Cortical GABAergic Cell Subtypes and Their Synaptic Connections

皮层γ-氨基丁酸（GABA）能细胞的亚型及其突触联系本实验对离体大鼠额叶皮层GABA能细胞的生理、形态、免疫组化和药理学特性进行了研究。(1)大的GABA能篮状细胞的生理和化学异质性。胆囊收缩素（CCK）细胞和小清蛋白细胞使终扣与其他细胞体并置。小清蛋白细胞属于快速尖峰（FS）细胞。与此相反，CCK细胞被发现是规则尖峰（RS）或爆发尖峰（BS）的非锥体（NP）细胞。大的生长抑素细胞属于RSNP类别，这似乎并不像大的CCK和小清蛋白细胞那样频繁地与胞体并列。(2)皮质GABA能细胞亚型的选择性胆碱能调节。胆碱能或毒蕈碱激动剂确实通过兴奋抑制性中间神经元在锥体细胞中诱导GABA能突触后电流。卡巴胆碱或毒蕈碱影响含肽GABA能细胞活性 ...更多信息 ls，但不包括含有小白蛋白的快峰型GABA能细胞和晚峰型GABA能细胞。生长抑素或VIP细胞去极化与尖峰放电。CCK细胞受到胆碱能激动剂的不均匀影响。较大的CCK细胞超极化后缓慢去极化，而较小的CCK细胞仅去极化。(3)GABA能细胞类型的去甲肾上腺素能兴奋和抑制。去甲肾上腺素（NA）和α-肾上腺素能激动剂6-氟肾上腺素（FNE）可引起锥体细胞IPSC频率的增加，而β-肾上腺素能激动剂则不能。这种增加被河豚毒素、荷包牡丹碱和α-肾上腺素能拮抗剂降低，表明GABA能细胞通过α-肾上腺素受体兴奋。快峰或晚峰细胞去极化的应用NA或FNE，但没有表现出尖峰放电。大多数生长抑素细胞去极化，并伴有锋电位放电。在少数情况下，这之前是超极化。胆囊收缩素细胞的影响是不均匀的：去极化，超极化，然后去极化，或超极化的结果。少

Cortical GABAergic Cell Subtypes and Their Synaptic ConnectionsPhysiological, morphological immunohistochemical and pharmacological characteristics of GABAergic cells in rat frontal cortex of rats were studied in vitro. (1) Physiological and chemical heterogeneity of large GABAergic basket cells. Cholecystokinin (CCK) cells and parvalbumin cells made boutons apposed to other cell bodies. Parvalbumin cells belonged to fast-spiking (FS) cells. In contrast, CCK cells were found to be regular-spiking (RS) or burst-spiking (BS) nonpyramidal (NP) cells. Large somatostatin cells belonged to the RSNP category which did not seem to be apposed to the somata so frequently as large CCK and parvalbumin cells. (2) Selective cholinergic modulation of cortical GABAergic cell subtypes. Cholinergic or muscarinic agonists indeed induced GABAergic postsynaptic currents in pyramidal cells by exciting inhibitory interneurons. Carbachol or muscarine affected the activities of peptide-containing GABAergic cel … More ls, but not of GABAergic cells of fast-spiking characteristics containing parvalbumin and GABAergic cells of late-spiking characteristics. Somatostatin or VIP cells were depolarized with spike firing. CCK cells were affected heterogeneously by cholinergic agonists. Larger CCK cells were hyperpolarized followed by a slow depolarization, whereas smaller CCK cells were only depolarized. (3) Noradrenergic excitation and inhibition of GABAergic cell types. Noradrenaline (NA) and an a-adrenergic agonist, 6 fluoronorepinephrine (FNE) induced an increase of IPSC frequency in pyramidal cells, but not a b-adrenergic agonist. This increase was reduced by tetrodotoxin, bicuculline and a-adrenergic antagonists, suggesting that GABAergic cells are excited via a-adrenoceptors. Fast spiking or late spiking cells were depolarized by application of NA or FNE, but none demonstrated spike firings. Most somatostatin cells were depolarized, accompanied by spike firing. In a few cases this was preceded by hyperpolarization. Cholecystokinin cells were affected heterogeneously: depolarization, hyperpolarization followed by depolarization, or hyperpolarization resulted. Less