an attempt to reveal the physiological effects of the hippocamposeptal GABAergic projection, we cross-correlated hippocampal sharp wave (SPW) ripples or theta activity and extracellular units recorded in the medial septum and diagonal band of Broca (MSDB) in freely moving rats. The majority of single MSDB cells (60%) were significantly suppressed during SPWs. Most cells inhibited during SPW (80%) fired rhythmically and phase-locked to the negative peak of the CA1 pyramidal layer theta waves. Because both SPW and the negative peak of local theta waves correspond to the maximum discharge probability of CA1 pyramidal cells and interneuron classes, the findings indicate that the activity of medial septal neurons can be negatively (during SPW) or positively (during theta waves) correlated with the activity of hippocampal interneurons. We hypothesize that the functional coupling between medial septal neurons and hippocampal interneurons varies in a state-dependent manner.

  10. Deep brain optical measurements of cell type-specific neural activity in behaving mice.

    PubMed

    Cui, Guohong; Jun, Sang Beom; Jin, Xin; Luo, Guoxiang; Pham, Michael D; Lovinger, David M; Vogel, Steven S; Costa, Rui M

    2014-01-01

    Recent advances in genetically encoded fluorescent sensors enable the monitoring of cellular events from genetically defined groups of neurons in vivo. In this protocol, we describe how to use a time-correlated single-photon counting (TCSPC)-based fiber optics system to measure the intensity, emission spectra and lifetime of fluorescent biosensors expressed in deep brain structures in freely moving mice. When combined with Cre-dependent selective expression of genetically encoded Ca(2+) indicators (GECIs), this system can be used to measure the average neural activity from a specific population of cells in mice performing complex behavioral tasks. As an example, we used viral expression of GCaMPs in striatal projection neurons (SPNs) and recorded the fluorescence changes associated with calcium spikes from mice performing a lever-pressing operant task. The whole procedure, consisting of virus injection, behavior training and optical recording, takes 3-4 weeks to complete. With minor adaptations, this protocol can also be applied to recording cellular events from other cell types in deep brain regions, such as dopaminergic neurons in the ventral tegmental area. The simultaneously recorded fluorescence signals and behavior events can be used to explore the relationship between the neural activity of specific brain circuits and behavior.

  11. The cancer gene WWOX behaves as an inhibitor of SMAD3 transcriptional activity via direct binding

    PubMed Central

    2013-01-01

    Background The WW domain containing protein WWOX has been postulated to behave as a tumor suppressor in breast and other cancers. Expression of this protein is lost in over 70% of ER negative tumors. This prompted us to investigate the phenotypic and gene expression effects of loss of WWOX expression in breast cells. Methods Gene expression microarrays and standard in vitro assays were performed on stably silenced WWOX (shRNA) normal breast cells. Bioinformatic analyses were used to identify gene networks and transcriptional regulators affected by WWOX silencing. Co-immunoprecipitations and GST-pulldowns were used to demonstrate a direct interaction between WWOX and SMAD3. Reporter assays, ChIP, confocal microscopy and in silico analyses were employed to determine the effect of WWOX silencing on TGFβ-signaling. Results WWOX silencing affected cell proliferation, motility, attachment and deregulated expression of genes involved in cell cycle, motility and DNA damage. Interestingly, we detected an enrichment of targets activated by the SMAD3 transcription factor, including significant upregulation of ANGPTL4, FST, PTHLH and SERPINE1 transcripts. Importantly, we demonstrate that the WWOX protein physically interacts with SMAD3 via WW domain 1. Furthermore, WWOX expression dramatically decreases SMAD3 occupancy at the ANGPTL4 and SERPINE1 promoters and significantly quenches activation of a TGFβ responsive reporter. Additionally, WWOX expression leads to redistribution of SMAD3 from the nuclear to the cytoplasmic compartment. Since the TGFβ target ANGPTL4 plays a key role in lung metastasis development, we performed a meta-analysis of ANGPTL4 expression relative to WWOX in microarray datasets from breast carcinomas. We observed a significant inverse correlation between WWOX and ANGPTL4. Furthermore, the WWOX lo /ANGPTL4 hi cluster of breast tumors is enriched in triple-negative and basal-like sub-types. Tumors with this gene expression signature could represent

  12. On a family of well behaved perfect fluid balls as astrophysical objects in general relativity

    NASA Astrophysics Data System (ADS)

    Maurya, S. K.; Gupta, Y. K.

    2011-07-01

    A family of well behaved perfect fluid balls has been derived starting with the metric potential g 44= B(1+ Cr 2) n for all positive integral values of n. For n≥4, the members of this family are seen to satisfy the various physical conditions e.g. c 2 ρ≥ p≥0, dp/ dr<0, dρ/ dr<0, along with the velocity of sound (sqrt{dp/c2dρ} )< 1 and the adiabatic index (( p+ c 2 ρ)/ p)( dp/( c 2 dρ))>1. Also the pressure, energy density, velocity of sound and ratio of pressure and energy density are of monotonically decreasing towards the pressure free interface ( r= a). The fluid balls join smoothly with the Schwarzschild exterior model at r= a. The well behaved perfect fluid balls so obtained are utilised to construct the superdense star models with their surface density 2×1014 gm/cm3. We have found that the maximum mass of the fluid balls corresponding to various values of n are decreasing with the increasing values of n. Over all maximum mass for the whole family turns out to be 4.1848 M Θ and the corresponding radius as 19.4144 km while the red shift at the centre and red shift at surface as Z 0=1.6459 and Z a =0.6538 respectively this all happens for n=4. It is interesting to note that for higher values of n viz n≥170, the physical data start merging with that of Kuchowicz superdense star models and hence the family of fluid models tends to the Kuchowicz fluid models as n→∞. Consequently the maximum mass of the family of solution can not be less than 1.6096 M Θ which is the maximum mass occupied by the Kuchowicz superdense ball. Hence each member of the family for n≥4 provides the astrophysical objects like White dwarfs, Quark star, typical neutron star.

