Search published articles


Showing 210 results for Subject: Nervous system (others)

Parviz Shahabi, Meysam Ghorbani, Abass Ebrahimi-Kalan, Hamid Soltani-Zangbar, Javad Mahmoudi, Soheila Bani, Behnaz Sadeghzadeh-Oskouei, Yusef Rafiee-Byraami, Omid Salimi,
Volume 0, Issue 0 (11-2018)
Abstract

Introduction: The use of standard rodent model, allows for the understanding of neuronal injury physiopathology, and helping development of therapeutic strategies. According to contusion type of spinal cord injury (SCI) and mild traumatic brain (TBI) injuries that are commonly occurred in the human, we designed a novel impactor device with ability to induce different degrees according to kilodyne from very mild to very severe of SCI and TBI models in rats. Methods: For standardization and determining of optimal performance of the device to induce varying injuries, 47 adult male Wistar rats were used, and 8 different forces were applied in spinal cord and brain tissues. Results: The Hematoxylin and Eosin (H&E), and 2, 3, 5-triphenyltetrazolium chloride (TTC) results demonstrated that by increasing the level of forces, histological changes in the spinal cord and brain were significantly enhanced. Different injuries had significant effect on the Basso, Beattie, and Brenham (BBB) and elevated body swing test (EBST) outcomes, and there were significant differences between groups in comparison with control group. Conclusion: Our results show that the novel device could be valid to produce precise SCI and TBI models, goal to replicate SCI and TBI in humans as much as possible. However, it might be considered that aspects of SCI and TBI models are complicate and more examination is necessary.
Esmaeil Akbari, Fereshteh Motamedi, Mohamamd Reza Vaez-Mahdavi,
Volume 4, Issue 1 (4-2000)
Abstract

Amitriptyline, a tricyclic antidepressant agent is used as one of the analgesic drugs in different kinds of pain. In the present study the effect of local (subcutaneous) injection of amitriptyline (50 and 100 µg) on the acute and chronic pain using formalin test, was investigated. Our data show that local injection of amitriptyline to the paw receiving formalin, causes a decrease in pain in both phasic and tonic phases of formalin test. On the other hand, in the group that this drug was injected (100 µg) to the contralateral paw, no significant change was observed in the pain score with respect to the control group. Therefore, it seems that the observed effect is due to the local action of amitriptyline and not as a result of its systemic effect. Considering the above-mentioned results, it is concluded that: 1) Amitriptyline acts like a local anesthetic in both acute and tonic phases of formalin test. 2) The mechanism of analgesia in the acute phase is probably caused by sodium channel blockade. 3) The analgesic effect of amitriptyline in the tonic phase of formalin test might be due to its antihistaminic and anti-inflammatory effects at the peripheral level, and also is due to the changes in the CNS plasticity which occurs during the acute phase.
Mehdi Saberi, Mohamamd Hossein Pourgholami, Masoumeh Jorjani,
Volume 4, Issue 1 (4-2000)
Abstract

It has been proved that kindling model of amygdala is sensitive to estradiol because the latter accelerates the overall rate of kindling. However the effect of estrogen on the seizure process has not been investigated. In this study fully kindled male rats were treated with different doses (10, 30, and 50 µg/kg, i.p.) of estradiol benzoate (EB) daily and such kindling parameters as seizure stage (SS), after-discharge duration (ADD) and stage 5 duration (S5D) were recorded 15 and 180 min and every 24 h following EB injection for a period of 96 h. While EB at a dose of 10 µg/kg failed to produce a significant effect, but its administration at doses of 30 and 50 µg/kg induced a triphasic effect on seizure parameters. In this regard an initial rapid increment of ADD (after 15 min) was followed by a significant decrease of all parameters after 48 h and then a significant increase in S5D after 96 h was observed. In addition, pretreatment with tamoxifen citrate (TAM) at a dose of 3 mg/kg inhibited the effects of EB (30 µg/kg) for 72 h and pretreatment with TAM at a dose of 10 mg/kg blocked only the inhibitory phase of EB effects after 48 h. Also treatment with the same dose of TAM alone induced a profile similar to EB treatment. These results may suggest that estradiol treatment both increases and decreases kindling parameters in a time- and dose-dependent manner in male rats. These effects probably manifest themselves in genomic and non-genomic forms. Moreover the tamoxifen effects alone could be attributed to its partial agonistic activity on the estrogen receptors.
Mohsen Khalili, Saeed Semnanian, Yaghoub Fathollahi,
Volume 4, Issue 1 (4-2000)
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.
Maryam Nourbakhshnia, Ali Haeri Rohani, Hoori Sepehri, Sirous Jalili, Hassan Ghoshouni, Hedayat Sahraei,
Volume 4, Issue 1 (4-2000)
Abstract

