Dopamine D1/D5 receptor m synaptic inputs to layer V pr

Dopamine acts mainly through the D1/D5 receptor in the prefronth( tal cortex (PFC) to modulate neural activity and behaviors associpe ated with working memory. To understand the mechanism of this effect, we examined the modulation of excitatory synaptic inputs M' onto layer V PFC pyramidal neurons by D1/D5 receptor stimulation. TI D1/D5 agonists increased the size of N-methyl-D-aspartate (NMDA) Sa component of excitatory postsynaptic currents (EPSCs) through a co postsynaptic mechanism. In contrast, D1/D5 agonists caused a thl slight reduction in the size of the non-NMDA component of EPSCs N; through a small decrease in release probability. With 20 Hz synaptic ac trains, we found that the D1/D5 agonists increased depolarization su of summating the NMDA component of excitatory postsynaptic ex potential (EPSP). By increasing the NMDA component of EPSCs, yet sli slightly reducing release, D1/D5 receptor activation selectively ini enhanced sustained synaptic inputs and equalized the sizes of ta EPSPs in a 20-Hz train. (1 Ce