Dopamine receptors in the anterior insular cortex modulate long-term nociception in the rat.
The rostral agranular insular cortex (RAIC) receives dopaminergic projections from the mesolimbic system, which has been involved in the modulation of nociceptive processes. In this study we determined the contribution of dopamine D(1) and D(2) receptors in the RAIC regarding nociception processing in a neuropathic pain model, as well as inflammatory articular nociception measured as pain-induced functional impairment in the rat (PIFIR). Microinjection of vehicle or substances into the RAIC was performed after the induction of nociception. The groups were treated with: a dopamine D(1) receptor antagonist (SCH-23390), a dopamine D(1) receptor agonist (SKF-38393), a dopamine D(2) receptor agonist (TNPA) and a dopamine D(2) receptor antagonist (spiperone). Chronic nociception, induced by denervation, was measured by the autotomy score in which onset and incidence were also determined. The SCH-23390 and TNPA groups showed a decrease in the autotomy score and a delay on the onset as compared to control, whereas the PIFIR groups did not show statistical differences. This work shows the differential role of dopamine receptors within the RAIC in which the activation of D(2) or the blockade of D(1) receptors elicit antinociception.
Coffeen
Ulises
U
Laboratorio de Neurofisiología Integrativa, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de Fuente, Camino a Xochimilco 101, San Lorenzo Huipulco, Tlalpan, México D.F. CP. 14370, Mexico.
López-Avila
Alberto
A
Ortega-Legaspi
J Manuel
JM
del Angel
Rosendo
R
López-Muñoz
Francisco J
FJ
Pellicer
Francisco
F
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000344:Afferent Pathways / Q000503:physiopathology; D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D002540:Cerebral Cortex / Q000502:physiology*; D002908:Chronic Disease; D004298:Dopamine / Q000502:physiology*; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D006358:Hot Temperature / Q000009:adverse effects; D008297:Male; D008845:Microinjections; D008959:Models, Neurological; D009437:Neuralgia / Q000503:physiopathology*; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D020426:Sciatic Neuropathy / Q000503:physiopathology*; D012652:Self Mutilation / Q000503:physiopathology*; D013134:Spiperone / Q000494:pharmacology
C531574:2,10,11-trihydroxy-N-propylnorapomorphine; D001552:Benzazepines; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D016194:Receptors, N-Methyl-D-Aspartate; D013134:Spiperone; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D001058:Apomorphine; D004298:Dopamine