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Background: Alzheimer is a neurodegenerative disease wich caused memory impairment, reduced cognitive functions, intellectual ability and behavior changes. In this study, the effect of Nacetyl- cysteine (NAC) as a strong antioxidant on memory deficiency and number of CA1 pyramidal neurons in Streptozotocine (STZ) - induced Alzheimeric rats were studied. Materials and Methods: 32 Male Wistar rats were divided into four groups: sham group, streptozotocin group, treated group with streptozotocin plus N-acetyl-cysteine, and treated group with Nacetyl- cysteine alone. Intracerebroventricular (ICV) administration of STZ was done in the first and the third day of surgery and i.p injection of N-acetyl-cysteine was done in the fourth of surgery. After the memory test, the animals were killed and their brains were fixed and density of intact neurons in the CA1 area of the hippocampus was investigated. Statistical analysis was performed with software SPSS, ANOVA and Prisme software. The level of statistical significance was set at p < 0.05. Results: The ICV injections of STZ significantly reduced memory retention and intact pyramidal cells compared to the sham group (p<0.001). Administration of N-acetyl-cysteine improved STZ-induced effects on memory retrieval and increased intact neurons in hippocampal CA1 area compared to the STZ group (p<0.001). N-acetyl-cysteine alone doesn't have any significant effect on memory retrieval and the number of intact neurons in hippocampal CA1 area compared to the sham group (p>0.05). Conclusion: N-acetyl-cysteine improved memory retrieval and hippocampal CA1 area intact neurons in streptozotocin-induced Alzheimeric male rats. [ABSTRACT FROM AUTHOR]

Background: Paragigantocellularis lateralis (LPGi) nucleus plays a key role in the processing of pain information related to the descending pain modulation. Also, 17β-estradiol is involved in the pain modulation. The aim of the present study was to investigate the role of estrogen receptors of LPGi nucleus in the 17β-estradiol-induced pain modulation in the ovariectomized rats. Materials and Methods: In this study, the female Wistar rats (180-250 gr) were used. In order to study the role of the NMDA receptors in the 17β-estradiol-induced pain modulation in the ovariectomized rats, primarily, rats were bilaterally ovariectomized and immediately cannulation of LPGi nucleus was performed. First, drugs were injected and 15 minutes later 50 μl of 5% formalin was injected into the rat's hind paw; and then, formalin-induced paw jerking behavior was recorded for 60 min. Results: Our results indicated that intra-LPGi injection of 17β-estradiol significantly attenuated paw jerking behavior in the both phases of formalin test. Intra-LPGi injection of estrogen receptor antagonist (ICI 182,780), had no effect on the paw jerking behavior. Pre-treatment of LPGi nucleus by ICI 182,780 counteracted the anti-nociceptive effect of 17β-estradiol both in the acute and in the chronic phases of formalin-induced paw jerking behaviour. Conclusion: Based on the results of this study, it can be concluded that the intra-LPGi 17βestradiol produces modest analgesia on the formalin-induced inflammatory pain in the ovariectomized rats, which is probably mediated via the esterogen receptors of this nucleus. [ABSTRACT FROM AUTHOR]

Background: 17β-Estradiol modulates nociception by binding to the estrogen receptors and also by allosteric interaction with other membrane-bound receptors like the NMDA receptors. The paragigantocellularis lateralis nucleus (LPGi) is also involved in the pain modulation. In this study, the role of NMDA receptors of the LPGi nucleus has been investigated in the 17β-estradiol-induced pain modulation in the ovariectomized rats. Materials and Methods: In this study, the female Wistar rats in the range of 200-270 gr were used. In order to study the role of the NMDA receptors in the 17β-estradiol-induced pain modulation in the ovariectomized rats, primarily, rats were bilaterally ovariectomized and immediately cannulation of the LPGi nucleus was performed. Then, drugs were injected and 15 minutes later 50 μl of 5% formalin was injected into the rat's hind paw; and formalin-induced paw jerking behaviour was recorded for 60 min. Results: The results of the present study showed that the intra-LPGi injection of 17β-estradiol significantly reduced the paw jerking behavior both in the first and in the second phases of formalin test. Pretreatment of the LPGi nucleus by NMDA receptor antagonist (AP5) neutralized the antinociceptive effect of 17β-estradiol on the paw jerking frequency in the both phases of formalin test; and induced hyperalgesia in the both phases of this behavior. Conclusion: These results indicated that the intra-LPGi injection of 17β-estradiol produces modest analgesia on the formalin-induced inflammatory pain. Therefore, it can be concluded that the NMDA receptors of the paragigantocellularis lateralis nucleus are probably involved in the antinociceptive effect of 17β-estradiol in the ovariectomized rats. [ABSTRACT FROM AUTHOR]

Background: Pain is a protective process in the body. There are different pathways for pain control in the central nervous system. Descending pain control system is one of pathways. The periaqueductal gray (PAG) is a structure known for its role in pain transmission and modulation. The aim of this study is to investigate the percent of interaction between the left and right PAG in unilateral left foot induced pain. Materials and Methods: In this study, 60 rats (280+30g) in six groups were used (3test groups and 3 controls groups). In test groups, 0.5 microliter lidocaine was injected in the left PAG, right PAG or both to make local anesthesia. In control groups, 0.5 microliter of normal saline were injected. After 15 minutes, 50 microliter of 2.5% of formalin were injected subcutaneously to right hind paw of rats and nociception was detected in every 15 seconds for one hour . Results: The induction of unilateral pain (left hind paw) in rats, can affect not only the ipsilateral but also the contralateral PAG nucleus. Conclusion: This study showed that the left and right PAG nuclei have significant role on unidirectional nociception in formalin test in rats. The contralateral PAG, however, has a minor effect on nociception. [ABSTRACT FROM AUTHOR]

Background: In various researches, ICA is used for detecting and removing eye artifacts; but here, for innovation, ICA algorithm is used not only for detecting eye artifacts but also for detecting brain signals of two conceptual categories of the words Danger and Information. Materials and Methods: In this descriptive- analytical study, recording is done by using a Micromed device and a 19-channel helmet in unipolar mode that the Cz electrode is selected as reference electrode. The statistical community included four men and four women in the age range of 25-30. In the designed task three groups of traffic signs are considered in which two groups refered to the concept of danger and the other one refered to the concept of information. Results: For two of the eight volunteers, alpha waves were observed with a very high power from back of the head in the test time, but in thinking time it was different. According to this alpha waves, in changing the task from thinking to rest, it takes for two volunteers at least 3 and at most 5 seconds till they go to the absolute rest. For seven of the eight volunteers, danger and information signals well separated; that these differences for five of the eight volunteers observed in the right hemisphere and for the other three volunteers in the left hemisphere. Conclusion: ICA algorithm as one of Blind Source Seperation(BSS) algorithms is suitable for recognizing the word's concept and its place in the brain. Achieved results from this experiment are the same as the results from other methods like fMRI and methods based on electroencephalograph (EEG) in vowel imagination and covert speech. [ABSTRACT FROM AUTHOR]