Relación entre privación de sueño paradójico y autoestimulación eléctrica intracraneal en ratas

Para estudiar el efecto de la privación de sueño paradójico (PSP) sobre los mecanismos nerviosos de la recompensa, varias ratas macho de la cepa Wistar fueron privadas de sueño paradójico mediante el método de la plataforma o de Jouvet. Se estudiaron las tasas de autoestimulación eléctrica intracraneal (AEIC) en el haz prosencefálico medial antes y después de la PSP. En general, la PSP no afectó significativamente a la conducta de AEIC. Los resultados son discutidos en términos que se refieren a la efectividad del método de PSP utilizado, al lugar cerebral de AEIC y a efectos inespecíficos del tratamiento experimentalREM sleep deprivation induced by flower-pot technique (Jouvet's technique) was applied to naive male Wistar rats. Rates of intracranial selfestimulation (ICSS) in medial forebrain bundle were tested before and after deprivation. Generally, ZCSS was not affected by the treatment. These findings are discussed in relation to flower-pot technique effectiveness, ZCSS brain sites and unspecific effects of treatmen

The AMPA receptor modulator S18986 in the prelimbic cortex enhances acquisition and retention of an odor-reward association

Systemic administration of S18986, a positive allosteric modulator of AMPA receptors, improves cognition. The present study further characterizes the drug's memory-enhancing properties and is the first to investigate its intracerebral effects on learning and memory. The results showed that rats receiving a single dose of S18986 (3 μg/site) into the prelimbic cortex, prior to olfactory discrimination acquisition, exhibited significantly shorter latencies and fewer errors to make the correct response, both in the acquisition and two drug-free retention tests. Such findings corroborate the involvement of glutamate receptors in odor-reward learning and confirm the role of the AMPAkine S18986 as a cognitive enhancer

D-cycloserine in the basolateral amygdala prevents extinction and enhances reconsolidation of odor-reward associative learning in rats

It is well established that D-cycloserine (DCS), a partial agonist of the NMDA receptor glycine site, enhances learning and memory processes. Although the effects of DCS have been especially elucidated in the extinction and reconsolidation of aversive behavioral paradigms or drug-related behaviors, they have not been clearly determined in appetitive tasks using natural reinforcers. The current study examined the effects of pre-retrieval intra-basolateral amygdala (BLA) infusions of DCS on the extinction and reconsolidation of an appetitive odor discrimination task. Rats were trained to discriminate between three odors, one of which was associated with a palatable food reward, and, 20 min prior to extinction learning (experiment 1) or reactivation (experiment 2), they received bilateral intra-BLA infusions of DCS or vehicle. In experiment 1, DCS infusion reduced the rate of extinction learning, weakened extinction retention in a post-extinction test and enhanced reacquisition of the ODT task. In experiment 2, DCS improved subsequent memory expression in the reconsolidation test performed one day after the reactivation session. Such results indicate the involvement of BLA NMDA receptors in odor-food reward associative memory and suggest that DCS may potentiate the persistence or strength of the original memory trace

D-cycloserine prevents relational memory deficits and suppression of long-term potentiation induced by scopolamine in the hippocampus

Previous research has demonstrated that systemic D-cycloserine (DCS), a partial agonist of the N-methyl-D-aspartate receptor (NMDAR), enhances memory processes in different learning paradigms and attenuates mnemonic deficits produced by diverse pharmacological manipulations. In the present study two experiments were conducted in rats to investigate whether DCS administered in the hippocampus may rescue relational memory deficits and improve deficient synaptic plasticity, both induced by an intracerebral injection of the muscarinic receptor antagonist scopolamine (SCOP). In experiment 1, we assessed whether DCS would prevent SCOP-induced amnesia in an olfactory learning paradigm requiring the integrity of the cholinergic system, the social transmission of food preference (STFP). The results showed that DCS (10 μg/site) injected into the ventral hippocampus (vHPC) before STFP acquisition compensated the 24-h retention deficit elicited by post training intra-vHPC SCOP (40μg/site), although it did not affect memory expression in non-SCOP treated rats. In experiment 2, we evaluated whether the perfusion of DCS in hippocampal slices may potentiate synaptic plasticity in CA1 synapses and thus recover SCOP-induced deficits in long-term potentiation (LTP). We found that DCS (50µM and 100µM) was able to rescue SCOP (100µM)-induced LTP maintenance impairment, in agreement with the behavioral findings. Additionally, DCS alone (50 µM and 100 µM) enhanced field excitatory postsynaptic potentials prior to high frequency stimulation, although it did not significantly potentiate LTP. Our results suggest that positive modulation of the NMDAR, by activation of the glycine-binding site, may compensate relational memory impairments due to hippocampal muscarinic neurotransmission dysfunction possibly through enhancements in LTP maintenance

