Basic and Clinical Neuroscience
Volume:4 Issue: 2, Spring 2013

Stroke is one of the most important reasons of death. Hence, trials to prevent or lessen the complications originated by stroke are a goal of public health worldwide. The ischemia-reperfusion causes hypoxia, hypoglycemia and incomplete repel of metabolic waste products and leads to accumulation of free radicals triggering neuronal death. The A1 adenosine receptoras an endogenous ligand of adenosine is known to improve cell resistance to destructive agentsby preventing apoptosis. Vitamin C as a cellular antioxidant is also known as an effective factor to reduce damages initiated by free radicals. We studied the protective effects of A1 receptor agonist in combination with vitamin C against ischemia-reperfusion. Ischemia was induced by common carotid artery occlusion in bulb-c mice (20-30 gr). Y-Maze was employed to scale the short-term memory and Nissl staining was used to count the cells in hippocampus. We found that concurrent treatment of A1 receptor agonist and vitamin C significantly reduced neuronal death in CA1. The Memory scores were also significantly improved (P<0.05). Our data point to the therapeutic effects of CPA/vitamin C co-administration and highlight the beneficial role of A1 adenosine receptor signaling in the context of stroke

The quality of life (QOL) has been defined as ‘‘a person’s sense of well-being that stems from satisfaction or dissatisfaction with the areas of life that are important to him/her’’. It is generally accepted that pain intensity and duration have a negative impact on the QOL. One specific type of control is “self-efficacy”, or the belief that one has the ability to successfully engage in specific actions. The ability to adapt to pain may play an important role in maintaining the QOL. In this study, we investigated the role of self-efficacy, pain intensity, and pain duration in various domains of quality of life such as physical, psychological, social and environmental domains. In this study, 290 adult patients (146 men, 144 women) completed coping self-efficacy and the WHOQOL-BREF Questionnaire. Moreover, we illustrated numerical rating scale for pain intensity. The results were analyzed using SPSS version of 19.0 and means, descriptive correlation, and regression were calculated. Our data revealed that self-efficacy but not the pain duration could significantly anticipate the QOL and its four related domains (P<0.001). In addition, it is noticeable that the effect of self-efficacy on the prediction of QOL is much more obvious in the psychological domain. However, the pain intensity could predict all of the QOL domains (P< 0.001) except social and environmental ones. In conclusion, to predict the quality of life (QOL) in person suffering from chronic pain, self-efficacy and pain intensity are more important factors than the pain duration and demographic variables.

Epilepsy is a common central nervous system (CNS) disorder characterized by seizures resulting from episodic neuronal discharges. The incidence of toxicity and refractoriness has compromised the clinical efficacy of the drugs currently used for the treatment of convulsions. Thus, there is a need to search for new medicines from plant origin that are readily available and safer for the control of seizures. Jobelyn® (JB) is a unique African polyherbal preparation used by the natives to treat seizures in children. This investigation was carried out to evaluate whether JB has anti-seizure property in mice. The animals received JB (5, 10 and 20 mg/kg, p.o) 30 min before induction of convulsions with intraperitoneal (i.p.) injection of picrotoxin (6 mg/kg), strychnine (2 mg/ kg) and pentylenetetrazole (85 mg/kg) respectively. Diazepam (2 mg/kg, p.o.) was used as the reference drug. Anti-seizure activities were assessed based on the ability of test drugs to prevent convulsions, death or to delay the onset of seizures in mice. JB (5, 10 and 20 mg/kg, p.o) could only delay the onset of seizures induced by pentylenetetrazole (85 mg/kg, i.p.) in mice. However, it did not offer any protection against seizure episodes, as it failed to prevent the animals, from exhibiting tonic-clonic convulsions caused by pentylenetetrazole (85 mg/kg, i.p.), strychnine (2 mg/kg) or picrotoxin (6 mg/kg, i.p.). On the other hand, diazepam (2 mg/kg, p.o.), offered 100% protection against convulsive seizures, induced by pentylenetetrazole (85 mg/kg, i.p.). However, it failed to prevent seizures produced by strychnine (2 mg/kg, i.p.) or picrotoxin (6 mg/kg, i.p.). Our results suggest that JB could not prevent the examined chemoconvulsants-induced convulsions. However, its ability to delay the latency to seizures induced by pentylenetetrazole suggests that JB might be effective in the control of the seizure spread in epileptic brains.

