Effect of norepinephrine receptors on trigeminal rhythm generation in newborn rats.
N-methyl-D,L-aspartate acid and bicuculline are required to enhance the trigeminal rhythmic activities in an in vitro isolated brainstem block preparation. In this study, we analyzed the effect of norepinephrine on the trigeminal neural circuit underlying rhythmic jaw movements. Rhythmic trigeminal activity is observed in brainstem preparations (inferior colliculus to obex) only following blockade of alpha(2)-adrenoceptors with idazoxan. This observation, combined with the inhibition of rhythm by alpha(2)-adrenoceptor agonists suggests endogenous alpha(2)-adrenoceptor mediated inhibition of trigeminal networks. A complex noradrenergic modulation of trigeminal systems is further supported by the prazosin-sensitive potentiation of rhythm by bath application of the alpha(1)-adrenoceptor agonist phenylephrine.
Kogo
M
M
The First Department of Oral and Maxillofacial Surgery, Osaka University, Faculty of Dentistry, Osaka, Japan. kogo@dent.osaka-u.ac.jp
Mori
A
A
Koizumi
H
H
Ishihama
K
K
Iida
S
S
Tanaka
S
S
Matsuya
T
T
D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000494:pharmacology; D000068438:Brimonidine Tartrate; D019329:Idazoxan / Q000494:pharmacology; D008409:Mastication / Q000187:drug effects* / Q000502:physiology; D009046:Motor Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016202:N-Methylaspartate / Q000494:pharmacology; D009434:Neural Pathways / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009638:Norepinephrine / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism; D009924:Organ Culture Techniques; D010656:Phenylephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism; D014278:Trigeminal Nuclei / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D058647:Adrenergic alpha-2 Receptor Agonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D011810:Quinoxalines; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2; D010656:Phenylephrine; D000068438:Brimonidine Tartrate; D016202:N-Methylaspartate; D009638:Norepinephrine; D011224:Prazosin; D019329:Idazoxan; D001640:Bicuculline