Activity-Dependent NPAS4 Expression and the Regulation of Gene Programs Underlying Plasticity in the Central Nervous System
Figure 1
Molecular mechanisms underlying long-lasting modifications of synaptic transmission. After presynaptic glutamate release, the NMDA channel opens only when the postsynaptic neuron is sufficiently depolarized. As a result, the permeability of Ca2+ increases and Ca2+ ions activate postsynaptic protein kinases. These kinases may then act to insert new AMPA receptors into the postsynaptic spine, thereby increasing the sensitivity to glutamate. The activation of second-messenger pathways (e.g., cAMP) that subsequently set in motion the catalytic subunit of the protein kinase A results in the phosphorylation of the transcriptional regulator CREB. This turns on the expression of a number of genes (those containing the CRE promoter area) that produce long-lasting structural and functional changes on the synapses.
