Mechanisms of the effect of lead on brain neurotransmission: a calcium mediated action

Data on the effect of chronic lead ingestion on brain neurochemistry in laboratory rodents show the involvement of several neurotransmitters including catecholamines. In the case of dopamine (DA), the action of lead is not uniform in all the DA-innervated areas. The reason for the regional susceptibility to the effect of lead is at present unknown, but points to the existence of specific neuronal mechanisms. Results obtained from animals exposed from birth to lead show that calcium channels are differentially modified in various brain areas. In particular, calcium antagonists display regional sensitivity both after in vivo lead treatment and after in vitro lead addition. These data support the concept that the area selective effects of the metal on neurotransmission may depend on the mechanisms controlling nerve terminal activity in different neuronal populations.