1CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
2Auditory Research Laboratory, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
3Department of Physiology, Binzhou Medical University, Yantai 264003, China
4Department of Otolaryngology - Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI 48201, USA

Abstract 

Rebound depolarization (RD) is a response to the offset from hyperpolarization of the neuronal membrane potential and is an important mechanism for the synaptic processing of inhibitory signals. In the present study, we characterized RD in neurons of the rat medial geniculate body (MGB), a nucleus of the auditory thalamus, using whole-cell patch-clamp and brain slices. RD was proportional in strength to the duration and magnitude of the hyperpolarization; was effectively blocked by Ni2? or Mibefradil; and was depressed when the resting membrane potential was hyperpolarized by blocking hyperpolarization-activated cyclic nucleotide-gated (HCN) channels with ZD7288 or by activating G-protein-gated inwardly-rectifying K+ (GIRK) channels with baclofen. Our results demonstrated that RD in MGB neurons, which is carried by T-type Ca2+ channels, is critically regulated by HCN channels and likely by GIRK channels.

Keywords

Medial geniculate body, Brain slice, Rebound depolarization, T-type calcium channel, HCN channel, GIRK channel, Resting membrane potential

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