Physiological and Psychological Effects of a High Dose of Alcohol in Young Men and Women

The objective of this study was to evaluate the effects of a high dose of alcohol on physiological and psychological parameters in young men and women with a previous history of alcohol consumption. Systolic and diastolic blood pressure, heart rate, state anxiety, attention, time estimation and manual dexterity were registered before (phase 1) and after (phase 2) intake of alcohol (38.4 g) or a non-alcoholic beverage. Trait anxiety was registered in phase 2 only. The results showed that acute consumption of a high dose of alcohol: i) improves attention in men (although the performance of alcohol consumers was not better than that of non-consumers); ii) blocks the systolic blood pressure habituation phenomenon (observed in controls) in women; and iii) blocks the improvement in manual dexterity (associated with experience in non-consumers) in both sexes. On the other hand, male consumers had a lower heart rate than non-consumers, independently of the phase, while female consumers had a higher state anxiety and performed worse in attention than controls, also independently of the phase. These results help to understand the extent of performance impairment of different tasks produced by risk alcohol consumption in young men and women

Binge Drinking and Memory in Adolescents and Young Adults

The binge drinking (BD) pattern of alcohol consumption, characterized by intermittent consumption of large quantities of alcohol in short periods, is currently prevalent during adolescence and early youth. This period is characterized by critical changes to the structural and functional development of brain areas related with memory, as well as other executive functions. As a result, BD has been associated with undermined learning and memory ability in adolescents and youths of both sexes. One distinctive contribution of this chapter is to evaluate, together, the impact of an acute BD episode, the sample’s history of consumption, and its effect on learning and memory performance and as potential gender differences. The main findings of the published research show that BD has differential effects on several types of memory and confirm that women are more vulnerable to these detrimental effects of alcohol than are men. These cognitive differences between men and women seem to be overridden as the blood alcohol concentration progressively increases. As BD pattern of consumption has been associated with inhibitory control deficits, future research also should investigate long-term implementation of inhibitory control training, emphasizing the importance of this training as part of the intervention strategies focused on this at-risk group

Learned immobility is also involved in the forced swimming test in mice

A modified version of the forced swimming test (FST) was utilised in order to test, for the first time in mice, the learned immobility hypothesis. From this point of view, the subjects learn to be immobile in the first session, being the second one a retention test. The development of habituation was observed by repeating the test. The forgetting was studied by allowing different time intervals between the first and the second session. A decrease in the activity was observed with intervals of up to 18 days, but not with longer intervals of 21 or 24 days. Scopolamine (1 or 2 mg/kg), a cholinergic antagonist, did not modify the swimming activity in the second session. Physostigmine, a cholinergic agonist, at a dose of 0.05 mg/kg was ineffective, and at a dose of 0.2 mg/kg decreased the swimming activity in the second session. These data extend to mice the findings previously obtained in rats, and lend additional support to the learned immobility hypothesis in the interpretation of the behaviour found in the FST.La Inmovilidad Aprendida está también Implicada en la Prueba de Natación Forzada en Ratones. Se utilizó una versión modificada de la prueba de natación forzada (P.N.F.) para poner a prueba, por primera vez en ratones, la hipótesis de la inmovilidad aprendida. Desde este punto de vista, los sujetos aprenden a estar inmóviles en la primera sesión, siendo la segunda un test de retención. Se observó el desarrollo de habituación a través de la repetición de la prueba. Se estudió el olvido utilizando diferentes intervalos de tiempo entre la primera y la segunda sesión. La actividad descendió con intervalos de 18 días o menores, pero no con los intervalos de 21 y 24 días. La escopolamina (1 o 2 mg/kg), un antagonista colinérgico, no modificó la actividad natatoria en la segunda sesión. La fisostigmina, un agonista colinérgico, no fue efectiva con una dosis de 0.05 mg/kg, pero sí lo fue con una dosis de 0.2 mg/kg: la actividad natatoria disminuyó en la segunda sesión. Estos datos extienden a ratones los hallazgos previamente obtenidos en ratas y dan apoyo a la hipótesis de la inmovilidad aprendida a la hora de interpretar la conducta en la P.N.F

