Mild and severe perinatal asphyxia induce opposite effects on cocaine sensitization in adult rats

GALEANO P1, BLANCO-CALVO E2,4, BISAGNO V3, ROMERO JI1, HOLUBIEC MI1, SARACENO GE1, LUQUE-ROJAS MJ4, RODRÍGUEZ DE FONSECA F4, FRANCISCO CAPANI

Congreso; Congreso sociedad Argentina de Neurociencias; 2012

Dysregulation of dopaminergic transmission is one of the long-lasting consequences of perinatal asphyxia (PA). Since the dopaminergic system plays a major role in addiction processes, we hypothesized that PA could be associated with an increased vulnerability to psychostimulant addiction. Adult rats born vaginally (CTL), by caesarean section (C+), or by caesarean section followed by 15 min (PA15) or 19 min (PA19) of birth asphyxia were submitted to a cocaine-induced behavioral sensitization test and the expression of tyrosine hydroxylase (TH) in the dorsal striatum was measured. During 5 days, all groups increased their locomotor activity in response to daily cocaine (coc) injections (15 mg/kg). 7 days later, CTL and C+ displayed a robust locomotor sensitization to an acute priming dose of coc (7.5 mg/kg). However, the acute priming injection of coc elicited an attenuated sensitized response in PA19, while PA15 displayed an exacerbated sensitized response. Expression of TH was significantly higher in PA15 compared to all other groups. These results demonstrate that PA induces opposite effects on behavioral sensitization to coc depending on its severity, and suggest that the increased TH levels in PA15 could be associated with the displayed hypersensitized response.