scholarly journals Sex Differences in Neurophysiological Changes Following Voluntary Exercise in Adolescent Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Lindsay Ferguson ◽  
Christopher C. Giza ◽  
Rebecka O. Serpa ◽  
Tiffany Greco ◽  
Hannah Robert ◽  
...  

Background: Adolescence is a period of time characterized by the onset of puberty and is marked by cognitive and social developments and gross physical changes that can play a role in athletic performance. Sex differences are present with differences in body size, height, physiology and behavior which contribute to differences in athletic performance as well. Pre-clinical studies representing this active group are lacking.Methods: Acute and chronic effects of exercise were evaluated. Male and female adolescent rats were given voluntary access to a running wheel for 10 consecutive days. Running behavior (males and females) and estrous cycling (females only) were analyzed daily. A second group was given 10 days of voluntary access to a running wheel, then rested for 10 days to determine the long-term effects of exercise on the adolescent brain. Brain and muscle tissue were harvested at 10 and 20 day time points to understand exercise-dependent changes in mitochondrial activity and neuroplasticity. Animal cohorts were carried out at two different sites: University of California Los Angeles and Pepperdine University.Results: On average, running distance, intensity of run, and length of running bout increased for both male and female rats across the 10 days measured. Females ran significantly further and for longer intervals compared to males. Cortical and muscle expression of PGC1α showed similar levels at 10 days regardless of sex and exercise. There was a significant increase in expression at 20 days in all groups correlating with body size (p's < 0.05). Cortical and hippocampal levels of BDNF were similar across all groups, however, BDNF was significantly higher in exercised females at the acute compared to long-term time point.Discussion: Adolescent rats allowed 10 days of exercise show changes in physiologic function. There are sex differences in running behavior not impacted by sex hormones. These results are important to further our understanding of how exercise impacts the adolescent brain.

2021 ◽  
pp. svn-2020-000834
Author(s):  
Koteswara Rao Nalamolu ◽  
Bharath Chelluboina ◽  
Casimir A Fornal ◽  
Siva Reddy Challa ◽  
David M Pinson ◽  
...  

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.


2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.


2019 ◽  
Vol 70 (2) ◽  
pp. 130-133
Author(s):  
L.I. Bugaeva ◽  
◽  
V.V. Bagmetova ◽  
Yu.V. Markina ◽  
A.A. Kolmakov ◽  
...  

2021 ◽  
Vol 45 (2) ◽  
pp. 14-20
Author(s):  
Omar H Azeez

Aspartame (ASP) is a sugar substitute. Its use rose because it has been demonstrated to have deleterious effects after being metabolized. In the presence of antioxidant vitamins C or E, the effects of ASP on reproductive hormones of adult male and female Albino Wister rats were investigated. A total of eighty male and female rats were used in this study. The rats were divided into four groups: group 1, received no treatment; group 2, received ASP at 40 mg/kg BW; group 3, received ASP at 40 mg/kg BW with vitamin C at 150 mg/kg BW; and group 4, received ASP at 40 mg/kg BW and vitamin E at 100 mg/kg BW. All treatments were given orally by gavage needle once daily for consecutive 90 days. The levels of estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone hormone (TH) were measured after 90 days in blood plasma. In comparison with the control group, ASP treatment resulted in lower levels of E2, FSH, and LH in male and female rats. When the antioxidants vitamin C or E was given, the effects of ASP were reversed, and the levels of E2, LH, and FSH were increased. The testosterone hormone was likewise significantly increased by ASP, but testosterone hormone concentrations were decreased by vitamin C or E treatments. Long-term ASP consumption caused interfering with testicular and ovarian hormonal activity, while vitamins C and E on the other hand, overcome longstanding consumption ASP's effects.


1976 ◽  
Vol 71 (1) ◽  
pp. 109-114 ◽  
Author(s):  
I. DONIACH ◽  
D. J. SHALE

SUMMARY From the differences in radiation profiles between 131I and 125I isotopes of iodine it would be expected that they would show different effects on thyroid function. The differences should lead to lower rates of thyroid gland destruction with 125I and hence less post-irradiation hypothyroidism. This difference in biological effect has been demonstrated in rats by indirect assessment of thyroid function. In this report the long-term effects of a range of similar doses of 131I and 125I were compared, in male and female rats, by direct assessment of thyroid function. Seventeen months after receiving 25 and 125 μCi of 131I, male and female rats showed significant elevation of serum TSH concentration and a reduction in 3 h radioiodine uptake. Rats receiving 1 and 5 μCi of 131I and all doses of 125I showed no significant changes in thyroid function. These findings confirm the previously reported differences in effect between the 131I and 125I isotopes of iodine in the rat.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Stavrakis ◽  
K Elkholey ◽  
L Morris ◽  
Y Li ◽  
S S Po

