Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole
Introduction. Valproic acid and metamizole are widely used in the treatment of primary headaches. However, despite the drugs’ proven clinical efficacy, the neurophysiological mechanisms underlying their therapeutic action are poorly understood. The ventral posteromedial nucleus of the thalamus (VPM)...
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| Format: | Article |
| Language: | Russian |
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Academician I.P. Pavlov First St. Petersburg State Medical University
2022-11-01
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| Series: | Учёные записки Санкт-Петербургского государственного медицинского университета им. Акад. И.П. Павлова |
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| Online Access: | https://www.sci-notes.ru/jour/article/view/901 |
| _version_ | 1797702356087865344 |
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| author | A. Yu. Sokolov O. A. Lyubashina |
| author_facet | A. Yu. Sokolov O. A. Lyubashina |
| author_sort | A. Yu. Sokolov |
| collection | DOAJ |
| description | Introduction. Valproic acid and metamizole are widely used in the treatment of primary headaches. However, despite the drugs’ proven clinical efficacy, the neurophysiological mechanisms underlying their therapeutic action are poorly understood. The ventral posteromedial nucleus of the thalamus (VPM) serves as the highest suprasegmental relay center for transmitting ascending nociceptive information from the cranial structures to the cerebral cortex and is considered as a potential neuroanatomical target for anticephalalgic drugs.The objective of the study was to evaluate the action of valproate and metamizole on the excitability of the VPM thalamic neurons.Methods and materials. In acute controlled experiments on anesthetized rats (n=31), we studied the action of cumulative dosing (three fixed dose injections every 30 minutes) of intravenously administered valproate (n=8, 100 mg/kg x 3) or metamizole (n=16,150 mg/kg · 3) on extracellularly recorded background and dura mater electrical stimulation-evoked activities of the convergent VPM neurons. Results. In all experiments, intravenous valproate significantly inhibited both background activity of the VPM neurons and their responses to dural electrostimulation. Metamizole had a similar action in more than half of the cases, whereas 44 % of the examined thalamic cells (7 out of 16) did not react to its infusion.Conclusion. One of the main neurophysiological mechanisms underlying anticephalalgic action of valproic acid and metamizole may be inhibition of the nociceptive transmission at the thalamic level due to the drugs-induced suppression of the meningeal-sensitive VPM neurons excitability. |
| first_indexed | 2024-03-12T04:48:48Z |
| format | Article |
| id | doaj.art-554819c5c82e4a019df0785dc6c1d116 |
| institution | Directory Open Access Journal |
| issn | 1607-4181 |
| language | Russian |
| last_indexed | 2024-03-12T04:48:48Z |
| publishDate | 2022-11-01 |
| publisher | Academician I.P. Pavlov First St. Petersburg State Medical University |
| record_format | Article |
| series | Учёные записки Санкт-Петербургского государственного медицинского университета им. Акад. И.П. Павлова |
| spelling | doaj.art-554819c5c82e4a019df0785dc6c1d1162023-09-03T09:26:34ZrusAcademician I.P. Pavlov First St. Petersburg State Medical UniversityУчёные записки Санкт-Петербургского государственного медицинского университета им. Акад. И.П. Павлова1607-41812022-11-01293556410.24884/1607-4181-2022-29-3-55-64606Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizoleA. Yu. Sokolov0O. A. Lyubashina1Pavlov University; Pavlov Institute of Physiology of the Russian Academy of SciencesPavlov University; Pavlov Institute of Physiology of the Russian Academy of SciencesIntroduction. Valproic acid and metamizole are widely used in the treatment of primary headaches. However, despite the drugs’ proven clinical efficacy, the neurophysiological mechanisms underlying their therapeutic action are poorly understood. The ventral posteromedial nucleus of the thalamus (VPM) serves as the highest suprasegmental relay center for transmitting ascending nociceptive information from the cranial structures to the cerebral cortex and is considered as a potential neuroanatomical target for anticephalalgic drugs.The objective of the study was to evaluate the action of valproate and metamizole on the excitability of the VPM thalamic neurons.Methods and materials. In acute controlled experiments on anesthetized rats (n=31), we studied the action of cumulative dosing (three fixed dose injections every 30 minutes) of intravenously administered valproate (n=8, 100 mg/kg x 3) or metamizole (n=16,150 mg/kg · 3) on extracellularly recorded background and dura mater electrical stimulation-evoked activities of the convergent VPM neurons. Results. In all experiments, intravenous valproate significantly inhibited both background activity of the VPM neurons and their responses to dural electrostimulation. Metamizole had a similar action in more than half of the cases, whereas 44 % of the examined thalamic cells (7 out of 16) did not react to its infusion.Conclusion. One of the main neurophysiological mechanisms underlying anticephalalgic action of valproic acid and metamizole may be inhibition of the nociceptive transmission at the thalamic level due to the drugs-induced suppression of the meningeal-sensitive VPM neurons excitability.https://www.sci-notes.ru/jour/article/view/901headachemigraineelectrical stimulationtrigeminal nervethalamusvalproic acidmetamizoleneuronal activity |
| spellingShingle | A. Yu. Sokolov O. A. Lyubashina Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole Учёные записки Санкт-Петербургского государственного медицинского университета им. Акад. И.П. Павлова headache migraine electrical stimulation trigeminal nerve thalamus valproic acid metamizole neuronal activity |
| title | Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| title_full | Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| title_fullStr | Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| title_full_unstemmed | Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| title_short | Ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| title_sort | ventral posteromedial nucleus of the thalamus as a neuroanatomical target for the anticephalalgic action of valproic acid and metamizole |
| topic | headache migraine electrical stimulation trigeminal nerve thalamus valproic acid metamizole neuronal activity |
| url | https://www.sci-notes.ru/jour/article/view/901 |
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