6-hydroxydopamine and ovariectomy has no effect on heart rate variability parameters of females

OBJECTIVES: In addition to the classic motor symptoms of Parkinson’s disease (PD), patients also present with non-motor symptoms, such as autonomic dysfunction, which is present in almost 90% of patients with PD, affecting the quality of life and mortality. Regarding sex differences in prevalence and presentation, there is increasing concern about how sex affects autonomic dysfunction. However, there are no previous data on autonomic cardiac function in females after 6-hydroxydopamine (6-OHDA) striatal injection. METHODS: Wistar female rats were ovariectomized. After 20 days, the animals received bilateral injections of 6-OHDA (total dose per animal: 48 mg) or a vehicle solution in the striatum. Thirty days after 6-OHDA injection, subcutaneous electrodes were implanted for electrocardiogram (ECG) recording. Ten days after electrode implantation, ECG signals were recorded. Analyses of heart rate variability (HRV) parameters were performed, and the 6-OHDA lesion was confirmed by analyzing the number of tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta (SNpc). RESULTS: A high dose of 6-OHDA did not affect HRV of females, independent of ovariectomy. As expected, ovariectomy did not affect HRV or lesions in the SNpc after 6-OHDA injection. CONCLUSIONS: We suggest that females with 6-OHDA present with cardioprotection, independent of ovarian hormones, which could be related to female vagal predominance

Maternal Exercise during Pregnancy Increases BDNF Levels and Cell Numbers in the Hippocampal Formation but Not in the Cerebral Cortex of Adult Rat Offspring

International audienceClinical evidence has shown that physical exercise during pregnancy may alter brain devel- opment and improve cognitive function of offspring. However, the mechanisms through which maternal exercise might promote such effects are not well understood. The present study examined levels of brain-derived neurotrophic factor (BDNF) and absolute cell num- bers in the hippocampal formation and cerebral cortex of rat pups born from mothers exer- cised during pregnancy. Additionally, we evaluated the cognitive abilities of adult offspring in different behavioral paradigms (exploratory activity and habituation in open field tests, spatial memory in a water maze test, and aversive memory in a step-down inhibitory avoid- ance task). Results showed that maternal exercise during pregnancy increased BDNF lev- els and absolute numbers of neuronal and non-neuronal cells in the hippocampal formation of offspring. No differences in BDNF levels or cell numbers were detected in the cerebral cortex. It was also observed that offspring from exercised mothers exhibited better cognitive performance in nonassociative (habituation) and associative (spatial learning) mnemonic tasks than did offspring from sedentary mothers. Our findings indicate that maternal exer- cise during pregnancy enhances offspring cognitive function (habituation behavior and spa- tial learning) and increases BDNF levels and cell numbers in the hippocampal formation of offspring

Spatial learning is faster in the offspring of exercised mothers.

<p>Latency of offspring from the exercise group (EX) and control group (CTL) to find the platform over 60 sec (n = 15 for EX group and n = 15 for CTL group) (A) and 120 sec (n = 15 for EX group and n = 15 for CTL group) (B) in the water maze test. No significant differences were detected between groups in either the 60-sec or 120-sec test (p > 0.05; one-way ANOVA with repeated measures). However, when analyzing the learning curve from each group separately, it was noted that offspring from the EX group exhibited better performance at finding the platform than those from the CTL group. In the 60-sec test (A), a statistical difference in comparison to the first test day emerged on the fifth day of testing for the EX group (•) and on the seventh day of testing for the CTL group (•). In the 120-sec test (B), a statistical difference in comparison to the first day emerged on the second day for the EX group (•) and on the third day for the CTL group (•). One day after the end of the last session in the water maze, the platform was removed (from quadrant 3) for a probe trial (a and b). Offspring were allowed to swim freely for 60 sec (a) or 120 sec (b), and time spent in quadrant 3 was used to assess offspring memory of the platform location. No significant difference in retention of this information was detected between the EX and CTL groups in 60 sec or 120 sec of investigation.</p

Exercise during pregnancy does not influence exploratory activity of offspring at P60.

<p>Open field quadrants (top right) and exploratory activity in offspring from the exercise group (EX; n = 14 for 5 min investigation and n = 21 for 10 min investigation) and control group (CTL; n = 14 for 5 min investigation and n = 22 for 10 min investigation) at P60. Offspring animals were monitored for 5 (A) and 10 (B) minutes. Exploratory activity of offspring is expressed as number of quadrants crossed (locomotion units) for both the 5 central quadrants (central) and the 8 peripheral quadrants (peripheral). Total locomotion corresponds to the sum of central and peripheral locomotion. Student's <i>t</i> test revealed no significant difference in exploratory activity between the studied groups for either 5 or 10 min of investigation.</p

BDNF is increased in the hippocampal formation of offspring of rats exercised during pregnancy.

<p>BDNF levels in the cortex and hippocampal formation of offspring from the exercise group (EX; n = 8) and control group (CTL; n = 9) at P60. No significant difference in cortical BDNF levels was observed between the studied groups (A). On the other hand, a significant increase in hippocampal BDNF levels was detected in the EX group when compared to the CTL group (*p < 0.05 by Student's <i>t</i> test) (B).</p

The pilocarpine model of epilepsy: what have we learned?

The systemic administration of a potent muscarinic agonist pilocarpine in rats promotes sequential behavioral and electrographic changes that can be divided into 3 distinct periods: (a) an acute period that built up progressively into a limbic status epilepticus and that lasts 24 h, (b) a silent period with a progressive normalization of EEG and behavior which varies from 4 to 44 days, and (c) a chronic period with spontaneous recurrent seizures (SRSs). The main features of the SRSs observed during the long-term period resemble those of human complex partial seizures and recurs 2-3 times per week per animal. Therefore, the pilocarpine model of epilepsy is a valuable tool not only to study the pathogenesis of temporal lobe epilepsy in human condition, but also to evaluate potential antiepileptogenic drugs. This review concentrates on data from pilocarpine model of epilepsy.<br>A administração sistêmica do potente agonista muscarínico pilocarpina em ratos promove alterações comportamentais e eletrográficas que podem ser divididas em três períodos distintos: (a) período agudo o animal evolui progressivamente para o status epilepticus, que perdura por até 24h; (b) período silencioso, caracterizado pela normalização progressiva do comportamento e do EEG e pode ter uma duração de 4 a 44 dias; período crônico, aparecimento de crises epilépticas espontâneas e recorrentes (SRSs). As características das SRSs observadas nos animas durante o período crônico são semelhantes às crises parciais complexas dos seres humanos e recorrem de 2-3 vezes por semana/animal. Além disso, o modelo de epilepsia induzido pela pilocarpina é válido não somente para se estudar a patogênese da epilepsia do lobo temporal em humanos como também para se testar a viabilidade de drogas antiepilépticas. Esse artigo de revisão aborda diversos aspectos do modelo de epilepsia induzido pela pilocarpina