Figure 3.
The effects of stress and glucocorticoids on glutamate synapses and neurotransmission. Several sites/mechanisms of regulation of the glutamate synapse have been shown to be targets of stress and hormones released in the stress response (glucocorticoids): (1) presynaptic release of glutamate; (2) postsynaptic ionotropic receptors for glutamate (NMDA and AMPA receptors); (3) reuptake of glutamate by glial glutamate membrane transporters; (4) glutamate metabolism and recycling by the glutamate/glutamine cycle. Major consequences of stress/glucocorticoid exposure on these sites/mechanisms are: (1) increased glutamate release; (2) altered trafficking/expression/function of ionotropic glutamate receptors; (3) altered clearing of glutamate from the synapse; (4) reduced glutamate/glutamine cycling and glial cell density (see section 7). Adapted from Sanacora et al., 2008.