Actions of a monoclonal antibody Tor 23 on rat brain presynaptic cholinergic processes.

Tor 23 is a monoclonal antibody, generated against cholinergic terminals of the Torpedo californica, that has been found to bind to the extracellular surface of cholinergic neurons in a variety of tissues. This study shows that Tor 23 inhibits: 1) high affinity [3H]hemicholinium-3 binding to detergent-solubilized membranes prepared from rat neocortices; 2) high affinity [3H]choline uptake in rat neocortical and striatal P2 preparations; and 3) [3H]acetylcholine synthesis in isolated nerve terminals. Tor 23 does not appear to affect low affinity [3H]choline uptake or [3H]acetylcholine release. These results are consistent with the hypothesis that Tor 23 may bind to nerve terminal high affinity choline transporters in the rat brain.