Abstract Background Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for 50% of HF and sudden death is the leading cause of mortality. There are considerable sex differences in cardiac structure and function, which may be related to outcomes in HFpEF. Transcutaneous vagus nerve stimulation (tVNS) is antiarrhythmic. Purpose To describe sex differences in mortality, autonomic tone and ECG parameters in rats with HFpEF and examine the effect of tVNS on these outcomes. Methods Dahl salt sensitive (DS) rats of either sex were randomized into high salt (HS, 8% NaCl) or low salt (LS) diet (0.3% NaCl) at 7 weeks of age. After 6 weeks of LS or HS diets, HS rats were randomized to receive active or sham tVNS, 30min daily (20Hz, 3mA) for 4 weeks. The rats were monitored daily for 4 weeks for the development of HFpEF. ECG and echocardiogram were performed at 13 weeks (baseline) and 17 weeks (endpoint). Heart rate variability (HRV) was calculated at the respective time points. ECG and HRV parameters were analyzed in a blinded fashion. Logistic regression analysis was performed to identify independent predictors of mortality. Results A total of 58 rats were included (5 male LS, 6 female LS, 22 male HS and 25 female HS). HS rats developed significant hypertension and signs of HFpEF, while 24% of females and 53% of males died (P=0.004). There were 4 sudden cardiac deaths in males (with ventricular tachycardia documented in 1 rat), whereas all the females died of HF or stroke. Corrected QT (QTc) at baseline significantly prolonged in HS compared to LS rats (250.5±14.4ms vs. 226.8±13.9ms, respectively, p=0.0007), while all other ECG parameters did not differ significantly between groups. In HS rats, QTc prolongation was significantly more pronounced in males compared to females (259.4±20.6ms vs. 243.8±14.5ms, respectively, P=0.002). In univariate analysis, prolonged baseline QTc (OR=1.04; 95% CI 1.01–1.06, p=0.003) and male sex (OR=3.21, 95% CI 1.19–8.66, p=0.016) predicted mortality. However, in multivariate analysis, QTc was the only significant predictor of mortality (OR=1.04; 95% CI 1.01–1.06, p=0.003). After 4 weeks of treatment, active tVNS significantly decreased QTc compared to sham (244.6±13.8ms vs. 255.8±14.0ms, respectively, p=0.017) in both male and female rats in a similar manner. The low frequency to high frequency ratio (LF/HF) of HRV, which reflects sympathovagal balance, was significantly decreased in active tVNS rats compared to sham (0.21±0.13 vs. 0.54±0.14, respectively; p=0.001) in both male and female rats in a similar manner. Conclusions Male rats with HFpEF exhibit worse survival compared to females and are at higher risk for sudden death. QTc prolongation accounts for the increased risk of sudden death in males compared to females. Autonomic modulation with tVNS attenuates the unfavorable changes in QTc and HRV induced by HS diet and may be used to prevent ventricular arrhythmias in patients with HFpEF.


1994 ◽  
Vol 76 (4) ◽  
pp. 1540-1547 ◽  
Author(s):  
D. J. Prezant ◽  
B. Richner ◽  
T. K. Aldrich ◽  
D. E. Valentine ◽  
E. I. Gentry ◽  
...  

The effects of long-term undernutrition (10 wk) on diaphragm contractility, fatigue, and fiber type proportions were studied in male and female rats. Contractility and fatigue resistance indexes were measured in an in vitro diaphragm costal strip preparation by using direct stimulation at 37 degrees C. Undernutrition allowed for continued growth in males and females but with substantial reductions in weight gain. Relative to control rats of the same sex, final weights were significantly lower in undernourished males (74 +/- 3%) than females (90 +/- 5%), but weight gain was not significantly different between undernourished males (58 +/- 5%) and females (60 +/- 3%). Only in males did undernutrition significantly reduce costal diaphragm weight (to 77 +/- 5% of control). Diaphragm forces, normalized for cross-sectional area, were not significantly different from male or female control values. Fatigue resistance indexes (fatigue/baseline force) were increased at all stimulation frequencies in undernourished males but not in undernourished females. Costal diaphragm atrophy, involving types I and II fibers, occurred in undernourished males but not in undernourished females. In conclusion, despite long-term undernutrition reducing weight gain to similar levels in males and females (relative to control), there was excellent preservation of diaphragm weight, function, and structure in females but, although diaphragm atrophy occurred, there was preserved contractility and increased fatigue resistance in males.


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