Effect of endurance training on seizure susceptibility, behavioral changes and neuronal damage after kainate-induced status epilepticus in spontaneously hypertensive rats

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.

Metabolic footprint in young, middle-aged and elderly rats with melatonin deficit

The pineal gland is suggested to be an essential area involved in the programming of fertility, growth, aging, and death of mammals via the released hormone melatonin.The present study aimed to ascertain the effect of melatonin deficit on several physiological and metabolic parameters, closely associated with the aging process, at certain stages of ontogenesis. Sham and rats with pinealectomy, operated at ages 3, 14, and 18-months, respectively, were tested two months later. Sham rats demonstrated an age-related decline of muscle strength, exercise endurance, motor activity, food intake, calorimetric parameters, and impaired lipid profile. Pinealectomy reduced the maximal time to exhaustion and body weight gain while diminished motor activity, food intake, O₂ consumption, CO₂ production, and energy expenditure during the Dark phase in the youngest rat group. In addition, melatonin deficit elevated arterial blood pressure (systolic, diastolic, and mean arterial pressure) and increased serum glucose and triglyceride level in 3-month-old rats while decreased the liver enzyme activity in 14-month-old rats. In conclusion, the present study brought new insights confirming the complex impact of melatonin deficit on important physiological, metabolic and biochemical markers related to aging and demonstrated for the first time that the lack of melatonin hormone is harmful in young adult rats.

The Potential Role of Previous Physical Exercise Program to Reduce Seizure Susceptibility: A Systematic Review and Meta-Analysis of Animal Studies

Background: Clinical and pre-clinical studies indicate a reduction in seizure frequency as well as a decrease in susceptibility to subsequently evoked seizures after physical exercise programs. In contrast to the influence of exercise after epilepsy previously established, various studies have been conducted attempting to investigate whether physical activity reduces brain susceptibility to seizures or prevents epilepsy. We report a systematic review and meta-analysis of different animal models that addressed the impact of previous physical exercise programs to reduce seizure susceptibility.

Methods: We included animal model (rats and mice) studies before brain insult that reported physical exercise programs compared with other interventions (sham, control, or naïve). We excluded studies that investigated animal models after brain insult, associated with supplement nutrition or drugs, that did not address epilepsy or seizure susceptibility, ex vivo studies, in vitro studies, studies in humans, or in silico studies. Electronic searches were performed in the MEDLINE (PubMed), Web of Science (WOS), Scopus, PsycINFO, Scientific Electronic Library Online (SciELO) databases, and gray literature, without restrictions to the year or language of publication. We used SYRCLE's risk of bias tool and CAMARADES checklist for study quality. We performed a synthesis of results for different types of exercise and susceptibility to seizures by random-effects meta-analysis.

Results: Fifteen studies were included in the final analysis (543 animals), 13 of them used male animals, and Wistar rats were the most commonly studied species used in the studies (355 animals). The chemoconvulsants used in the selected studies were pentylenetetrazol, penicillin, kainic acid, pilocarpine, and homocysteine. We assessed the impact of study design characteristics and the reporting of mitigations to reduce the risk of bias. We calculated a standardized mean difference effect size for each comparison and performed a random-effects meta-analysis. The meta-analysis included behavioral analysis (latency to seizure onset, n = 6 and intensity of motor signals, n = 3) and electrophysiological analysis (spikes/min, n = 4, and amplitude, n = 6). The overall effect size observed in physical exercise compared to controls for latency to seizure onset was −130.98 [95% CI: −203.47, −58.49] (seconds) and the intensity of motor signals was −0.40 [95% CI: −1.19, 0.40] (on a scale from 0 to 5). The largest effects were observed in electrophysiological analysis for spikes/min with −26.96 [95% CI: −39.56, −14.36], and for spike amplitude (μV) with −282.64 [95% CI: −466.81, −98.47].

Discussion:Limitations of evidence. A higher number of animal models should be employed for analyzing the influence of exerciseon seizure susceptibility. The high heterogeneity in our meta-analysis is attributable to various factors, including the number of animals used in each study and the limited number of similar studies. Interpretation. Studies selected in this systematic review and meta-analysis suggest that previous physical exercise programs can reduce some of the main features related to seizure susceptibility [latency seizure onset, spikes/min, and spike amplitude (μV)] induced by the administration of different chemoconvulsants.

Systematic Review Registration: PROSPERO, identifier CRD42021251949; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=251949.

Electrochemical Sensing of Ascorbate as an Index of Neuroprotection from Seizure Activity by Physical Exercise in Freely Moving Rats

Physical exercise (PE) has been drawing increasing attention to prevent and alleviate neural damage of brain diseases; however, in vivo sensing of the neuroprotection ability of PE remains a challenge. Here, we find that ascorbate can be used as a small molecular index for neuroprotective function of PE and the neuroprotection ability of PE can thus be in vivo monitored with an online electrochemical system (OECS) in freely moving animals. With the OECS as the sensing system, we find that the concentration of ascorbate in the microdialysate from the striatum increases greatly in kainic acid (KA)-induced seizure rats and reaches twice the basal level (i.e., 214.4 ± 32.7%, p < 0.001, n = 4) at a time point 90 min after KA microinjection. Such an increase of ascorbate is obviously attenuated (i.e., 153.6 ± 23.9% of the basal level, p < 0.05, n = 3) after PE, showing the neuroprotective activity of PE. This finding is believed to be significant in providing chemical insight into the neuroprotection ability of PE.

