This research was supported by grants from the German Research Foundation (DFG) to MCS (FOR 1581, STU 544/1-1) and OG (FOR 1581, SFB 874). The website of the DFG is http://www.dfg.de/en/index.jsp. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The authors thank Thomas Seidenbecher for providing us with the gold-plating protocol as well as Tobias Otto for help with setting up the electrophysiological recording equipment.

<ol>
	<li>Bingman, V. P., Gasser, B. A., Colombo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+of+pigeon+(Columba+livia)+wulst+neurons+during+acquisition+and+reversal+of+a+visual+discrimination+task.">Responses of pigeon (Columba livia) wulst neurons during acquisition and reversal of a visual discrimination task.</a> Behav Neurosci. 122, 1139-1147 (2008).</li><li>Herry, C., Ciocchi, S., Senn, V., Demmou, L., M&#252;ller, C., L&#252;thi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switching+on+and+off+fear+by+distinct+neuronal+circuits.">Switching on and off fear by distinct neuronal circuits.</a> Nature. 454, 600-606 (2008).</li><li>Quirk, G. J., Repa, C., LeDoux, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fear+conditioning+enhances+short-latency+auditory+responses+of+lateral+amygdala+neurons:+parallel+recordings+in+the+freely+behaving+rat.">Fear conditioning enhances short-latency auditory responses of lateral amygdala neurons: parallel recordings in the freely behaving rat.</a> Neuron. 15, 1029-1039 (1995).</li><li>Quirk, G. J., Armony, J. L., Ledoux, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Components+of+Tone-Evoked+Spike+Trains+in+Auditory+Cortex+and+Lateral+Amygdala.">Components of Tone-Evoked Spike Trains in Auditory Cortex and Lateral Amygdala.</a> Neuron. 19, 613-624 (1997).</li><li>Maren, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+fear+conditioning+increases+CS-elicited+spike+firing+in+lateral+amygdala+neurons+even+after+extensive+overtraining.">Auditory fear conditioning increases CS-elicited spike firing in lateral amygdala neurons even after extensive overtraining.</a> Eur J Neurosci. 12, 4047-4054 (2000).</li><li>Milad, M. R., Quirk, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurons+in+medial+prefrontal+cortex+signal+memory+for+fear+extinction.">Neurons in medial prefrontal cortex signal memory for fear extinction.</a> Nature. 420, 713-717 (2002).</li><li>Hobin, J. A., Goosens, K. A., Maren, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Context-dependent+neuronal+activity+in+the+lateral+amygdala+represents+fear+memories+after+extinction.">Context-dependent neuronal activity in the lateral amygdala represents fear memories after extinction.</a> J Neurosci. 23, 8410-8416 (2003).</li><li>Maren, S., Hobin, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+regulation+of+context-dependent+neuronal+activity+in+the+lateral+amygdala.">Hippocampal regulation of context-dependent neuronal activity in the lateral amygdala.</a> Learn Mem. 14, 318-324 (2007).</li><li>Knapska, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+involvement+of+the+central+amygdala+in+appetitive+versus+aversive+learning.">Differential involvement of the central amygdala in appetitive versus aversive learning.</a> Learn Mem. 13, 192-200 (2006).</li><li>Harloe, J. P., Thorpe, A. J., Lichtman, A. 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C., Kasties, N., Lengersdorf, D., Starosta, S., G&#252;nt&#252;rk&#252;n, O., J&#228;kel, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suboptimal+criterion+setting+in+a+perceptual+choice+task+with+asymmetric+reinforcement.">Suboptimal criterion setting in a perceptual choice task with asymmetric reinforcement.</a> Behav Processes. 96, 59-70 (2013).</li><li>Rose, J., Otto, T., Dittrich, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Biopsychology-Toolbox:+a+free,+open-source+Matlab-toolbox+for+the+control+of+behavioral+experiments.">The Biopsychology-Toolbox: a free, open-source Matlab-toolbox for the control of behavioral experiments.</a> J Neurosci Methods. 175, (2008).</li><li>Bilkey, D. K., Muir, G. 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The authors have nothing to disclose.