  13. Functional contribution of mandibular advancement to awake upper airway patency in obstructive sleep apnea.

    PubMed

    Tsuiki, Satoru; Ryan, C Frank; Lowe, Alan A; Inoue, Yuichi

    2007-12-01

    In the narrowed upper airway of patients with obstructive sleep apnea (OSA), a neuromuscular compensatory mechanism augments the activity of the upper airway dilator muscles in defense of upper airway patency, particularly during inspiration. We hypothesized that mechanical enlargement of the upper airway by a mandibular advancement oral appliance would permit a reduction in this neuromuscular compensation during wakefulness. To test this hypothesis, we focused on changes in the cross-sectional (CS) area of the upper airway before and after emplacement of a ventrally titrated oral appliance in 12 awake OSA patients. The CS areas at the end of tidal expiration (CS area-EET) and at the nadir of intraluminal pressure during inspiration (CS area-IN) were obtained using videoendoscopy. The median apnea-hypopnea index decreased with mandibular advancement. Before mandibular advancement, there was no difference between CS area-EET and CS area-IN in the velopharynx, oropharynx, and hypopharynx. This indicates that upper airway dilator muscle activity increased during inspiration to counteract the intraluminal negative pressure of the upper airway. After mandibular advancement, CS area-EET increased in the velopharynx, oropharynx, and hypopharynx, but CS area-IN was unchanged at any level and was less than CS area-EET in the velopharynx and oropharynx. These findings suggest that mandibular advancement enlarges the upper airway and may reduce upper airway dilator muscle activity during inspiration. We conclude that oral appliances act to return the upper airway towards a normal configuration and pattern of muscle function in OSA patients.

  14. Respiratory pattern in awake rats: effects of motor activity and of alerting stimuli.

    PubMed

    Kabir, Muammar M; Beig, Mirza I; Baumert, Mathias; Trombini, Mimosa; Mastorci, Francesca; Sgoifo, Andrea; Walker, Frederick R; Day, Trevor A; Nalivaiko, Eugene

    2010-08-04

    Our aim was to assess the impact of motor activity and of arousing stimuli on respiratory rate in the awake rats. The study was performed in male adult Sprague-Dawley (SD, n=5) and Hooded Wistar (HW, n=5) rats instrumented for ECG telemetry. Respiratory rate was recorded using whole-body plethysmograph, with a piezoelectric sensor attached for the simultaneous assessment of motor activity. All motor activity was found to be associated with an immediate increase in respiratory rate that remained elevated for the whole duration of movement; this was reflected by: i) bimodal distribution of respiratory intervals (modes for slow peak: 336+/-19 and 532+/-80 ms for HW and SD, p<0.05; modes for fast peak 128+/-6 and 132+/-7 ms for HW and SD, NS); and ii) a tight correlation between total movement time and total time of tachypnoea, with an R(2) ranging 0.96-0.99 (n=10, p<0001). The extent of motor-related tachypnoea was significantly correlated with the intensity of associated movement. Mild alerting stimuli produced stereotyped tachypnoeic responses, without affecting heart rate: tapping the chamber raised respiratory rate from 117+/-7 to 430+/-15 cpm; sudden side move--from 134+/-13 to 487+/-16 cpm, and turning on lights--from 136+/-12 to 507+/-14 cpm (n=10; p<0.01 for all; no inter-strain differences). We conclude that: i) sniffing is an integral part of the generalized arousal response and does not depend on the modality of sensory stimuli; ii) tachypnoea is a sensitive index of arousal; and iii) respiratory rate is tightly correlated with motor activity.

  15. Awake canine fMRI predicts dogs’ preference for praise vs food

    PubMed Central

    Cook, Peter F.; Prichard, Ashley; Spivak, Mark

    2016-01-01

    Dogs are hypersocial with humans, and their integration into human social ecology makes dogs a unique model for studying cross-species social bonding. However, the proximal neural mechanisms driving dog–human social interaction are unknown. We used functional magnetic resonance imaging in 15 awake dogs to probe the neural basis for their preferences for social interaction and food reward. In a first experiment, we used the ventral caudate as a measure of intrinsic reward value and compared activation to conditioned stimuli that predicted food, praise or nothing. Relative to the control stimulus, the caudate was significantly more active to the reward-predicting stimuli and showed roughly equal or greater activation to praise vs food in 13 of 15 dogs. To confirm that these differences were driven by the intrinsic value of social praise, we performed a second imaging experiment in which the praise was withheld on a subset of trials. The difference in caudate activation to the receipt of praise, relative to its withholding, was strongly correlated with the differential activation to the conditioned stimuli in the first experiment. In a third experiment, we performed an out-of-scanner choice task in which the dog repeatedly selected food or owner in a Y-maze. The relative caudate activation to food- and praise-predicting stimuli in Experiment 1 was a strong predictor of each dog’s sequence of choices in the Y-maze. Analogous to similar neuroimaging studies of individual differences in human social reward, our findings demonstrate a neural mechanism for preference in domestic dogs that is stable within, but variable between, individuals. Moreover, the individual differences in the caudate responses indicate the potentially higher value of social than food reward for some dogs and may help to explain the apparent efficacy of social interaction in dog training. PMID:27521302

  16. Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats.

    PubMed

    Quagliotto, E; Casali, K R; Dal Lago, P; Rasia-Filho, A A

    2015-02-01

    The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP50) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP50, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV.

  17. Awake reactivation of emotional memory traces through hippocampal-neocortical interactions.

    PubMed

    de Voogd, Lycia D; Fernández, Guillén; Hermans, Erno J

    2016-07-01

    Emotionally arousing experiences are typically well remembered not only due to immediate effects at encoding, but also through further strengthening of subsequent consolidation processes. A large body of research shows how neuromodulatory systems promote synaptic consolidation. However, how emotionally arousing experiences alter systems-level interactions, presumably a consequence of modifications at a synaptic level, remains unclear. Animal models predict that memory traces are maintained by spontaneous reactivations across hippocampal-neocortical circuits during "offline" periods such as post-learning rest, and suggest this might be stronger for emotional memories. The present study was designed to test this hypothesis in humans using functional Magnetic Resonance Imaging. Participants underwent a two-category localizer paradigm followed by a categorical differential delay fear conditioning paradigm interleaved with blocks of awake rest. Counterbalanced across participants, exemplars of one category (CS+), but not the other (CS-), were paired with mild electrical shocks. Fear recall (differential conditioned pupil dilation) was tested 24h later. Analyses of the localizer paradigm replicate earlier work showing category-specific response patterns in neocortical higher-order visual regions. Critically, we show that during post-learning rest, spontaneous reactivation of these neocortical patterns was stronger for the CS+ than the CS- category. Furthermore, hippocampal connectivity with the regions exhibiting these reactivations predicted strength of fear recall 24h later. We conclude that emotional arousal during learning promotes spontaneous post-learning reactivation of neocortical representations of recent experiences, which leads to better memory when coinciding with hippocampal connectivity. Our findings reveal a systems-level mechanism that may explain the persistence of long-term memory for emotional experiences.

