Central Hypothermic Effects of Ethanol and Acetaldehyde in Newborn Rats Regulated through Associative Learning Processes?

D'ALOISIO, G. 1; HAYMAL, O. B.; CASTELLO, S.; MOLINA J.C.; ACEVEDO, M. B.

Córdoba

Congreso; XXXIII SAN MEETING; 2018

Sociedad Argentina en Neurociencias

Different effects of ethanol (EtOH) during early ontogeny are modulated by the central accumulation of acetaldehyde (ACD). Newborns are sensitive to the reinforcing effects of ACD as well as to its depressant effects upon respiration. Both phenomena, studied in older organisms, have been linked with thermoregulatory disruptions caused by ACD. In this study, EtOH (100 mg%) or ACD (0.52 µM) were intracisternally administered during postnatal days (PDs) 2 and 4. Control pups received no explicit treatment (Untreated, UT) or were centrally administered with buffer (PB). Pups experienced the drug effects when exposed to EtOH odor. At PD6 pups were administered with PB with the sole exception of the UT group. Body temperatures and ultrasound emissions (USVs) under the presence of EtOH odor were recorded. In newborns USVs are elicited by stress-related events. During PD2, significant levels of hypothermia were observed in PB, EtOH and ACD groups. At PD4, only ACD pups showed heightened hypothermia. At test, pups pre-exposed to ACD again showed hypothermia despite being administered with buffer; an effect suggestive of a conditioned thermal response elicited by stimuli previously associated with ACD. USVs were not affected by prior treatments. Yet, temperature decrements were negatively correlated with USVs. The results show that central ACD recruits poikilothermic alterations in newborns which are associated with stimuli that later elicit isodirectional conditioned responses.