This protocol describes a complex behavioral task suitable for concurrent single-unit recordings. We have described the SIFC task for pigeons, but it can be easily adapted to rodents&#160;by requiring nose pokes or lever pressing rather than key pecks, and substituting visual by olfactory, auditory, or tactile stimuli.
Perhaps the most critical steps during the training procedure are 1) gradual reduction of reward probability and 2) increase in trial number. Regarding intermittent reinforcemen...

Learning new stimulus-response-outcome associations engages a wide range of neural plasticity processes. These processes are ultimately reflected in the changing spike output of individual neurons. Arguably, one of the most frequently employed learning paradigms is Pavlovian fear conditioning conducted with rodents. In this setting, the acquisition and extinction of a conditioned response take place within a few dozen trials2. The rapid development of conditioned fear can be advantageous because it allows running a large number of animals within a short time. Also, acquisition and extinction can be observed within a few tens of trials on a single day in naive animals3,4 or spread across 2&#160;to 3&#160;days2,5-8. However, the insights gained about the changes of neural activity during learning in these experiments do not necessarily apply outside the domain of fear conditioning. For example, goal-directed behavior driven by positive reinforcement is more adequately modeled by operant rather than Pavlovian conditioning procedures, and may in part depend on different neural substrates9,10. Also, fear conditioning develops so rapidly that neural responses to the CS can only be observed for a few dozen trials, placing severe limits on the analysis of changes of neural activity during learning.
Unfortunately, the acquisition and extinction of operant responding usually takes many days. This is detrimental for neurophysiological investigations, because it is notoriously difficult to record the activity of single cells over more than a few hours. Due to the high similarity of the waveforms of extracellularly recorded action potentials, it is problematic to claim that spikes recorded on one day are generated from the same cell as spikes with similar waveforms recorded on the next11,12, especially in areas with a high cell density such as the hippocampus.
To address these issues, we developed a novel behavioral paradigm utilizing 3&#160;learning conditions within one experimental session on a single day. This requires that the experimental animal is willing to perform hundreds of trials under varying conditions on a thin schedule of reinforcement. Homing pigeons (Columbia livia forma domestica) are classic model organisms in experimental psychology13-17. These birds are able to perform complex visual discriminations18, can flexibly adapt behavior to changing reinforcement contingencies19,20, and are uniquely avid workers, performing 1,000 trials with minimal amount of reinforcement. These characteristics make them especially suitable for the experiments described below.

<table><tbody><tr><td>Resistance wire (for use as electrodes)</td><td>California Fine Wire, Grover Beach, CA, USA</td><td></td><td>Stablohm 675; formvar-coated nichrome wires (outer diameter 25 &amp;micro;m)</td></tr><tr><td>Microconnectors</td><td>Ginder Scientific, Nepean, Ontario, Canada</td><td></td><td>GS18PLG-220 (plug) &amp;amp; GS18SKT-220 (socket to build headstage)</td></tr><tr><td>Cannulae</td><td>Henke Sass Wolf, Tuttlingen, Germany</td><td></td><td>0.4 x 20 mm/ 27 Gx3/4&quot;</td></tr><tr><td>Gold solution for plating</td><td>Neuralynx, Bozeman, MT, USA</td><td></td><td>SIFCO Process Gold Non-Cyanide, Code 5355</td></tr><tr><td>Solution for ultrasonic bath</td><td>Alconox, Inc., New York, USA</td><td>1304</td><td>Tergazyme</td></tr><tr><td>Conductive glue</td><td>Henkel Loctite</td><td></td><td>LOCTITE 3888 Silver filled, conductive, adhesive</td></tr><tr><td>Stainless steel screws</td><td>J.I. Morris, Southbridge, MA, USA</td><td></td><td>F0CE125 self-tapping miniature screws, body length 1/8 inches</td></tr><tr><td>Light-curing dental cement</td><td>van der Ven Dental, Duisburg, Germany</td><td></td><td>Omniceram Evo Flow A2</td></tr><tr><td>Light-curing unit</td><td>van der Ven Dental, Duisburg, Germany</td><td></td><td>Jovident Excelled 215 Curing Light (wireless LED light curing unit)</td></tr><tr><td>Filter amplifiers</td><td>npi electronic GmbH, Germany</td><td>DPA-2FS</td><td></td></tr><tr><td>A/D converter</td><td>Cambridge Electronic Design, Cambridge, UK</td><td>power 1401</td><td></td></tr><tr><td>Spike2 software</td><td>Cambridge Electronic Design, Cambridge, UK</td><td></td><td>Version 7.06a</td></tr><tr><td>MATLAB</td><td>The Mathworks, Natick, MA, USA</td><td></td><td>R2012a</td></tr></tbody></table>

