Basic and Clinical Neuroscience
Volume:6 Issue: 2, Spring 2015

The hippocampus (HIP), the primary brain structure related to learning and memory, receives sparse but comprehensive dopamine innervations and contains dopamine D1/D2-like receptors. It is demonstrated that dopamine receptors in dentate gyrus (DG) region of HIP have a remarkable function in spatial reward processing. Much less is known about the involvement of HIP and its D1/D2 dopamine receptors in drug-seeking behaviors, more particularly, in the morphine extinguished conditioned place preference (CPP). To find out the role of D1/D2-like receptors within the DG in morphine-seeking behaviors, forty adult male albino Wistar rats weighing 220-280g were unilaterally implanted by a cannula into the DG. The CPP paradigm was done; conditioning score and locomotors activity were recorded by Ethovision software. All drugs/vehicles were microinjected one day after extinction (just before the CPP test) into the DG as reinstatement day. The results showed that intra-DG administration of different dose of SCH23390 (0.25, 1 and 4μg/0.5μl saline), as a selective D1-like receptor antagonist and sulpiride (0.25, 1 and 4μg/0.5μl DMSO), as a selective D2-like receptor antagonist dose-dependently attenuated the morphine-extinguished CPP reinstated by priming injection of morphine (1 mg/kg;sc). It can be concluded that D1/D2-like receptors within this region have an important role in morphine-seeking behaviors in extinguished rats.

Neuroinflammation may play as an important risk factor in progressive degeneration of dopaminergic cells. Antioxidants have protective effects against free radicalsinduced neural damage in Parkinson’s disease (PD). In the present study, we examined the effects of ellagic acid (EA) on locomotion and neuroinflammatory biomarkers in a rat model of PD induced by 6-hydroxidopamine (6-OHDA). 6-OHDA (16 μg/2 μl) was injected into the right medial forebrain bundle (MFB) in MFB-lesioned rat’s brain. Sham group received vehicle instead of 6-OHDA. PD-model was confirmed by rotational test using apomorphine injection. EA (50 mg/kg/2 ml, by gavages) was administered in PD+EA group. One group of MFB-lesioned rats received pramipexole (PPX; 2 mg/kg/2 ml, by gavages) as positive control group (PD+PPX group). Motor activity was assessed by stride length and cylinder tests. The levels of TNF-α and IL-1β were measured in both striatum and hippocampus tissues. MFB lesion caused significant reduction of stride-length (P<0.001) and also increased the contralateral rotations (P<0.001) and score of the cylinder test (P<0.001). Use of 6-OHDA to induce the PD significantly increased the levels of TNF-α (P<0.001) and IL-1β (P<0.001) in MFB-lesioned rats. EA significantly restored all of the above parameters. EA can improve the motor impairments in the MFB-lesioned rats via reducing the neuroinflammatory biomarkers and protect the brain against free radicals-induced neural damage. The results suggest that EA can be helpful in management of PD treatment.

Alzheimer’s disease (AD) is an age-related neurodegenerative disease, which impairs memory and cognitive function. Walnuts are a dietary source of polyphenols, antioxidants and other compounds with health beneficial effects. These characteristic of walnuts make them perfect candidates for evaluation of their possible effects on neurodegenerative diseases. Therefore the present study was designed to investigate the effects of walnuts consumption (2%, 6% and 9% walnut diets) on memory enhancement and acetylcholinesterase (AChE) activity of brain in scopolamine-induced amnesic rats. Learning, memory and locomotor activity parameters were evaluated using Morris water maze (MWM), passive avoidance and rotarod tests. Our results showed that consumption of walnuts at doses of 6% and 9% significantly restored the scopolamine-induced memory impairments in the MWM and passive avoidance tests. Moreover, the potential of walnuts to prevent scopolamine neurotoxicity was also reflected by the decreased AChE activity in the whole brain in comparison with the scopolamine group. These results suggest that walnuts may be useful against memory impairment and it may exert these anti-amnesic activities via inhibition of AChE activity in the brain. It would be worthwhile to explore the potential of this nut and its active components in the management of the AD.

