INVESTIGADORES
PAUTASSI Ricardo Marcos
congresos y reuniones científicas
Título:
Early neonatal stress lessens sensitivity to Ethanol-Induced motor sedation
Autor/es:
MACARENA FERNÁNDEZ; PAUTASSI RM
Lugar:
Huerta Grande
Reunión:
Congreso; XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2013
Institución organizadora:
Sociedad Argentina de Investigación en Neurociencias
Resumen:
An early onset of alcohol consumption (Pilatti et al., 2013) and exposure to neonatal stress
constitute vulnerability factors that promote problematic use of alcohol. A significant source
of early stress comes are the alterations in quantity or quality of maternal care (Pautassi et
al., 2008). The maternal separation paradigm (Plotsky and Meaney, 1993) is a model of early
stress that has been shown to alter sensibility to the motivational (i.e., appetitive, aversive
and negative reinforcing) effects of ethanol. These effects are important modulators of
etanol-seeking and intake. Ethanol-induced motor activity has been used as a proxy for the
appetitive effects of the drug. Alcohol induces biphasic motor effects, motor activation and
depression, at low and high doses, respectively (Pautassi et al, 2009). In a previous
Experiment of our lab we assessed etanol-induced motor activity in 15-day old infant rats
that had been exposed to normal rearing conditions or that had experienced daily maternal
separation [240 min per day] from postnatal day (PD) 1 to PD 14. Results indicated greater
sensibility to etanol-induced activation (dose: 1.25 g/kg) in pups with history of maternal
separation. The present study further analyzed behavioral activation induced by ethanol as a
function of chronic maternal separation during PDs 1-14. On PD 15, animals were removed
from the maternal cage and administered high-dose ethanol (2.5 g/kg). They were
subsequently asssed in activity chambers during post-administration time 5-20 min. Data
Analysis (ANOVA) indicated similar activating effects of 2.5 g/kg ethanol in control or
maternally separated animals. Control animals, however, also exhibited a significant
reduction in motor activity by the end of testing, when compared with vehicle-treated
counterparts. This difference, indicative of ethanol-induced motor depression, was not
observed in animals thah had been exposed to early neonatal stress. In other words, pups
exposed to chronic maternal separation were insensitive to the sedative effects of ethe
drug. Altogether, these results indicate that early neonatal stress alters the balance
between the different motivational effects of ethanol. Specifically, stressed pups seems to
be more sensitive to the behavioral activating effects of ethanol, but less sensitive to the
motor depressing effects of ethanol.