Reorganization of Basolateral Amygdala-Subiculum Circuitry in Mouse Epilepsy Model

• Published in: Frontiers in neuroanatomy Vol. 9; p. 167
• Main Authors: Ma, Dong Liang, Qu, Jian Qiang, Goh, Eyleen L K, Tang, Feng Ru
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Research Foundation 14.01.2016; Frontiers Media S.A
• Subjects: Amygdala; Basolateral Amygdala-Subiculum; Brain research; C-fos expression; c-Fos protein; Contextual fear memory; Convulsions & seizures; Epilepsy; Fear conditioning; Footshock; Gene expression; Hippocampus; Hospitals; Memory; Neuropathology; Neuroscience; Neurosciences; Physiology; Pilocarpine; Subiculum; Temporal Lobe Epilepsy (TLE); Singapore; epilepsy; pilocarpine; mouse; contextual fear memory test; c-Fos; subiculum; basolateral amygdala; reorganization
• ISSN: 1662-5129; 1662-5129
• DOI: 10.3389/fnana.2015.00167

In this study, we investigated the reorganized basolateral amygdala (BLA)-subiculum pathway in a status epilepticus (SE) mouse model with epileptic episodes induced by pilocarpine. We have previously observed a dramatic loss of neurons in the CA1-3 fields of the hippocampus in epileptic mice. Herein, we observed a 43-57% reduction in the number of neurons in the BLA of epileptic mice. However, injection of an anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHA-L) into the BLA indicated 25.63% increase in the number of PHA-L-immunopositive terminal-like structures in the ventral subiculum (v-Sub) of epileptic mice as compared to control mice. These data suggest that the projections from the basal nucleus at BLA to the vSub in epileptic mice are resistant to epilepsy-induced damage. Consequently, these epileptic mice exhibit partially impairment but not total loss of context-dependent fear memory. Epileptic mice also show increased c-Fos expression in the BLA and vSub when subjected to contextual memory test, suggesting the participation of these two brain areas in foot shock-dependent fear conditioning. These results indicate the presence of functional neural connections between the BLA-vSub regions that participate in learning and memory in epileptic mice.