Down-regulation of β1-adrenoceptors gene expression by short interfering RNA impairs the memory retrieval in the basolateral amygdala of rats

The influence of basolateral amygdala (BLA) on memory is known to depend critically on adrenergic neurotransmission. However, the roles of noradrenergic receptors on memory retrieval have been elusive and controversial. Here, we investigated the effect of β1-adrenoceptor (β1-AR) on auditory fear memory in the rat BLA. We attenuated the expression of β1-AR by RNA interference, a popular means to specific suppress gene expression. Bilaterally microinjection of β1-AR short interfering RNA (siRNA) could reach a satisfying transfection in the BLA: β1-AR protein expression was reduced transiently by siRNA in vivo at day 3. The behavioral tests indicated that memory retrieval was impaired as β1-AR protein expression was prevented, and the memory was restored when the β1-AR protein got back to normal level. The results suggested that β1-AR might be critical for the retrieval of auditory fear memory.