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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: 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]