recording single neurons' action potentials from freely moving pigeons across three stages of learning

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman&#160;et al.1 for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity.
Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons&#39; action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning.

Behavior
Figure 4A shows the behavioral performance of an animal in one example session. The performance level of the animal reaches criterion for NS 2 within 180 trials (45 stimulus presentations) and is close to 100% for the NS 1 from the beginning. This strategy - first responding to the same key for both new stimuli, and then adjusting responses for one of the stimuli - is about as often observed as initial random responding to both NS. In this session, the NS 2 was randomly ...

Watch this Scientific Journal Video about Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning at JoVE.com

Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session.

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed ...

recording-single-neurons-action-potentials-from-freely-moving-pigeons

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

11.9K Views.  Ruhr-University Bochum. Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session.

Video: Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

A Fully Automated and Highly Versatile System for Testing Multi-cognitive Functions and Recording Neuronal Activities in Rodents

We have developed a fully automated system for operant behavior testing and neuronal activity recording by which multiple cognitive brain functions can be investigated in a single task sequence. The unique feature of this system is a custom-made, acoustically transparent chamber that eliminates many of the issues associated with auditory cue control in most commercially available chambers. The ease with which operant devices can be added or replaced makes this system quite versatile, allowing for the implementation of a variety of auditory, visual, and olfactory behavioral tasks. Automation of the system allows fine temporal (10 ms) control and precise time-stamping of each event in a predesigned behavioral sequence. When combined with a multi-channel electrophysiology recording system, multiple cognitive brain functions, such as motivation, attention, decision-making, patience, and rewards, can be examined sequentially or independently.

In this report, we present a fully automated and highly versatile system capable of simultaneously testing multi-cognitive behaviors and recording neuronal activities for rodents.

We have developed a fully automated system for operant behavior testing and neuronal activity recording by which multiple cognitive brain functions can be ...

Recordings of Neural Circuit Activation in Freely Behaving Animals

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. Traditional non-invasive methods require at least partially restrained research subjects, and they only allow identification of large numbers of simultaneously activated neurons. On the other hand, small ensembles of neurons or individual neurons can only be measured using single-cell recordings obtained from largely reduced preparations. Since the expression of natural behavior is limited in restrained and dissected animals, the underlying neural mechanisms that control such behavior are difficult to identify. 
Here, I present a non-invasive physiological technique that allows measuring neural circuit activation in freely behaving animals. Using a pair of wire electrodes inside a water-filled chamber, the bath electrodes record neural and muscular field potentials generated by juvenile crayfish during natural or experimentally evoked escape responses. The primary escape responses of crayfish are mediated by three different types of tail-flips which move the animals away from the point of stimulation. Each type of tail-flip is controlled by its own neural circuit; the two fastest and most powerful escape responses require activation of different sets of large &#8220;command&#8221; neurons. In combination with behavioral observations, the bath electrode recordings allow unambiguous identification of these neurons and the associated neural circuits. Thus activity of neural circuitry underlying naturally occurring behavior can be measured in unrestrained animals and in different behavioral contexts.

Non-invasive measurements of neural activity patterns in freely behaving animals are obtained by combining neurophysiological recordings with high speed videography.

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. ...

