title: Possible synaptic connections of expiratory neurons in the medulla of newborn rat in vitro.
abstract: To elucidate synaptic interactions between expiratory (Exp) and other respiratory neurons in the ventrolateral medulla of brain stem-spinal cord preparations from newborn rats, we analyzed postsynaptic potentials in Exp and a subclass of inspiratory (Insp) neurons using whole-cell recordings. About 72% of the Exp neurons (Exp-p-i) showed Cl--dependent synaptic inhibition during the Insp and pre/post-Insp phases, corresponding to the active phase of the Insp and pre-inspiratory (Pre-I) neurons, respectively. The other 28% neurons (Exp-i) received Cl--dependent inhibition during the Insp phase only. Some Insp neurons showed reversed IPSPs during the active phase of Exp-p-i after Cl-loading. We suggest the existence of inhibitory connections from Pre-I and Insp to Exp and from Exp to Insp neurons. Basic synaptic connections among respiratory neurons similar to those in intact adult mammals may already exist in newborn rats.
authors.affiliation: Department of Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Arata
authors.forename: H
authors.initials: H
authors.lastname: Onimaru
authors.forename: I
authors.initials: I
authors.lastname: Homma
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001933:Brain Stem / Q000502:physiology; D002712:Chlorides / Q000494:pharmacology; D001239:Inhalation / Q000502:physiology; D008526:Medulla Oblongata / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009761:Nystatin / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*; D013569:Synapses / Q000502:physiology*
chemical_list: D002712:Chlorides; D009761:Nystatin; D011188:Potassium