  18. Plasma and CSF oxytocin levels after intranasal and intravenous oxytocin in awake macaques.

    PubMed

    Freeman, Sara M; Samineni, Sridhar; Allen, Philip C; Stockinger, Diane; Bales, Karen L; Hwa, Granger G C; Roberts, Jeffrey A

    2016-04-01

    Oxytocin (OT) is a neuropeptide that mediates a variety of complex social behaviors in animals and humans. Intranasal OT has been used as an experimental therapeutic for human conditions characterized by deficits in social functioning, especially autism spectrum disorder and schizophrenia. However, it is currently under intense debate whether intranasal delivery of OT reaches the central nervous system. In this study, four female rhesus macaques were implanted with chronic intrathecal catheters and used to investigate the pharmacokinetic profile of OT in the central nervous system and the peripheral vasculature following intravenous (IV) and intranasal (IN) administration of OT. In a randomized, crossover design, OT was given to four awake monkeys at three different doses based on body weight (0.1 IU/kg; 1 IU/kg; 5 IU/kg). A time course of concurrent cerebrospinal fluid (CSF) and plasma samples were taken following administration. We found a dose-dependent effect of IV OT treatment on plasma OT levels, which peaked at 5 min post-dose and gradually returned to baseline by 120 min. In contrast, a change in CSF OT was only observed at the highest IV dose (5 IU/kg) at 15 min post-dose and gradually returned to baseline by 120 min. After IN administration, there was no significant change in plasma OT at any of the three doses. However, at the highest dose level, we found a significant increase in CSF OT at 15-30 min post- dose. The results of this study in light of recent, similar publications highlight the importance of methodological consistency across studies. This study also establishes a non-human primate model that can provide a stable platform for carrying out serial sampling from the central nervous system and peripheral vasculature concurrently.

  19. Rapid plasticity follows whisker pairing in barrel cortex of the awake rat.

    PubMed

    Sellien, Heike; Ebner, Ford F

    2007-02-01

    Synaptic plasticity can be induced easily throughout life in the rodent somatic sensory cortex. Trimming all but two whiskers on one side of an adult rat's face, called 'whisker pairing', causes the active (intact) whiskers to develop a stronger drive on cortical cells in their respective barrel columns, while inactive (trimmed) whisker efficacy is down-regulated. To date, this type of activity-dependent plasticity has been induced by trimming all but two whiskers, letting the rats explore their environment from 1 day to 1 month, after which cortical responses were analyzed physiologically under anesthesia. Such studies have enhanced our understanding of cortical plasticity, but the anesthesia complicates the examination of changes that occur in the first few hours after whisker trimming. Here we assayed the short-term changes that occur in alert, active animals over a period of hours after whisker trimming. The magnitude of barrel cortex evoked responses was measured in response to stimulation of the cut and paired whiskers of rats under several conditions: (a) whisking in air (control), (b) active whisking of an object by the rat, and (c) epochs of passive whisker stimulation to identify the onset of whisker pairing plasticity changes in cortex. The main difference between whisking in air without contact and passive whisker stimulation is that the former condition induces an increased response to stimulation of inactive cut whiskers, while the latter condition increases the responses to the stimulated whiskers. The results support the conclusion that whisker pairing plasticity in barrel cortex occurs within 4 h after whisker trimming in an awake, alert animal.

  20. Changes in neurochemicals within the ventrolateral medullary respiratory column in awake goats after carotid body denervation

    PubMed Central

    Miller, Justin Robert; Neumueller, Suzanne; Muere, Clarissa; Olesiak, Samantha; Pan, Lawrence; Hodges, Matthew R.

    2013-01-01

    A current and major unanswered question is why the highly sensitive central CO2/H+ chemoreceptors do not prevent hypoventilation-induced hypercapnia following carotid body denervation (CBD). Because perturbations involving the carotid bodies affect central neuromodulator and/or neurotransmitter levels within the respiratory network, we tested the hypothesis that after CBD there is an increase in inhibitory and/or a decrease in excitatory neurochemicals within the ventrolateral medullary column (VMC) in awake goats. Microtubules for chronic use were implanted bilaterally in the VMC within or near the pre-Bötzinger Complex (preBötC) through which mock cerebrospinal fluid (mCSF) was dialyzed. Effluent mCSF was collected and analyzed for neurochemical content. The goats hypoventilated (peak +22.3 ± 3.4 mmHg PaCO2) and exhibited a reduced CO2 chemoreflex (nadir, 34.8 ± 7.4% of control ΔV̇E/ΔPaCO2) after CBD with significant but limited recovery over 30 days post-CBD. After CBD, GABA and glycine were above pre-CBD levels (266 ± 29% and 189 ± 25% of pre-CBD; P < 0.05), and glutamine and dopamine were significantly below pre-CBD levels (P < 0.05). Serotonin, substance P, and epinephrine were variable but not significantly (P > 0.05) different from control after CBD. Analyses of brainstem tissues collected 30 days after CBD exhibited 1) a midline raphe-specific reduction (P < 0.05) in the percentage of tryptophan hydroxylase–expressing neurons, and 2) a reduction (P < 0.05) in serotonin transporter density in five medullary respiratory nuclei. We conclude that after CBD, an increase in inhibitory neurotransmitters and a decrease in excitatory neuromodulation within the VMC/preBötC likely contribute to the hypoventilation and attenuated ventilatory CO2 chemoreflex. PMID:23869058

