D-1 receptor in interneurons of macaque prefrontal cortex: Distribution and subcellular localization

Working memory performance is influenced by dopamine activation of D1 famil y dopamine receptors in the prefrontal cortex; working memory performance i s maximal at moderate stimulation of D1 family receptors and is reduced by either higher or lower levels of D1 stimulation. The neuronal mechanisms th at underlie this complex relationship are not yet understood. Previous work from this laboratory has demonstrated that the D1 family receptors, D-1 an d D-5, are located in different compartments of pyramidal cells. Here we us e an antibody specific to the D-1 receptor and double-label immunohistochem istry at the light and electron microscopic level to demonstrate that D-1-l ike immunoreactivity (D-1-LIR) is also present in interneurons. D-1 recepto r is prevalent in parvalbumin-containing interneurons and is less common in calretinin-containing interneurons. At the ultrastructural level, D-1-LIR is found associated with the Golgi apparatus and endoplasmic reticulum in t he soma, with the membranes of vesicles in proximal dendrites, and with the plasma membrane on distal dendrites, where it is often located near asymme tric synapses. In addition, D-1-LIR is also seen in presynaptic axon termin als, which give rise to symmetric synapses onto dendritic shafts and soma. These results raise the possibility that the circuit basis of working memor y in the prefrontal cortex involves a D-1-mediated inhibitory component.