Attenuated behavioral response to an unexpected incentive downshift in perinatally asphyxiated rats.

GALEANO, P.; KAMENETZKY, G; CUENYA, L.; AON, BERTOLINO, M.; SARRACENO, G.; ITURBE, L.; BLANCO-CALVO, E.; MILES, J.; MUSTACA, A.; CAPANI, F.

RAI Convention Center, Amsterdam, Holanda.

Congreso; 7th Forum of European Neuroscience (Federation of European Neurosciences Society).; 2010

Federation of European Neurosciences Society

Reduction of anxiety-related behaviors (Hoeger et al., 2000, 2006), memory impairments (Simola et al., 2008), and alterations of the mesolimbic DA pathway (Boksa and El-Khodor, 2003), which is involved in reward processes, have been observed in perinatally asphyxiated rats (PAR). Rats expose to an unexpected downshift from 32% to 4% sucrose solution show an exaggerated reduction of intake of the devaluated reward (Pecoraro et al., 2008). The aim of this work was to evaluate whether PAR display alterations in the behavioral response when exposed to an incentive downshift. Asphyxia was induced by immersing foetuses-containing uterine horns, removed from ready-to-deliver Sprague-Dawley rats, into a water bath at 37ºC for 19 min. Control subjects (CTL) were born by vaginal delivery (see further details in Capani et al., 2009). At 92-93 days, CTL rats (n=8) and PAR (n=7) were submitted to a daily 5-min trial throughout 10 days, in which free-access to a 32% sucrose solution was available (pre-shift trials). On days 11-14, all animals received access to a 4% sucrose solution (post-shift trials). Rats were maintained at 89-83% of their free-feeding body weight. Since the mean baseline body weight of the PAR was significantly lower in comparison to CLT rats (p<0.01), consumption was standardized to body weight. During the pre-shift trials, the relative consumption (RC) was not different between groups, except for days 2, 4, 5 and 6, when PAR showed a significantly higher RC (p<0.05 for every case). In all post-shift trials the RC of CTL rats was significantly lower in comparison to their RC during the last pre-shift trial (p<0.01 for every case), while RC of PAR was only significantly lower in the first post-shift trial (p<0.01). Moreover, in the four post-shift trials PAR showed a significantly higher RC in comparison to CTL rats (p<0.05). Further studies are needed to determine if the strongly attenuated behavioral response to the incentive downshift in PAR is due to anxiolysis, impairments in encoding/retrieving information from previous trials, and/or alterations of reward processes.