  1. Auditory Cortical Responses Elicited in Awake Primates by Random Spectrum Stimuli

    PubMed Central

    Barbour, Dennis L.; Wang, Xiaoqin

    2007-01-01

    Contrary to findings in subcortical auditory nuclei, auditory cortex neurons have traditionally been described as spiking only at the onsets of simple sounds such as pure tones or bandpass noise and to acoustic transients in complex sounds. Furthermore, primary auditory cortex (A1) has traditionally been described as mostly tone responsive and the lateral belt area of primates as mostly noise responsive. The present study was designed to unify the study of these two cortical areas using random spectrum stimuli (RSS), a new class of parametric, wideband, stationary acoustic stimuli. We found that 60% of all neurons encountered in A1 and the lateral belt of awake marmoset monkeys (Callithrix jacchus) showed significant changes in firing rates in response to RSS. Of these, 89% showed sustained spiking in response to one or more individual RSS, a substantially greater percentage than would be expected from traditional studies, indicating that RSS are well suited for studying these two cortical areas. When firing rates elicited by RSS were used to construct linear estimates of frequency tuning for these sustained responders, the shape of the estimate function remained relatively constant throughout the stimulus interval and across the stimulus properties of mean sound level, spectral density, and spectral contrast. This finding indicates that frequency tuning computed from RSS reflects a robust estimate of the actual tuning of a neuron. Use of this estimate to predict rate responses to other RSS, however, yielded poor results, implying that auditory cortex neurons integrate information across frequency nonlinearly. No systematic difference in prediction quality between A1 and the lateral belt could be detected. PMID:12904480

  2. Encoding Odorant Identity by Spiking Packets of Rate-Invariant Neurons in Awake Mice

    PubMed Central

    Gschwend, Olivier; Beroud, Jonathan; Carleton, Alan

    2012-01-01

    Background How do neural networks encode sensory information? Following sensory stimulation, neural coding is commonly assumed to be based on neurons changing their firing rate. In contrast, both theoretical works and experiments in several sensory systems showed that neurons could encode information as coordinated cell assemblies by adjusting their spike timing and without changing their firing rate. Nevertheless, in the olfactory system, there is little experimental evidence supporting such model. Methodology/Principal Findings To study these issues, we implanted tetrodes in the olfactory bulb of awake mice to record the odorant-evoked activity of mitral/tufted (M/T) cells. We showed that following odorant presentation, most M/T neurons do not significantly change their firing rate over a breathing cycle but rather respond to odorant stimulation by redistributing their firing activity within respiratory cycles. In addition, we showed that sensory information can be encoded by cell assemblies composed of such neurons, thus supporting the idea that coordinated populations of globally rate-invariant neurons could be efficiently used to convey information about the odorant identity. We showed that different coding schemes can convey high amount of odorant information for specific read-out time window. Finally we showed that the optimal readout time window corresponds to the duration of gamma oscillations cycles. Conclusion We propose that odorant can be encoded by population of cells that exhibit fine temporal tuning of spiking activity while displaying weak or no firing rate change. These cell assemblies may transfer sensory information in spiking packets sequence using the gamma oscillations as a clock. This would allow the system to reach a tradeoff between rapid and accurate odorant discrimination. PMID:22272291

  3. “Next Door” intraoperative magnetic resonance imaging for awake craniotomy: Preliminary experience and technical note

    PubMed Central

    Mathias, Roger Neves; de Aguiar, Paulo Henrique Pires; da Luz Oliveira, Evandro Pinto; Verst, Silvia Mazzali; Vieira, Vinícius; Docema, Marcos Fernando; Calfat Maldaun, Marcos Vinícius

    2016-01-01

    Background: During glioma surgery “maximal safe resection” must be the main goal. Intraoperative magnetic resonance imaging (iMRI) associated with awake craniotomy (AC) is a valuable tool to achieve this objective. In this article, AC with a “next-door” iMRI concept is described in a stepwise protocol. Methods: This is a retrospective analysis of 18 patients submitted to AC using iMRI; a stepwise protocol is also discussed. Results: The mean age was 41.7 years. Hemiparesis, aphasia, and seizures were the main initial symptoms of the patients. Sixty-six percent of the tumors were located in the left hemisphere. All tumors were near or within eloquent areas. Fifty-three percent of the cases were glioblastomas multiforme and 47% of the patients had low grade gliomas. The mean surgical time and iMRI time were 4 h 4 min and 30 min, respectively. New resection was performed in 33% after iMRI. Extent of resection (EOR) higher than 95% was possible in 66.7% of the patients. The main reason of EOR lower than 95% was positive mapping of eloquent areas (6 patients). Eighty percent of the patients experienced improvement of their deficits immediately after the surgery or had a stable clinical status whereas 20% had neurological deterioration, however, all of them improved after 30 days. Conclusion: AC associated with “next-door” iMRI is a complex procedure, but if performed using a meticulous technique, it may improve the overall tumor resection and safety of the patients. PMID:28144477

  4. Negative Expiratory Pressure Technique: An Awake Test to Measure Upper Airway Collapsibility in Adolescents

    PubMed Central

    Carrera, Helena Larramona; Marcus, Carole L.; McDonough, Joseph M.; Morera, Joan C. Oliva; Huang, Jingtao; Farre, Ramon; Montserrat, Josep M.

