Early exercise promotes positive hippocampal plasticity and improves spatial memory in the adult life of rats.
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.
Department of Physiology, Universidade Federal de São Paulo, São Paulo, Brazil. sergio.gomes@unifesp.br
Sérgio
S
Gomes da Silva
Nicolas
N
Unsain
Daniel Hugo
DH
Mascó
Michelle
M
Toscano-Silva
Henrique Alves
HA
de Amorim
Bruno Henrique
BH
Silva Araújo
Priscila Santos Rodrigues
PS
Simões
Maria da Graça
Mda G
Naffah-Mazzacoratti
Renato Arruda
RA
Mortara
Fulvio Alexandre
FA
Scorza
Esper Abrão
EA
Cavalheiro
Ricardo Mario
RM
Arida
D000818:Animals; D015153:Blotting, Western; D002452:Cell Count; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D019599:Mossy Fibers, Hippocampal / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013037:Spatial Behavior / Q000502:physiology