Biology

A Procedure for Implanting Organized Arrays of Microwires for Single-unit Recordings in Awake, Behaving Animals

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell level. The technique allows experimenters to examine temporally and regionally specific firing patterns in order to correlate recorded action potentials with ongoing behavior. Moreover, single-unit recordings can be combined with a plethora of other techniques in order to produce comprehensive explanations of neural function. In this article, we describe the anesthesia and preparation for microwire implantation. Subsequently, we enumerate the necessary equipment and surgical steps to accurately insert a microwire array into a target structure. Lastly, we briefly describe the equipment used to record from each individual electrode in the array. The fixed microwire arrays described are well-suited for chronic implantation and allow for longitudinal recordings of neural data in almost any behavioral preparation. We discuss tracing electrode tracks to triangulate microwire positions as well as ways to combine microwire implantation with immunohistochemical techniques in order to increase the anatomical specificity of recorded results.

Implanting organized arrays of microwires for use in single-unit electrophysiological recordings presents a number of technical challenges.&#160;Methods for performing this technique and the equipment necessary are described.&#160;Also, the beneficial use of organized microwire arrays to record from distinct neural subregions with high spatial selectivity is discussed.

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell ...

Juxtacellular Monitoring and Localization of Single Neurons within Sub-cortical Brain Structures of Alert, Head-restrained Rats

There are a variety of techniques to monitor extracellular activity of single neuronal units. However, monitoring this activity from deep brain structures in behaving animals remains a technical challenge, especially if the structures must be targeted stereotaxically. This protocol describes convenient surgical and electrophysiological techniques that maintain the animal&#8217;s head in the stereotaxic plane and unambiguously isolate the spiking activity of single neurons. The protocol combines head restraint of alert rodents, juxtacellular monitoring with micropipette electrodes, and iontophoretic dye injection to identify the neuron location in post-hoc histology. While each of these techniques is in itself well-established, the protocol focuses on the specifics of their combined use in a single experiment. These neurophysiological and neuroanatomical techniques are combined with behavioral monitoring. In the present example, the combined techniques are used to determine how self-generated vibrissa movements are encoded in the activity of neurons within the somatosensory thalamus. More generally, it is straightforward to adapt this protocol to monitor neuronal activity in conjunction with a variety of behavioral tasks in rats, mice, and other animals. Critically, the combination of these methods allows the experimenter to directly relate anatomically-identified neurophysiological signals to behavior.

This protocol describes the design and surgical implantation of a head-restraining mechanism to monitor neuronal activity in sub-cortical brain structures in alert rats. It delineates procedures to isolate single neurons in the juxtacellular configuration and to efficiently identify their anatomical locations.

There are a variety of techniques to monitor extracellular activity of single neuronal units. However, monitoring this activity from deep brain structures ...

Simultaneous Long-term Recordings at Two Neuronal Processing Stages in Behaving Honeybees

In both mammals and insects neuronal information is processed in different higher and lower order brain centers. These centers are coupled via convergent and divergent anatomical connections including feed forward and feedback wiring. Furthermore, information of the same origin is partially sent via parallel pathways to different and sometimes into the same brain areas. To understand the evolutionary benefits as well as the computational advantages of these wiring strategies and especially their temporal dependencies on each other, it is necessary to have simultaneous access to single neurons of different tracts or neuropiles in the same preparation at high temporal resolution. Here we concentrate on honeybees by demonstrating a unique extracellular long term access to record multi unit activity at two subsequent neuropiles1, the antennal lobe (AL), the first olfactory processing stage and the mushroom body (MB), a higher order integration center involved in learning and memory formation, or two parallel neuronal tracts2 connecting the AL with the MB.&#160;The latter was chosen as an example and will be described in full. In the supporting video the construction and permanent insertion of flexible multi&#160;channel wire electrodes is demonstrated. Pairwise differential amplification of the micro&#160;wire electrode channels drastically reduces the noise and verifies that the source of the signal is closely related to the position of the electrode tip. The mechanical flexibility of the used wire electrodes allows stable invasive long&#160;term recordings over many hours up to days, which is a clear advantage compared to conventional extra&#160;and intracellular in vivo recording techniques.