    2015-01-01

    Study Objectives: Upper airway (UA) collapsibility is a major pathophysiologic feature of the obstructive sleep apnea syndrome (OSAS). In adolescents, it is measured by obtaining the slope of pressure-flow relationship (SPF) while applying negative nasal pressure during sleep. An easier technique to assess UA collapsibility, consisting of application of negative expiratory pressure (NEP) during wakefulness, has demonstrated differences between control and OSAS subjects. We hypothesized that the NEP technique would correlate with SPF as a measurement of UA collapsibility in adolescents. Design: During wakefulness, NEP of −5 cm H2O in the seated and supine position was applied during the first second of expiration. The area under the expiratory flow-volume curve during NEP was compared to tidal breathing (RatioNEP). In addition, adolescents underwent SPF measurements during sleep. Two SPF techniques were performed to measure the activated and relatively hypotonic UA. Setting: Pediatric sleep laboratory. Participants: Seven adolescents with OSAS and 20 controls. Results: In the seated position, there was a correlation between RatioNEP and both hypotonic SPF (r = −0.39, P = 0.04) and activated SPF (r = −0.62, P = 0.001). In the supine position, there was a correlation between RatioNEP and activated SPF (r = −0.43, P = 0.03) and a trend for hypotonic SPF (r = −0.38, P = 0.06). Conclusions: The negative expiratory pressure (NEP) technique correlates with the hypotonic and activated slope of pressure-flow relationship measurements. The seated position showed the strongest correlation. The NEP technique can be used as an alternative method to evaluate upper airway collapsibility in adolescents. Citation: Carrera HL, Marcus CL, McDonough JM, Morera JC, Huang J, Farre R, Montserrat JM. Negative expiratory pressure technique: an awake test to measure upper airway collapsibility in adolescents. SLEEP 2015;38(11):1783–1791. PMID:26158888

  5. Histamine in the posterodorsal medial amygdala modulates cardiovascular reflex responses in awake rats.

    PubMed

    Quagliotto, E; Neckel, H; Riveiro, D F; Casali, K R; Mostarda, C; Irigoyen, M C; Dall'ago, P; Rasia-Filho, A A

    2008-12-10

    Centrally injected histamine (HA) affects heart rate (HR), arterial blood pressure (BP), and sympathetic activity in rats. The posterodorsal medial amygdala (MePD) has high levels of histidine decarboxylase, connections with brain areas involved with the modulation of cardiovascular responses, and is relevant for the pathogenesis of hypertension. However, there is no report demonstrating the role of the MePD histaminergic activity on the cardiovascular function in awake rats. The aims of the present work were: 1) to study the effects of two doses (10-100 nM) of HA microinjected in the MePD on basal cardiovascular recordings and on baroreflex- and chemoreflex-mediated responses; 2) to reveal whether cardiovascular reflex responses could be affected by MePD microinjections of (R)-alpha-methylhistamine (AH3), an agonist of the inhibitory autoreceptor H3; and, 3) to carry out a power spectral analysis to evaluate the contribution of the sympathetic and parasympathetic components in the variability of the HR and BP recordings. When compared with the control group (microinjected with saline, 0.3 microl), HA (10 nM) promoted an increase in the MAP50, i.e. the mean value of BP at half of the HR range evoked by the baroreflex response. Histamine (100 nM) did not affect the baroreflex activity, but significantly decreased the parasympathetic component of the HR variability, increased the sympathetic/parasympathetic balance at basal conditions (these two latter evaluated by the power spectral analysis), and promoted an impairment in the chemoreflex bradycardic response. Microinjection of AH3 (10 microM) led to mixed results, which resembled the effects of both doses of HA employed here. Present data suggest that cardiovascular changes induced by baroreceptors and chemoreceptors involve the histaminergic activity in the MePD. This neural regulation of reflex cardiovascular responses can have important implications for homeostatic and allostatic conditions and possibly for the

  6. Comparison between remifentanil and dexmedetomidine for sedation during modified awake fiberoptic intubation

    PubMed Central

    LIU, HUI-HUI; ZHOU, TAO; WEI, JIAN-QI; MA, WU-HUA

    2015-01-01

    Cricothyroid membrane injections and the application of a coarse fiberoptic bronchoscope (FOB) below the vocal cords for topical anesthesia have a number of limitations for certain patients. Thus, the aim of the present observational study was to assess the effect of a novel modified topical anesthesia method using the effective sedation drugs, remifentanil (Rem) or dexmedetomidine (Dex), during awake fiberoptic orotracheal intubation (AFOI). In total, 90 adult patients, who had been classified as American Society of Anesthesiologists I–II, were included in the study. The patients had anticipated difficult airways and were to undergo orotracheal intubation for elective surgery. The patients were enrolled in the double-blinded randomized pilot study and received Rem or Dex for sedation during the modified AFOI procedure. The two groups received 2% lidocaine for topical anesthesia via an epidural catheter, which was threaded through the suction channel of the FOB. The main clinical outcomes were evaluated by graded scores representing the conditions for intubation and post-intubation. Additional parameters analyzed included airway obstruction, hemodynamic changes, time required for intubation, amnesia level and subjective satisfaction. All 90 patients were successfully intubated using the modified AFOI technique. The comfort scores and airway events during intubation did not significantly differ between the two groups. However, the Rem group experienced less coughing, and less time was required for tracheal intubation when compared with the Dex group. No statistically significant differences were observed in the changes to the mean arterial pressure and heart rate at any time point between the two groups. Therefore, the current study demonstrated that the modified AFOI method is feasible and effective for difficult airway management, and that Dex and Rem exhibit similar efficacy as adjuvant therapies. PMID:25780419

  7. What keeps us awake? The role of clocks and hourglasses, light, and melatonin.

    PubMed

    Cajochen, Christian; Chellappa, Sarah; Schmidt, Christina

    2010-01-01

    What is it that keeps us awake? Our assumption is that we consciously control our daily activities including sleep-wake behavior, as indicated by our need to make use of an alarm clock to wake up in the morning in order to be at work on time. However, when we travel across multiple time zones or do shift work, we realize that our intentionally planned timings to rest and to remain active can interfere with an intrinsic regulation of sleep/wake cycles. This regulation is driven by a small region in the anterior hypothalamus of the brain, termed as the "circadian clock". This clock spontaneously synchronizes with the environmental light-dark cycle, thus enabling all organisms to adapt to and anticipate environmental changes. As a result, the circadian clock actively gates sleep and wakefulness to occur in synchrony with the light-dark cycles. Indeed, our internal clock is our best morning alarm clock, since it shuts off melatonin production and boosts cortisol secretion and heart rate 2-3h prior awakening from Morpheus arms. The main reason most of us still use artificial alarm clocks is that we habitually carry on a sleep depth and/or the sleep-wake timing is not ideally matched with our social/work schedule. This in turn can lead hourglass processes, as indexed by accumulated homeostatic sleep need over time, to strongly oppose the clock. To add to the complexity of our sleep and wakefulness behavior, light levels as well as exogenous melatonin can impinge on the clock, by means of their so-called zeitgeber (synchronizer) role or by acutely promoting sleep or wakefulness. Here we attempt to bring a holistic view on how light, melatonin, and the brain circuitry underlying circadian and homeostatic processes can modulate sleep and in particular alertness, by actively promoting awakening/arousal and sleep at certain times during the 24-h day.

