Mechanisms underlying post-inspiratory depolarization in post-inspiratory neurons of the cat.
The mechanism of the post-inspiratory depolarization in bulbar post-inspiratory neurons was investigated in decerebrate cats with a coaxial multibarrelled microelectrode technique. Iontophoresed tetrodotoxin eliminated a dominant part of the post-inspiratory depolarization and left a small depolarization to occur. This residual potential was increased with depolarization. When depolarization exceeded a potential of average -63 mV, there appeared a large bell-shaped depolarization that was suppressed by iontophoresed cadmium. These results suggest that the post-inspiratory depolarization in this neuron is formed by the cooperation between excitatory synaptic potentials and voltage-dependent Ca2+ currents.
Takeda
R
R
Department of Pharmacology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Haji
A
A
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002104:Cadmium / Q000008:administration & dosage / Q000494:pharmacology; D002415:Cats; D003655:Decerebrate State; D001239:Inhalation / Q000502:physiology; D007478:Iontophoresis; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000008:administration & dosage / Q000494:pharmacology; D014628:Vagotomy; D014630:Vagus Nerve / Q000502:physiology
D002104:Cadmium; D013779:Tetrodotoxin