Simultaneous extracellular long term recordings from two different brain neuropiles or two different anatomical tracts were established in honeybees. These recordings allow the investigation of temporal aspects of neuronal processing across different brain areas at the single neuron as well as at the ensemble level in a behaving animal.

In both mammals and insects neuronal information is processed in different higher and lower order brain centers. These centers are coupled via convergent ...

Extracellular Recording of Neuronal Activity Combined with Microiontophoretic Application of Neuroactive Substances in Awake Mice

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and awake animals. Therefore, methods allowing the manipulation of synaptic systems in awake animals are required in order to determine the contribution of synaptic inputs to neuronal processing unaffected by anesthetics. Here, we present methodology for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. By combining these procedures, we performed microiontophoretic injections of gabazine to selectively block GABAA receptors in neurons of the inferior colliculus of head-restrained mice. Gabazine successfully modified neural response properties such as the frequency response area and stimulus-specific adaptation. Thus, we demonstrate that our methods are suitable for recording single-unit activity and for dissecting the role of specific neurotransmitter receptors in auditory processing.
The main limitation of the described procedure is the relatively short recording time (~3 hr), which is determined by the level of habituation of the animal to the recording sessions. On the other hand, multiple recording sessions can be performed in the same animal. The advantage of this technique over other experimental procedures used to manipulate the level of neurotransmission or neuromodulation (such as systemic injections or the use of optogenetic models), is that the drug effect is confined to the local synaptic inputs to the target neuron. In addition, the custom-manufacture of electrodes allows adjustment of specific parameters according to the neural structure and type of neuron of interest (such as the tip resistance for improving the signal-to-noise ratio of the recordings).

We present methods for the construction of electrodes to simultaneously record extracellular neural activity and release multiple neuroactive substances at the vicinity of the recording sites in awake mice. This technique allows the detailed analysis of putative local synaptic inputs to the neuron of interest.

Differences in the activity of neurotransmitters and neuromodulators, and consequently different neural responses, can be found between anesthetized and ...

Extracellular Electrophysiological Recording in the Motor Cortex of Mice

Multichannel Extracellular Recording in Freely Moving Mice

The protocol aims to uncover the properties of neuronal firing and network local field potentials (LFPs) in behaving mice carrying out specific tasks by correlating the electrophysiological signals with spontaneous and/or specific behavior. This technique represents a valuable tool in studying the neuronal network activity underlying these behaviors. The article provides a detailed and complete procedure for electrode implantation and consequent extracellular recording in free-moving conscious mice. The study includes a detailed method for implanting the microelectrode arrays, capturing the LFP and neuronal spiking signals in the motor cortex (MC) using a multichannel system, and the subsequent offline data analysis. The advantage of multichannel recording in conscious animals is that a greater number of spiking neurons and neuronal subtypes can be obtained and compared, which allows the evaluation of the relationship between a specific behavior and the associated electrophysiological signals. Notably, the multichannel extracellular recording technique and the data analysis procedure described in the present study can be applied to other brain areas when conducting experiments in behaving mice.

Author Spotlight: Advancements in Multichannel Extracellular Recording for Studying Neuronal Activity in Freely Moving Mice 

The protocol describes the methodology of extracellular recording in the motor cortex (MC) to reveal extracellular electrophysiological properties in freely moving conscious mice, as well as the data analysis of local field potentials (LFPs) and spikes, which is useful for evaluating the network neural activity underlying behaviors of interest.

The protocol aims to uncover the properties of neuronal firing and network local field potentials (LFPs) in behaving mice carrying out specific tasks by ...