Parafascicular thalamic nucleus deep brain stimulation decreases NMDA receptor GluN1 subunit gene expression in the prefrontal cortex

The rodent parafascicular nucleus (PFn) or the centromedian-parafascicular complex of primates is a posterior intralaminar nucleus of the thalamus related to cortical activation and maintenance of states of consciousness underlying attention, learning and memory. Deep brain stimulation (DBS) of the PFn has been proved to restore arousal and consciousness in humans and to enhance performance in learning and memory tasks in rats. The primary expected effect of PFn DBS is to induce plastic changes in target neurons of brain areas associated with cognitive function. In this study, Wistar rats were stimulated for 20mins in the PFn following a DBS protocol that had previously facilitated memory in rats. NMDA and GABAB receptor binding, and gene expression of the GluN1subunit of the NMDA receptor (NMDAR) were assessed in regions related to cognitive functions, such as the prefrontal cortex and hippocampus. The results showed that PFn DBS induced a decrease in NMDAR GluN1 subunit gene expression in the cingulate and prelimbic cortices, but no significant statistical differences were found in the density of NMDA or GABAB receptors in any of the analyzed regions. Taken together, our findings suggest a possible role for the NMDAR GluN1 subunit in the prefrontal cortex in the procognitive actions of the PFn DBS

Intra-hippocampal d-cycloserine rescues decreased social memory, spatial learning reversal, and synaptophysin levels in aged rats

Aging is characterized by a decrease in N-methyl-D-aspartate receptors (NMDARs) in the hippocampus, which might be one of the factors involved in the age-dependent cognitive decline. D-Cycloserine (DCS), a partial agonist of the NMDAR glycine recognition site, could improve memory deficits associated to neurodegenerative disorders and cognitive deficits observed in normal aging. Objectives and Methods: The aim of the present study was to explore whether DCS would reverse age-dependent memory deficits and decreases in NMDA receptor subunits (GluN1, GluN2A, and GluN2B) and the presynaptic protein synaptophysin in Wistar rats. We investigated the effects of pre-training infusions of DCS (10 μg/hemisphere) in the ventral hippocampus on two hippocampal-dependent learning tasks, the social transmission of food preference (STFP), and the Morris water maze (MWM). Results: The results revealed that infusions of DCS administered before the acquisition sessions rescued deficits in the STFP retention and MWM reversal learning in old rats. DCS also significantly increased the hippocampal levels of synaptophysin in old rats, which correlated with STFP and MWM performance in all tests. Moreover, although the levels of the GluN1 subunit correlated with the MWM acquisition and reversal, DCS did not enhance the expression of such synaptic protein. Conclusions: The present behavioral results support the role of DCS as a cognitive enhancer and suggest that enhancing the function of NMDARs and synaptic plasticity in the hippocampus may be related to improvement in social memory and spatial learning reversal in aged animals

Una dieta saludable i l'esport per contrarestar l'aparició de malalties associades amb l'edat

Una dieta nutritiva baixa en calories i la pràctica esportiva allarguen l'esperança de vida de les persones i redueixen la possibilitat de desenvolupar malalties neurodegeneratives associades a l'envelliment. En aquest marc s'inscriu l'experiment del laboratori de Psicobiologia de la Facultat de Psicologia i de l'Institut de Neurociències de la UAB que ha estudiat l'efecte d'una alimentació amb reducció del consum de calories i d'una altra amb excés en el rendiment òptim de les facultats cognitives i memorístiques en rates d'edat avançada, així com els mecanismes cerebrals conseqüents, en comparació amb rates joves.Una dieta nutritiva baja en calorías y la práctica deportiva alargan la esperanza de vida de las personas y reducen la posibilidad de desarrollar enfermedades neurodegenerativas asociadas al envejecimiento. En este marco se inscribe el experimento del laboratorio de Psicobiología de la Facultad de Psicología y del Instituto de Neurociencias de la UAB que ha estudiado el efecto de una alimentación con reducción del consumo de calorías y de otra con exceso en el rendimiento óptimo de las facultades cognitivas y memorísticas en ratas de edad avanzada, así como los mecanismos cerebrales consecuentes, en comparación con ratas jóvenes.A low-calorie nutritious diet and the sport practice prolong people's life expectancy and reduce the chance of developing neurodegenerative diseases associated with aging. The Laboratory of Psychobiology of the Faculty of Psychology and the Institute of Neurosciences of the UAB have realized an experiment in order to study the effect of a diet with reduced calorie intake and another with excess on the optimal performance of the cognitive and memory faculties in elderly rats, as well as the consequent brain mechanisms, compared with young rats