  8. Activity of Caudate Nucleus Neurons in a Visual Fixation Paradigm in Behaving Cats

    PubMed Central

    Nagypál, Tamás; Gombkötő, Péter; Barkóczi, Balázs; Benedek, György; Nagy, Attila

    2015-01-01

    Beside its motor functions, the caudate nucleus (CN), the main input structure of the basal ganglia, is also sensitive to various sensory modalities. The goal of the present study was to investigate the effects of visual stimulation on the CN by using a behaving, head-restrained, eye movement-controlled feline model developed recently for this purpose. Extracellular multielectrode recordings were made from the CN of two cats in a visual fixation paradigm applying static and dynamic stimuli. The recorded neurons were classified in three groups according to their electrophysiological properties: phasically active (PAN), tonically active (TAN) and high-firing (HFN) neurons. The response characteristics were investigated according to this classification. The PAN and TAN neurons were sensitive primarily to static stimuli, while the HFN neurons responded primarily to changes in the visual environment i.e. to optic flow and the offset of the stimuli. The HFNs were the most sensitive to visual stimulation; their responses were stronger than those of the PANs and TANs. The majority of the recorded units were insensitive to the direction of the optic flow, regardless of group, but a small number of direction-sensitive neurons were also found. Our results demonstrate that both the static and the dynamic components of the visual information are represented in the CN. Furthermore, these results provide the first piece of evidence on optic flow processing in the CN, which, in more general terms, indicates the possible role of this structure in dynamic visual information processing. PMID:26544604

  9. Seeing the whole picture: A comprehensive imaging approach to functional mapping of circuits in behaving zebrafish.

    PubMed

    Feierstein, C E; Portugues, R; Orger, M B

    2015-06-18

    In recent years, the zebrafish has emerged as an appealing model system to tackle questions relating to the neural circuit basis of behavior. This can be attributed not just to the growing use of genetically tractable model organisms, but also in large part to the rapid advances in optical techniques for neuroscience, which are ideally suited for application to the small, transparent brain of the larval fish. Many characteristic features of vertebrate brains, from gross anatomy down to particular circuit motifs and cell-types, as well as conserved behaviors, can be found in zebrafish even just a few days post fertilization, and, at this early stage, the physical size of the brain makes it possible to analyze neural activity in a comprehensive fashion. In a recent study, we used a systematic and unbiased imaging method to record the pattern of activity dynamics throughout the whole brain of larval zebrafish during a simple visual behavior, the optokinetic response (OKR). This approach revealed the broadly distributed network of neurons that were active during the behavior and provided insights into the fine-scale functional architecture in the brain, inter-individual variability, and the spatial distribution of behaviorally relevant signals. Combined with mapping anatomical and functional connectivity, targeted electrophysiological recordings, and genetic labeling of specific populations, this comprehensive approach in zebrafish provides an unparalleled opportunity to study complete circuits in a behaving vertebrate animal.

  10. Quantum-behaved particle swarm optimization: analysis of individual particle behavior and parameter selection.

    PubMed

    Sun, Jun; Fang, Wei; Wu, Xiaojun; Palade, Vasile; Xu, Wenbo

    2012-01-01

    Quantum-behaved particle swarm optimization (QPSO), motivated by concepts from quantum mechanics and particle swarm optimization (PSO), is a probabilistic optimization algorithm belonging to the bare-bones PSO family. Although it has been shown to perform well in finding the optimal solutions for many optimization problems, there has so far been little analysis on how it works in detail. This paper presents a comprehensive analysis of the QPSO algorithm. In the theoretical analysis, we analyze the behavior of a single particle in QPSO in terms of probability measure. Since the particle's behavior is influenced by the contraction-expansion (CE) coefficient, which is the most important parameter of the algorithm, the goal of the theoretical analysis is to find out the upper bound of the CE coefficient, within which the value of the CE coefficient selected can guarantee the convergence or boundedness of the particle's position. In the experimental analysis, the theoretical results are first validated by stochastic simulations for the particle's behavior. Then, based on the derived upper bound of the CE coefficient, we perform empirical studies on a suite of well-known benchmark functions to show how to control and select the value of the CE coefficient, in order to obtain generally good algorithmic performance in real world applications. Finally, a further performance comparison between QPSO and other variants of PSO on the benchmarks is made to show the efficiency of the QPSO algorithm with the proposed parameter control and selection methods.

  11. Well-behaved dynamics in a dissipative nonideal periodically kicked rotator.

    PubMed

    Chacón, R; Martínez García-Hoz, A

    2003-12-01

    Well-behaved dynamical properties are found in a dissipative kicked rotator subjected to a periodic string of asymmetric pulses of finite amplitude and width. The stability boundaries of the equilibrium are determined to arbitrary approximation for trigonometric pulses by means of circular harmonic balance, and to first approximation for general elliptic pulses by means of an elliptic harmonic balance method. The bifurcation behavior at the stability boundaries is determined numerically. We show how the extension of the instability region of the equilibrium in pulse parameter space reaches a maximum as the pulse width is varied. We also characterize the dependence of the mean duration of the transients to the equilibrium on the pulse width. The evolution of the basins of attraction of chaotic attractors when solely the pulse width is varied is characterized numerically. Finally, we show that the order-chaos route when solely the width of the pulses is altered appears to be especially rich, including different types of crises. The mechanism underlying these reshaping-induced crises is discussed with the aid of a two-dimensional map.

