Changes in regional brain 2[ 14C]deoxyglucose uptake induced in postnatal developing rats by single and repeated nonconvulsant doses of lindane

Abstract

The effects of the organochlorine insecticide lindane on the functional status of the postnatal developing brain were studied by the 2[ 14C]deoxyglucose (2-DG) autoradiographic technique. The neurotoxic agent-induced alterations in the normal pattern of cerebral 2-DG uptake were analyzed in 58 brain regions from 15- and 29-day-old rats, after oral administration of single (10 and 20 mg/kg) and repeated (10 mg/kg/day over 7 days) doses. The pattern of modifications observed at both ages showed a quite similar profile, although the youngest animals exhibited a much more marked sensitivity to lindane after both single and repeated doses. Single administration of 20 mg/kg lindane produced the greatest number of alterations in 2-DG uptake. On the other hand, the administration of single 10 mg/kg produced less modifications thatn 10 mg/kg repeated dosing, in either 15- or 29-day-old animals. Increases of 2-DG uptake in somatosensory and motor areas were the main effects caused by lindane exposure. Significant effects were also registered in the limbic system with increases in septal nuclei, while decreases occurred in hippocampus. The results obtained allow the conclusion that young animals, especially those of 15 days of age, are more sensitive to functional alterations elicited by the neurotoxic action of lindane compared to adult rats. This fact may be in close relation with the immaturity of the nervous system during early postnatal development. Motor system-related areas appear to be the most affected by the neurotoxic action of lindane, which could be connected to its neurostimulant properties.