Acoustic priming lowers the threshold for electrically induced seizures in mice inferior colliculus, but not in the deep layers of superior colliculus

Abstract

Mice become highly susceptible to audiogenic seizures (AGS) after exposing them to an intense noise in their early life (priming). To elucidate the brain mechanisms for this priming effect of AGS, we compared the threshold current intensities inducing AGS syndromes between primed ( n=88) and non-primed ( n=84) mice by electrically stimulating the central nucleus and external cortex of the inferior colliculus (CIC and ECIC), and the deep layers of the superior colliculus (DLSC). The threshold for wild running was significantly lower for the primed mice than for the control mice in the case of the CIC and ECIC, but not the DLSC. The current intensity for inducing clonic seizure was lower for the primed mice than for the control mice in the case of the ECIC. These results show that the inferior colliculus (IC) plays an important role in the priming effect of AGS in mice, but that the DLSC does not.