COLLECTIVE BINDING-PROPERTIES OF RECEPTOR ARRAYS

Binding kinetics of receptor arrays can differ dramatically from that of the isolated receptor. We simulate synaptic transmission using a mi croscopically accurate Brownian dynamics routine. We study the factors governing the rise and decay of the activation probability as a funct ion of the number of transmitter molecules released. Using a realistic receptor array geometry, the simulation reproduces the time course of lpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-medi ated excitatory postsynaptic currents. A consistent interpretation of experimentally observed synaptic currents in terms of rebinding and sp atial correlations is discussed.