Early exercise promotes positive hippocampal plasticity and improves spatial memory in the adult life of rats

Abstract

There is a great deal of evidence showing the capacity of physical exercise to enhance cognitive function, reduce anxiety and depression, and protect the brain against neurodegenerative disorders. Although the effects of exercise are well documented in the mature brain, the influence of exercise in the developing brain has been poorly explored. Therefore, we investigated the morphological and functional hippocampal changes in adult rats submitted to daily treadmill exercise during the adolescent period. Male Wistar rats aged 21 postnatal days old (P21) were divided into two groups: exercise and control. Animals in the exercise group were submitted to daily exercise on the treadmill between P21 and P60. Running time and speed gradually increased over this period, reaching a maximum of 18 m/min for 60 min. After the aerobic exercise program (P60), histological and behavioral (water maze) analyses were performed. The results show that early-life exercise increased mossy fibers density and hippocampal expression of brain-derived neurotrophic factor and its receptor tropomyosin-related kinase B, improved spatial learning and memory, and enhanced capacity to evoke spatial memories in later stages (when measured at P96). It is important to point out that while physical exercise induces hippocampal plasticity, degenerative effects could appear in undue conditions of physical or psychological stress. In this regard, we also showed that the exercise protocol used here did not induce inflammatory response and degenerating neurons in the hippocampal formation of developing rats. Our findings demonstrate that physical exercise during postnatal development results in positive changes for the hippocampal formation, both in structure and function.

A Little Goes a Long Way: How the Adult Brain Is Shaped by Musical Training in Childhood

“…Our findings are consistent with reports that adult nonhuman animals receive residual behavioral benefits from brief auditory training that they received as juveniles (Sarro and Sanes, 2011), that regular physical activity early in life is associated with better cognitive function later in life in humans (Dik et al, 2003) and nonhumans (Gomes da Silva et al, 2012), and that past musical experience is predictive of enhanced cognitive performance in older adults (Hanna-Pladdy and MacKay, 2011). Although the present study did not investigate the enduring behavioral benefits of childhood music training, we draw from prior work linking enhanced auditory brainstem encoding with heightened auditory perception, executive function, and auditory-based communication skills (Parbery-Clark et al, 2009;Ruggles et al, 2011;Kraus et al, 2012;Krizman et al, 2012;Song et al, 2012) to suggest that musical training during development may produce long-lasting positive effects on the adult brain.…”

A bout of voluntary running enhances context conditioned fear, its extinction, and its reconsolidation

“…Rodents provided with access to running wheels for several weeks and then shocked in a distinctive context exhibit more fear (typically freezing responses) than sedentary controls (Baruch et al 2004;Burghardt et al 2004Burghardt et al , 2006Van Hoomissen et al 2004;Clark et al 2008;Kohman et al 2011). This increase in conditioned fear is consistent with running-induced improvements in learning and memory found in other tasks, such as the Morris water maze (O'Callaghan et al 2007; Gomes da Silva et al 2012).…”

Influenza vaccine and learning in C57BL mice with an acute experimental autoimmune encephalomyelitis

“…Animal studies have provided a number of evidence for the role of exercise in spatial memory. Rodents undergoing treadmill running on a daily basis show that the time needed to swim to a submerged platform, in Morris Water Maze pool, is decreased at a greater rate compared to the rodents who had not run on a treadmill [25].…”

“…One should keep in mind that scoring of disability in EAE animals could be a subjective evaluation and potentially influenced by observer bias. Also, physical activity has been observed to have a large impact on hippocampal growth and neurogenesis, and therefore on spatial memory [25]. Animal studies have provided a number of evidence for the role of exercise in spatial memory.…”