Introduction: Motor learning consolidates in adulthood, and its defects begin to appear with aging. Ghrelin, an endogenous peptide, improves memory and learning, targeting dopaminergic circuits. While cytidine diphosphate choline (citicoline) is known as a common drug for enhancing memory and learning in aging, it is not recommended for adults due to its side effects. The current study aimed at investigating if ghrelin treatment would improve motor learning via the expression of a relevant gene. Methods: For this experimental study, adult male Wistar rats were randomly divided into five groups: control group, three groups of ghrelin treatment (0. 3, 1. 5, and 3 nmol/μ L), and one group with citicoline treatment. The injections were done intra-hippocampally. The motor learning rate was determined using the rotarod performance test by measuring the resistance to falling. Then the expression of dopamine receptor type D1 (Drd1) gene in the hippocampus was measured by a real-time polymerase chain reaction (PCR). Results: Ghrelin (3 nmol/μ L) and citicoline had similar and significant effects on motor learning improvement (P<0. 01). Both drugs significantly increased Drd1 gene expression (P <0. 001). Conclusion: Ghrelin, like citicoline, improves motor learning by altering the expression of Drd1 gene in the hippocampus.

Introduction: Motor behavior and coordination impairment are known side effects of opioid treatment, yet very few studies have investigated the effects of tramadol on motor behavior, or compared its effect with the effect of an opioid. This study investigates the effects of chronic injection of morphine and tramadol on rat motor function during infancy.Methods: Neonate rats (n=56) were randomly divided into three groups. On postnatal days 8-14, one group received saline and two other groups received tramadol and morphine with a dose-dependent manner. On postnatal day 21, each group was divided into subgroups, which received morphine, tramadol or saline again on postnatal days 22-26. Finally, on postnatal days of 22 and 26, the motor behavior was studied.Results: On postnatal day 23, tramadol caused an increase the falling rate from Rotarod (P<0.001), But there was not any significant difference between morphine groups. On postnatal day 26 rat, there was a significant difference only for morphine groups that received additive doses.Conclusion: The last dose of morphine (15 mg/kg) interferes with motor behavior of immature rats, whereas tramadol with additive doses on the first two days (3-6 mg/kg) caused an impairment in motor behavior of immature rats, but could not maintain this ability for the rest of the days of the injection (until 26 day).

Background: Many efforts have been made to find a proper animal model for Parkinson’s disease, in order to improve our knowledge about this disorder and find therapeutic approaches. Generally the reproducibility of experiments in laboratory animals is accompanied by some troubles. Therefore the validity of model is certified by certain behavioral tests. Thus the present study was aimed to find an accurate and reproducible rat model of Parkinson’s disease by rotenone.Methods: Male Wistar rats weighting 400±50 g (10-12 months) received several doses of rotenone (1, 2, 3 mg/kg) or its vehicle subcutaneously every 48 hours. Three behavioral tests (rotarod, rearing and bar) were run in order to check the development of model.Findings: Results indicated that rotenone (2 mg/kg/48h) was an efficient dose beside its low mortality. It was found that the latency time of rotarod test and movement skills in rearing test decreased significantly in rotenone (2 mg/kg/48h) treated animals (p<0.05). In addition, the results of bar test showed the augmentation of catalepsy in rotenone group compared to vehicle treated animals (p<0.05). In addition the statistical correlation between behavioral tests justified the development of movement disorders in the model.Conclusion: According to the results, it was concluded that rotenone (2 mg/kg/48h) was the best approach with reproducible capacity for induction of Parkinson’s disease model.

Objective (s): The present study aims at examining the motor coordination performance, serum and cerebellar estrogen, as well as ERβ levels, of ovariectomized rats (as menopausal model) following regular exercise.Materials and Methods: Ten female Sprague Dawley rats aged 12 weeks old were randomly divided into two groups; all of which underwent ovariectomy. The first group was treated with regular exercise of moderate intensity, in which the rats were trained to run on a treadmill for 60 min per day for 12 weeks. The second group served as control. Rotarod test was carried out before and after exercise treatment. All rats were euthanized thereafter, and blood and cerebellums of the rats were collected. The serum and cerebellar estrogen as well as cerebellar ERβ levels were measured using ELISA assays.Results: The number of falls in the rotarod task of the exercise group was significantly lower than that of control group. The cerebellar estrogen level of the exercise group was significantly higher than that of control group. Accordingly, there was a significantly negative correlation between the number of falls and cerebellar estrogen level in the exercise group.Conclusion: The present study shows that a lengthy period of regular exercise improves the cerebellar estrogen level and motor coordination performance in ovariectomized rats.

Background: A Brief interruption of blood supply to the brain can cause significant changes in the function of central nervous system. Patients usually show cognitive, emotional and electrophysiological changes during recovery from stroke. Preliminary pharmacokinetic studies have shown that Thymus vulgaris is useful in the treatment of seizures, respiratory diseases, smooth muscular spasm and bloating.Methods: In an experimental study, for inducing temporary acute ischemia carotid artery was closed for 60 minutes and then blood flowwas restored. Thyme extract (50, 100 and 200 mg/kg) was injected daily after induction of ischemia. Shuttle box test was carried out for the first 4 days and rotarod test was conducted at the last day. After the rotarod test, blood samples were collected from heart and brain tissue was removed under deep anesthesia. One way-ANOVA followed by Tukey and t-paired tests were used for comparing the groups at 0.05 level of significance. All data were analyzed by using the statistical package for social sciences (SPSS-19) software.Results: In passive avoidance test, the initial latency time was significantly longer in the ischemia group compared to the control group. Administration of thyme extract into ischemic rats significantly increased second latency time and reduced MDA levels of brain cortex.Conclusions: Our results indicated that Thymus vulgaris extract has a neuroprotective activity. Mechanisms of neuroprotective action might be associated with antioxidant activity and inhibition of oxidative stress in rat brain.

Zinc is an essential dietary element for many biological processes that modulates neurotransmission in brain regions. Zinc is also necessary for many homeostatic processes in the brain, some of which indicate neurotransmitter function. Zinc is essential for normal central nervous system development and function. Imbalances of this metal, either excess or deficiency, can result in neuronal apoptosis. Some researches indicate that zinc deficiency in animals cause to malformations and abnormal motility and motor coordination. But other researches has been shown, that the level of zinc in Parkinson disease unchanged or increased. In this study, we examined the effect of the different doses of Zinc Supplementation on motor activity in young male rats, with rotarod. To evaluate the peripheral effect, oral administration of zinc chloride in five different doses (20, 30, 50, 70, 100 mg/kg/day) for two weeks were used by gavage methods. The criteria which have been used for the movement test were motor resistance and coordination. This experiment showed that among of the different doses of zinc chloride, just 30 and 50mg/kg/day doses had positive effect on motor coordination (P<0.05). Motor coordination in groups which received zncl2 (100 mg/kg/day) were decreased (P<0.05).