Postsynaptic Specialization Assembly

Recent biochemical, genetic, and imaging studies have begun to elucidate the molecular mechanisms underlying synapse formation, growth, and maturation. At excitatory synapses, postsynaptic sites harbor a specialized protein complex called the postsynaptic density (PSD). Its functions include the regulation of adhesion and the control of receptor clustering, which are, in turn, central to synaptic transmission and plasticity. At inhibitory synapses, postsynaptic membranes are devoid of a clear PSD, because the molecular composition of the postsynaptic compartment is much simpler. Dendrites of each neuron receive both excitatory and inhibitory synapses that are located in cross-proximity and whose numbers and ratios are strictly controlled in order to allow the correct functioning of brain circuits.