Figure 6.

Schematic representation of NO signaling mediating NMDA-R activation in the central nucleus of the IC. A presynaptic glutamatergic terminal containing both VGluT1 and VGluT2 is in close apposition to a postsynaptic multiprotein complex consisting of NMDA-R, nNOS, and sGC attached to the scaffold protein PSD95. Initial depolarization by glutamate binding to AMPA receptor allows the activation of the NMDA-R. Calcium ions enter the cell through the NMDA-R and activate nNOS (via calmodulin not shown), leading to the synthesis of NO. NO in turn activates sGC which produces the second messenger cGMP. Other excitatory and inhibitory terminals not terminating on NOSergic multiprotein complexes are shown. Note also the presence of a separate pool of NMDA-Rs not linked to the NO signaling pathway.