Based on the previous studies, we know that the hemispheric lateralization defects, increase the probability of psychological disorders. We also know that dominant limb is controlled by dominant hemisphere and limb preference is used as an indicator for hemisphere dominance. In this study we attempted to explore the hemispheric dominance by the use of three limbs (hand, foot and eye). We performed this survey on two samples, psychiatric patients compared with normal population. For this purpose, knowing that the organ dominance is stabilized in adolescence, and age has no effect on the people above 15, we used 48 high school girls and 65 boys as the final samples of normal population. The patient group included 57 male and 26 female who were chronic psychiatric patients. The result shows that left-eye dominance is more in patients than the normal group(p=0.000) but the handedness and footedness differences are not significance. In psychotic, bipolar and depressive disorders, eye dominance had significant difference (P= 0.018). But this is not true about hand and foot dominance. Our findings proved that generally in psychiatric patients, left-eye dominance is more common, left-eye dominance is also more in psychotic and depressive disorders. It is less common in bipolar disorders. Key words: hemispheric lateralization, limb dominance, mental disorders.

Although hippocampus is the most famous brain area involved in temporal lobe epilepsy, hippocampal kindling (HK) develops very slowly. Hence, rapid kindling is usually preferred to the traditional kindling and it is widely used. In this article we aimed at finding the optimal stimulus pattern, which yields the fastest HK rate. Stimulus patterns with different duration (2, 3, 5 and 10 s) and inter-train interval (ITI) (5, 10 and 30 min) as well as number of trains in 24 h (8 and 12) were exerted to rats’ dorsal hippocampus. The stimuli were continued until appearance of 3 consecutive generalized seizures or maximum 7 days stimulations. While the protocol with train duration of 10 s and ITI of 30 min caused the fastest kindling rate and the most growth of afterdischarges, the protocol with train duration of 5 s and ITI of 5 min was the most time-consuming protocol among protocols tested. Rapid HK develops with a time course of days compared to weeks in traditional kindling. Train duration and inter-train interval are key factors for rapid HK. Among the patterns, 12 trains/24h of 50Hz monophasic square wave with 10 s duration and 30 min interval between trains, is the best stimulus pattern for eliciting rapid dorsal HK.

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by high levels of inattention, hyperactivity and impulsivity which may result in mothers’ stress. The current study aims to compare stress among 45 mothers of ADHD children who had referred to “Rofeydeh psychiatric center” with 45 mothers of normal children. Brief demographic researcher-made questionnaire, Child Symptom Inventory-4 (CSI- 4), the Child Behavior Checklist (CBCL), and Parental Stress Index-Short Form (PSI/SF) were completed for each mother and child. The results showed that except the component of acceptance, ADHD children had more problems in the field of attention compared with normal children. Mothers of ADHD children had also more stress compared with mothers of normal children. ADHD can impair mothers’ mental health by inducing stress and this issue has important clinical and treatment implications. Specific treatment programs should be designed and implemented in Iran for the mothers of ADHD children to reduce stress among them and therefore, improve their mental health status.

Seizures are symptoms associated with abnormal electrical activity in electroencephalogram (EEG). The present study was designed to determine the effect of absence seizure on heart rate (HR) changes in electrocardiogram (ECG). HR alterations were recorded simultaneous with spike and wave discharges (SWD) by EEG in 6 WAG/Rij rats as a well characterized and validated genetic animal epilepsy model. Moreover, 6 control rats were used to distinguish the differences of HR changes between various groups. Electrodes were placed on the skull and under the chest skin, minimizing time delay and signal attenuation. HR was calculated by an adaptable algorithm based on continues wavelet transform (CWT) particular for this study. Three main features of HR; minimum, maximum, and mean values were estimated for pre-ictal and ictal intervals for all seizures. ECG beats detected with sensitivity of 99.9% and positive predictability of 99.8% based on CWT. HR deceleration was found in 86% of the seizures. There were statistically significant (P<0.001) reductions of these values from pre-ictal to ictal intervals. Interictal HR acceleration and ictal deceleration were the major feature of alterations and in 23% of seizures, this decrease had priority to the onsets. These findings may lead to design a seizure alarm system based on HR and to obtain new insights about sudden unexpected death in epilepsy (SUDEP) phenomenon and side-effects of antiepileptic drugs (AED).

Herpes zoster is a rare cause of non-discogenic sciatica. A combination of case rarity and name similarity was nearly leading to an inopportune surgery in a 21 years old woman. The clinical presentation was completely similar to a cauda equina syndrome associated with urinary incontinence and bilateral leg involvement. Concurrently, lumbosacral imaging of another patient with exactly similar name in the picture archiving communications system (PACS) has shown a huge L5-1 disc herniation. Careful attention to all diverse causes of sciatica and identifying details of the images could prevent improper discectomy in our patient.