In the present research, the effect of morphine consumption during pregnancy on the development of the embryo’s spinal cord was studied in Wistar rat. Female Wistar rats (Wt: 250-300 g) were mated with males. The test group received morphine (0.01 mg/ml) in their drinking water. Pregnant rats were later killed with chloroform on the 12th, 13th and 14th days of pregnancy, and the embryos were taken out surgically. The embryos were fixed in formalin 10% for 2 weeks. Then, the weight of fixed embryos was calculated by a scale. In addition, several animals’ sizes including fronto-posterior and lateral length were measured by a caliper. Tissue processing, sectioning and hematoxylin and eosin (H&E) staining were applied for the embryos. The sections were examined for spinal cord development by light microscope and MOTIC software. Significant decrease was observed in the fronto-posterior and lateral length and the weight of the embryos in the test groups. The thickness of the white matter layer decreased on the 12th, 13th and 14th embryonic days. The thickness of the spine's grey layer was also less than the control group, on the same days. Increase in the length of the ependimal duct observed as well. Number of grey substance cells decreased compared to the control group within the same days. Meanwhile, thickness of the germinal layer reduced in comparison to the control group on the mentioned days. In conclusion, morphine consumption during pregnancy causes defects in growth and completion of the spinal cord.

The primary somatosensory cortex has an important role in nociceptive sensory-discriminative processing. Altered peripheral inputs produced by deafferentation or by long-term changes in levels of afferent stimulation can result in plasticity of cortex. Capsaicin-induced depletion of C-fiber afferents results in plasticity of the somatosensory system. Plasticity includes short-term and long-term changes in synaptic strength. We studied the interaction between paired-pulse facilitation, as one form of short-term plasticity, with long-term potentiation (LTP) in the neocortex of normal and C-fiber depleted freely moving rat. Neonatally capsaicin-treated rats and their controls were allowed to mature until they reached a weight between 250 and 300g. Then animals were anesthetized with ketamine and xylazine. For recording and stimulation, twisted teflon-coated stainless steel wires were implanted into somatosensory cortex or corpus callusom. In experiments for LTP induction, after two weeks of recovery period, 30 high frequency pulse trains were delivered once per day for 12 days. Paired-pulse ratio (PPR) was monitored before and after the induction of LTP in capsaicin-treated and control rats. Paired-pulse stimulation affected all field potential components at intervals < 200 ms. The largest changes occurred at intervals between 20- 30 ms. C-fiber depletion postponed the development of LTP, whereas it had no effect on PPR. This finding provides further evidence that the expression of this form of LTP is postsynaptic. Furthermore, these results suggest that the effect of C-fiber depletion on cortical LTP is also postsynaptic and, therefore, is not caused by a decrease in neurotransmitter release.

Calcium/calmodulin-dependent protein kinase II (CaMKII) is highly expressed in the hippocampus, which has a pivotal role in reward-related memories and morphine dependence. In the present study, morphine tolerance was induced in male Wistar rats by 7 days repeated morphine injections once daily, and then gene expression profile of α-isoform of CaMKII (CaMKIIα) in the hippocampus was evaluated after discontinuation of morphine injection during 21 days of morphine withdrawal. Control groups received saline for 7 consecutive days. For gene expression study, the rat brains were removed and the hippocampus was dissected in separate groups on 1, 3, 7, 14, and 21 day(s) of morphine withdrawal. A semi-quantitative RT-PCR method was used for evaluating gene expression profile. Tolerance to morphine was verified by a significant decrease in morphine analgesia in a hotplate test on day 8 (one day after the final repeated morphine injections). The results showed that gene expression of CaMKIIα at mRNA level on day 1, 3, 7, 14 and 21 of morphine withdrawal compared to saline control group was significantly altered. Post hoc Tukey’s test revealed that gene expression of CaMKIIα on day 14 was significantly increased. It can be concluded that expression of the CaMKIIα gene during repeated injections of morphine would be increased and continued until 14 days of withdrawal, and then settle at a new set point. Therefore, morphine abstinence animals may have a strong memory for morphine reward, at least partly, due to up-regulation of CaMKIIα in the hippocampus during 14 days of morphine withdrawal.