Una dieta saludable i l'esport per contrarestar l'aparició de malalties associades amb l'edat

Una dieta nutritiva baixa en calories i la pràctica esportiva allarguen l'esperança de vida de les persones i redueixen la possibilitat de desenvolupar malalties neurodegeneratives associades a l'envelliment. En aquest marc s'inscriu l'experiment del laboratori de Psicobiologia de la Facultat de Psicologia i de l'Institut de Neurociències de la UAB que ha estudiat l'efecte d'una alimentació amb reducció del consum de calories i d'una altra amb excés en el rendiment òptim de les facultats cognitives i memorístiques en rates d'edat avançada, així com els mecanismes cerebrals conseqüents, en comparació amb rates joves.Una dieta nutritiva baja en calorías y la práctica deportiva alargan la esperanza de vida de las personas y reducen la posibilidad de desarrollar enfermedades neurodegenerativas asociadas al envejecimiento. En este marco se inscribe el experimento del laboratorio de Psicobiología de la Facultad de Psicología y del Instituto de Neurociencias de la UAB que ha estudiado el efecto de una alimentación con reducción del consumo de calorías y de otra con exceso en el rendimiento óptimo de las facultades cognitivas y memorísticas en ratas de edad avanzada, así como los mecanismos cerebrales consecuentes, en comparación con ratas jóvenes.A low-calorie nutritious diet and the sport practice prolong people's life expectancy and reduce the chance of developing neurodegenerative diseases associated with aging. The Laboratory of Psychobiology of the Faculty of Psychology and the Institute of Neurosciences of the UAB have realized an experiment in order to study the effect of a diet with reduced calorie intake and another with excess on the optimal performance of the cognitive and memory faculties in elderly rats, as well as the consequent brain mechanisms, compared with young rats

Relación entre privación de sueño paradójico y autoestimulación eléctrica intracraneal en ratas

Para estudiar el efecto de la privación de sueño paradójico (PSP) sobre los mecanismos nerviosos de la recompensa, varias ratas macho de la cepa Wistar fueron privadas de sueño paradójico mediante el método de la plataforma o de Jouvet. Se estudiaron las tasas de autoestimulación eléctrica intracraneal (AEIC) en el haz prosencefálico medial antes y después de la PSP. En general, la PSP no afectó significativamente a la conducta de AEIC. Los resultados son discutidos en términos que se refieren a la efectividad del método de PSP utilizado, al lugar cerebral de AEIC y a efectos inespecíficos del tratamiento experimentalREM sleep deprivation induced by flower-pot technique (Jouvet's technique) was applied to naive male Wistar rats. Rates of intracranial selfestimulation (ICSS) in medial forebrain bundle were tested before and after deprivation. Generally, ZCSS was not affected by the treatment. These findings are discussed in relation to flower-pot technique effectiveness, ZCSS brain sites and unspecific effects of treatmen

Núcleos intralaminares posteriores del tálamo y procesos cognitivos

8 páginasThe parafascicular nucleus in rats and the centromedian parafascicular complex in primates and other mammals constitute the so-called posterior intralaminar nuclei (ILp) of the thalamus. Like the ascending reticular activating system and that of the basal ganglia-thalamo-cortical system, the ILp nuclei are part of the cerebral arousal systems.El núcleo parafascicular en las ratas y el complejo centromediano parafascicular en los primates y otros mamíferos constituyen los llamados núcleos intralaminares posteriores (ILp) del tálamo. Al igual que el sistema reticular activador ascendente y el de los ganglios basales-tálamo-cortical, los núcleos ILp forman parte de los sistemas de arousal cerebral