Tseng Kuei Y, Mallet Nicolas, Toreson Kathy L, Le Moine Catherine, Gonon François, O'Donnell Patricio
Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York 12208, USA.
Synapse. 2006 Jun 1;59(7):412-7. doi: 10.1002/syn.20255.
Prefrontal cortical (PFC) pyramidal neurons (PN) and fast spiking interneurons (FSI) receive dopaminergic (DA) and non-DA inputs from the ventral tegmental area (VTA). Although the responses of PN to VTA stimulation and DA administration have been extensively studied, little is known about the response of FSI to mesocortical activation. We explored this issue using single and double in vivo juxtacellular recordings of medial PFC PN and FSI with chemical VTA stimulation. Electrophysiological characteristics combined with Neurobiotin staining and parvalbumin immunohistochemistry allowed identification of recorded cells as FSI or PN. NMDA injection into the VTA increased firing in all FSI tested (n = 7), whereas most PN (7/11) responded with an inhibition. Furthermore, FSI excitation matching the temporal course of PN inhibition was observed with FSI-PN paired recordings (n = 5). These divergent electrophysiological responses to mesocortical activation could reflect PFC GABAergic interneurons contributing to silencing PN. Thus, the mesocortical system could provide a critical control of PFC circuits by simultaneously affecting FSI and PN firing.
前额叶皮质（PFC）锥体神经元（PN）和快速放电中间神经元（FSI）从腹侧被盖区（VTA）接收多巴胺能（DA）和非多巴胺能输入。尽管对PN对VTA刺激和多巴胺给药的反应已进行了广泛研究，但关于FSI对中皮质激活的反应却知之甚少。我们使用内侧PFC的PN和FSI的单细胞和双细胞体内近胞记录结合化学VTA刺激来探究这个问题。电生理特征结合神经生物素染色和小白蛋白免疫组织化学可将记录的细胞鉴定为FSI或PN。向VTA注射N-甲基-D-天冬氨酸（NMDA）可增加所有测试的FSI（n = 7）的放电，而大多数PN（7/11）则表现为抑制反应。此外，在FSI-PN配对记录中（n = 5）观察到FSI兴奋与PN抑制的时间进程相匹配。这些对中皮质激活的不同电生理反应可能反映了PFCγ-氨基丁酸能中间神经元对PN沉默的作用。因此，中皮质系统可能通过同时影响FSI和PN的放电来对PFC回路提供关键控制。
