Department of Neuroscience, City University of Hong Kong, Hong Kong, China.
Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.
FASEB J. 2021 Oct;35(10):e21944. doi: 10.1096/fj.202100757R.
Information represented by principal neurons in anterior piriform cortex (APC) is regulated by local, recurrent excitation and inhibition, but the circuit mechanisms remain elusive. Two types of layer 2 (L2) principal neurons, semilunar (SL), and superficial pyramidal (SP) cells, are parallel output channels, and the control of their activity gates the output of APC. Here, we examined the hypothesis that recurrent inhibition differentially regulates SL and SP cells. Patterned optogenetic stimulation revealed that the strength of recurrent inhibition is target- and layer-specific: L1 > L3 for SL cells, but L3 > L1 for SP cells. This target- and layer-specific inhibition was largely attributable to the parvalbumin (PV), but not somatostatin, interneurons. Intriguingly, olfactory experience selectively modulated the PV to SP microcircuit while maintaining the overall target and laminar specificity of inhibition. Together, these results indicate the importance of target-specific inhibitory wiring for odor processing, implicating these mechanisms in gating the output of piriform cortex.
前梨状皮层 (APC) 中的主要神经元所表示的信息受到局部、递归兴奋和抑制的调节，但回路机制仍不清楚。两种类型的 2 层 (L2) 主要神经元，半月形 (SL) 和浅层金字塔形 (SP) 细胞，是平行的输出通道，其活动的控制决定了 APC 的输出。在这里，我们检验了这样一个假设，即递归抑制对 SL 和 SP 细胞有不同的调节作用。模式化的光遗传刺激表明，递归抑制的强度具有靶区和层特异性：对于 SL 细胞，L1 > L3，但对于 SP 细胞，L3 > L1。这种靶区和层特异性抑制主要归因于 PV，但不是 SST 中间神经元。有趣的是，嗅觉经验选择性地调节了 PV 到 SP 的微电路，同时保持了抑制的总体靶区和层特异性。总之，这些结果表明，目标特异性抑制性连接对于嗅觉处理很重要，这些机制参与了梨状皮层输出的门控。
