創薬科学研究科主催 第81回創薬科学セミナー
概要 | Network-Level Control of Frequency Tuning in Auditory Cortex |
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日時 | 2018年08月06日月曜日・15:30-17:00 |
場所 | 創薬科学研究館 2階 講義室(205) |
講師 | 加藤 紘之 博士(ノースカロライナ大学 チャペルヒル校 神経科学センター・研究室主宰者) |
連絡先 | 小坂田 文隆(6814) |
ファイル | 1533175735第81回創薬科学セミナー.pdf |
Lateral inhibition is a fundamental circuit operation that sharpens the tuning properties of cortical neurons. This operation is classically attributed to an increase in GABAergic synaptic input triggered by non-preferred stimuli. Here we use in vivo whole-cell recording and two-photon Ca2+ imaging in awake mice to show that lateral inhibition shapes frequency tuning in primary auditory cortex via an unconventional mechanism: non-preferred tones suppress both excitatory and inhibitory synaptic inputs onto layer 2/3 cells ("network suppression"). Moreover, optogenetic inactivation of inhibitory interneurons elicits a paradoxical increase in inhibitory synaptic input. These results indicate that GABAergic interneurons regulate cortical activity indirectly via the suppression of recurrent excitation (inhibition-stabilized network model), rather than via the direct inhibition. Together with our previous finding that inhibitory SOM cells are regulated by the behavioral relevance attached
to sounds, these results demonstrate a dynamic nature of sensory tuning that is enabled by cortical inhibitory circuits.
to sounds, these results demonstrate a dynamic nature of sensory tuning that is enabled by cortical inhibitory circuits.