Quantitative analysis of synaptic contacts on cortical pyramidal cells

2017 Fiscal Year Final Research Report

• Project/Area Number: 25290012
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Neurophysiology / General neuroscience
• Research Institution: National Institute for Physiological Sciences
• Principal Investigator: Kubota Yoshiyuki 生理学研究所, 基盤神経科学研究領域, 准教授 (90192567)
• Project Period (FY): 2013-04-01 – 2018-03-31
• Keywords: 大脳皮質 / 神経回路 / 錐体細胞 / 非錐体細胞 / 抑制 / 可塑性 / in vivo imaging / シナプス

Outline of Final Research Achievements

Understanding the brain’s circuit architecture is critical to elucidating its function. We quantitatively analyzed synapse distribution on layer 5 pyramidal cell of rat cortex and found the cell receive totally about 20,000 synapses. About 20 % of them are inhibitory synapse. The inhibitory synapse junction size is varied and correlated with their target size. It probably acts for an efficient inhibition. We found that inhibitory synapses on dendritic spines are exceptionally dynamic as compared to other synaptic populations, due to the fact that a large proportion of them disappear and recur again in the same location on a timescale of days. Inhibitory synapses are often found on dendritic spines which receive direct thalamic input. Thus, the function of inhibitory synaptic remodeling at this locale may serve as a mechanism for gating feedforward excitation, rather than, as proposed for excitatory synapses, as a mechanism to remodel circuitry and exchange partners.

Free Research Field

神経科学