AMPA receptors regulate transcription of the plasticity-related immediate-early gene Arc.

Learning and memory depend critically on long-term synaptic plasticity, which requires neuronal gene expression. In the prevailing view, AMPA receptors mediate fast excitatory synaptic transmission and effect short-term plasticity, but they do not directly regulate neuronal gene expression. By studying regulation of Arc, a gene required for long-term plasticity, we uncovered a new role for AMPA receptors in neuronal gene expression. Spontaneous synaptic activity or activity induced by brain-derived neurotrophic factor (BDNF) elicited Arc expression in cultures of rat cortical neurons and in organotypic brain slices. Notably, inhibiting AMPA receptors strongly potentiated activity-dependent Arc expression. We found that AMPA receptors negatively regulate Arc transcription, but not translation or stability, through a mechanism involving a pertussis toxin-sensitive G protein. These results provide insights into the activity-dependent mechanisms of Arc expression and suggest that, in addition to effecting short-term plasticity, AMPA receptors regulate genes involved in long-term plasticity.