Descending axonal projections from the medial parabrachial and Kölliker-Fuse nuclear complex to the nucleus raphe magnus in cats.
In 9 Nembutal-anesthetized and vagotomized cats, a total of 42 units, including 2 respiratory units, recorded from the medial parabrachial (NPBM) and Kölliker-Fuse (KF) nuclear complex were found to be antidromically activated by electrical stimulation of the nucleus raphe magnus (NRM). The latencies ranged from 0.4 to 2.5 ms (mean 1.1 ms). In 5 cats, following injection of WGA-HRP (wheat germ agglutinin-conjugated horseradish peroxidase) into the NRM, a number of retrogradely labelled neurons were observed in the rostral pons, mainly in the NPBM, KF and nearby pontine area. These results demonstrate that mainly non-respiratory neurons in the rostral pons, especially in the NPBM and KF nucleus, send monosynaptic axonal projections to the NRM.
Department of Physiology, Sapporo Medical College, Japan.
S
S
Gang
A
A
Mizuguchi
N
N
Kobayashi
M
M
Aoki
D000818:Animals; D001369:Axons / Q000502:physiology*; D002415:Cats; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000502:physiology; D006735:Horseradish Peroxidase; D009434:Neural Pathways / Q000502:physiology; D011149:Pons / Q000502:physiology*; D011903:Raphe Nuclei / Q000502:physiology*; D011930:Reaction Time; D014630:Vagus Nerve / Q000502:physiology; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase