[Effect of intra-hippocampal injection of origanum vulgare L. ssp. Viridis leaf extract on spatial learning and memory consolidation]

Hippocampus is well known to be involved in learning and memory. It is proved that antioxidants improve learning and memory. Origanum vulgare L. ssp. Viridis [ORG] is a rich source of antioxidants. The aim of this study was to investigate the effect of intra-hippocampal injection of aqueous extract of ORG on spatial learning and memory. Twenty-eight adult male Wistar rats [275-300gr] were used in this study. The animals were bilaterally canulated in dorsolateral hippocampus. One week after recovery the animals were trained [4 trails for four consecutive days] in Morris water maze [MWM]. Then, the retention of spatial training was evaluated in the fifth day. Twenty minutes before the training or retrieval test, different concentrations of ORG [0.003, 0.03 and 0.3 micro l/rat] or saline were injected into the hippocampus. Repeated-measure ANOVA showd that intra-hippocampal injection of ORG significantly decreased the distance and time of reaching to hidden platform in MWM, Intrahippocampal injection of ORG in the retrieval day did not show any significant difference in the duration of target zone and the platform proximity compared to the saline group. The intra-hippocampal injection of Origanum aqueous extract improves the rat working memory in MWM however it doesn't affect on the consolidation of memory

effect of intracerebroventricular microinjection of retinoic acid on pain threshold of male rats

Pain is an unpleasant feeling which humans experience. It is a warning sign of the damaged tissue. Due to the awful sense of pain, scientists always attempt to relieve it. Retinoic acid [RT], an active metabolite of natural vitamin A has important roles in modulation of the inflammatory responses. The aim of the present study was to analyze the pain threshold of rats which had microinjections of RT, applying acute and chronic models. In this study, the tail flick and formalin tests were used to determine pain threshold. In each test, the acute and chronic pain thresholds of 252 Wistar male rats [275 +/- 25 gr] were assayed. The druge were injected in the acute model one-dose 30 minutes before behavioral testing and in chronic model two-dose for one or two-weeks. The rats of both models divided randomly into six groups [n = 7]. In four treatment groups retinoic acid [RT] intra cerebro ventricular [i.C.V] were injected as dosage of 0.5, 3 and 6 [micro g/kg] micrograms per kilogram. In control group, was microinjected by ACSF. In vehicle group injected RT solvent [DMSO+ Distil water]. The resuits Showed acute injection of RT did not change pain thresholds in the tail-flick methd, but the chronic administration of RT [0.5, 1, 3, 6 micro g/kg] reduced tail-flick latencies of the rats [p < 0.05] in compare to DMSO group. The threshold of pain in the first phase of formalin test was reduced after injection of 3 micro g/kg of RT for two weeks. It was concluded that chronic i.c.v. injections of RT can induce significant hyperalgesia in rat

satisfaction rate of authors from Journal of Kerman University of Medical Sciences in 2005 and 2006

Scholarly activities as well as growth in Science and technology have been well established as the basis for development in every country. In recent years due to more attention to research the number of research projects and published articles in Iranian and International journals has gained a rapid increase. Therefore, the evaluation of Medical journals as sources of publishing the results of research projects is necessary. This study was performed to assess the satisfaction rate of authors from Journal of Kerman University of Medical Sciences and compare it with their satisfaction rate from other Iranian journals. In this descriptive-analytic study a three-part questionnaire was designed and distributed among corresponding authors whose manuscripts were accepted or were under consideration by Journal of Kerman University of Medical Sciences. The questionnaire's reliability was confirmed by using alpha-Cronbach and validity was confirmed by getting experts opinions. Data analysis was done by using Wilcoxon and Chi-square tests. The response rate was 78.2%; and the mean age of the participants was 43.7 [28-62] years and mean number of their published articles was 18.9 +/- 2.3. In regard to satisfaction rate, 14.8% were very satisfied, 40.7% were satisfied and 44.4% were neither satisfied nor dissatisfied. The satisfaction rate of the same authors for other journals was as follows: 14.3% were very satisfied, 35.7% were satisfied, 47.6% were neither satisfied nor dissatisfied and 2.4% were dissatisfied. There was no significant difference in this regard

[ effect of enalapril on brain edema and cytokine production following transient focal cerebral ischemia in mice]

Cytokines production as one of the inflammatory pathways in CNS is responsible for most brain damages following ischemia. On the other hand, during inflammation and brain ischemia, most of the renin- angiotensin components [RAS] increase locally. While it is established that blockade of RAS especially AT1 receptors has a protective effect on ischemia, the interaction of cytokines and angiotensin II is not well understood. This study was designed to investigate the effect of angiotensin II inhibitor on cytokine production as well as brain edema. Fifty-four male mice were randomly divided into 5 groups of normal, Sham operated, ischemia, Pretreatment with enalapril [high dose], and Pretreatment with enalapril [low dose] for the measurement of IL-IB and TNF-alpha in the brain and blood serum by ELIZA method. Ischemia caused a significant increase in water content and neurological deficit scores as well as cytokine levels. Treatment with enalapril had paradoxical effect on ischemia. In high dose, 85% of the animals showed convulsion after reperfusion. The IL-1 beta in serum and neurological deficit scores of this group were high, in accordance with clinical signs. In contrast, the low dose of enalapril, had protective effect on ischemia. It caused a significant reduction in brain concentration of both IL-1 beta and TNF- alpha [P<0.05] and improved significantly the neurological deficit scores and brain water content as well. [P<0.05]. Enalapril as an ACE inhibitor, has a dual effect on stroke. At low dose, it has a protective role at least in part by suppressing the local production of pro-inflammatory cytokines while, at high dose, it increases the inflammation by an unknown mechanism

[Effect of the dorsal raphe nucleus electrical stimulation on evoked response of the IV layers and V barrel cortical neurons in rat]

Seretonergic pathway is one of the neuromodulatory mechanisms which mainly originates from dorsal raphe nucleus [DRN]. In order to explore the role of serotonin on sensory processing, we investigated the effect of DRN stimulation on response properties of the IV layer and V neurons of whisker related area of rat somatosensory cortex. In this study twenty adult male Wistar rats [250-350gr] were used. DRN was stimulated at 0, 50, 100, 200 and 400ms before principal or adjacent whiskers deflection individually or in a condition test paradigm. For assessing the effect of DRN stimulation on inhibitory receptive field of barrel neurons, adjacent whisker was also deflected 20ms before principal whisker deflection. DRN stimulation decreased the On response magnitude of layer V neurons to principal whisker deflection [p<0.05]. The On response latency of the layer IV of neurons increased when DRN was stimulated 200 or 400ms before principal whisker deflection [p<0.05 and p<0.01 respectively]. DRN stimulation had no effect on both the On response magnitude and latency of neurons to adjacent whisker deflection. We observed a decrease in inhibitory effect of adjacent whisker deflection on the magnitude of neuronal response to principal whisker deflection on the IV layer when DRN was stimulated 200ms before principal whisker deflection [p<0.05]. Our results suggest that DRN have a modulatory effect on information processing in somatosensory cortex of rats

Synthesis and anticonvulsant activity of novel 2-amino-5-[4-chloro-2-[2-chlorophenoxy] phenyl] -1, 3, 4-thiadiazole derivatives

Several novel 2-amino-5-[4-chloro-2-[2-chlorophenoxy]phenyl]-1, 3, 4-thiadiazole derivatives 4a-d were synthesized and their anticonvulsant activity was determined by evaluation of the ability of theses compounds to protect mice against convulsion induced by a lethal doses of pentylentetrazole [PTZ] and maximal electroshock [MES]. The result of anticonvulsant data shows that among the synthesized compounds, 5-[4-chloro-2-[2-chlorophenoxy]phenyl]-N-ethyl-1, 3, 4-thiadiazol-2-amine 4c was the most active compound in both MES and PTZ tests with an ED[50] of 20.11 and 35.33 mg/kg, respectively

Effect of GABA[b] agonist and antagonist microinjection into cuneiformis nucleus [CNF] on morphine induced antinociception by formalin test in rat

There are several evidences that show cuneiformis nucleus is involved in nociception. In the present study the effect of intra cuneiformis micro injection of GABA[B] agonist [baclofen] and antagonist [CGP35348] on morphine induced antinociception in rat were investigated. In this expremental study, through canulation of cuneifoprmis nucleus in rat the effect of intra cuneiformis [CNF] microinjection of GABA[B] receptor agonist [baclofen] and antagonist [CGP35348] on morphine -iduced antinociception were investigated by formalin test. Microinjection of morphine [l0 micro g /0.5 micro l/saline] or different doses of baclofen [0.25,0.5,1 micro g per rat] had antinociception in the both first and second phases of formalin test. The response induced by morphine or baclofen in both phases were reduced by CGP 35348. The responses induced by combination of baclofen [1 micro g per rat] and intraperitoneal [ip] injection of naloxan were reduced in both phases of formalin test. Microinjection of CGP35348 alone has produced antinociception in first phase of the formalin test. Morphine with different doses of baclofen did not increase the antinociception effect whereas microinjection of CGP35348 administration significantly increased the antinociception in acute phase. It may be concluded that CNF GABA[B] receptor induced antinociception via opioid receptor in the formalin test

[The effect of nitric oxide microinjection in nucleus accumbens shell on morphine withdrawal signs in male rats]

This study was performed to evaluate the effects of intra-nucleus accumbens shell microinjection of Larginine [NO precursor] and L-NAME [nitric oxide synthase [NOS] inhibitor] on morphine withdrawal signs in male rats. Rats were anaesthetized with a combination of ketamine and xylazine, and placed in stereotaxic apparatus, and a guide cannula was inserted into nucleus accumbens [Nacc] shell, [1.7 mm Anterior to bregma, 0.8 mm bilaterally to bregma and 7.1 mm depth from skull surface]. Morphine dependency was induced by subcutaneous administration of morphine [10-20 mg/kg for 5 days], and morphine withdrawal signs were precipitated by naloxone administration [4mg/kg/ip]. Rats received either single or repeated microinjections of saline, L-arginine or L-NAME into Nacc shell during the scheduled periods for 5 days. In Sham group, bilateral canulla was inserted into Nacc shell, but no drug was microinjected, and in saline group only normal saline was injected into Nacc shell in the same way as the experimental groups during the scheduled periods. Control group was intact. The results of this study showed no significant difference between control and saline treated groups in the expression of morphine withdrawal signs. Single dose microinjection of L-NAME / L-arginine, just prior to the last injection of morphine, had no effect on morphine withdrawal signs, but repeated microinjection of L-arginine / LNAME decreased jumping, rearing and weight loss [only in L-NAME group], as compared to control rats. The obtained results indicate that NO injection in Nacc shell may be involved in some of morphine withdrawal signs

effect of neonatal capsaicin injection on barrel cortical neuron response properties after controlled mechanical displacement of vibrissa in adult rats

Introduction: Systemic application of capsaicin to neonatel rodents depletes their primary afferent C-fibers and also results in a wide variety of changes observable in adulthood. The manual methods used for stimulation of vibrissa provide limited information on response properties of barrel cortical Neurons. In this study the effect of C-fiber depletion induced by neonatal capsaicin [Cap] treatment on response properties of barrel cortical neurons, after controlled mechanical displacement, was examined in adult rats. Material and We destroyed C-fibers of neonatal rats by adminstration of capsaicin [50mg/kg dissolved in 10% ethanol, 10% tween 80, 80% salin, ip] in the first day of birth. Single unit recording was done on barrel cortical cell from both [untreated control and vehicle-treated] and Cap-treated adult rats. The magnitude and latency period of response to the controlled mechanical displacement of principal and peripheral vibrissa were recorded and analyzed. The magnitude of responses evoked by deflection of principal and peripheral vibrissa in Cap-treated rats were significantly [P<0.001] higher than in control rats. There was no difference between control and Cap-treated rats in the response latency to principal vibrissae deflection. [P<0.467] But response latency was significantly decreased redused during peripheral vibrissa deflection [P<0.001]. The magnitude of response during principal vibrissae deflection was higher and the response latency was shorter compared to peripheral vibrissae deflection in both groups. These results suggest that C- fibers play an important role in the natural functions of the somatosensory system and are probably required for normal shaping of the functional properties of central somatosensory neurons