Differential ethanol exposure during the brain growth spurt period in the rat: Alterations in respiratory plasticity and motivational effects of the drug?.

MACCHIONE, A.F.; MOLINA, J.C.; D'ALOISIO, G.; ACEVEDO, MB; ANUNZIATA, F; HAYMAL, OB

Denver, Colorado

Congreso; 40th Annual RSA Scientific Meeting; 2017

The aim of the preset study was to analyze the impact of early ethanol exposure on respiratory plasticity, the psychomotor effects of the drug and its motivational properties.The study was conducted during postnatal days (PDs) 3,5,7, 9 and 11. During the first four days pups were exposed to a given texture (conditioned stimulus) while intoxicated with ethanol (E: 2.0 g/kg, i.g.) or vehicle (V). Four groups were defined as a function of drug and days: V-V-V-V, V-V-E-E, E-E-V-V or E-E-E-E. Respiratory frequencies were registered on a daily basis. Ethanol was observed to systematically and significantly depress respiratory frequencies across days. When the drug was administered during 4consecutive days (E-E-E-E), a progressive sensitization effect was observed. In addition, pups treated with ethanol during the first two days and later exposed to vehicle (E-E-VV) showed respiratory depressions during PD7 that appear to indicate an isodirectional conditioned response relative to the unconditioned effects of the drug. This effect was not observed during PD9 probably because an extinction phenomenon. At PD9, all pups were evaluated in terms of locomotion while sober or intoxicated. Ethanol clearly exerted stimulatory locomotive effects independently from prior history with the drug. At PD11 pups were evaluated in a two-way texture preference test while sober. One of the textures (either sandpaper or a soft rubber surface) represented the conditioned stimulusdifferentially paired with ethanol or vehicle. Relative to vehicle control subjects (V-V-VV) a significant tactile-conditioned preference was observed in pups that always received ethanol during PDs 3, 5, 7 and 9 (E-E-E-E). This learned preference was also present in pups that received ethanol during the first two days of drug treatment (PDs 3 and 5, group E-E-V-V). The results of the present study indicate that ethanol exposure during a stage in development comparable to the 3rd human gestational trimester, alters the respiratory plasticity of the organism while also exerts positive reinforcing effects.