Temporal patterns of trigeminal respiratory activity in rat brainstem-spinal cord in vitro.
Respiratory activity in trigeminal (V) motoneurons was studied in rhythmically active en bloc brainstem-spinal cord preparations isolated from neonatal rats (P0-P3). In the majority of preparations (83%), the temporal pattern of V activity consisted of spontaneous inspiratory phasic discharge with onset delayed or coincident with onset of phrenic motoneuron discharge. Blockade of alpha-2 noradrenergic receptor activation shifted onset of V respiratory discharges earlier than phrenic discharges, while elevation of extracellular potassium concentration or blockade of GABAergic and glycinergic inhibitory synaptic transmission had little effect on temporary pattern of V respiratory discharges. We conclude V motoneurons in the in vitro preparation generate respiratory activity during inspiratory phase, and their temporal patterns are modulated by inhibitory noradrenergic synaptic transmission.
Koizumi
H
H
The First Department of Oral and Maxillofacial Surgery, Osaka University Faculty of Dentistry, Suita, Japan.
Nomura
K
K
Ishihama
K
K
Kogo
M
M
Matsuya
T
T
D000818:Animals; D000831:Animals, Newborn; D001933:Brain Stem / Q000502:physiology*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000502:physiology; D010791:Phrenic Nerve / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration; D013116:Spinal Cord / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D014276:Trigeminal Nerve / Q000502:physiology*
D009638:Norepinephrine