Investigation of transmitter-receptor interactions by analyzing postsynaptic membrane noise using stochastic kinetics.

The stoichiometric and kinetic details of transmitter-receptor interaction (the number of conformations and the rate constants of conformation changes( in synaptic transmission have been investigated analyzing postsynaptic membrane noises by the aid of the fluctuation-dissipation theorem of stochastic chemical kinetics. The main assumptions are the following: (i) the transmitter-receptor interactions is modelled by a closed compartment system (a special complex chemical reaction) of unknown length,--(ii) the quantity of transmitter is maintained at a constant level,--(iii) the conductance is a linear function of the conformation quantity vector.--The main conclusion is: the conductance spectral density function is determined by three qualitatively different factors: (i) the length of the compartment system,--(ii) the precise form of the conductance-conformation quantity vector--(iii) the matrix of the reaction rate constants.