High-intensity training with short and long intervals regulate cortical neurotrophic factors, apoptosis markers and chloride homeostasis in rats with stroke

Continuous Use During Disuse: Mechanisms and Effects of Spontaneous Activity of Unloaded Postural Muscle

In most mammals, postural soleus muscles are involved in the maintenance of the stability of the body in the gravitational field of Earth. It is well established that immediately after a laboratory rat is exposed to conditions of weightlessness (parabolic flight) or simulated microgravity (hindlimb suspension/unloading), a sharp decrease in soleus muscle electrical activity occurs. However, starting from the 3rd day of mechanical unloading, soleus muscle electrical activity begins to increase and reaches baseline levels approximately by the 14th day of hindlimb suspension. This phenomenon, observed in the course of rat hindlimb suspension, was named the "spontaneous electrical activity of postural muscle". The present review discusses spinal mechanisms underlying the development of such spontaneous activity of rat soleus muscle and the effect of this activity on intracellular signaling in rat soleus muscle during mechanical unloading.

Effect of high-intensity interval training on self-care and anxiety-like behaviors in naive rats

Self-care behavior covers individual's health, life and well-being to maintain the necessary activities. The aim of this study is to examine the self-care and possible anxiolytic effects of high-intensity interval exercise (HIIT). Eight-week-old Wistar Albino male rats were divided into Control (n = 8), and Exercise (n = 8). Rat exercised for 38 min a day, 5 days a week, for 8 weeks The animals were then subjected to open field test and splash test, and the behaviors were video recorded. Student t test and Shapiro-Wilk test were used as statistical tests. In the exercise group, spray-induced grooming behavior increased significantly in terms of duration and frequency (p < 0.05), but no significant difference was observed in the latency of grooming (p > 0.05). In the open-field test, the total distance traveled, which is a locomotor activity parameter, did not change between the groups. Anxiolytic-like behaviors such as total rearing behavior, unsupported rearing, central time, and central region entries increased remarkably in the exercise group vs. control (p < 0.0001). Freezing as an anxiogenic behavior decreased in the exercise group positively (p < 0.0001). Intermittent high-intensity exercise improved and increased self-care behaviors. Further, the present study shows that HIIT has beneficial effects on different aspects of behaviors such as exploratory behaviors, increasing anxiolytic behaviors, and reducing anxiogenic behavior. The present study is a preclinical study that will pave the way for new studies.

High-intensity interval training improves long-term memory and increases hippocampal antioxidant activity and BDNF levels in ovariectomized Wistar rats

Menopause is the period in which women cease to produce the hormone estrogen, which can trigger physiological, cognitive, and behavioral changes. In this context, alternatives are needed that can reduce the effects provided by menopause, specifically in terms of cognitive and behavioral aspects. High-intensity interval training (HIIT) is an exercise protocol that has shown the potential to improve cognition by promoting an increase in antioxidant defenses and BDNF levels. Therefore, the aim of this study was to evaluate the effects of HIIT on behavior and hippocampal neurochemistry in ovariectomized adult rats. Four groups of rats were divided into: females without ovariectomy surgery and sedentary (SHAM-SED); females with ovariectomy surgery and sedentary (OVX-SED); females without ovariectomy surgery and trained (SHAM-HIIT); females with ovariectomy surgery and trained (OVX-HIIT). After the surgical procedure and the HIIT protocol, the animals underwent anxiety (elevated plus maze and open field) and memory (novel object recognition) tests. Corticosterone was measured in blood and BDNF levels and redox status were evaluated in the hippocampus. The OVX-SED group showed low BDNF levels and antioxidant enzymes, which may be linked to the observed memory impairments. The HIIT protocol (SHAM-HIIT and OVX-HIIT groups) increased the BDNF levels and antioxidant enzymes in the hippocampus, improving the animals' memory. However, HIIT also led to increased plasma corticosterone and anxiety-like behaviors. The ovariectomy procedure induced memory impairment probably due to reductions in hippocampal BDNF levels and redox imbalance. The HIIT protocol demonstrates promising results as an alternative to improve memory in ovariectomized rats.