Acrobatic training prevents learning impairments and astrocyte remodeling in the hippocampus of rats undergoing chronic cerebral hypoperfusion: sex-specific benefits.

Background: Chronic cerebral hypoperfusion (CCH) leads to memory and learning impairments associated with degeneration and gliosis in the hippocampus. Treatment with physical exercise carries different therapeutic benefits for each sex. We investigated the effects of acrobatic training on astrocyte remodeling in the CA1 and CA3 subfields of the hippocampus and spatial memory impairment in male and female rats at different stages of the two-vessel occlusion (2VO) model. Methods: Wistar rats were randomly allocated into four groups of males and females: 2VO acrobatic, 2VO sedentary, sham acrobatic, and sham sedentary. The acrobatic training was performed for 4 weeks prior to the 2VO procedure. Brain samples were collected for morphological and biochemical analysis at 3 and 7 days after 2VO. The dorsal hippocampi were removed and prepared for Western blot quantification of Akt, p-Akt, COX IV, cleaved caspase-3, PARP, and GFAP. GFAP immunofluorescence was performed on slices of the hippocampus to count astrocytes and apply the Sholl's circle technique. The Morris water maze was run after 45 days of 2VO. Results: Acutely, the trained female rats showed increased PARP expression, and the 2VO-trained rats of both sexes presented increased GFAP levels in Western blot. Training, mainly in males, induced an increase in the number of astrocytes in the CA1 subfield. The 2VO rats presented branched astrocytes, while acrobatic training prevented branching. However, the 2VO-induced spatial memory impairment was partially prevented by the acrobatic training. Conclusion: Acrobatic training restricted the astrocytic remodeling caused by 2VO in the CA1 and CA3 subfields of the hippocampus. The improvement in spatial memory was associated with more organized glial scarring in the trained rats and better cell viability observed in females.

Neuroplasticity induced by the retention period of a complex motor skill learning in rats.

Learning complex motor skills is an essential process in our daily lives. Moreover, it is an important aspect for the development of therapeutic strategies that refer to rehabilitation processes since motor skills previously acquired can be transferred to similar tasks (motor skill transfer) or recovered without further practice after longer delays (motor skill retention). Different acrobatic exercise training (AE) protocols induce plastic changes in areas involved in motor control and improvement in motor performance. However, the plastic mechanisms involved in the retention of a complex motor skill, essential for motor learning, are not well described. Thus, our objective was to analyze the brain plasticity mechanisms involved in motor skill retention in AE . Motor behavior tests, and the expression of synaptophysin (SYP), synapsin-I (SYS), and early growth response protein 1 (Egr-1) in brain areas involved in motor learning were evaluated. Young male Wistar rats were randomly divided into 3 groups: sedentary (SED), AE, and AE with retention period (AER). AE was performed three times a week for 8 weeks, with 5 rounds in the circuit. After a fifteen-day retention interval, the AER animals was again exposed to the acrobatic circuit. Our results revealed motor performance improvement in the AE and AER groups. In the elevated beam test, the AER group presented a lower time and greater distance, suggesting retention period is important for optimizing motor learning consolidation. Moreover, AE promoted significant plastic changes in the expression of proteins in important areas involved in control and motor learning, some of which were maintained in the AER group. In summary, these data contribute to the understanding of neural mechanisms involved in motor learning in an animal model, and can be useful to the construction of therapeutics strategies that optimize motor learning in a rehabilitative context.

The effects of acrobatic exercise on brain plasticity: a systematic review of animal studies.

Acrobatic exercise is considered a complex motor activity and may promote motor learning and neuroplasticity. The objective of this systematic review was to verify possible plastic brain changes induced by acrobatic exercise in non-lesioned rat and mouse through the analysis of experimental studies. Manual and electronic searches were conducted in MEDLINE, EMBASE and ISI Web of Science databases, without restriction to language or publication date. Synaptogenesis and neurogenesis were selected as the primary outcomes. To evaluate the risk of bias of individual studies, we used the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) RoB tool. We found 1780 studies, from which 18 fulfilled the inclusion criteria in this review. Seventeen studies evaluated the cerebellum, six the motor cortex, five the striatum and two evaluated the hippocampus. The results showed that acrobatic exercise promotes plastic changes in brain areas of rats, and such changes are dependent of training frequency and duration. However, studies were heterogeneous regarding the proteins analyzed and the training protocols, which made it difficult to compare and determine ideal acrobatic exercise parameters for neuroplasticity. Concerning the methodological quality of studies, most of them presented high risk of bias with absence of relevant study design information. New research with detailing training protocols and analysis might contribute to clarify the role of acrobatic exercise in neuroplasticity and how it could be used in translational research.

Distinct neuroplasticity processes are induced by different periods of acrobatic exercise training.

Short and long-term physical exercise induce physiological and structural changes in brain motor areas. The relationship between changes of structural and synaptic proteins in brain motor areas and acrobatic exercise is less understood. Our aim was to evaluate the expression of synapsin I (SYS), synaptophysin (SYP), microtubule-associated protein 2 (MAP2), neurofilament (NF), and a marker for recent neuronal activity (Egr-1) in the motor cortex, striatum and cerebellum of adult rats subjected to acrobatic exercise (AE, for 1-4 weeks). We used adult Wistar rats, divided into 4 groups based on duration of acrobatic training, namely 1 week (AE1, n=15), 2 weeks (AE2, n=15), 4 weeks (AE4, n=15), and sedentary (SED, n=15). In AE groups, the rats covered 5 times a circuit that was composed of obstacles, three times a week. The protein levels were analyzed by immunoblotting and immunohistochemistry. The results revealed that short-term AE (AE1 and AE2) induced MAP2 decreases and NF, SYP and Egr-1 increases in the motor cortex; an increase of MAP2, SYS and SYP in the dorsolateral striatum, whereas the dorsomedial striatum showed increased NF, SYS, SYP and Egr-1. Granular cerebellar layer showed increased NF and Egr-1, with increased NF and SYP in the molecular layer. Long-term AE (AE4) promoted an increase of MAP2, SYP and Egr-1 in motor cortex; MAP2, SYS and SYP in the dorsomedial striatum; and NF and Egr-1 in the cerebellar granular layer. In conclusion, our data suggest that different durations of AE induce distinct plastic responses among distinct cortical and subcortical circuits.