title: CCK-8S increases the firing frequency of CCK-positive neurons and facilitates excitatory synaptic transmission in primary rat hippocampal neurons.
abstract: The neuropeptide cholecystokinin octapeptide (CCK) is involved in a variety of brain functions. In the hippocampus, most CCK is released from CCK-positive (CCK+) neurons, but the effects of CCK on CCK+ neurons are poorly understood. We employed primary hippocampal cultures to explore the modulatory effect of CCK on CCK+ neurons. CCK-8S (0.2 μM) was added to the culture medium from day in vitro 2 (DIV-2) to DIV-11. An adenovirus integrated with the CCK promoter was used to label CCK+ neurons. Whole-cell patch clamp recording was carried on to record the electrophysiology properties. The results show that: (1) CCK-8S significantly decreased membrane capacity but increased the membrane resistance (Rm) of CCK+ neurons, (2) CCK-8S increased action potential (AP) firing frequency of CCK+ neurons but did not affect the firing pattern, (3) CCK-8S facilitated CCK+ neuron excitatory synaptic transmission but attenuated inhibitory synaptic transmission, and (4) the expression of postsynaptic density-95 (PSD-95) in cultured hippocampal neurons was elevated by CCK-8S treatment. Our results demonstrate that CCK-8S significantly alters the membrane electrophysiological characteristics and synaptic activity of cultured hippocampal CCK+ neurons. These findings may enhance our understanding of the modulatory effect of CCK in the brain.
authors.affiliation: Zhejiang Provincial Key Laboratory of Pathophysiology, Department of Physiology and Pharmacology, Ningbo University, School of Medicine, Ningbo 315211, China. weixiaofei_ff@hotmail.com
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Wei
authors.forename: Yang-Hui
authors.initials: YH
authors.lastname: Zhang
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Zhang
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Xu
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Chen
authors.forename: Chuang
authors.initials: C
authors.lastname: Wang
authors.forename: Jun-Qiang
authors.initials: JQ
authors.lastname: Si
authors.forename: Ke-Tao
authors.initials: KT
authors.lastname: Ma
authors.forename: Qin-Wen
authors.initials: QW
authors.lastname: Wang
mesh_terms: D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002478:Cells, Cultured; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects* / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C090019:8-sulfocholecystokinin octapeptide; D012844:Sincalide
keywords: CCK-positive neuron; Cholecystokinin; Hippocampus; Interneuron; Whole-cell patch clamp