Background The amygdala is a central component of the neural circuitry that underlies fear
learning. N-methyl-D-aspartate receptor–dependent plasticity in the amygdala is required for
pavlovian fear conditioning and extinction. N-methyl-D-aspartate receptor activation requires
the binding of a coagonist, D-serine, which is synthesized from L-serine by the neuronal
enzyme serine racemase (SR). However, little is known about SR and D-serine function in
the amygdala. Methods We used immunohistochemical methods to characterize the cellular …