Neuroplasticity and Healthy Lifestyle: How Can We Understand This Relationship?

Our brain has this extraordinary ability to experience functional and structural changes before environmental stimuli, cognitive demand, or our experience itself. Exercise, diet, an appropriate sleep pattern, and reading habits are among those activities proposed to induce effects on cerebral architecture—an active lifestyle seems to induce changes in the brain function that favour welfare and better quality of life. This special issue is intended to extend the knowledge about the relationship between neuroplasticity and a healthy lifestyleFil: Begega, Azucena. Universidad de Oviedo; EspañaFil: Santín, Luis J.. Universidad de Málaga; EspañaFil: Galeano, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Cutuli, Debora. Universita Di Roma; ItaliaFil: Sampedro Piquero, Patricia. Universidad Autonoma de Madrid. Facultad de Psicología. Departamento de Psicología Biológica y de la Salud; Españ

¿Previene la actividad física y mental el deterioro cognitivo? Evidencia de la investigación animal

In recent decades, several pharmacological strategies have been developed to prevent age-related cognitive impairment. However, the ineffectiveness of the majority of these strategies has led to growing interest in behavioural intervention. Cognitive stimulation and physical activity have been shown to provide significant benefits by counteracting cognitive impairment and dementia. Animal models have provided information on the neurobiological mechanisms that mediate the formation of cognitive and brain reserve. This paper reviews several studies on aged rodents showing the positive effects of environmental enrichment and aerobic exercise on brain and cognitive function of these animals. The implications of this research for human aging is discussed.En las últimas décadas se han desarrollado varias estrategias farmacológicas para prevenir el declive cognitivo en el envejecimiento, sin embargo la inefectividad de la mayoría de ellas ha hecho que las intervenciones conductuales estén recibiendo cada vez más atención. La estimulación cognitiva y la actividad física han mostrado importantes beneficios al reducir las alteraciones cognitivas relacionadas con la edad y la demencia. Gracias a los modelos animales cada vez se sabe más acerca de los mecanismos neurobiológicos que subyacen a la reserva cognitiva y cerebral que promueven estas intervenciones. En esta revisión presentaremos varias investigaciones en roedores viejos en las que se muestran los efectos positivos del enriquecimiento ambiental y ejercicio aeróbico sobre la función cerebral y cognitiva de estos animales. La implicación de estas investigaciones para el envejecimiento humano será también discutida

Functional brain networks underlying latent inhibition of conditioned disgust in rats

The present experiment examined the neuronal networks involved in the latent inhibition of conditioned disgust by measuring brain oxidative metabolism. Rats were given nonreinforced intraoral (IO) exposure to saccharin (exposed groups) or water (non-exposed groups) followed by a conditioning trial in which the animals received an infusion of saccharin paired (or unpaired) with LiCl. On testing, taste reactivity responses displayed by the rats during the infusion of the saccharin were examined. Behavioral data showed that preexposure to saccharin attenuated the development of LiCl-induced conditioned disgust reactions, indicating that the effects of taste aversion on hedonic taste reactivity had been reduced. With respect to cumulative oxidative metabolic activity across the whole study period, the parabrachial nucleus was the only single region examined which showed differential activity between groups which received saccharin-LiCl pairings with and without prior non-reinforced saccharin exposure, suggesting a key role in the effects of latent inhibition of taste aversion learning. In addition, many functional connections between brain regions were revealed through correlational analysis of metabolic activity, in particular an accumbens-amygdala interaction that may be involved in both positive and negative hedonic responses

Long-term consequences of alcohol use in early adolescent mice: Focus on neuroadaptations in GR, CRF and BDNF.

Our aim was to assess the cognitive and emotional state, as well as related-changes in the glucocorticoid receptor (GR), the corticotropin-releasing factor (CRF) and the brain-derived neurotrophic factor (BDNF) expression of adolescent C57BL/6J male mice after a 5-week two-bottle choice protocol (postnatal day [pd]21 to pd52). Additionally, we wanted to analyse whether the behavioural and neurobiological effects observed in late adolescence (pd62) lasted until adulthood (pd84). Behavioural testing revealed that alcohol during early adolescence increased anxiety-like and compulsive-related behaviours, which was maintained in adulthood. Concerning cognition, working memory was only altered in late adolescent mice, whereas object location test performance was impaired in both ages. In contrast, novel object recognition remained unaltered. Immunohistochemical analysis showed that alcohol during adolescence diminished BDNF+ cells in the cingulate cortex, the hippocampal CA1 layer and the central amygdala. Regarding hypothalamic-pituitary-adrenal axis (HPA) functioning, alcohol abuse increased the GR and CRF expression in the hypothalamic paraventricular nucleus and the central amygdala. Besides this, GR density was also higher in the prelimbic cortex and the basolateral amygdala, regardless of the animals' age. Our findings suggest that adolescent alcohol exposure led to long-term behavioural alterations, along with changes in BDNF, GR and CRF expression in limbic brain areas involved in stress response, emotional regulation and cognition.post-print4591 K

Odor-taste pairings lead to the acquisition of negative hedonic qualities by the odor in aversion learning

