Effects of subacute treatment with toluene on central monoamine receptors in the rat. Reduced affinity in [³H]5-hydroxytryptamine binding sites and in [³H]spiperone binding sites linked to dopamine receptors

Subacute treatment with toluene leads to a dose-related reduction of affinity in the [³H]spiperone binding sites labeling striatal dopamine (DA) receptors of the D₂ type and cortical [³H] 5-hydroxytryptamine (5-HT)-binding sites. It is suggested that these results represent a down regulation of activity at striatal DA and cortical 5-HT synapses, since they now may operate at higher concentrations of transmitters. The reduced affinity may be caused by the physicochemical properties of toluene leading to changes in membrane fluidity and thus in the regulation of DA and 5-HT receptors in the local circuits of the striatum and the dorsal cerebral cortex.