title: Functional Organization of Flash-Induced V1 Offline Reactivation.
abstract: The primary visual cortex exhibits a late, long response with a latency of >300 ms and an immediate early response that occurs ∼100 ms after a visual stimulus. The late response is thought to contribute to visual functions such as sensory perception, iconic memory, working memory, and forming connections between temporally separated stimuli. However, how the visual late response is generated and organized is not completely understood. In the mouse primary visual cortex in vivo, we isolated long-delayed responses by using a brief light-flash stimulus for which the stimulus late response occurred long after the stimulus offset and was not contaminated by the instantaneous response evoked by the stimulus. Using whole-cell patch-clamp recordings, we demonstrated that the late rebound response was shaped by a net-balanced increase in excitatory and inhibitory synaptic conductances, whereas transient imbalances were caused by intermittent inhibitory barrage. In contrast to the common assumption that the neocortical late response reflects a feedback signal from the downstream higher-order cortical areas, our pharmacological and optogenetic analyses demonstrated that the late responses likely have a thalamic origin. Therefore, the late component of a sensory-evoked cortical response should be interpreted with caution.
  
  
  
  The long-delayed responses of neocortical neurons are thought to arise from cortical feedback activity that is related to sensory perception and cognition. The mechanism of neocortical late responses was investigated using multiple electrophysiological techniques and the findings indicate that it actually arises from the thalamus. In addition, during the late response, excitation and inhibition are balanced, but inhibition is dominant in patterning action potentials.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Funayama
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka 565-0871, Japan, and.|Graduate School of Frontier Biosciences, Osaka University, Suita City, Osaka 565-0871, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hagura
authors.affiliation: Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka 565-0871, Japan, and.|Graduate School of Frontier Biosciences, Osaka University, Suita City, Osaka 565-0871, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ban
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan, yuji@ikegaya.jp.|Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka 565-0871, Japan, and.
authors.forename: Yuji
authors.identifier: 0000-0003-2260-8191
authors.initials: Y
authors.lastname: Ikegaya
mesh_terms: D000328:Adult; D000818:Animals; D063132:Connectome / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009415:Nerve Net / Q000502:physiology / Q000528:radiation effects; D009433:Neural Inhibition / Q000502:physiology* / Q000528:radiation effects; D009434:Neural Pathways / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology* / Q000528:radiation effects; D014793:Visual Cortex / Q000502:physiology* / Q000528:radiation effects*; D014796:Visual Perception / Q000502:physiology* / Q000528:radiation effects
keywords: bottom-up; patch-clamp; top-down; visual cortex