Developmental changes in expression of inhibitory neuronal proteins in the Fragile X Syndrome mouse basolateral amygdala

In humans, Fragile X Syndrome (FXS) is characterized by enhanced fear, hyperactivity, social anxiety, and, in a subset of individuals, autism. Many of the emotional and social deficits point to defects in the amygdala. We have previously shown defects in inhibitory neuron drive onto excitatory projection neurons in the basolateral amygdala (BLA) of juvenile Fmr1(-/y) knockout (KO) mice. Using pharmacological approaches, we have also previously revealed dynamic functional deficits in alpha 1, alpha 2, and alpha 3 subunit-containing GABA(A) receptors (GABA(A)Rs alpha 1, alpha 2, and alpha 3) during early postnatal development. In this study, we sought to determine whether these defects in GABA(A)R function are accompanied by changes in protein expression of GABA(A)Rs alpha 1, alpha 2, and alpha 3 and the post-synaptic GABA(A)R-clustering protein gephyrin. Interestingly, we found that while the expression of these proteins did not significantly differ between wildtype (WT) and KO mice at each time point, the timing of developmental expression of GABA(A)R alpha 1, alpha 2, and gephyrin was altered. Collectively, these data reveal novel defects in inhibitory synapse protein expression during critical periods of early postnatal development that could contribute to observed inhibitory neurotransmission deficits in the KO mouse BLA. (C) 2013 Elsevier B.V. All rights reserved.