Nucleus accumbens (Nac) has been considered as a center for the induction of drug dependence. Since a high concentration of the enzyme, nitric oxide synthase (NOS) has been found in the Nac, and this fact that the role of nitric oxide (NO) in acquisition and expression of drug dependence has become clear in recent years, therefore in this study the effects of intraaccumbal injections of L-arginine (NO precursor) and L-NAME (N-ω-nitro-L-arginine methyl ester) or aminobiguanidine (NOS inhibitor) on induction of conditioned place preference (CPP) in rat were investigated. For this purpose, male Wistar rats (250-300 g) were used. Five days after surgery and cannulation, different doses of L-arginine, L-NAME or aminobiguanidine were injected to animals and conditioning was performed. The results showed that: I) intraaccumbal injection of L-arginine at doses of 0.3, 1 and 3 µg/rat induced CPP. 2) Acute administration of L-NAME (50 mg/kg i.p.) reduces the effect of L-arginine and chronic administration of the drug (10, 50, and 200 mg/kg i.p.) has no effect. 3) intraaccumbal injection of both L-NAME and aminobiguanidine (0.3, 1, and 3 µg/rat) produces no effect. In conclusion, it seems likely that intraaccumbal injection of L-arginine could induce CPP and part of its effect might be due to the release of NO from L-arginine.
Mohamamd Reza Palizvan, Yaghoub Fathollahi,
Volume 4, Issue 1 (4-2000)
Abstract

Epilepsy is one of the common disorders in human community. Clinical observations have shown that epileptic patients have often difficulty in learning and memory. Kindling is a laboratory model for studying epilepsy and its complications. This experiment was designed to study the effect of chemical kindling on Schaffer collateral-CA1 pyramidal cell synaptic transmission using pentylenetetrazole in urethane-anesthetized rats. Experiments were carried out on the hippocampal CA1 region from control and kindled rats at two periods post-kindling, i.e. 48-144 h (early phase) and 30-33 day (long-lasting phase). Population spike (PS) was recorded at stratum pyramidale following stimulation of the stratum fibers. The results showed that 48-144 h after kindling, the slope of population excitatory post-synaptic potential (pEPSP), the PS amplitude and spike latency in CA1 region of kindled rats were not significantly different than that of control. In contrast, 30 to 33 days after kindling, the amplitude of PS was significantly greater than that of control (p<0.01). These results suggest that chemical kindling entails long lasting changes in the function of CA1 that appear as enhanced excitability after one month
Taghi Ghafghazi, Fatemeh Zeraati, Minoo Adib, Abbas Rezaei,
Volume 4, Issue 1 (4-2000)
Abstract

