Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi
A B S T R A C TIntroduction: The nucleus cuneiformis (NCF) and ventrolateral periaqueductal gray (vlPAG), two adjacent areas, mediate the central pain modulation and project to the nucleus raphe magnus (NRM). Methods: This study examined whether the antinociceptive effect of morphine microinjected i...
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Iran University of Medical Sciences
2010-08-01
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| Series: | Basic and Clinical Neuroscience |
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| Online Access: | http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-40&slc_lang=en&sid=1 |
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| author | Abbas Haghparast Mehdi Ordikhani-Seyedlar Maryam Ziaei Pegah Azizi Mohammad Ebrahimzadeh-Sarvestani |
| author_facet | Abbas Haghparast Mehdi Ordikhani-Seyedlar Maryam Ziaei Pegah Azizi Mohammad Ebrahimzadeh-Sarvestani |
| author_sort | Abbas Haghparast |
| collection | DOAJ |
| description | A B S T R A C TIntroduction: The nucleus cuneiformis (NCF) and ventrolateral periaqueductal gray (vlPAG), two adjacent areas, mediate the central pain modulation and project to the nucleus raphe magnus (NRM). Methods: This study examined whether the antinociceptive effect of morphine microinjected into the NCF is influenced by inactivation of vlPAG and NRM in rats. Animals were bilaterally microinjected with morphine (2.5 µg/0.3 µl saline) into the NCF. Electrolytic lesions were made in vlPAG (0.1 mA, 45 sec) and/or NRM (1 mA, 30 sec). Tail-flick latency (TFL) was measured at 30, 60, 90 and 120 min after microinjection. Results: The results showed that TFLs are significantly decreased in vlPAG+NRM lesions group at 30 (P<0.001) and 60 (P<0.01) min after intra- NCF administration of morphine whereas TFLs did not affect in solely vlPAG lesion animals. Our findings show that concurrent lesions of NRM and vlPAG completely reversed the analgesic effect of morphine in NCF. However, vlPAG do not play a critical role directly in pain modulatory system elicited from NCF, at least at the level of morphine-induced analgesia. Discussion: It can be concluded that its interactive effect in descending pain modulation from NCF to NRM should not be neglected. |
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| format | Article |
| id | doaj.art-a4dcbf3cd5cc4691bfa2acfa57c0e3fc |
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| issn | 2008-126X 2228-7442 |
| language | English |
| last_indexed | 2024-03-07T17:37:14Z |
| publishDate | 2010-08-01 |
| publisher | Iran University of Medical Sciences |
| record_format | Article |
| series | Basic and Clinical Neuroscience |
| spelling | doaj.art-a4dcbf3cd5cc4691bfa2acfa57c0e3fc2024-03-02T16:44:44ZengIran University of Medical SciencesBasic and Clinical Neuroscience2008-126X2228-74422010-08-01142633Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus CuneiformiAbbas Haghparast0Mehdi Ordikhani-Seyedlar1Maryam Ziaei2Pegah Azizi3Mohammad Ebrahimzadeh-Sarvestani4 A B S T R A C TIntroduction: The nucleus cuneiformis (NCF) and ventrolateral periaqueductal gray (vlPAG), two adjacent areas, mediate the central pain modulation and project to the nucleus raphe magnus (NRM). Methods: This study examined whether the antinociceptive effect of morphine microinjected into the NCF is influenced by inactivation of vlPAG and NRM in rats. Animals were bilaterally microinjected with morphine (2.5 µg/0.3 µl saline) into the NCF. Electrolytic lesions were made in vlPAG (0.1 mA, 45 sec) and/or NRM (1 mA, 30 sec). Tail-flick latency (TFL) was measured at 30, 60, 90 and 120 min after microinjection. Results: The results showed that TFLs are significantly decreased in vlPAG+NRM lesions group at 30 (P<0.001) and 60 (P<0.01) min after intra- NCF administration of morphine whereas TFLs did not affect in solely vlPAG lesion animals. Our findings show that concurrent lesions of NRM and vlPAG completely reversed the analgesic effect of morphine in NCF. However, vlPAG do not play a critical role directly in pain modulatory system elicited from NCF, at least at the level of morphine-induced analgesia. Discussion: It can be concluded that its interactive effect in descending pain modulation from NCF to NRM should not be neglected.http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-40&slc_lang=en&sid=1Nucleus Cuneiformis;Ventrolateral PeriaqueductalNucleus Raphe Magnus;Electrolytic Lesion;Morphine Analgesia |
| spellingShingle | Abbas Haghparast Mehdi Ordikhani-Seyedlar Maryam Ziaei Pegah Azizi Mohammad Ebrahimzadeh-Sarvestani Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi Basic and Clinical Neuroscience Nucleus Cuneiformis;Ventrolateral Periaqueductal Nucleus Raphe Magnus;Electrolytic Lesion;Morphine Analgesia |
| title | Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi |
| title_full | Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi |
| title_fullStr | Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi |
| title_full_unstemmed | Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi |
| title_short | Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi |
| title_sort | effects of electrolytic lesions of the ventrolateral periaqueductal gray and nucleus raphe magnus on morphine induced antinociception in the nucleus cuneiformi |
| topic | Nucleus Cuneiformis;Ventrolateral Periaqueductal Nucleus Raphe Magnus;Electrolytic Lesion;Morphine Analgesia |
| url | http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-40&slc_lang=en&sid=1 |
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