A calculation method for evaluating the time course of GABA removal from a synaptic cleft by presynaptic uptake systems.

A calculation method for evaluating the time course of gamma-aminobutyric acid (GABA) removal from a synaptic cleft by presynaptic uptake is suggested. The evaluation of the actual time required to remove GABA requires the knowledge of: (a) KM's and Vmax's (mol/min/mg protein) of the synaptosomal uptake systems in a certain brain area; (b) the synaptosomal volume per mg of protein in the synaptosomal preparation used; (c) the mean sphere diameter for synaptic boutons in the brain area considered and the proportion of GABAergic nerve terminals.