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Showing 6 results for Afarinesh

Mohammad Reza Afarinesh, Baharak Akhtardanesh, Tahereh Haghpanah, Fatemeh Golshan, Gholam Hossein Meftahi, Niousha Ghanbarpour, Ayoob Fakhri, Saeed Sheyhshoaei, Vahid Sheibani,
Volume 0, Issue 0 (9-2018)
Abstract

Introduction: Noise pollution is an unwanted inevitable distribution of the modern and industrialized life of mankind. With the expansion of urban life, humans are daily exposed to noise pollution which can cause anxiety and disorders in cognitive activities. The present study was aimed to investigate the impact of sub-chronic urban traffic noise pollution on learning, memory and anxiety-like behavior in adult male rats.
Methods: Thirty two male adult Wistar rats (weighing 275-300gr) were used in the present experimental study. The animals were divided into two groups; the control (n=16) and the noise-exposed (n=16). The rats in the test group were exposed to a 90dB noise recorded from a crowded street traffic for 6h/10 days. Control rats were intact. Morris water maze (MWM) and an elevated plus maze (EPM) were used to assess spatial learning and memory and anxiety-like behavior in rats.
Results: The findings displayed that both control and noise-exposed group improved their maze steering over 4 days of experiment in MWM; however, noise-exposed group had more latency and traveled-distance in MWM to find the hidden platform in probe trial compared to those of control (P<0.05). Moreover, noise-exposed group showed a significant increase in weight gain compared to the control group (P<0.05). In addition, the spent time in open arm of the EPM was significantly decreased compared to controls (P<0.05).
Conclusion: Urban traffic noise pollution for a short-term period causes a meaningful increase on weight gain, disorders in retrieval memory and increase in anxiety-like behavior in rats.
Mehdi Abbasnejad, Mansour Mirtajadini, Mohammad Reza Afarinesh, Neda Hassibi,
Volume 10, Issue 2 (Summer 2006)
Abstract

Introduction: Origanum vulgare a rich source of natural phenolic antioxidants and has potential to be a source nutritional ingredients for functional food. Herbs such as Origanum have long been used in food preservation d in traditional medicine in the treatment of common ailments and have potential for positive modulation oxidation-linked diseases such as diabetes. Here we investigated the effect of aqueous extract of Origanum aves, stems and flowers) on spatial learning. Methods: After scientific identification, the leaves were used for extraction. 35 adult NMRI male rats weighing 0-350 gr were utilized in 5 groups. Control group (no injection), the second group (saline injected), the extracts h different doses (150, 300, 450) mg/kg were injected intraperitoneally to experimental animals. All animals re trained for a spatial learning task using T-maze and were then trained subsequently daily based on standard thod. Results: Statistic analysis ANOVA showed that Origanum aqueous extract significantly decreased the number learning and error in simple and reverse learning (p<0.05) and it had no significant effect on delay time in both e of learning. Conclusion: It can be concluded that the effect of Origanum extract on learning can be due to its antioxidant d presence of anti acetylcholine estrase compounds such as ursolic acid.
Vahid Sheibani, Sahel Motaghi, Rasool Farazifard, Hossein Joneidi, Mohammad Reza Afarinesh,
Volume 10, Issue 2 (Summer 2006)
Abstract

Introduction: It is believed that Locus Coeruleus (LC) influences the sensory information processing. However, its role in cortical surround inhibitory mechanism is not understood. In this experiment, using controlled mechanical displacement of whiskers we investigated the effect of phasic electrical stimulation of LC on response of layer V barrel cortical neurons in anesthetized rat. Methods: LC was stimulated 0, 50, 100, 200 and 400ms before principal or adjacent whiskers deflection. For assessing the effect of LC stimulation on inhibitory receptive field of the barrel neurons, adjacent whisker was also deflected 20ms before principal whisker deflection, and LC stimulation was applied 0-400ms before principal whisker displacement. Results: We found that LC stimulation increased the response magnitude of layer V neurons to principal whisker deflection (significance level (p<0.05) at 50-400ms intervals). This increase in response magnitude was observed to adjacent whisker deflection too (significant (p<0.01) at 100ms interval). The response latency of neurons was decreased when LC was stimulated 400ms before principal whisker deflection (p<0.01). LC stimulation did not affect the neuronal response latency to adjacent whisker displacement or spontaneous activity of neurons. Inhibitory effect of adjacent whisker deflection on neuronal response magnitude was increased by LC stimulation when tested when combined whisker displacement. Conclusion: These findings suggest that LC by modulating the neuronal responses enhances the neuronal responsiveness to sensory stimuli and increases their surround inhibition in cortex.
Ali Shamsizadeh, Vahid Sheibani, Yaghoub Fathollahi, Mohammad Javan, Javad Mirnajafi-Zadeh, Mohammad Reza Afarinesh,
Volume 11, Issue 2 (Summer 2007)
Abstract