Restraint-induced stress (RS) increases histamine concentration in the brain. There is no previous report regarding the role of histamine receptors in immunomodulatory effect of RS. In the present study the role of brain histamine receptors on reduction of humoral and cellular immune function induced by RS was evaluated. For this purpose male Wistar rats (200-250 g) were immunized with sheep red blood cells (SRBCs). The results showed that RS reduced the humoral and cell-mediated immunity in immunized rats (p<0.01). Similarly, ICV injection of histamine (150 µg/rat) without stress reduced significantly humoral and cellular immune function (p<0.01). Pretreatment with chlorpheniramine (50 µg/rat) reduced the inhibitory effect of RS. In addition, histamine (150 µg/rat) could inhibit the effect of chlorpheniramine if injected simultaneously. Ranitidine (10 µg/rat) had no significant effect. ICV injection of lower doses of R-α-methyl histamine reduced the effect of RS on immune function, but the effect of RS on immunity increased at higher doses (10 µg/rat) of the drug. These results indicated that histamine has a central role in RS-induced immunosuppression through brain's H1 receptors. Furthermore H3 histamine receptors induce a dose-dependent bi-directional effect, which may be due to the role of this receptor in non- histaminic nervous system.
Sadegh Valizadeh, Mohammad Reza Zarrindast,
Volume 4, Issue 1 (4-2000)
Abstract

This study was designed to investigate the role of GABAB receptor agents on imipramine-induced antinociception in ligated and non-ligated mice using hot-plate test. The data showed that different doses of morphine (3, 6, and 9 mg/kg) induced a dose-dependent antinociception in ligated and non-ligated mice. However, the opioid response was decreased in ligated animals. Intracerebroventricular (i.c.v.) administration of imipramine (5, 10, 20, and 40 µg/mouse) did not induce antinociception in either non-ligated or ligated mice. However, the induced response in the ligated mice was less than that induced in the non-ligated mice. Intraperitoneal (i.p.) administration of imipramine (10, 20, 30, and 40 mg/kg) induced antinociception in both ligated and non-ligated mice. The responses to the drug were not significantly different in the two groups. Administration of baclofen either i.c.v. (0.125, 0.25, and 0.5 µg/mouse) or i.p. (0.5, 1,2, and 4 mg/kg) induced antinociception. The response to the drug was not significantly different in ligated and non-ligated mice. Intracerebroventricular administration of a lower dose of baclofen (0.125 µg/mouse) with different doses of imipramine (2.5, 5, and 10 mg/kg) potentiated the response to imipramine. This effect was reduced by i.c.v. injection of GABAB receptor antagonist, CGP35348 [P-(3-aminopropyl)-p-diethoxymethyl- phosphinic acid] at a dose of 20 µg/mouse. The higher dose of antagonist (20 µg /mouse) also decreased the response induced by baclofen or imipramine. CGP35348 itself (2.5, 5, 10, and 20 µg/mouse) induced a dose-dependent antinociception with no significant difference in the ligated and non-ligated mice. It is concluded that a GABA receptor mechanism(s) may modulate the antidepressant-induced antinociception.
Mitra Mahmoudi, Mohammad Reza Zarrindast,
Volume 4, Issue 2 (10-2000)
Abstract

In the present study, the effect of GABA (γ-aminobutyric acid) receptor agonists and antagonists on morphine-induced antinociception was investigated in formalin test in rats. Intraperitoneal (i.p.) injection of different doses of morphine (1, 3, 6 and 9 mg/kg) and intracerebroventricular (i.c.v.) injection of different doses of muscimol (0.5, 1 and 2 g/rat) or baclofen (0.25, 0.5 and 1 g/rat) induced a dose-dependent antinociception in both phases of formalin test. The responses induced by muscimol or baclofen in both phases reduced by bicuculline or CGP35348 respectively. Morphine in combination with different doses of muscimol or baclofen tends to elicit higher response. The opioid receptor antagonist reduced the response induced by both GABA receptor agonists. It can be concluded that stimulation of GABAA and GABAB receptors are responsible for antinociception in formalin test. However, at least part of the antinociception is due to the opioid receptor mechanism.
Mohammad Rostampour, Yaghoub Fathollahi, Saeed Semnanian, Sohrab Hajizadeh, Javad Mirnajafi-Zadeh,
Volume 4, Issue 2 (10-2000)
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.
Abasali Vafaei, Ali Rashidipour, Mohammad Reza Sharifi, John Bouresh,
Volume 4, Issue 2 (10-2000)
Abstract

There is strong evidence that two cerebral hemispheres are differentially involved in emotional memory and that amygdala is a key subcortical structure for emotional experience. The present research investigated the possible involvement of lateralization of basolateral amygdala (BLA) and central amygdala (CEA) in place avoidance memory. For this purpose, male Long-Evans rats (280-320 g) were implanted bilaterally with cannulae aimed at the BLA and CEA. One week later, the rats were trained in place avoidance apparatus as a spatial learning model. During the training session (30 min), the animal learned to avoid and recognize the places with a possibility of shock. One day later, bilateral or unilateral injection of TTX (5 ng/ml/side) were performed to inactivate temporarily the BLA and CEA during retrieval of the place avoidance task. Control rats were injected with the same volume of saline. Place avoidance training occurred in a single 30 min session and one day later, the avoidance memory was assessed during a 30 min extinction trial. The time to the first entrance and the number of entrances into the punished sector during extinction were used to measure the avoidance memory. The results indicated that bilateral or only right BLA inactivation significantly impaired retrieval of memory, although inactivation of the CEA and left BLA had no significant effect. Taken together, these results suggested that the right and left BLA make differential contribution to the expression of spatial memory and that the contribution of the right BLA may be more important.
Farnaz Nikbakht, Zhila Behzadi,
Volume 4, Issue 2 (10-2000)
Abstract

It has been reported that neurons in the VL PAG projecting to nucleus raphe magnus (NRM) utilize excitatory amino acids as neurotransmitter. This projection plays an important role in the descending pain modulatory system. In order to determine the role of this pathway in pain perception, male rats received unilateral injection of ibotenic acid stereotaxically. For lesioning VL PAG, unilateral injection of ibotenic acid (0.2 and 0.5 µl) (a specific neurotoxin for EAA-containing neurons) was made. After a week recovery period, the nociception was evaluated using formalin test for a period of 60 min. At the end of experiments, animals were perfused by formaldehyde 10%. Serial sections (80 µm) wee prepared using vibratome. The sections were then Nissl stained and examined to determine the lesion location. The results revealed a significant increase in the first phase of formalin test. However, in the second phase, only 0.5 µl of the neurotoxin caused a significant decrease in pain perception. It is concluded that NMDA receptors within the PAG are involved in the perception of pain as measured in the formalin test.
Parvin Zareian, Mahyar Janahmadi, Seyed Mohamamd Firoozabadi, Fereshteh Motamedi,
Volume 4, Issue 2 (10-2000)
Abstract

Ion channels are responsible for control of cell function in excitable tissues such as heart and brain and also in organs and tissues traditionally thought to be non- excitable including liver and epithelium. In the present research, the effect of lead (Pb2+) on Ca2+ -dependent action potential and currents was studied in F77 neuronal soma membrane of Helix aspersa. For this purpose, action potential generation and Ca2+ currents were investigated in the absence and presence of Pb2+ using two-electrode voltage clamp and current clamp methods. Two distinct types of high voltage activated (HVA) calcium currents were recorded. In this respect, one of them was sensitive to nifedipine (1 µM) and the other one was resistant to nifedipine. Extracellular application of Pb2+ at concentrations of 0.6 and 3 µM suppressed the firing behavior of F77 neurons. It also decreased the amplitude and the duration of calcium action potentials. The voltage clamp findings demonstrated that lead blocked more than 50% of HVA Ca2+ currents. The blocking effect of Pb2+ on Ca2+ was time-dependent. Therefore, it can be concluded that Pb2+ may alter the bioelectrical properties of F77 neuron through blocking high voltage activated Ca2+ currents, particularly L-type that are nifedipine sensitive.
Masoumeh Shafiie, Gholamreza Omrani, Masood Mahmoudian,
Volume 4, Issue 2 (10-2000)
Abstract

The internal mammary artery (IMA) is currently the preferred conduit for myocardial revascularization. However, pre-operative vasospasm and a hypoperfusion state during maximal exercise may limit its use as a bypass graft. The mechanism of spasm has not been clearly defined. Since β-adrenoceptor activation plays a major role in vasorelaxation, the present study was carried out to investigate the β-adrenoceptor responsiveness of human IMA smooth muscle. For this purpose, IMA was obtained from patients with atherosclerosis of coronary artery whom have undergone coronary artery bypass. The endothelium-denuded rings of IMA were placed on platinum wires (L-shaped) in a Krebs solution containing tissue bath, and were connected to an isometric transducer. It was found out that Isoproterenol produced a dose-dependent relaxation in endothelium-denuded MA segments, precontracted with phenylephrine (maximal relaxation was 46.33 ± 5.45 %). Isoproterenol-induced relaxation was inhibited by atenolol (10-6 M) and proprano1ol (2 x 10-7 M). While atenolol-induced inhibition was partial, propranolol-induced inhibition was complete in a majority of the segments. BRL 37344, a selective 3-adrenoceptor agonist, produced a dose-dependent relaxation in phenylephrine pre contracted rings of endothelium-denuded IMA (maximal relaxation was 40.35 ± 4.07 %). Cyanopindolol, α-adrenoceptor partial agonist, produced a marked relaxation in endothelium-denuded IMA rings, precontracted with phenylephrine (maximal relaxation was 58.65 ± 6.2 %). Cyanopindolol-induced relaxation was resistant to blockade by propranolol (2 x 10-7 M). In addition, spontaneous contractions of IMA rings were observed in some of the cases that were inhibited by isoproterenol and BRL 37344. This observation may indicate the important role of β-adrenoceptor activation in prevention of human IMA spasm. Therefore, it is concluded that human IMA smooth muscle possesses both βl- and β2-adrenoceptors. The existence of β3-adrenoceptor in this tissue is also suggested.
Mohamamd Badavi, Ali Khoshbaten, Sohrab Hajizadeh, Farzaneh Nazari,
Volume 4, Issue 2 (10-2000)
Abstract

The effect of chronic inflammation induced by complete Freund's adjuvant (CFA) on anterior blood vessels of knee joint and its diameter was studied. Blood flow changes in response to phenylephrine (αl-adrenoceptor agonist) in CFA-treated and contralateral knee joints were observed over a 40-day period, using laser Doppler flowmetery (LDF) technique. Unilateral injection of CFA (0.2 ml) increased the diameter of injected knee at all days post-injection (p<0.001) and reached to its maximum level (49.7 ± 2%) at day 3. Then, the diameter decreased gradually but did not return to its initial value. In control animals, topical application of phenylephrine (10-13-10-17 M) to the exposed joint capsule decreased blood flow in a dose-dependent manner (11.1 ± 4.4 to 58.2 ± 4.5%, p<0.001). Unilateral injection of CFA attenuated the phenylephrine response in both ipsilateral and contralateral knees compared to the response of control animals (5.2 ± 1.6 to 48.3 ± 6.1% and 1.9 ± 2.2 to 45.3 ± 5.6 % respectively, p<0.05). The reduction persisted for three weeks after CFA injection (ipsilateral for 21 days contralateral for 30 days, p<0.001). Then, the above response returned to its normal value. To evaluate the role of nitric oxide (NO) on the observed responses, amino guanidine (inducible-NO synthase inhibitor) was injected (120 mg/kg/day, i.p.) in other groups of CFA-treated animals. Arninoguanidine potentiated (p<0.001) the vasoconstrictor response to phenylephrine in both CFA injected and contralateral knees at 7, 14 and 21 days post-injection, and the increment of knee joint diameter was also less prominent. These findings may indicate that the vasoconstrictor response to phenylephrine is decreased in chronic inflammation, and increased production of NO during chronic inflammation might be involved.
Mousa Sahebgharani, Mohammad Reza Zarrindast, Morteza Samini,
Volume 4, Issue 2 (10-2000)
Abstract

