RESUMO
The retrosplenial cortex (RSC) plays a critical role in complex cognitive functions such as contextual fear memory formation and consolidation. Perineuronal nets (PNNs) are specialized structures of the extracellular matrix that modulate synaptic plasticity by enwrapping the soma, proximal neurites and synapsis mainly on fast spiking inhibitory GABAergic interneurons that express parvalbumin (PV). PNNs change after contextual fear conditioning (CFC) in amygdala or hippocampus, yet it is unknown if similar remodeling takes place at RSC. Here, we used Wisteria floribunda agglutinin (WFA), a ubiquitous marker of PNNs, to study the remodeling of PNNs in RSC during the acquisition or retrieval of contextual fear conditioning (CFC). Adult male mice were exposed to paired presentations of a context and footshock, or to either of these stimuli alone (control groups). The mere exposure of animals to the footshock, either alone or paired with the context, evoked a significant expansion of PNNs, both in the number of WFA positive neurons and in the area occupied by WFA staining, across the entire RSC. This was not associated with c-Fos expression in RSC nor correlated with c-Fos expression in individual PNNs-expressing neurons in RSC, suggesting that PNNs remodeling is triggered by inputs external to the RSC. We also found that PNNs remodeling was independent of the level of PV expression. Notably, PNNs in RSC remained expanded long-after CFC. These results suggest that, in male mice, the threatening experience is the main cause of PNNs remodeling in the RSC.
RESUMO
Ethanol-induced conditioned taste aversion (CTA) is greater in late adolescence or young adulthood than in early adolescence. The role of the sigma receptor system in this age-related difference has not been extensively explored, particularly in female rats. This study assessed the effects of the activation of sigma-1 receptors (S1-R), via the selective S1-R agonist PRE-084, on ethanol-induced CTA at early or at terminal adolescence/emerging adulthood (28 or 56 days-old at the beginning of the procedures, respectively) in female Wistar rats. The modulation of binge-like ethanol intake by PRE-084 was assessed at terminal adolescence. S1-R activation at the acquisition of ethanol-induced CTA attenuated such learning at terminal but not at early adolescence. PRE-084 did not significantly affect ethanol binge drinking in the terminal adolescents. These results highlight the role of S1-R in ethanol-induced CTA and suggest that differential functionality of this transmitter system may underlie age-specific sensitivities to the aversive effects of ethanol.
Assuntos
Etanol , Paladar , Consumo de Bebidas Alcoólicas , Animais , Aprendizagem da Esquiva , Etanol/farmacologia , Feminino , Morfolinas , Ratos , Ratos Wistar , Receptores sigma , Receptor Sigma-1RESUMO
Alcohol (ethanol) use is almost normative by late adolescence, in most western countries. It is important to identify factors that distinguish those who progress from alcohol initiation to sustained use of the drug, from those that keep a controlled pattern of drinking. The factors precipitating this transition may change across development. This study analyzed associations between behavioral endophenotypes and ethanol intake at three developmental periods. Exp. 1 measured ethanol drinking at postnatal day 18, via an intraoral infusion procedure, in male or female pre-weanling rats screened for anxiety response in the light-dark box test and for distance traveled in a novel open field. Exp. 2 measured, in juvenile/adolescent or young adult rats, the association between shelter seeking, exploratory/risk-taking behaviors, anxiety or hedonic responses, and ethanol intake. Ethanol intake in pre-weanlings was explained by distance traveled in a novel environment, whereas anxiety responses, measured in the multivariate concentric square field apparatus (MSCF), selectively predicted ethanol intake at adolescence, but not at adulthood. Those juvenile/adolescents with lower mean duration of visit to areas of the MSCF that evoke anxiogenic responses exhibited heightened ethanol intake. These findings suggest that the association between anxiety and ethanol intake may be specifically relevant during adolescence.
Assuntos
Consumo de Bebidas Alcoólicas , Etanol , Animais , Ansiedade , Feminino , Masculino , Ratos , Ratos Wistar , AutoadministraçãoRESUMO
Resumen El juego patológico se caracteriza por un patrón persistente y excesivo de juego, con interferencias en la vida personal, social, familiar y laboral. Objetivo: Examinar en estudiantes universitarios diferencias en impulsividad rasgo, distorsiones cognitivas y severidad en el involucramiento con los juegos de apuestas en función de los juegos de apuestas de preferencia (estratégicos y no estratégicos); y variaciones en impulsividad en función de los diferentes niveles de severidad en el involucramiento con los juegos de apuestas (sin riesgo, bajo riesgo, alto riesgo). Método: Participaron 295 estudiantes que completaron instrumentos para medir: 1-ocurrencia y preferencia de juegos de apuestas (cuestionario ad-hoc), 2-severidad en el involucramiento con los juegos de apuestas (versión en español del South Oaks Gambling Screen, 3-impulsividad rasgo (versión en español de UPPS-P Impulsive Behavior Scale), 4-distorsiones cognitivas (versión en español del Gamblers' Beliefs Questionnaire). Resultados: Se encontraron diferencias estadísticamente significativas en impulsividad, distorsiones cognitivas y severidad en el involucramiento con los juegos de apuestas en función de la preferencia por determinados tipos de apuestas, y en impulsividad en función del nivel de severidad en el involucramiento con los juegos de apuestas. Conclusión: Los hallazgos describen características psicológicas asociadas a una mayor vulnerabilidad a exhibir modalidades problemáticas de involucramiento con los juegos de apuestas; y sugieren que quienes exhiben preferencias por juegos de apuestas categorizados como estratégicos, o por apuestas estratégicas y no estratégicas combinadas, son quienes parecen estar en mayor riesgo de presentar problemas con el juego de apuestas.
Abstract Pathological gambling is characterized by a persistent and excessive pattern of gambling, with interference in personal, social, family and work life. Objective: To examine, in college students, differences in impulsivity trait, cognitive distortions and severity in gambling involvement as a function gambling preference (strategic and non-strategic); and variations in impulsivity as a function of levels of severity in gambling involvement (no risk, low risk, risk). Method: 295 students completed a survey to measure: 1-occurrence and preference of gambling (ad-hoc questionnaire), 2-severity of gambling involvement (Spanish version of the South Oaks Gambling Screen), 3- impulsivity trait (Spanish version of the UPPS-P Impulsivity Behavior Scale), 4-cognitive distortions (Spanish version of the Gamblers' Beliefs Questionnaire). Results: Analysis of Variance revealed significant differences in impulsivity, cognitive distortions and gambling severity as a function of gambling preference; and significant differences in trait-like impulsivity as a function of gambling severity. Conclusion: These findings describe psychological characteristics associated with increased vulnerability to exhibit gambling problems. The findings also suggest that individuals with a preference for strategic gambling or strategic and no strategic gambling, seem to be at heightened risk for problematic gambling.