Effect of exercise on synaptophysin and calcium/calmodulin-dependent protein kinase levels in prefrontal cortex and hippocampus of a rat model of developmental stress.
Stress affects the brain differently depending on the timing, duration and intensity of the stressor. Separation from the dam for 3 h per day is a potent stressor for rat pups which causes activation of the hypothalamic-pituitary-adrenal (HPA) axis, evidenced by increased plasma levels of adrenocorticotropin (ACTH) and glucocorticoids. Behaviourally, animals display anxiety-like behaviour while structurally, changes occur in neuronal dendrites and spines in the hippocampus and prefrontal regions involved in emotion and behaviour control. The aim of the present study was to determine whether maternal separation alters expression of synaptic markers, synaptophysin and calcium/calmodulin-dependent protein kinase II (CaMKII), in rat hippocampus and prefrontal cortex. A second aim was to determine whether voluntary exercise had a beneficial effect on the expression of these proteins in rat brain. Maternal separation occurred from postnatal day 2 (P2) to P14 for 3 h per day. Exercised rats were housed in cages with attached running wheels from P29 to P49. At P65, the prefrontal cortex and hippocampus were removed for protein quantification. Maternal separation did not have any effect while exercise increased synaptophysin and CaMKII in the ventral hippocampus but not in the dorsal hippocampus or prefrontal cortex. Since the ventral hippocampus is associated with anxiety-related behaviour, these findings are consistent with the fact that voluntary exercise increases anxiety-like behaviour and improves learning and memory.
Hescham
Sarah
S
Department of Human Biology, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
Grace
Laurian
L
Kellaway
Lauriston A
LA
Bugarith
Kishor
K
Russell
Vivienne A
VA
D000375:Aging / Q000502:physiology; D000818:Animals; D001008:Anxiety Disorders / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D015415:Biomarkers / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism*; D004195:Disease Models, Animal; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006624:Hippocampus / Q000254:growth & development / Q000378:metabolism / Q000503:physiopathology; D007859:Learning Disabilities / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008426:Maternal Deprivation; D010805:Physical Conditioning, Animal / Q000502:physiology; D017397:Prefrontal Cortex / Q000254:growth & development / Q000378:metabolism / Q000503:physiopathology; D016548:Prosencephalon / Q000254:growth & development / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy*; D009435:Synaptic Transmission / Q000502:physiology; D016708:Synaptophysin / Q000378:metabolism*; D013995:Time; D016896:Treatment Outcome; D015854:Up-Regulation / Q000502:physiology
D015415:Biomarkers; D016708:Synaptophysin; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2