In this study, the effect of α-adrenoceptor agents on imipramine-induced antinociception was investigated using formalin test. Intraperitoneal (i.p.) administration of imipramine at different doses (10-80 mg/kg) induced antinociception in both phases of formalin test. In addition, intracerebroventricular (i.c.v.) injection of imipramine (1, 5, and 10 µg/rat) did not elicit any effect, although i.c.v. injection of clonidine, an α2-adrenoceptor agonist at doses of 0.05-0.8 µg/rat also elicited antinociception in both phases of the test. Furthermore, clonidine increases the antinociception induced by imipramine and yohimbine, an α2-adrenoceptor antagonist at a dose of 2 µg/rat (i.c.v.) reduced the response to imipramine at a low dose (10 mg/kg, i.p.) and clonidine (0.05 µg/rat, i.c.v.), but did not alter the response induced by higher doses of imipramine (20 and 40 mg/kg) alone or in combination with clonidine. Yohimbine by itself elicited no response. Meanwhile, phenylephrine (0.07-1.5 µg/rat, i.c.v.), an αl-adrenoceptor agonist induced antinociception in both phases of formalin test, but did not alter the imipramine-induced antinociception. The αl -adrenoceptor antagonist, prazocin neither elicited antinociception nor altered the imipramine response. Yohimbine (2 µg/rat, i.c.v.) in combination with prazocin (0.5 µg/rat, i.c.v.) further inhibited the response for imipramine alone or in combination with clonidine. Taken together, it is concluded that α2-adrenoceptor-mediated mechanism might be involved in the development of imipramine-induced antinociception.

Volume 5, Issue 1 (4-2001)
Abstract

It has been shown that enhanced acid secretion can be suppressed in the rat by systemic administration of glucose. We have recently reported that enhancement of acid secretion as a result of pentagastrin was diminished by intragastric administration of D-glucose. Present study was designed to investigate whether intragastric D-glucose influences gastric acid secretion associated with carbachol and histamine in rat, and then we compared these results with our previous results obtained by pentagastrin-induced hyperacidity. Intravenous infusion of carbachol (1 mg/100 g/h) and histamine (0.5 mg/100 g/h) caused an immediate increase in acid secretion with a peak starting after 40 and 60 min and then reached to a steady state respectively. 1ntragastric administration of D-glucose significantly reduced the hyperacidity induced by histamine and carbachol (p<0.01). The effect of intragastric D-glucose on hyperacidity induced by pentagastrin or histamine when compared with carbachol-induced hyperacidity was significantly greater than carbachol group. In conclusion, it is suggested that the inhibitory effect of intragastric D-g1ucose observed in hyperacidity may be the result of glucose-induced modification of intragastric pathways in parietal cells that control gastric acid secretion.
,
Volume 5, Issue 1 (4-2001)
Abstract



Volume 5, Issue 2 (11-2001)
Abstract

Post-operative pain and its management remains one of the most important issues in the field of surgery and health care system. On the other hand, opioid drug abuse has a large prevalence in Iran. Formalin test has been used as a method for assessing pain and analgesia in rats. In the present study, the post-operative pain in morphine addicted rats was compared with that of non-addicted ones using formalin test. For this purpose, 26 rats were chosen and randomly divided into two groups. First group received morphine sulphate in their drinking water for 21 days. The other group received only tap water. On the day of their assessment, a longitudinal incision (1-cm) was made through skin fascia of their plantar aspect of one foot under ether anesthesia. One hour later, their pain was assessed with formalin test through intra-plantar subcutaneous injection of 0.05 ml of 2.5% formalin solution. Our results showed that acute pain (the first 5 minutes after injection) in both groups was not different significantly, but chronic pain (the next 15-45 minutes) was much intense in morphine-addicted rats.

Volume 6, Issue 1 (4-2002)
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.

Page 1 from 11    
First
Previous
1
...