Effect of etomidate on excitatory synaptic transmission efficacy in rat hippocampus

Abstract

Abstract:

AIM: To investigate the effect of etomidate on excitatory synaptic transmission efficacy in stratum radiatum of CA1 area of rat hippocampus and the underlying mechanism. METHODS: Twenty-four adult male Wistar rats were randomly divided into 4 groups (n=6 each): control group, bicuculline group, etomidate group and etomidate + bicuculline group. The animals were anesthetized with intraperitoneal (IP) pentobarbital 50 mg/kg. The stimulating and recording electrodes were inserted into the stratum radiatum of CA1 area of the hippocampus. The paired pulse stimulation with the interval 30 ms between the 2 pulse stimulation was used. Excitatory post-synaptic potential (EPSP) was elicited in vivo before (baseline) and after IP bicuculline (2 mg/kg) or/and etomidate (10 mg/kg) administration. The EPSP2/EPSP1 (E2/E1) ratio was recorded during paired pulse stimulation.RESULTS:Compared with control group, the E1 amplitude was significantly decreased in etomidate group (P<0.05), but no significant change was found in bicuculline group and etomidate + bicuculline group (P>0.05). Compared with control group, E2 and E2/E1 ratio were significantly increased in bicuculline group, while significantly decreased in etomidate group (P<0.05). E2 and E2/E1 ratio were significantly lower in etomidate group and etomidate + bicuculline group than in bicuculline group (P<0.05). CONCLUSION: The results suggest that etomidate might depress the excitatory synaptic transmission efficacy in the CA1 area of the rat hippocampus through presynaptic GABA energic inhibitory circuit.

Key words: etomidate, synaptic transmission, hippocampus

CLC Number:

R965.2

WEI Huiming, LIU Chao, YANG Yunli . Effect of etomidate on excitatory synaptic transmission efficacy in rat hippocampus[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2017, 22(7): 775-778.

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