Previous studies have shown that the receptive field properties, spontaneous activity and spatio-temporal interactions of low-threshold mechanical somatosensory cells in the barrel cortex are influenced by C-fibers. In this study, we examined the effect of C-fiber depletion on response properties of barrel cortex neurons following experience dependent plasticity. Methods: In this study, exteracellular single unit recording was performed on 154 barrel cortex neurons in 70 male Wistar rats (38-41days old). For depleting of C-fibers, neonatal rats received an intra-peritoneal injection of capsaicin solution (50 mg/kg) on the first neonatal day. For induction of experience dependent plasticity, all whiskers but D2 on the left muzzle, were plucked from first neonatal day. Neuronal ON and OFF responses were recorded in right barrel cortex following principal whisker (PW) and its caudal adjacent whisker (AW) deflection. Results: Whisker plucking increased PW–evoked ON responses both in capsaicin and vehicle treated rats (all P<0.05). In vehicle treated rats, AW-evoked ON responses were decreased in plucked animals (P< 0.05). Of particular interest, in capsaicin treated rats, AW-evoked ON responses were not decreased in plucked animals. Analyzing OFF responses showed similar result to ON responses. Conclusion: These findings indicate that c-fibers can modulate neuronal response properties following experience dependent plasticity in layer IV of barrel cortex.
Vahid Sheibani, Somaye Arabzadeh, Mohamadreza Afarineshkhaki, Ali Shamsizadeh, Hossein Aminizadeh, Saeed Azizolahi,
Volume 11, Issue 4 (Winter 2008)
Abstract

Introduction: Barrel cortex of rats is a part of somatosensory cortex, which receives information from facial whiskers. Vibrisectomy by sensory deprivation leads to some changes in the barrel cortex, which have been known as experience dependent plasticity. On the other hand, Norepinephrine (NE) and locus coeruleus, which is the main source of NE, influenced response properties of cortical barrel neurons. In this study, the effect of NE depleted and sensory deprivation on induction of experience dependent plasticity was investigated. Materials and methods: In this study sixty wistar rats (250±25gr) were used. Rats were divided into four groups: 1.Control group (Intact). 2. NE depleted group in which Norepinephrine was selectively depleted by IP injection of DSP4. 3. Sensory deprivation group that all whiskers (except the whisker D2) on the left side were trimmed every other day. 4. NE depleted + sensory deprivation group. By using extracellular single unit recordings, the excitatory (magnitude and latency) and initiatory (Conditioning Test Ratio, CTR index) receptive fields of barrel cortical neurons were calculated. Results: Sensory deprivation led to an increase both in the response magnitude to principle whisker deflection (spared whisker) and in the CTR. In NE depleted + sensory deprivation group, the response magnitude and CTR index were the same as control group. Conclusion: The result showed that experience dependent plasticity has a facilitating effect on excitatory receptive field while decreasing the inhibitory circuits in the brain. When NE content of the brain was depleted before sensory deprivation, these changes were not seen. We conclude that NE depletion inhibits the plastic changes in the response properties of neurons following sensory deprivation.
Ali Siyahposht Khachaki, Vahid Sheibani, Mohammad Reza Afarinesh Khaki, Hamid Sheikhkanloui Milan, Ali Shamsizadeh,
Volume 13, Issue 4 (Winter 2010)
Abstract

Introduction: Barrel cortex of rodents is responsible for sensory information processing from muzzle whiskers. Locus coeruleus (LC) as the main source of norepinephrine (NE) in the cortex, is effective on the sensory information processing. Methods: Rats were divided to 2 groups. One group underwent sensory deprivation (P4) and the other group served as control and did not undergo sensory deprivation. Response properties of the neurons were evaluated by extracellular single unit recordings following a controlled mechanical deflection of the principal whisker (spared whisker), or before the simultaneous deflection of principal and adjacent whiskers (trimmed whisker) were assessed. In the P4 group, all whiskers on the left muzzle, except D2, were trimmed every other day for two months. In both groups, LC was electrically stimulated 0, 50, 100, 200, 400 and 800 ms before controlled principal whisker deflection. Response magnitude, latency and CTR index (lateral inhibition index) were assessed. Results: In the P4 group, deflection of the principal whisker without LC electrical stimulation, increased the response magnitude and CTR index, but decreased the response latency compared to the control group. The magnitude of the response of neurons to the principal whisker deflection was significantly different between P4 and control groups, in following of principal whisker deflection in times of LC stimulation showed significant difference only in 50 ms subgroup. In both groups, pro-stimulation differences in CTR index and response latency remained unchanged after LC stimulation. Conclusion: Our data showed that electrical stimulation of LC following sensory deprivation modulates neuronal response properties and changes their response pattern.

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