Aerobic exercise has an anxiolytic effect on streptozotocin‑induced diabetic rats

Diabetes is a metabolic disorder characterized by hyperglycemia and impaired insulin secretion or action. Psychological comorbidities, such as depression and anxiety, are more common in people with diabetes. Exercise results in anxiolytic effects, as demonstrated in numerous studies. This study aims to evaluate potential anxiolytic effects of aerobic exercise in streptozotocin (STZ)‑induced diabetes. Male Wistar albino rats (n=40) were randomly divided into four groups of control, exercise, diabetes, and diabetes + exercise. Diabetes was induced with a single i.p. injection of STZ. The incremental load test was applied to exercise groups to determine maximal exercise capacity. Rats exercised on a treadmill at 70% of their maximal capacity for 45 min, five days per week for 12 weeks. On the day after the last exercise session the open field test and elevated plus maze test were carried out. Diabetes caused an increase in anxiety level, reflected in stretch‑attend posture, self‑grooming behaviors, and freezing time, with no significant changes for other behavioral parameters. Training normalized diabetes‑induced deteriorations and also induced a significant anxiolytic effect both on diabetic and non‑diabetic rats. This effect was observed for all behavioral parameters. The results of the open field test and elevated plus maze were consistent. The current results demonstrated a slight increase in anxiety with diabetes and a prominent anxiolytic effect of aerobic exercise. Considering the conflicting results in exercise‑anxiety studies, this study hig hlights the importance of individually designed exercise protocols.

Effects of exercise training on anxiety in diabetic rats

Diabetes mellitus (DM) is a common health problem, which manifests itself with chronic hyperglycemia and impaired insulin action. The prevalence of anxiety disorders tends to be high in the diabetic population. Exercise has a well-known anxiolytic effect, also demonstrated on rodents, but the effect of exercise on the DM-induced anxiety is still unknown. Female, Wistar albino rats were randomly divided into four groups (n=8) (C; EX; DM; DM+EX). DM was induced by injection (i.p.; 50 mg/kg) of Streptozotocin (STZ). Rats exercised in moderate intensity on the treadmill (15m/min; 5°; 30 min) for 5 weeks. Anxiety-like behavior (ALB) was evaluated by Open field test (OFT) and Elevated Plus Maze (EPM). According to OFT, central time and central entry have increased with in EX but not in DM+EX. There was no difference between C and DM. Central latency time didn't differ among groups. Unsupported rearing increased in both EX and DM+EX. There was no significant decrease in DM. Freezing time was significantly increased in the DM group. Exercise training reduced freezing time both in diabetic and non-diabetic animals. EPM results were similar. Time spent in open arm was increased significantly in exercise groups compared to their sedentary matches, and freezing time data were also parallel to OFT. Our study revealed that diabetes had shown an anxiogenic effect, which was not severe, and it only manifested itself on some behavioral parameters. Exercise training was reduced anxiety-like behavior both in diabetic and non-diabetic rats. However, because of the nature of exercise studies, it is hard to separate the anxiolytic effect of exercise from the alteration of locomotion.

Enhancing effect of aerobic training on learning and memory performance in rats after long-term treatment with Lacosamide via BDNF-TrkB signaling pathway

Aerobic training has a neuroprotective effect, reduces the risk of developing neurodegenerative diseases and facilitates functional recovery. The present study assesses the effect of aerobic training on cognitive functions, hippocampal BDNF/TrkB ligand receptor system expression and serum levels of BDNF and corticosterone in intact rats after chronic treatment with Lacosamide (LCM). Male Wistar rats were randomly divided into two groups. One group was exercised on a treadmill (Ex) and the other one was sedentary (Sed). Half of the rats from each group received saline (veh) while the other half - LCM. The rats underwent a month-long training and LCM treatment before being subjected to one active and two passive avoidance tests. Both trained groups increased significantly the number of avoidances compared with the sedentary animals during the learning session and on memory retention tests, while the number of avoidances of the LCM-treated rats was significantly lower in comparison with the saline-treated animals. Both passive avoidance tests revealed that trained animals spent more time in the lighted compartment or caused longer stay on the platform than did the sedentary rats during acquisition and short- and long-term memory retention tests. Aerobic training increased BDNF and TrkB hippocampal immunoreactivity. We found no significant difference between BDNF serum levels but corticosterone levels of the Sed-LCM rats were lower than those of the Sed-veh animals. Our results show that aerobic training increases the hippocampal BDNF/TrkB expression suggesting a role in preventing the negative effect of Lacosamide on cognitive functions in rats.

Long-Term Treatment with Losartan Attenuates Seizure Activity and Neuronal Damage Without Affecting Behavioral Changes in a Model of Co-morbid Hypertension and Epilepsy

Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy.