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Showing 24 results for Semnanian

Farshad Alizadeh Mansouri, Fereshteh Motamedi, Fereshteh Fathollahi, Nafiseh Atapour, Saeed Semnanian,
Volume 1, Issue 1 (Spring and Summer 1997)
Abstract

The effects of chronic morphine administration on the development of long-term potentiation (LTP) were investigated at the Schaffer collateral-CA1 pyramidal cell synapses of the rat hippocampal slices using primed-bursts tetanic stimulation. Significant enhancement of orthodromic population spike (OPS) was found for all stimulus intensities after tetanic stimulation. OPS enhancement was greatest when tested with low to mid-range stimulus intensities (25, 50 and 100 µA). There was also significant decrease in OPS delay. These responses were similar in slices from both control and morphine dependent rats. At all delivered stimulus intensities, the amount of LTP of OPS in slices from dependent rats was larger than that of control slices. However, these differences in LTP of OPS were significant at low stimulus intensities. These findings suggest that chronic morphine administration had induced changes in CA1 neurocircuitry which modulated synaptic plasticity during high frequency stimulation and appeared as augmented LTP and also inhibition of LTP decay.
Farshad Alizadeh Mansouri, Fereshteh Motamedi, Fereshteh Fathollahi, Nafiseh Atapour, Saeed Semnanian,
Volume 1, Issue 1 (Spring and Summer 1997)
Abstract

  The effects of chronic morphine administration on the development of long-term potentiation (LTP) were investigated at the Schaffer collateral-CA1 pyramidal cell synapses of the rat hippocampal slices using primed-bursts tetanic stimulation. Significant enhancement of orthodromic population spike (OPS) was found for all stimulus intensities after tetanic stimulation. OPS enhancement was greatest when tested with low to mid-range stimulus intensities (25, 50 and 100 µ A). There was also significant decrease in OPS delay. These responses were similar in slices from both control and morphine dependent rats. At all delivered stimulus intensities, the amount of LTP of OPS in slices from dependent rats was larger than that of control slices. However, these differences in LTP of OPS were significant at low stimulus intensities. These findings suggest that chronic morphine administration had induced changes in CA1 neurocircuitry which modulated synaptic plasticity during high frequency stimulation and appeared as augmented LTP and also inhibition of LTP decay.


Saeed Semnanian, Ghasem Attarzadeh, Mohammad Hossein Pourgholami,
Volume 1, Issue 1 (Spring and Summer 1997)
Abstract

Recently, vast studies have been focused on the antinociceptive and anesthetic effects of α2 adrenergic receptors, using specific drugs such as medetomidine and dexmedetomidine. In the present study, we tried to assess the peripheral and central effects of dexmedetomidine in phasic and tonic pain, on rats, using tail flick and formalin tests. Dexmedetomidine, administered intraperitoneally (25, 50 and 100 µg/kg, i.p.) or intracerebroventrically (7.5, 10 and 20 µg, i.c.v.) induced total anesthesia. This effect could be seen by 10 and 20 µg, i.c.v. doses of the drug in spinal animals, too, which was reversed by 5 µg, i.c.v. of yohimbine. Dexmedetomidine (6.5 µg, i.c.v. or 20 µg, i.p.) showed antinociceptive effects in formalin test which was reversed by yohimbine (5 µg, i.c.v.). Dexmedetomidine (5, 6.5, 7.5, 10 and 20 µg, i.c.v. or 20, 25, 50 and 100 µg/kg, i.p.) had significant antinociceptive effects in tail flick test, which could be reversed by 5 µg, i.c.v. administration of yohimbine. The results of tail flick test in the spinal animals, shows that dexmedetomidine (6 µg, i.c.v.) in these animals induces antinociception, which was reversed by yohimbine pretreatment (1 mg/kg, i.p.). These results indicate that, dexmedetomidine probably exerts, its antinociceptive effect, through spinal α2 adrenergic receptors.
Fereshteh Motamedi, Ali Pourmotabbed, Yaghub Fathollahi, Farshad Alizadeh Mansouri, Saeed Semnanian,
Volume 1, Issue 2 (Fall and Winter 1997)
Abstract

  The involvement of NMDA receptors and voltage-dependent calcium channels in augmentation of long-term potentiation (LTP) was investigated at the Schaffer collateral CA1 pyramidal cell synapses in hippocampal slices of morphine dependent rats, using primed-burst tetanic simulation. The amplitude of the population spike and its delay were measured as indices of increase in postsynaptic excitability. D,L-APV and nifedipine were used as an NMDA receptor antagonist and a voltage-dependent calcium channel blocker, respectively. The amount of LTP of the orthodromic population spike (OPS) was higher in slices from dependent rats. Perfusion of slices from control and dependent rats with ACSF containing D,L-APV (25 µ M) and delivering tetanic simulation showed that D,L- APV completely blocked the LTP of OPS in slices from both control and dependent rats, while nifedipine (10 µ M) attenuated the amount of LTP of OPS in dependent slices and had no effect on controls. The results suggest that the enhanced LTP of OPS in the CA1 area of hippocampal slices from morphine-dependent rats is primarily induced by NMDA receptor activity, and the voltage-dependent calcium channels may also be partially involved in this phenomenon.


Abolhassan Ahmadiani, Saeed Semnanian, Masoud Fereydouni,
Volume 1, Issue 2 (Fall and Winter 1997)
Abstract

  Pharmacologists believe analgesic and anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs (NSAIDs) and opioid compounds, due to their side-effects and, in some cases, inadequacy, are not always useful. Therefore it seems necessary to search for newer analgesic compounds. In traditional Iranian Medicine, the leaf and rhizome of Sambucus ebulus is used as a topical medication in the treatment of pain caused by bee stings, nettle stings and joint inflammation. We therefore decided to study the analgesic effects of this plant. Two methods, the tail flick test for acute pain and the formalin test for chronic pain were employed to measure pain. Analgesic effects of 50, 100 and 200 mg/kg doses of S. ebulus rhizome extract were compared with 300 mg/kg sodium salicylate as a positive control. The plant extract relieved pain in the tail flick test and in both phases of the formalin test, while sodium salicylate only treated pain in the formalin test. In none of the two tests was naloxone effective in inhibiting the analgesic effect of S. ebulus extract. Phytochemical investigations and previous reports suggest flavinoids to be the probable analgesic compounds.


Mohsen Khalili, Saeed Semnanian, Yaghoub Fathollahi,
Volume 4, Issue 1 (Spring and Summer 2000)
Abstract

In this study the effect of adenosine and caffeine on spontaneous activity of paragigantocellularis (PGi) neurons was investigated. The spontaneous activity of PGi neurons was significantly decreased by microinjection of adenosine (10 nM, 0.5 µl) into PGi nucleus of both control and morphine-dependent rats. The decrease in firing rate of PGi neurons of morphine-dependent rats was greater than that of control. There was also significant enhancement of spontaneous activity of PGi neurons 8-15 min after caffeine administration (50 mg/kg i.p.) in both control and morphine-dependent rats. However, the effect of caffeine in morphine-dependent rats was higher than that of control. These data suggest that there is an increase in the sensitivity to chemicals, which interact with adenosine receptors in morphine- dependent rats. Nevertheless, considering a common second messenger system (cAMP) for adenosine (A1) and opioid (µ) receptor, it is proposed that up-regulation and hypersensitivity of A1 adenosine receptors are responsible for these results in morphine-dependent rats.
Mohammad Rostampour, Yaghoub Fathollahi, Saeed Semnanian, Sohrab Hajizadeh, Javad Mirnajafi-Zadeh,
Volume 4, Issue 2 (Fall and Winter 2000)
Abstract

The effect of cysteamine, a somatostatin depletor, on synaptic plasticity induced by tetanic and paired-pulse stimulation was investigated in rat hippocampal CA1. For this purpose, hippocampal slices from saline (1 ml/kg, s.c.) and cysteamine (200 fig/kg, s.c.)-treated and intact rats were used. Population spikes were recorded following Schaffer collateral stimulation. To induce LTP, primed burst tetanic stimulation was used. Paired-pulse stimulation at IPIs of 10, 20, 60, 120, 240, 360, and 480 ms were used and then EPI and PPI of CA1 were calculated. The results showed that the amplitude of population spike (PSA) increased 5, 15, 30, and 60 min after tetanic stimulation and 60 min after primed bursts, PSA increased at all stimulus intensities for all groups. In cysteamine-treated group, the magnitude of LTP was decreased as compared to intact and saline-treated groups. In the latter group, the magnitude of LTP Increased as compared to Intact and cysteamme- treated group. At IPI of 10 ms, mean value of EPI was greater than 1 for intact group and less than 1 for saline- and cysteamine-treated groups. In cysteamine-treated group, the mean value of EPI was significantly less than intact group. At IPIs from 20 to 480 ms, mean value of EPI was greater than or equal to I for all of the groups and no significant difference was observed among them. At IPI of 10 ms, mean value of PPI was greater than I in intact group and less than I in saline- and cysteamine-treated groups. In these groups, mean value of PPI was significantly less than intact group. At IPI of 20 ms, mean value of PPI was greater than I in intact and saline-treated group and less than I in cysteamine-treated group. In the latter group, the mean value of PPI was significantly less than saline-treated and intact groups. At IPIs of 60-680 ms, mean value of PPI was greater than I in all of the groups with no significant difference among them. It is concluded that cysteamine can alter susceptibility of hippocampal CA1 for synaptic plasticity induced by tetanic and paired-pulse paradigms.
Semnanian, Ghaderi Pakdel, Fathollahi, Firoozabadi,
Volume 6, Issue 1 (Spring and Summer 2002)
Abstract

Single unit recording has been used as a well-known technique to study the electrical behavior of neurons. In this respect, the classical methods are rather expensive. In this study a simple and inexpensive method for single unit recording studies has been introduced. Computer sound card was used for data acquisition. Neural responses were saved via simple sound applicable packages and then analyzed for peristimulus time histogram (PSTH) extraction by home-made software. Analog to digital (AID) converter board and sound card simultaneously recorded neuronal activities in two brainstem nuclei (paragigantocellularis lateralis (PGi) and locus ceruleus (LC)). Then, PSTH of data were calculated online for AID captured data and offline for sound card captured data. The results showed that there were no significant differences between PSTH of PGi or LC neurons in two protocols. Therefore, sound cards can be used as well as AID boards for data acquisition in electrophysiological laboratories
Yagoob Fathollahi, Batool Rahmati, Saeed Semnanian, Mohammad Reza Vaez Mahdavi, Mahshid Shafizadeh,
Volume 7, Issue 1 (Spring and Summer 2003)
Abstract

The effect of ketamine (1-100 µM), which has NMDA receptor antagonist properties, on synaptic transmission and long-term potentiation (LTP) in CAl area of rat hippocampus was examined in vitro. Field potentials were recorded in pyramidal cell layer following Schaffer collateral stimulation. Primed-burst stimulation (PEs) was used for induction of LTP. The amplitude of population spiks (PS) was used as a measure of LTP induction. The results showed that ketamine (1-100 µM) affected baseline synaptic transmission in a concentration-dependent pattern. Furthennore, ketamine application at a high concentration (50-100 µM) for a period of 20-30 min markedly blocked the induction of LTP, whereas lower concentrations of ketamine (1-10 µM) failed to block LTP. However, ketamine at a concentration of 20 µM affected NMDA-mediated LTP induction in a different pattern. It is concluded that the effect of ketamine on baseline synaptic transmission and LTP induced by a l00 Hz PBs depends on ketamine concentration.
Masoud Fereidoni, Mohammad Javan, Saeed Semnanian, Abolhasan Ahmadiani,
Volume 10, Issue 4 (Winter 2007)
Abstract

Introduction: Different mechanisms are involved in stress induced analgesia (SIA) and hyperalgesia (SIH). Repeated stress induces development of tolerance to SIA. The role of HPA axis and Gs signaling pathway in these effects are investigated in the current study. Methods: Forced swim stress (5 min/day) in water (20±1 ºC) was employed to adult male Wistar rats (200-250 g). The nociceptive threshold was assessed using tail flick test. Adrenalectomized (ADX) rats were also subjected to stress tests. Oseltamivir was used to block Gs signaling pathway. Results: Stress produced analgesia for 1 h (p<0.001) and hyperalgesia during 3-24 h after its induction (p<0.05). Repeated administration of the stress caused tolerance development to SIA and increased SIH recorded at 24 h after each session (p<0.001). Oseltamivir couldn’t reverse the SIH. Dexamethasone produced hyperalgesia from 30 min (p<0.001) to 24 h after its administration (p<0.01). Repeated injection of dexamethasone increased the hyperalgesia recorded at 24 h after treatment (p<0.001). In ADX animals SIA continued for 24 h (p<0.01). Adrenalectomy attenuated the chronic stress-induced SIA tolerance and eliminated SIH. Conclusion: SIH is suggested to be related to adrenal activity which also has a role in SIA tolerance. Upper parts of HPA axis seems to be responsible for SIA. Oseltamivir could not reverse the SIH. Therefore, the Gs signaling pathway activation by opioid system may not be responsible for SIH.
Farideh Bahrami, Saeed Semnanian, Ali Khoshbaten,
Volume 11, Issue 2 (Summer 2007)
Abstract

Assessing the variety and quality of the articles presented in the biennial national congresses of physiology and pharmacology is important to investigators in these fields. Analytic assessment of these presentations are of great use to know the stand points of physiology and pharmacology departments in different universities, and also can be informative for policy makers in higher education nation wide. Methods: In this research we have studied the presentations in the 10th to 17th congresses from different point of views such as general and specified scientific fields, and also the quantity of data production from various departments, universities, and cities. The total number of articles presented in the 10th to 17th congresses was 281, 404, 529, 390, 723, 693, 719, and 687 respectively. Results: This study shows that the city Tehran is a center for productive universities. In addition, the majority of the studies have been systemic and molecular and cellular studies have not still found their expected stand point. Graduate studies seem to be the active generator for research in these fields and need more attention from policy makers. Overall there has been a steady quantitative growth in these presentations. Conclusion: Overall the research activity of Iranian physiologist and pharmacologists could be positively graded but needs great attention to remove the weak points and improve the strong ones.
Hassan Azhdari Zarmehri, Saead Semnanian, Yaghoub Fathollahi,
Volume 12, Issue 3 (Fall 2008)
Abstract

Introduction: Orexin-A and B (Hypocretin 1 and 2) are neuropeptides that are mostly expressed in the posterior and lateral hypothalamus (LH). Intracisternal (ICV) and intratechal (IT) injections of orexin-A (hypocretin-1) have been shown to elicit analgesic responses in formalin test. However, the locations of central sites that may mediate these effects have not been clearly elucidated. Orexin-containing fibers are projected to periaqueductal gray matter (PAG), which is involved in pain modulation. Methods: Behavioral study was done on male Sprague Dawley rats (200-300 g) in formalin induced nociceptive behaviour. Results: Intra-PAG microinjection of orexin-A produced a dose-dependent inhibition of formalin-evoked behaviour in interphase and phase 2, but not in phase 1, indicating an antinociceptive role of exogenous orexin-A in the PAG. Analgesic effect of orexin-A was less than and specific to inter- and late phase of formalin test, when compared with that of morphine (5 μg/0.5μl) after intra-PAG administration. Conclusion: The obtained results suggest that orexin-A plays an anti-nociceptive role in PAG, on the interphase and late phase of formalin test in rats. So it is possible that orexin-A might be involved in the mechanisms of inter- and last phases of formalin induced behaviours.
Fatemeh Khojasteh, Majid Hasanpour-Ezati, Seyed Javad Mirnajafi-Zadeh, Saeed Semnanian,
Volume 13, Issue 1 (Spring 2009)
Abstract

Abstract Introduction: Matrix metalloproteinase 2 is one of the inflammatory mediators that is involved in nociceptive processing and its production is regulated by many inflammatory factors such as nitric oxide. We studied the role of MMP-2 on the analgesic effects of nNOS inhibitor. Methods: Considering that nitric oxide has many roles in pain processing, we studied the CSF levels of MMP-2 after hind paw formalin injection (50µl, 2.5%) and neuronal nitric oxide synthase inhibition intrathecally. We also studied the effect of MMP-2 inhibitor on pain behavior and its role on analgesic effect of neuronal nitric oxide synthase (nNOS) inhibitor. Results: Rats that received MMP-2 inhibitor (30mM) showed severe responses to the formalin injection. Pain was reduced after nNOS inhibition. Prior to nNOS inhibitor injection, MMP-2 inhibition reduced the analgesic effects of nNOS inhibitor. Immunological study showed that MMP-2 increased in rats that received nNOS inhibitor. Conclusion: These data suggest the possible roles for MMP-2 in analgesic effect of nNOS inhibitor.
Mojdeh Navidhamidi, Mohammad Javan, Yaghoub Fatholahi, Saeed Semnanian,
Volume 14, Issue 2 (Summer 2010)
Abstract

Introduction: The aim of this study was to assess the effect of Ca2+/calmodulin-dependent kinase IIα (CaMKIIα) inhibitor (KN-93) injection into the locus coeruleus (LC) on the modulation of withdrawal signs. We also sought to study the effect of chronic morphine administration on CaMKIIα activity in the rat LC. Methods: The research was based on behavioral and molecular studies. In the behavioral study, we cannulated the LC with stereotaxic surgery and after 7 days of recovery, injections of KN-93, KN-92 (inactive analogue of KN-93) or DMSO (vehicle) was performed. Morphine and saline were injected in control groups. In the molecular study, we assessed the amount of phosphorylated CaMKIIα (pCaMKIIα) protein expression in LC nucleus using western blot technique. Results: Behavioral study There was a significant difference in withdrawal signs between KN-93 and morphine dependent groups (P<0.05). No significant difference was observed between KN-92 and morphine dependent groups and also between DMSO and morphine dependent groups. Molecular study Morphine and control groups and also morphine and naloxone groups showed significant differences in the level of pCaMKIIα (P<0.05). There was no significant difference between control and naloxone groups. Conclusion: Chronic morphine administration can increase the amount of CaMKIIα activity in LC nucleus and inhibition of this enzyme can decrease some withdrawal signs in dependent rats.
Maryam Zeraati, Javad Mirnajafi-Zadeh, Mohammad Javan, Saeed Semnanian, Simin Namvar,
Volume 14, Issue 2 (Summer 2010)
Abstract

Introduction: Considering high prevalence of epileptic disease and considering that 40 percent of epileptic patients are resistant to drug therapy, it needs more researches to find new therapeutic ways. LFS is among the new methods for epilepsy treatments. One possible mechanism involved in the anticonvulsant effect of LFS is increased adenosine. Therefore, in this study the role of adenosine production from ATP by ectonucleotidase enzyme pathway in exerting the anticonvulsant effects of LFS were evaluated. Methods: Animals were kindled by electrical stimulation of perforant path in a rapid kindling manner (12 stimulation per day). One group of animals received LFS after kindling stimulation. In one another group, AOPCP a blocker of ectonucleotidase inhibitor was micro injected (50 micro molar) intra cerebro ventricular each day before LFS stimulation. Some group of animals were also received AOPCP (50 and 100 micro molar) but were not applied to LFS. Seizure behavior and electrophysiological parameters (including ADD and field potential) were recorded. Results: Like previous investigations, application of LFS, decreased all seizure parameters significantly. Microinjection of AOPCP had no significant effect on anticonvulsant actions of LFS. However microinjection of AOPCP at doses of 100 micro molar in animals that received just kindling stimulations, increased the seizure parameters significantly. Conclusion: The results show that adenosine production via ectonucleotidase enzyme pathway may has no role in anticonvulsant effects of LFS however endogenous adenosine produced through this pathway has an important role in kindling development.
Roghaieh Khakpay, Saeed Semnanian, Mohammad Javan, Mahyar Janahmadi,
Volume 14, Issue 3 (Fall 2010)
Abstract

Introduction: Estradiol is a neuroactive steroid, which is found in several brain areas such as locus coeruleus (LC). Estradiol modulates nociception by binding to its receptors and also by allosteric interaction with other membranebound receptors like glutamate and GABAA receptors. LC is involved in noradrenergic descending pain modulation. Methods: In order to study the effect of 17β-estradiol on both acute and persistent pain modulation and its mechanisms, formalin was injected into the hind paw of male rats. Formalin-induced responses including licking and flexing duration and paw jerking frequency were recorded for 60 min after injection of 50 μl of 2% formalin. Also, the expression of α2 and γ1 subunits of GABAA receptor genes were examined by RT-PCR technique. Results: The results of the current study showed that intra-locus coeruleus injection of 17β-estradiol attenuated the second phase, but not the acute phase of formalin induced pain (P< 0.05). GABAA receptor antagonist (bicuculline) reversed the antinociceptive effect of 17β-estradiol, but the expression level of α2 and γ1 subunits of GABAA receptor genes were not significantly changed. Conclusion: It may be concluded that the analgesic effect of 17β-estradiol in formalin induced inflammatory pain is possibly mediated through the interaction with membrane-bound GABAA receptors, however this effect is not exerted at the gene expression level.
Masoumeh Kourosh Arami, Saeed Semnanian, Mohammad Javan, Sohrab Hajizadeh, Abdolrahman Sarihi,
Volume 14, Issue 4 (Winter 2011)
Abstract

Introduction: In the present work, spontaneous postsynaptic currents were assessed to investigate the postnatal development of excitatory postsynaptic currents in locus coeruleus neurons. Methods: In this study, AMPA and NMDA receptor-mediated spontaneous synaptic currents in the neurons of locus coeruleus were assessed using whole cell voltage-clamp recording during the first three weeks. Results: The frequency and amplitude of NMDA sEPSCs and the frequency of AMPA sEPSCs were increased in the second and third postnatal weeks compared with these parameters recorded in the first postnatal week. However, the ratio of the AMPA to NMDA current frequency and amplitude was constant until the 3rd postnatal week. Conclusion: These findings suggest that a vast majority of nascent glutamatergic synapses express both functional AMPA and NMDA receptors in the postnatal locus coeruleus, so that AMPA/NMDA sEPSCs remained constant during this period.
Kambiz Rohampour, Homa Manaheji, Saeed Semnanian, Hossein Azizi,
Volume 14, Issue 4 (Winter 2011)
Abstract

