Differential effects of swimming training on neuronal calcium sensor-1 expression in rat hippocampus/cortex and in object recognition memory tasks

Abstract

AbstractPhysical activity has been proposed as a behavioral intervention that improves learning and memory; nevertheless, the mechanisms underlying these health benefits are still not well understood. Neuronal Calcium Sensor-1 (NCS-1) is a member of a superfamily of proteins that respond to local Ca2+ changes shown to have an important role in learning and memory. The aim of the present study was to investigate the effects of swimming training on NCS-1 levels in the rat brain after accessing cognitive performance. Wistar rats were randomly assigned to sedentary (SG) or exercised groups (EG). The EG was subject to forced swimming activity, 30min/day, 5 days/week, during 8 weeks. Progressive load trials were performed in the first and last week in order to access the efficiency of the training. After the 8 week training protocol, memory performance was evaluated by the novel object preference and object location tasks. NCS-1 levels were measured in the cortex and hippocampus using immunoblotting. The EG performed statistically better for the spatial short-term memory (0.73±0.01) when compared to the SG (0.63±0.02; P<0.05). No statistically significant exercise-effect was observed in the novel object preference task (SG 0.65±0.02 and EG 0.68±0.02; p>0.05). In addition, chronic exercise promoted a significant increase in hippocampal NCS-1 levels (1.8±0.1) when compared to SG (1.17±0.08; P<0,05), but had no effect on cortical NCS-1 levels (SG 1.6±0.1 and EG 1.5±0.1; p>0.05). Results suggest that physical exercise would modulate the state of the neural network regarding its potential for plastic changes: physical exercise could be modulating NCS-1 in an activity dependent manner, for specific neural substrates, thus enhancing the cellular/neuronal capability for plastic changes in these areas; which, in turn, would differentially effect ORM task performance for object recognition and displacement