retrograde-fluorescent-labeling-allows-for-targeted-extracellular

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons <em>In vivo</em>

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Washington University in St. Louis 

Nagoya University

The coding of stimulus information into patterns of spike times occurs widely in sensory systems. Determining how temporally coded information is decoded by central neurons is essential to understanding how brains process sensory stimuli. Mormyrid weakly electric fishes are experts at time coding, making them an exemplary organism for addressing this question. Mormyrids generate brief, stereotyped electric pulses. Pulse waveform carries information about sender identity, and it is encoded into submillisecond-to-millisecond differences in spike timing between receptors. Mormyrids vary the time between pulses to communicate behavioral state, and these intervals are encoded into the sequence of interspike intervals within receptors. Thus, the responses of peripheral electroreceptors establish a temporally multiplexed code for communication signals, one consisting of spike timing differences between receptors and a second consisting of interspike intervals within receptors. These signals are processed in a dedicated sensory pathway, and recent studies have shed light on the mechanisms by which central circuits can extract behaviorally relevant information from multiplexed temporal codes. Evolutionary change in the anatomy of this pathway is related to differences in electrosensory perception, which appears to have influenced the diversification of electric signals and species. However, it remains unknown how this evolutionary change relates to differences in sensory coding schemes, neuronal circuitry and central sensory processing. The mormyrid electric communication pathway is a powerful model for integrating mechanistic studies of temporal coding with evolutionary studies of correlated differences in brain and behavior to investigate neural mechanisms for processing temporal codes.

Multiplexed temporal coding of electric communication signals in mormyrid fishes.

Le codage de l&#39;information de stimulation en une s&eacute;rie de reprises de spike est r&eacute;pandue dans les syst&egrave;mes sensoriels. Information comment temporellement cod&eacute;e d&eacute;terminante est d&eacute;cod&eacute;e en neurones centraux est essentielle pour comprendre comment le cerveau processus stimuli sensoriels. Mormyridae faiblement poissons &eacute;lectriques sont des experts en temps de codage, ce qui les rend un organisme exemplaire pour r&eacute;pondre &agrave; cette question. Mormyrid&eacute;s g&eacute;n&egrave;rent des impulsions &eacute;lectriques br&egrave;ves et st&eacute;r&eacute;otyp&eacute;es. Forme d&#39;onde de pouls transporte des informations sur l&#39;identit&eacute; de l&#39;exp&eacute;diteur, et submillisecond-&agrave;-milliseconde des diff&eacute;rences de minutage de pointe entre les r&eacute;cepteurs, il est cod&eacute;. Mormyrid&eacute;s varient le temps entre deux impulsions pour communiquer l&#39;&eacute;tat comportemental, et ces intervalles sont cod&eacute;s dans la s&eacute;quence des intervalles de stimuli dans les r&eacute;cepteurs. Ainsi, les r&eacute;ponses des p&eacute;riph&eacute;riques &eacute;lectror&eacute;cepteurs &eacute;tablissent un code temporel multiplex&eacute; pour signaux de communication, un compos&eacute; du spike calendrier les diff&eacute;rences entre les r&eacute;cepteurs et l&#39;autre consistant en des intervalles de stimuli dans les r&eacute;cepteurs. Ces signaux sont trait&eacute;s dans une voie sensorielle d&eacute;di&eacute;e, et des &eacute;tudes r&eacute;centes ont mis en lumi&egrave;re les m&eacute;canismes en qui les circuits centraux peuvent extraire des informations pertinentes sur le plan comportemental multiplex&eacute;s codes temporels. Changements &eacute;volutifs dans l&#39;anatomie de cette voie est li&eacute;e aux diff&eacute;rences de perception &eacute;lectrosensoriel, qui semble avoir influenc&eacute; la diversification des esp&egrave;ces et des signaux &eacute;lectriques. Cependant, on ne sait toujours comment cette &eacute;volution est li&eacute;e &agrave; des diff&eacute;rences dans les syst&egrave;mes de codage sensoriels, circuit neuronal et centre de traitement sensoriel. La voie de communication &eacute;lectrique Mormyridae est un mod&egrave;le puissant pour l&#39;int&eacute;gration des &eacute;tudes m&eacute;canistes de codage temporel avec des &eacute;tudes sur l&#39;&eacute;volution des diff&eacute;rences corr&eacute;l&eacute;es dans le cerveau et le comportement d&#39;enqu&ecirc;ter sur les m&eacute;canismes neuronaux pour le traitement des codes temporels.

Tsunehiko Kohashi

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