IIPSI   26795
INSTITUTO DE INVESTIGACIONES PSICOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ETHANOL-RELATED LEARNING IN RAT NEONATES IMPACT UPON APNEIC EPISODES AND PROMOTE SEEKING BEHAVIOR OF STIMULI THAT SIGNALED THE STATE OF INTOXICATION
Autor/es:
D'ALOISIO, G.; MACCHIONE, A.F.; ACEVEDO, M.B.; ANUNZIATA, F; MOLINA, J.C.
Lugar:
Córdoba
Reunión:
Congreso; X LASBRA INTERNATIONAL MEETING; LATIN AMERICAN SOCIETY FOR BIOMEDICAL RESEARCH ON ALCOHOLISM; 2019
Institución organizadora:
LATIN AMERICAN SOCIETY FOR BIOMEDICAL RESEARCH ON ALCOHOLISM
Resumen:
ETHANOL-RELATED LEARNING IN RAT NEONATES IMPACT UPON APNEIC EPISODES AND PROMOTE SEEKING BEHAVIOR OF STIMULI THAT SIGNALED THE STATE OF INTOXICATIONIn rats, high ethanol (EtOH) doses during neoantal life exert deleterious effects upon brain development that impact on social and cognitive abilities. This stage in development partially overlaps with the 3rd human gestational trimester in terms of synaptogenesis (1-2) . At this stage, human fetuses and rat neonates (postnatal days 3-9) exhibit relatively high respiratory rates that are affected by subteratogenic ethanol doses (3-4-5-6). Recent studies suggest conditioned breathing responses in the developing organism given explicit associations between exteroceptive stimuli and the state of EtOH intoxication (6). Furthermore, studies performed with near term rat fetuses suggest heightened sensitivity to EtOH?s motivational effects (7-8). Nevertheless, little is known during this ontogenetic stage about EtOH?s motivational properties and the emergence of associative memories dependent on the effects of the drug.The main goals of the present study were as follows:I. Analyze the unconditioned effects of EtOH intoxication and the possible co-occurrence of learning mechanisms that can impact upon respiratory plasticity and preference for cues that signal the state of intoxication through an associative discrimination procedure.II. Determine how apneic episodes are affected by the drug itself or through learning processes involving this psychotropic agent.III. Examine whether the expression of early EtOH-related memories can be modified through other learning experiences such as sensitization, habituation, latent inhibition or extinction.CONCLUDING REMARKSDuring the developmental stage that partially overlaps with the brain growth spurt corresponding to the 3rd human gestational trimester, it was clear that EtOH exerts significant effects upon breathing plasticity, particularly when focusing on apneic episodes.The drug was found to systematically delay the onset of apneas and also inhibited frequencies of these respiratory disruptions relative to pups treated with vehicle. Prior studies indicate that intragastric administrations are highly aversive during neonatal life6 (Macchione et al., 2018). In this study, pups that always received vehicle (group VVVV) prior to CS+ exposure, showed very high levels of apneic episodes. EtOH systematically inhibited this high level of respiratory disruptions. Apparently, and in accordance with prior studies9, EtOH?s negative reinforcing effects (antianxiety) attenuated the level of stress arising from the administration procedure. Ethanol?s effects upon apneas appeared to be intimately related with associative learning processes. Notice that at PD7, pups administered with vehicle but previously exposed to the drug (PDs 3 and 5; group EEVV) exhibited infrequent apneic episodes comparable to those that were always treated with EtOH (group EEEE). When considering apneic episodes, the results indicate that EtOH intoxication as well as learning processes derived from the unconditioned effects of the drug play a significant role in the control of these disruptions.At PD11, pups were tested in a two-way tactile preference test defined by the textures previously experienced. This test revealed that early EtOH administration (groups EEVV and EEEE) increased the levels of preference towards the tactile cue associated with the drug. This result seems to reveal EtOH?s early positive reinforcing properties. Yet, pups that always experienced the tactile CS+ associated with vehicle administration, showed very low levels of preference towards this cue (30%; Figure 5). This low preference score might be indicative of a conditioned aversion given the stress of the administration procedure. Under this perspective, and taking into account the scores of groups EEVV and EEEE, it can be hypothesized that EtOH exerted antianxiety effects that counteracted the stress of administration.As a whole, the study emphasizes the need to consider ethanol?s motivational effects during early development upon the regulation of breathing patterns and subsequent affinity for ambient cues that signal the state of intoxication.