La maprotilina anula las diferencias entre ratones machos y hembras en el laberinto de agua de Morris

Maprotiline removes differences between male and female mice in the Morris water maze. The effects of subchronic administration of maprotiline (15, 20 and 25 mg/kg) on spatial learning, utilising the Morris water maze, and on general activity were assessed in male and f emale mice. In the acquisition phase, maprotiline (15 and 25 mg/kg) impaired learning in males but not in females. Also in this phase, sex differences were not found in the control group. In the retention phase, all three levels of maprotiline removed the sex differences found in the control group. In the general activity test, all three doses of maprotiline decreased activity and removed the sex differences found in the control group. Sexual dimorphism in the effects of maprotiline on spatial learning agrees with findings in studies of the effects of antidepressants and antipsychotics on different learning tasks in mice. When this dimorphism is present, the drug effect is observed only in males or, if present in males and females, it is stronger in the former. The absence of sex differences in the maprotiline treated groups in the retention phase could be due to the anticholinergic pr operties of the drug.Se estudiaron los efectos de la administración subcrónica de maprotilina (15, 20 y 25 mg/kg) sobre el aprendizaje espacial con el laberinto de agua de Morris, así como sobre la actividad general, en ratones machos y hembras. En la fase de adquisición, la administración de maprotilina (15 y 25 mg/kg) deterioró el aprendizaje en los machos pero no en las hembras, y no se observaron diferencias de sexo en el grupo control. En la fase de retención, la maprotilina, en las tres dosis, anuló las diferencias de sexo. Sobre la actividad general, la maprotilina, en las tres dosis, tuvo un efecto supresor de la misma y anuló las diferencias de sexo. El efecto sexodimórfico del fármaco en la fase de adquisición está en la línea del encontrado en otros e xperimentos, en los que se han usado otros fármacos, tanto antidepresivos como antipsicóticos, y otras tareas de aprendizaje en ratones. Este sexodimorfismo consiste en que el efecto del fármaco se observa sólo en los machos o, si se observa en los dos sexos, es mayor en los machos que en las hembras. La anulación de las diferencias de sexo en la fase de retención puede ser debida a la acción anticolinérgica de la maprotilina

Psicothema

Resumen tomado de la publicaciónEl antibiótico anisomicina inhibe la síntesis de proteínas, la cual muchos estudios indican que es necesaria para la formación de la memoria a largo plazo. En el presente trabajo se estudiaron los efectos de la administración aguda subcutánea de anisomicina sobre la consolidación de la memoria en una tarea de evitación inhibitoria en ratones CD1 de ambos sexos. Los animales fueron separados por sexo y distribuidos al azar en tres grupos: dos grupos fueron inyectados con 150 mg/kg de anisomicina, uno inmediatamente después de la fase de entrenamiento y el otro 24 h después, mientras que el grupo control recibió suero salino. El intervalo entre el entrenamiento y el test fue de cuatro días. La anisomicina administrada inmediatamente después del entrenamiento produjo un deterioro de memoria estadísticamente significativo, deterioro que no fue observado cuando el fármaco fue administrado 24 h después del entrenamiento. No se observaron diferencias de sexo en los efectos de la anisomicina. Estos resultados extienden a las hembras los efectos deteriorantes de la anisomicina sobre la memoria previamente observados en machos y respaldan la hipótesis de que el establecimiento de la memoria a largo plazo depende de la síntesis de proteínas poco después del entrenamiento.AsturiasColegio Oficial de Psicólogos de Asturias; Calle Ildefonso Sánchez del Rio, 4-1õB; 33001 Oviedo; Tel. +34985285778; Fax +34985281374;ES

Efectos de la fisostigmina y de la nicotina sobre la inmovilidad aprendida en la prueba de natación forzada