  12. Methods for functional magnetic resonance imaging in normal and lesioned behaving monkeys.

    PubMed

    Pinsk, Mark A; Moore, Tirin; Richter, Marlene C; Gross, Charles G; Kastner, Sabine

    2005-04-30

    Methods for performing functional magnetic resonance imaging (fMRI) studies in behaving and lesioned monkeys using a human MR scanner are reported. Materials for head implant surgery were selected based on tests for magnetic susceptibility. A primate chair with a rigid head fixation system and a mock scanner environment for training were developed. To perform controlled visual studies, monkeys were trained to maintain fixation for several minutes using a novel training technique that utilized continuous juice rewards. A surface coil was used to acquire anatomical and functional images in four monkeys, one with a partial lesion of striate cortex. High-resolution anatomical images were used after non-uniform intensity correction to create cortical surface reconstructions of both lesioned and normal hemispheres. Our methods were confirmed in two visual experiments, in which functional activations were obtained during both free viewing and fixation conditions. In one experiment, face-selective activity was found in the fundus and banks of the superior temporal sulcus and the middle temporal gyrus in monkeys viewing pictures of faces and objects while maintaining fixation. In a second experiment, regions in occipital, parietal, and frontal cortex were activated in lesioned and normal animals viewing a cartoon movie. Importantly, in the animal with the striate lesion, fMRI signals were obtained in the immediate vicinity of the lesion. Our results extend those previously reported by providing a detailed account of the technique and by demonstrating the feasibility of fMRI in monkeys with lesions.

  13. The embodiment of tourism among bisexually-behaving Dominican male sex workers.

    PubMed

    Padilla, Mark B

    2008-10-01

    While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality.

  14. A Valuable and Promising Method for Recording Brain Activity in Behaving Newborn Rodents

    PubMed Central

    Sokoloff, Greta; Tiriac, Alexandre; Del Rio-Bermudez, Carlos

    2015-01-01

    Neurophysiological recording of brain activity has been critically important to the field of neuroscience, but has contributed little to the field of developmental psychobiology. The reasons for this can be traced largely to methodological difficulties associated with recording neural activity in behaving newborn rats and mice. Over the last decade, however, the evolution of methods for recording from head-fixed newborns has heralded a new era in developmental neurophysiology. Here, we review these recent developments and provide a step-by-step primer for those interested in applying the head-fix method to their own research questions. Until now, this method has been used primarily to investigate spontaneous brain activity across sleep and wakefulness, the contributions of the sensory periphery to brain activity, or intrinsic network activity. Now, with some ingenuity, the uses of the head-fix method can be expanded to other domains to benefit our understanding of brain-behavior relations under normal and pathophysiological conditions across early development. PMID:25864710

  15. Pericytes of Multiple Organs Do Not Behave as Mesenchymal Stem Cells In Vivo.

    PubMed

    Guimarães-Camboa, Nuno; Cattaneo, Paola; Sun, Yunfu; Moore-Morris, Thomas; Gu, Yusu; Dalton, Nancy D; Rockenstein, Edward; Masliah, Eliezer; Peterson, Kirk L; Stallcup, William B; Chen, Ju; Evans, Sylvia M

    2017-03-02

    Pericytes are widely believed to function as mesenchymal stem cells (MSCs), multipotent tissue-resident progenitors with great potential for regenerative medicine. Cultured pericytes isolated from distinct tissues can differentiate into multiple cell types in vitro or following transplantation in vivo. However, the cell fate plasticity of endogenous pericytes in vivo remains unclear. Here, we show that the transcription factor Tbx18 selectively marks pericytes and vascular smooth muscle cells in multiple organs of adult mouse. Fluorescence-activated cell sorting (FACS)-purified Tbx18-expressing cells behaved as MSCs in vitro. However, lineage-tracing experiments using an inducible Tbx18-CreERT2 line revealed that pericytes and vascular smooth muscle cells maintained their identity in aging and diverse pathological settings and did not significantly contribute to other cell lineages. These results challenge the current view of endogenous pericytes as multipotent tissue-resident progenitors and suggest that the plasticity observed in vitro or following transplantation in vivo arises from artificial cell manipulations ex vivo.

  16. A class of well-behaved generalized charged analogues of Vaidya-Tikekar type fluid sphere in general relativity

    NASA Astrophysics Data System (ADS)

    Kumar, Jitendra; Gupta, Y. K.

    2014-05-01

    In this paper first ever we have developed a class of well behaved charged fluid spheres expressed by a space time with its hypersurfaces . as spheroid for the case 0< K<1 with surface density 2×1014 gm/cm3. The same utilized to construct a superdense star and seen that star satisfies all well behaved condition for 0< K≤0.038. The maximum mass occupied and the corresponding radius are found to be 4.830982M Θ and 20.7612 km respectively. The redshift at the center and on the surface is given z 0=0.425367 and z a =0.240901.

  17. Extrinsic tongue and suprahyoid muscle activities during mastication in freely feeding rabbits.

    PubMed

    Inoue, Makoto; Ariyasinghe, Sajjiv; Yamamura, Kensuke; Harasawa, Yohji; Yamada, Yoshiaki

    2004-09-24

    To evaluate the coordination of tongue and suprahyoid muscle activities during natural mastication, electromyograms (EMGs) of jaw-closer, jaw-opener, suprahyoid (mylohyoid, MH), tongue-retractor (styloglossus, SG) and tongue-protractor (genioglossus, GG) muscles were recorded as well as the jaw-movement trajectories in vertical and horizontal axes in awake rabbits. Each masticatory cycle had three components including the fast-closing (FC), slow-closing (SC) and opening (Op) phases. The duration of the SC phase was much longer during pellet chewing while the durations of the FC and Op phases were much shorter during pellet chewing than bread or banana chewing. The jaw movements during banana chewing had a small amplitude of lateral excursion and a large amplitude of gape as compared with those during pellet and bread chewing. The MH muscle exhibited double-peaked EMG bursts during the Op phase. The MH bursts in the late part of the Op phase were dominant on the non-chewing side during pellet and bread chewing. The SG muscle also exhibited double-peaked EMG bursts. During pellet and bread chewing, the SG bursts during the SC phase were significantly larger on the chewing side than the non-chewing side. These bursts were also dominant during pellet chewing as compared with banana chewing. There was little difference in the GG bursts between the chewing and non-chewing sides or among the foods. Our results suggest that patterns of the MH and SG muscle activity are affected by the peripheral inputs and/or chewing patterns while those of the GG muscle activity was less modulated regardless of the consistency of foods.