Three experiments examined the affective responses conditioned to an odorous stimulus in the taste-mediated odor aversion learning paradigm. Experiment 1 analyzed the microstructure of licking behavior during voluntary consumption. Before conditioning, water-deprived rats had access to a bottle containing either a tasteless odor (0.01% amyl acetate) diluted in water or mixed with 0.05% saccharin. Next, the rats were injected with either LiCl or saline immediately after drinking saccharin. At test, they received the odor and taste solutions on separate days. Lick cluster size was used as a direct measure of the hedonic response to the odor cue. Rats receiving odor-taste pairings prior to the saccharin devaluation showed both lower consumption and lick cluster size, reflecting a reduced hedonic evaluation of the odor. Experiments 2a and 2b used the orofacial reactivity method. After pretraining in the drinking boxes with the odor alone or mixed with saccharin, the rats were intraorally infused with saccharin before injection with LiCl or saline. At test, they were infused in separate sessions with the odor and taste and their orofacial reactions video recorded. There were increased aversive orofacial responses to the odor in rats that had prior odor-taste experience, a result indicating a negative hedonic evaluation of the odor. These results provide evidence of conditioned changes in affective value of odor cues through taste-mediated learning and are consistent with the idea that odor-taste pairings lead to the acquisition of taste qualities by the odor

Influence of pre-reproductive maternal enrichment on coping response to stress and expression of c-Fos and glucocorticoid receptors in adolescent offspring

Environmental enrichment (EE) is an experimental setting broadly used for investigating the effects of complex social, cognitive, and sensorimotor stimulations on brain structure and function. Recent studies point out that parental EE experience, even occurring in the pre-reproductive phase, affects neural development and behavioral trajectories of the offspring. In the present study we investigated the influences of pre-reproductive EE of female rats on maternal behavior and adolescent male offspring's coping response to an inescapable stressful situation after chronic social isolation. For this purpose female Wistar rats were housed from weaning to breeding age in enriched or standard environments. Subsequently, all females were mated and housed in standard conditions until offspring weaning. On the first post partum day (ppd 1), mother-pup interactions in undisturbed conditions were recorded. Further, after weaning the male pups were reared for 2 weeks under social isolation or in standard conditions, and then submitted or not to a single-session Forced Swim Test (FST). Offspring's neuronal activation and plastic changes were identified by immunohistochemistry for c-Fos and glucocorticoid receptors (GRs), and assessed by using stereological analysis. The biochemical correlates were measured in the hippocampus, amygdala and cingulate cortex, structures involved in hypothalamic-pituitary-adrenocortical axis regulation. Enriched dams exhibited increased Crouching levels in comparison to standard reared dams. In the offspring of both kinds of dams, social isolation reduced body weight, decreased Immobility, and increased Swimming during FST. Moreover, isolated offspring of enriched dams exhibited higher levels of Climbing in comparison to controls. Interestingly, in the amygdala of both isolated and control offspring of enriched dams we found a lower number of c-Fos immunopositive cells in response to FST and a higher number of GRs in comparison to the offspring of standard dams. These results highlight the profound influence of a stressful condition, such as the social isolation, on the brain of adolescent rats, and underline intergenerational effects of maternal experiences in regulating the offspring response to stress

An evaluation of hedonic responses in taste-potentiated odor aversion using the analysis of licking microstructure and orofacial reactivity

Two experiments examined the hedonic responses conditioned to odor cues in the phenomenon of taste-potentiated odor aversion. Experiment 1 analyzed the microstructure of licking behavior during voluntary consumption. A tasteless odor (amyl acetate) was delivered to rats either diluted in water or mixed with saccharin before being injected with LiCl. At test, subjects which had received the odor-taste compound during conditioning showed both lower odor consumption and lick cluster size, a result indicating an increased negative evaluation of the odor. Experiment 2 examined the orofacial reactions elicited by the odor as index of its hedonic impact. During conditioning, the rats were intraorally infused with either the odor alone or the odor-saccharin compound before being injected with LiCl. At test, they were infused with the odor and their orofacial responses video recorded. More aversive orofacial responses were elicited by the odor cue in rats that had compound conditioning, again a result indicating a strengthened negative hedonic reactivity compared to animals experiencing odor aversion conditioning alone. Taken together, these results indicate that taste-mediated potentiation of odor aversion conditioning impacts on the acquisition of conditioned hedonic reactions as well as consumption

Reversible changes in hippocampal CA1 synapses associated with water maze training in rats

ABSTRACT Long-term memories seem to require protein synthesis to be established. This process can be related with synaptogenesis resulting in changes in the form or even in the number or proportion of synaptic contacts. Results from behavioral studies assessing quantitative changes associated with different learning tasks are controversial. The aim of our work was to assess whether the number of CA1 hippocampal synaptic contacts can be modified after training in different tasks in the Morris water maze (MWM). We found transient changes in the synaptic density of the symmetric synapses associated with place learning. A reduced synaptic density of the symmetric synapses in the stratum radiatum of CA1 was found at 48 h posttraining, returning to control levels 72 h posttraining. The same effect was observed 1 h after training in a nonspatial task. Synaptic changes found in the CA1 shortly after water maze training suggest a possible participation of the hippocampus in the acquisition of nonspatial tasks together with a role in the short-term consolidation of spatial memory. As no changes were found in the total number of synapses counted, it is likely that subtle changes in synaptic efficacy than new synapse generation may be sufficient to support the acquisition and maintenance of new memories