Effects of physostigmine and nicotine on learned immobility in the forced swimming test. The learned immobility hypothesis in the forced swimming test (FST) suggests that the subjects learn to be immobile in the first session, the second one being a retention test. In the frame of this interpretation, the effects of two memory enhancers, the cholinergic agonists physostigmine (0.1, 0.2 and 0.3 mg/kg) and nicotine (0.15 and 0.6 mg/kg), were studied in mice. After a 24 day interval, the animals were exposed to the second session, and a loss of the learned immobility (similar swimming activity in both sessions) was observed in control groups, 0.1 and 0.2 mg/kg of physostigmine, and 0.15 mg/kg of nicotine groups. Retention of immobilily (a decrease in the swimming activity in the second session) was observed with the highest doses of physostigmine and nicotine. The effects of both drugs on FST provide support to the learned immobility hypothesis, and cannot be interpreted in the light of the "behavioural despair" hypothesis.La hipótesis de la inmovilidad aprendida en la prueba de natación forzada (PNF) mantiene que los animales aprenden a estar inmóviles en la primera sesión de la PNF, siendo la segunda sesión un test de retención. En el marco de esta interpretación se estudiaron, en ratones, los efectos de dos fármacos favorecedores de la memoria, los agonistas colinérgicos fisostigmina (0.1, 0.2 y 0.3 mg/kg) y nicotina (0.15 y 0.6 mg/kg). Tras un intervalo de 24 días, los animales fueron expuestos a una segunda sesión, observándose olvido de la inmovilidad (similar actividad natatoria en ambas sesiones) en los grupos de control, en los que recibieron 0.1 y 0.2 mg/kg de fisostigmina, y 0.15 mg/kg de nicotina. Se observó retención de la inmovilidad (disminución de la actividad natatoria en la segunda sesión) con la dosis más alta de fisostigmina y de nicotina. Los efectos de ambos fármacos en la PNF dan apoyo a la hipótesis de la inmovilidad aprendida y no pueden ser interpretados a la luz de la hipótesis tradicional del "desánimo conductual"

Hippocampus and two way active avoidance conditioning: contrasting effects of cytotoxic lesion and temporary inactivation

Hippocampal lesions tend to facilitate two way active avoidance (2WAA) conditioning, where rats learn to cross to the opposite side of a conditioning chamber to avoid a tone-signaled footshock. This classical finding has been suggested to reflect that hippocampus-dependent place/context memory inhibits 2WAA (a crossing response to the opposite side is inhibited by the memory that this is the place where a shock was received on the previous trial). However, more recent research suggests other aspects of hippocampal function that may support 2WAA learning. More specifically, the ventral hippocampus has been shown to contribute to behavioral responses to aversive stimuli and to positively modulate the meso-accumbens dopamine system, whose activation has been implicated in 2WAA learning. Permanent hippocampal lesions may not reveal these contributions because, following complete and permanent loss of hippocampal output, other brain regions may mediate these processes or because deficits could be masked by lesion-induced extra-hippocampal changes, including an upregulation of accumbal dopamine transmission. Here, we re-examined the hippocampal role in 2WAA learning in Wistar rats, using permanent NMDA-induced neurotoxic lesions and temporary functional inhibition by muscimol or tetrodotoxin (TTX) infusion. Complete hippocampal lesions tended to facilitate 2WAA learning, whereas ventral or dorsal hippocampal lesions had no effect. In contrast, ventral or dorsal hippocampal muscimol or TTX infusions impaired 2WAA learning. Ventral infusions caused an immediate impairment, whereas after dorsal infusions rats showed intact 2WAA learning for 40-50 min, before a marked deficit emerged. These data show that functional inhibition of ventral hippocampus disrupts 2WAA learning, while the delayed impairment following dorsal infusions may reflect the time required for drug diffusion to ventral hippocampus. Overall, using temporary functional inhibition, our study shows that the ventral hippocampus contributes to 2WAA learning. Permanent lesions may not reveal these contributions due to functional compensation and extra-hippocampal lesion effects