The secretion of amino acid transmitters from cerebellar primary cultures probed by alpha-latrotoxin

Using amino acid transmitter release, inositol phosphate production and 45Ca2+ accumulation as cellular responses to alpha-latrotoxin treatment, we studied the susceptibility of rat primary cerebellar granule cultures to toxin. Binding studies as well as immunofluorescence of toxin-treated cells, allow an evaluation of the expression, properties and distribution of toxin-binding sites. After binding, the toxin develops its releasing action on amino acid transmitters, in a manner reminiscent of the events described for cholinergic and catecholaminergic cell systems. Although few peculiarities emerge, toxin-dependent release of amino acid transmitters from granule cells in culture appears to be a fully exocytotic process.