Introduction: Glial activation and secretion of cytokines at the spinal level is known as part of chronic pain pathogenesis. Although changes in TNFα at the supraspinal level are reported during chronic pain, its exact role and site of action remain to be elucidated. We investigated the effect of microinfusion of TNFα into the LC in a rat model of neuropathic pain. Methods: Male Wistar rats were cannulated in the LC. The cannula was connected to an Alzet mini-osmotic pump, which was filled by the drug (vehicle, TNFα or TNFα-antibody) and placed subcutaneously behind the neck. Twenty four-48 hours after cannulation, a chronic constriction injury (CCI) surgery was performed on the contralateral sciatic nerve. Hyperalgesia and allodynia symptoms were assessed 2, 4, 6, 8, 10 and 12 days after CCI. Results: Microinfusion of TNFα (100ng/day) into the LC significantly exacerbated the hyperalgesia in rat models of neuropathic pain on days 2 and 8 after CCI. On the other hand, microinfusion of TNFα antibody (250ng/day) decreased the symptoms of hyperalgesia on days 2, 4, 6, 8, 10 and 14. TNFα antibody also significantly alleviated the CCIinduced allodynia. Conclusion: These data suggest that alterations of TNFα levels in the LC play a crucial role in the development and maintenance of neuropathic pain.
Mir-Shahram Safari, Abbas Haghparast, Saeed Semnanian, Abolhassan Ahmadiani,
Volume 15, Issue 1 (Spring 2011)
Abstract

Introduction: Previous studies have shown that stimulation of lateral hypothalamus (LH) produces antinociception. Orexin-A (OXA) receptor is strongly expressed in the nucleus locus coeruleus (LC) and orexinergic fibers densely project from LH to LC. In this study, we assessed the role of LC and its OXA receptors in antinociceptive response induced by LH chemical stimulation in the rat. Methods: The cholinergic agonist carbachol (125nmol/0.5μl saline) and lidocaine (2% 0.5μl) were unilaterally microinjected into the LH with the concurrent LC inactivation. In another set of experiments, SB-334867 an OXA selective antagonist or its vehicle were unilaterally infused in LC to study its effect on LH stimulation-induced antinociception. Antinociceptive responses were obtained by the tail flick test and were presented as maximal possible effect (MPE) at 5, 10, 15, 20, 30 and 60 min after drug administrations. Results: The results showed that microinjection of carbachol into the LH significantly induced antinociception at 5 and 10 min (p<0.001). This effect was significantly blocked by microinjection of lidocaine into the LC. Additionally, intra-LC administration of SB-334867 (4.5 μg) could suppress the LH stimulation-induced antinociception by carbachol at 5 and 10 min post-injection times (p<0.001). Conclusion: Our findings showed that analgesic response induced by LH stimulation is mediated in part by the subsequent activation of LC neurons and results from the activation of orexinergic inputs into the LC that can modulate the pain processing.
Shiva Khezri, Mohammad Javan, Hossein Baharvand, Saeed Semnanian,
Volume 15, Issue 2 (Summer 2011)
Abstract

Introduction: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease. In the present study, we investigated the response of subventricular zone (SVZ) adult stem cells in the experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and also the differentiation fate of these stem cells. Methods: Mice were immunized with MOG peptide emulsified in complete Freund's adjuvant (CFA) and pertussis toxin (PT). Control mice received CFA and PT. To study SVZ stem cells migration, mice received seven i.p. injections of BrdU at 2-h intervals on the day before EAE induction. Demyelination was studied using specific staining with luxol fast blue. The number of BrdU+ cells in SVZ and olfactory bulb (OB) was counted using immunohistochemical staining. To understand the fate of the stem cells, NG2 marker was used to detect oligodendrocyte precursors. Results: Lumbar spinal cord of EAE animals showed significant demyelination and the volume of demyelinated areas was increased on days 14 to 21 post lesion. In the EAE group, more Brdu+ cells were observed in the OB compared to the SVZ. The number of Brdu+/NG2 + cells in OB was significantly increased after EAE induction. Conclusion: The demyelinating context of EAE promotes the migration of SVZ stem cells to the OB. These cells mostly differentiate to oligodendrocyte precursors and may contribute to myelin repair.

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