Noradrenergic receptors and in vitro respiratory rhythm: possible interspecies differences between mouse and rat neonates.
Similar in vitro experiments were performed on brainstem-spinal cord preparations from mouse and rat neonates to compare the noradrenergic regulations of the respiratory network. In preparations retaining the pons, rhythmic phrenic bursts occurred in rats but not in mice. Transection of the pons, electrolytic lesions and noradrenaline applications showed that the pontine noradrenergic A5 group inhibited the respiratory rhythm generator in both species but the inhibition was especially potent in mice. After pons elimination, noradrenaline applications to the medulla decreased the respiratory frequency in rats but increased it in mice. Noradrenergic agent applications revealed that the frequency changes implicated medullary alpha 1 and alpha 2 noradrenergic receptors in mice and rats, respectively. Thus, interspecies differences seem to exist in the noradrenergic regulations of the rat and mouse medullary respiratory networks.
Jean-Charles
Viemari
V
Groupe d'Etudes des Réseaux Moteurs, Biology of Rhythms and Development, GERM, CNRS, Université de la Méditerranée, 280 Boulevard de Sainte Marguerite, 13009 Marseille, France.
Gérard
Hilaire
H
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D003714:Denervation; D004525:Efferent Pathways / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism* / Q000494:pharmacology; D010507:Periodicity; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects / Q000378:metabolism; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects / Q000378:metabolism; D012119:Respiration / Q000187:drug effects*; D012125:Respiratory Center / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012249:Rhombencephalon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism
D000317:Adrenergic alpha-Antagonists; D011941:Receptors, Adrenergic; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2; D009638:Norepinephrine; D011224:Prazosin