Cypermethrin causes its neurotoxic effect through voltage-dependent sodium channels and integral protein ATPases in the neuronal membrane. Brain and nerve damage are often associated with low residual level of pesticides. In vitro and in vivo studies have also shown that pesticides cause free radical-mediated tissue damage in brain. Propolis has antioxidant properties. The main chemical classes found in propolis are flavonoids and phenolics. Bioflavonoids are antioxidant molecules that play important roles in scavenging free radicals, which are produced in neurodegenerative diseases and aging. To determine the protective role of propolis, rainbow trouts were treated with cypermethrin, followed by biochemical analyses of brain tissue. Fish were divided into four groups: control, propolis-treated, cypermethrin-treated, and cypermethrin+propolis-treated. In fish brains, catalase (CAT) activity decreased (P≤0.001) and malondialdehyde (MDA) level increased (P≤0.001) in cypermethrin-treated group compared to control group. In cypermethrin + propolis-treated group CAT activity increased (P≤0.001) and MDA level decreased (P≤0.001) compared to cypermethrin group. The results demonstrated that the negative effects, observed as a result of cypermethrin treatment, could be reversed by adding supplementary propolis. Propolis may improve some biochemical markers associated with oxidative stress in fish brain, after exposure to cypermethrin.

This study has examined the functional importance of nucleus accumbens (NAc)-ventral tegmental area (VTA) interactions. As it is known, this interaction is important in associative reward processes. Under urethane anesthesia, extracellular single unit recordings of the shell sub-region of the nucleus accumbens (NAcSh) neurons were employed to determine the functional contributions of the VTA to neuronal activity across NAcSh in rats. The baseline firing rate of NAcSh neurons varied between 0.42 and 11.44 spikes/sec and the average frequency of spontaneous activity over 45-minute period was 3.21±0.6 spikes/sec. The majority of NAcSh neurons responded excitatory in the first and second 15-min time blocks subsequent to the inactivation of VTA. In the next set of experiments, eight experimental rats received morphine (5 mg/kg; sc). Three patterns of neuronal activity were found. Among the recorded neurons only three had an increase followed by morphine administration. Whereas the other three neurons were attenuated following morphine administration; and there were no changes in the firing rates of the two neurons left. Finally, unilateral reversible inactivation of VTA attenuated the firing activity of the majority of ipsilateral NAcSh neuron in response to morphine, except for a single cell. These results suggest that transient inactivation of VTA reduces the ability of neurons in the NAcsh to respond to systemic morphine, and that NAcSh neuron activity depends on basal firing rate of VTA inputs.

we report a 56-year-olds female with supraventricular arrhythmia due acute ischemic stroke without structural heart disease. Case Description: A patient presented with sudden onset of lethargy, right hemiplegia, and global aphasia. There was previous history of stroke 1 year ago presented with left hemiplegia that recovered completely during 10 days. There was no history of comorbid illness. The brain CT revealed extensive hypodensity in left temporoparietal region suggestive of infarct without midline shift. General examination revealed hypotension and bradycardia that treated with dopamine that gradually recovered during 5 days thus infusion of dopamine discontinued, and muscular power in paretic limbs and aphasia was recovered. In 6th day of admission electrocardiographic monitoring of patient showed a rapidly changing tachyarrhythmia including sinus tachycardia, atrial fibrillation, and atrial flutter that quickly interchanged to another, without hemodynamic instability and alteration in mental status. Laboratory tests and TEE study were normal. During 48 hour arrhythmia relived spontaneously. Stroke can cause any type of cardiac arrhythmias that may not be constant.

Spinal cord injury (SCI) is a debilitating disease which leads to progressive functional damages. Because of limited axonal regeneration in the central nervous system, there is no or little recovery expected in the patients. Different cellular and molecular approaches were investigated in SCI animal models. Cellular transplantation of stem cells can potentially replace damaged tissue and provide a suitable microenvironment for axons to regenerate. Here, we reviewed the last approaches applied by our colleagues and others in order to improve axonal regeneration following SCI. We used different types of stem cells via different methods. First, fetal olfactory mucosa, schwann, and bone marrow stromal cells were transplanted into the injury sites in SCI models. In later studies, was applied simultaneous transplantation of stem cells with chondroitinase ABC in SCI models with the aid of nanoparticles. Using these approaches, considerable functional recovery was observed. However, considering some challenges in stem cell therapy such as rejection, infection, and development of a new cancer, our more recent strategy was application of cytokines. We observed a significant improvement in motor function of rats when stromal derived factor-1 was used to attract innate stem cells to the injury site. In conclusion, it seems that co-transplantation of different cells accompanies with other factors like enzymes and growth factors via new delivery systems may yield better results in SCI.