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Electrophysiological characteristics of hippocampal postnatal early development mediated by AMPA receptors in rats

CHEN Xue-Yi¹, ZHANG Ai-Feng², Zhao Wen^1,3,4, GAO Yu-Dan^1,3,4, DUAN Hong-Mei^1,3,4, HAO Peng^1,3,4, ANG Zhao-Yang^1,3,4, LI Xiao-Guang^1,3,4,*

¹Department of Neurobiology, Capital Medical University, Beijing 100069, China；²Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China；³Beijing Key Laboratory for Biomaterials and Neural Regeneration, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China；⁴Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100191, China

Abstract

The present study was aimed to investigate the electrophysiological characteristics of hippocampal postnatal early development mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in rats. Forty-eight Wistar rats were divided into postnatal 0.5-, 1-, 2- and 3-month groups (n = 12). Spontaneous excitatory postsynaptic currents (sEPSCs) and field excitatory postsynaptic potentials (fEPSPs) mediated by AMPA receptors were recorded to evaluate the changes in the intrinsic membrane properties of hippocampal CA1 pyramidal neurons by using patch-clamp and MED64 planar microelectrode array technique respectively. The results showed that, during the period of postnatal 0.5–3 months, some of the intrinsic membrane properties of hippocampal CA1 pyramidal neurons, such as the membrane capacitance (Cm) and the resting membrane potential (RMP), showed no significant changes, while the membrane input resistance (Rin) and the time constant (τ) of the cells were decreased significantly. The amplitude, frequency and kinetics (both rise and decay times) of sEPSCs were significantly increased during the period of postnatal 0.5–1 month, but they were all decreased during the period of postnatal 1–3 months. In addition, the range of evoked fEPSPs in hippocamal CA1 region was significantly expanded, but the fEPSP amplitudes were decreased significantly during the period of postnatal 0.5–3 months. Furthermore, the evoked fEPSPs could be significantly inhibited by extracellular application of the AMPA receptor antagonist 6-cyano- 7-nitroquinoxaline-2,3-dione (CNQX). These results suggest that AMPA receptor may act as a major type of excitatory receptor to regulate synaptic transmission and connections during the early stage of hippocampal postnatal development, which promotes the development and functional maturation of hippocampus in rats.

Key words: AMPA receptor; early postnatal development; patch clamp technique; planar microelectrode array recording technique

Received: 2017-12-23　　Accepted: 2018-03-30

Corresponding author: 李晓光　　E-mail: lxgchina@sina.com

DOI: 10.13294/j.aps.2018.0031

Citing This Article：

CHEN Xue-Yi, ZHANG Ai-Feng, Zhao Wen, GAO Yu-Dan, DUAN Hong-Mei, HAO Peng, ANG Zhao-Yang, LI Xiao-Guang. Electrophysiological characteristics of hippocampal postnatal early development mediated by AMPA receptors in rats. Acta Physiol Sin 2018; 70 (2): 106-114 (in Chinese with English abstract).