Angled Silicon Multielectrode Recordings for Deep Brainstem Structures in Mice

Acute Single-Unit Multi-Electrode Recordings from the Brainstem of Head-Fixed Mice

Silicon multielectrode-based recordings are increasingly popular for studying neuronal activity at the temporal resolution of action potentials in many brain regions. However, recording neuronal activity from deep caudal structures like the brainstem using multi-channel probes remains challenging. A significant concern is finding a trajectory for probe insertion that avoids large blood vessels, such as the superior sagittal venous sinus and the transverse venous sinus. Injuring these large veins can cause extensive bleeding, damage to the underlying brain tissue, and potentially death. This approach describes targeting brainstem structures by coupling anterior coordinates with an angled approach, allowing the recording probe to penetrate the brain below high-risk vascular structures. Compared to a strictly vertical approach, the angled approach maximizes the number of brain regions that can be targeted. Using this strategy, the ventrolateral periaqueductal gray (vlPAG), a brainstem region associated with REM sleep, can be reproducibly and reliably accessed to obtain single-unit, multi-electrode recordings in head-fixed mice before and during sevoflurane anesthesia. The ability to record neuronal activity in the vlPAG and surrounding nuclei with high temporal resolution is a step forward in advancing the understanding of the relationship between REM sleep and anesthesia.

Author Spotlight: Investigating Anesthesia-Induced Sleep Pathways and Neuronal Excitability in Mice

This protocol describes a method to obtain in vivo, high-density single-neuron recordings from the brainstem of head-fixed mice. This approach is deployed to measure the action potential firing of neurons in the ventrolateral periaqueductal gray - a brainstem region inactive during Rapid Eye Movement (REM) sleep - before and during general anesthesia.

Silicon multielectrode-based recordings are increasingly popular for studying neuronal activity at the temporal resolution of action potentials in many ...

Photodiode-Based Optical Imaging for Recording Network Dynamics with Single-Neuron Resolution in Non-Transgenic Invertebrates

The development of transgenic invertebrate preparations in which the activity of specifiable sets of neurons can be recorded and manipulated with light represents a revolutionary advance for studies of the neural basis of behavior. However, a downside of this development is its tendency to focus investigators on a very small number of &#8220;designer&#8221; organisms (e.g., C. elegans and Drosophila), potentially negatively impacting the pursuit of comparative studies across many species, which is needed for identifying general principles of network function. The present article illustrates how optical recording with voltage-sensitive dyes in the brains of non-transgenic gastropod species can be used to rapidly (i.e., within the time course of single experiments) reveal features of the functional organization of their neural networks with single-cell resolution. We outline in detail the dissection, staining, and recording methods used by our laboratory to obtain action potential traces from dozens to ~150 neurons during behaviorally relevant motor programs in the CNS of multiple gastropod species, including one new to neuroscience &#8211; the nudibranch Berghia stephanieae. Imaging is performed with absorbance voltage-sensitive dyes and a 464-element photodiode array that samples at 1,600 frames/second, fast enough to capture all action potentials generated by the recorded neurons. Multiple several-minute recordings can be obtained per preparation with little to no signal bleaching or phototoxicity. The raw optical data collected through the methods described can subsequently be analyzed through a variety of illustrated methods. Our optical recording approach can be readily used to probe network activity in a variety of non-transgenic species, making it well suited for comparative studies of how brains generate behavior.

This protocol presents a method for imaging neuronal population activity with single-cell resolution in non-transgenic invertebrate species using absorbance voltage-sensitive dyes and a photodiode array. This approach enables a rapid workflow, wherein imaging and analysis can be pursued over the course of a single day.

The development of transgenic invertebrate preparations in which the activity of specifiable sets of neurons can be recorded and manipulated with light ...

Recording of Induced Seizures through Electroencephalography in Freely Moving Rat Pups

Source: Huo, Q. et al. <a href="https://appjove.unicartagenaproxy.elogim.com/v/55489">Recording EEG in Freely Moving Neonatal Rats Using a Novel Method.</a> J. Vis. Exp. (2017)
The video demonstrates the recording of electroencephalogram (EEG) signals from seizure-induced rat pups. Take a freely moving pup implanted with electrodes connected to a data acquisition system. A neurotoxin is administered to induce epileptic seizures, and the resulting electrical bursting activity is monitored using the EEG signal.

Rejestracja indukowanych napadów za pomocą elektroencefalografii u swobodnie poruszających się szczeniąt szczurów

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
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