The role of dentate gyrus dopaminergic receptors in the lateral hypothalamic-induced antinociception during persistent inflammatory pain in male rats
Autor: | Ali-Mohammad Aghakhani-Lobnani, Abbas Haghparast, Mina Rashvand, Mohammad Rahban, Farbod Torkamand, Hossein Khaleghzadeh-Ahangar |
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Rok vydání: | 2021 |
Předmět: |
Male
Nociception medicine.medical_specialty Carbachol Lateral hypothalamus medicine.medical_treatment Hippocampus Pain Receptors Dopamine 03 medical and health sciences Behavioral Neuroscience 0302 clinical medicine Internal medicine medicine Animals Rats Wistar Receptor Saline 030304 developmental biology Pain Measurement 0303 health sciences Analgesics business.industry Dentate gyrus Dopaminergic Neurons Analgesics Non-Narcotic Benzazepines Rats Endocrinology Dopamine receptor Hypothalamic Area Lateral Dentate Gyrus Dopamine Antagonists Sulpiride business 030217 neurology & neurosurgery medicine.drug |
Zdroj: | Behavioural brain research. 412 |
ISSN: | 1872-7549 |
Popis: | The lateral hypothalamus (LH) is one of the key brain areas involved in pain modulation. Also, the dentate gyrus (DG) of the hippocampus expresses various receptors, including dopaminergic receptors. Dopaminergic receptors play a key role in pain transmission and modulation within the brain. The present study aimed to investigate the involvement of DG dopaminergic receptors in the LH-induced antinociception during the presence of inflammatory pain. Male Wistar rats were used in this study. Cannulae were unilaterally implanted in their skull for microinjections into the LH and DG. The LH was chemically stimulated by carbachol injection (250 nM/0.5 μl saline). In separate groups, different doses (0.25, 1, and 4 μg/0.5 μl vehicle) of the D1- and D2-like dopamine receptor antagonists (SCH23390 and Sulpiride, respectively) were microinjected into the DG, 5 min prior to intra-LH injection of carbachol. Five min after the second injection, formalin test as a persistent inflammatory pain model in animals was done in all rats. The results revealed that carbachol could induce antinociception following formalin injection into rat's hind paw. The 4 μg dose of both antagonists significantly reduced the LH stimulation-induced antinociception in both phases of formalin pain responses. Although the 1 μg dose of sulpiride significantly reduced antinociception during both phases, 1 μg SCH23390 could only reduce this antinociception during the late phase. These findings demonstrate the involvement of DG dopaminergic receptors in the LH-induced antinociception. The results also suggest that the effectiveness of DG dopaminergic receptors is more pronounced during the late phase of formalin-induced pain responses. |
Databáze: | OpenAIRE |
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