Increased intrinsic excitability and synaptic excitation in the rat hippocampus CAI following cortical contusion head injury

• DOI: 10.3760/cma.j.issn.1001-2346.2012.02.014
• Publication Date: 2012-02-28
• Authors: Ming-Liang Zhao; Shi-Xiang Cheng; Guolong Liu; Yue Tu; Qunliang Hu; Sai Zhang
• Keywords: Neural facilitation; Facilitation

Objective To explore electrophysiologic mechanisms underlying posttraumatic epilepsy on the cellular and synaptic level.Methods Whole cell voltage - clamp recordings were used to examine intrinsic excitability evoked events from CA1 pyramidal cells in slices prepared fluid percussion injury (FPI) rat at various times after brain injury.Results We find that FPI rats show:( 1 ) increased membrane input resistance time constant,and decreased threshold current of action potential,( 2 paired pulse ratio (PPR) a shift facilitation (PPF) depression (PPD),which may suggest increase presynapse transmitter release probability. Conclusions These findings there is trauma induced excitation level hippocampus following cortical contusion head injury.These alterations facilitate progress towards development epilepsy.

Key words: Traumatic injury; Epilepsy; Hippocampus; Patch clamp; Synaptic transmission