  18. [The effects of selective 5HT3 receptor blockade on physiological markers of abdominal pain in awake dogs].

    PubMed

    Panteleev, S S; Busygina, I I; Liubashina, O A

    2013-04-01

    In awake dogs, the visceromotor and cardioautonomic responses to the rectal balloon distension were studied before and after intravenous administration of a selective 5HT3 receptor antagonist granisetron. It was shown that balloon distension level up to 60 mmHg caused neither noticeable muscle responses nor substantial changes in heart rate. In turn, distending pressures of 80 mmHg and higher induced vigorous abdominal muscle contractions and tachycardia that were graded with increasing intensities of stimulation. Thus, the rectal stimulation with pressures 80 mmHg and more produced the changes in visceromotor and cardiovascular indices which could be considered as suitable indicators of visceral nociception in conscious animals. Based on monitoring of these physiological markers in a model of abdominal pain the dose-dependent antinociceptive effect of granisetron in awake dogs has been demonstrated for the first time. It was determined that granisetron in doses of 0.25, 0.5 or 1.0 mg/kg induced correspondingly 33.6 +/- 9.2, 58.0+/- 8.6 [see text] 76.7 +/- 5.5 % decrease in visceromotor response of dogs to nociceptive visceral stimulation. The effect occurred immediately after the drug administration and was lasting more than 90 min. In turn, the dose-dependent suppression of the rectal distension-induced tachycardia was less prominent and only observed during the initial period of granisetron action. The described model of abdominal pain in awake dogs might be useful for preclinical screening of new pharmacological substances, whereas the obtained data could contribute to the development of more efficient analgesics aimed in patients with irritable bowel syndrome.

  19. Comparison between human awake, meditation and drowsiness EEG activities based on directed transfer function and MVDR coherence methods.

    PubMed

    Dissanayaka, Chamila; Ben-Simon, Eti; Gruberger, Michal; Maron-Katz, Adi; Sharon, Haggai; Hendler, Talma; Cvetkovic, Dean

    2015-07-01

    This study examined the electroencephalogram functional connectivity (coherence) and effective connectivity (flow of information) of selected brain regions during three different attentive states: awake, meditation and drowsiness. For the estimation of functional connectivity (coherence), Welch and minimum variance distortionless response (MVDR) methods were compared. The MVDR coherence was found to be more suitable since it is both data and frequency dependent and enables higher spectral resolution, while Welch's periodogram-based approach is both data and frequency independent. The directed transfer function (DTF) method was applied in order to estimate the effective connectivity or brain's flow of information between different regions during each state. DTF enables to identify the main brain areas that initiate EEG activity and the spatial distribution of these activities with time. Analysis was conducted using the EEG data of 30 subjects (ten awake, ten drowsy and ten meditating) focusing on six main electrodes (F3, F4, C3, C4, P3, P4, O1 and O2). For each subject, EEG data were recorded during 5-min baseline and 15 min of a specific condition (awake, meditation or drowsiness). Statistical analysis included the Kruskal-Wallis (KW) nonparametric analysis of variance followed by post hoc tests with Bonferroni alpha correction. The results reveal that both states of drowsiness and meditation states lead to a marked difference in the brain's flow of information (effective connectivity) as shown by DTF analyses. In specific, a significant increase in the flow of information in the delta frequency band was found only in the meditation condition and was further found to originate from frontal (F3, F4), parietal (P3, P4) and occipital (O1, O2) regions. Altogether, these results suggest that a change in attentiveness leads to significant changes in the spectral profile of the brain's information flow as well as in its functional connectivity and that these changes can

  20. Reduction of pentylenetetrazole-induced seizure activity in awake rats by seizure-triggered trigeminal nerve stimulation.

    PubMed

    Fanselow, E E; Reid, A P; Nicolelis, M A

    2000-11-01

    Stimulation of the vagus nerve has become an effective method for desynchronizing the highly coherent neural activity typically associated with epileptic seizures. This technique has been used in several animal models of seizures as well as in humans suffering from epilepsy. However, application of this technique has been limited to unilateral stimulation of the vagus nerve, typically delivered according to a fixed duty cycle, independently of whether ongoing seizure activity is present. Here, we report that stimulation of another cranial nerve, the trigeminal nerve, can also cause cortical and thalamic desynchronization, resulting in a reduction of seizure activity in awake rats. Furthermore, we demonstrate that providing this stimulation only when seizure activity begins results in more effective and safer seizure reduction per second of stimulation than with previous methods. Seizure activity induced by intraperitoneal injection of pentylenetetrazole was recorded from microwire electrodes in the thalamus and cortex of awake rats while the infraorbital branch of the trigeminal nerve was stimulated via a chronically implanted nerve cuff electrode. Continuous unilateral stimulation of the trigeminal nerve reduced electrographic seizure activity by up to 78%, and bilateral trigeminal stimulation was even more effective. Using a device that automatically detects seizure activity in real time on the basis of multichannel field potential signals, we demonstrated that seizure-triggered stimulation was more effective than the stimulation protocol involving a fixed duty cycle, in terms of the percent seizure reduction per second of stimulation. In contrast to vagus nerve stimulation studies, no substantial cardiovascular side effects were observed by unilateral or bilateral stimulation of the trigeminal nerve. These findings suggest that trigeminal nerve stimulation is safe in awake rats and should be evaluated as a therapy for human seizures. Furthermore, the results

  1. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla

    PubMed Central

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H.; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1–3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1–6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla

  2. Oscillatory patterns in hippocampus under light and deep isoflurane anesthesia closely mirror prominent brain states in awake animals.

    PubMed

    Lustig, Brian; Wang, Yingxue; Pastalkova, Eva

    2016-01-01

    The hippocampus exhibits a variety of distinct states of activity under different conditions. For instance the rhythmic patterns of activity orchestrated by the theta oscillation during running and REM sleep are markedly different from the large irregular activity (LIA) observed during