These findings provide one of the first examples of LTD gating under the control of a G protein-coupled receptor that might lead to imbalanced synaptic plasticity and memory impairment following a nonphysiological elevation of extracellular serotonin.
While there are multiple changes in the hippocampal proteome in the irradiated rats that have impaired spatial memory performance, with 203 proteins being detected (or upregulated) only in these rats, it would appear that spatial memory impairment may also arise from an inability of these rats to express "good spatial memory" (GSM) proteins, many of which play an important role in neuronal homeostasis and function, axonogenesis, presynaptic membrane organization and G-protein coupled receptor (GCPR) signaling.