The Potential Role of Otx1 in Epileptic-like Behavior Mice: the “Modulator” of Physiological Function of Layer V Pyramidal Neurons in the Cerebral Cortex

Abstract: The transcription factor Otx1 is specifically expressed in layer V pyramidal neurons (L5PNs) in the cerebral cortex. This study used the whole-cell patch clamp recording and 3D neuronal morphological reconstruction and analysis to investigate the potential role of Otx1 in epileptic-like behavior mice. Four types of L5PNs with distinct firing patterns， namely intrinsically bursting (IB)， rhythmic oscillatory bursting (ROB)， adapting regular spiking (RSAD) and tonic firing (TF) were confirmed. Compared with controls， the proportion of regular spiking neurons increased significantly while the burst firing neurons decreased remarkably with enhanced excitability in the Otx1 mutant mice. The AP-thresholds， input resistance and fast after-hyperpolarization of L5PNs decreased markedly in the Otx1 mutant mice， leading to an enhanced neuronal excitability. Moreover， Otx1 mutation reduced basal dendritic morphological structural complexity， which mainly exhibited as the significant decrements in the surface area， the volume， the segment surface area and the segment volume. It suggested that change in physiological function of L5PNs resulting from the mutation of Otx1 in the cerebral cortex was a potential mechanism of the epileptic-like behavior of the Otx1 mutant mice.

CSTR: 32200.14.cjcb.2015.05.0009