ETHANOL EXPOSURE POTENTIALLY REVERSES SUBTLE DOPAMINERGIC IMPAIRMENTS IN C. ELEGANS EXPOSED TO LEAD DURING DEVELOPMENT

ALBRECHT, PAULA A.; FERNANDEZ HUBEID, LUCIA; DEZA PONZIO ROMINA; ASCHNER MICHAEL; VIRGOLINI MIRIAM B

Córdoba

Congreso; IX INTERNATIONAL MEETING of the Latin American Society for Biomedical Research on Alcoholism (LASBRA); 2019

Previous studies in rats have demonstrated that developmentally lead (Pb) exposure induces a higher susceptibility to the stimulant and motivational effects of ethanol, both responses modulated by the dopaminergic (DAergic) system. In the present study we have employed the model organism Caenorhabditis elegans to evaluate the basal slowing response (BSR), an adaptive mechanism that depends on the DA-containing neural circuit. In this test, the increase in the rate of body bends showed in the absence of food (E. Coli OP50) is compared to the movement exhibited in a food condition, as an evidence of the integrity of the DAergic neurotransmission. Accordingly, both control and developmentally-low-level Pb-exposed worms from the following strains: N2 (wild type), MT15620 (thyroxine hydroxylase (TH) knock-out) and UA57 (TH over expressing) were evaluated in the presence or absence of food. Moreover, on the basis of the differential responses to ethanol previously described in rats and C. elegans, the animals were also tested in both conditions (food/no food) after 200mM ethanol exposure. The results demonstrated that the N2 wild type animals evidenced a good discrimination between the food and no food conditions, an effect present in both groups, independently of the ethanol exposure. However, the disruption of DA synthesis in the MT15620 strain prevented the discrimination of both conditions in the control and Pb-exposed groups, an effect reversed selectively in the latter in the presence of ethanol. Interestingly, the UA57 strain showed a reduced food/no food ratio in both groups of animals (as compared to the N2 strain), an effect that seemed to be improved after ethanol addition, particularly in the Pb-exposed group. Overall, these results highlight the importance of a normal DA functionality in the BSR test, with ethanol playing a preponderant role in this behavior, particularly in the Pb-exposed animals in conditions of altered DAergic functionality; a finding probably related to the drug-stimulating effects that we have previously reported in these animals.