Figure 10.

Cocaine experience and D1DR stimulation alter the balance between synaptic and extrasynaptic NMDAR-mediated signaling. A working model summarizing changes in relative contributions of synaptic (black) and extrasynaptic (gray) NMDARs. Following cocaine experience, an increased contribution of extrasynaptic NMDAR receptors is masked by elevated glutamate reuptake. D1DR stimulation has no effect on NMDAR-mediated currents in this group. In saline controls, D1DR stimulation is sufficient to induce an increase in extrasynaptic NMDAR-mediated signaling. This is accompanied by a reduction of synaptic NMDAR signaling and occurs in the absence of changes in glutamate reuptake. Note that for the purposes of this diagram, glutamate reuptake occurs at unspecified (either glial or neuronal) sites.