title: Coherent inspiratory oscillation of cranial nerve discharges in perfused neonatal cat brainstem in vitro.
abstract: 1. To understand the neural organization of respiratory movement control and its developmental transformation, we studied the temporal characteristics of inspiratory activities, especially nerve-to-nerve short-term synchronization, in an in vitro preparation of the isolated, perfused brainstem of kittens aged 0-14 days (postnatal day (P) 0-14). 2. In the inspiratory discharges of facial, vagus, glossopharyngeal and hypoglossal nerves, a stable oscillation with a period of 30-40 ms (i.e. approximately 30 Hz) was observed in all preparations examined. In addition, we demonstrated that this oscillation presents a strong short-term synchrony between distinct inspiratory nerves. This nerve-to-nerve synchronization was already apparent at approximately 12 h after birth. The degree of synchronization as evaluated by coherence spectral analysis was larger than 0.85 in all cases at any age examined. 3. This nerve-to-nerve coherence was not affected by changes in temperature (28-36 degrees C), whereas respiratory rate, oscillation frequency and oscillation amplitude as estimated by power spectral analysis were highly temperature sensitive. 4. The nerve-to-nerve synchronization, as well as the approximately 30 Hz oscillation, remained unchanged after a pontomedullary transection, indicating that the medullary network, completely isolated from other structures and afferents, is sufficient to produce both fast oscillation and nerve-to-nerve synchronization. 5. Based on these observations in vitro, we conclude that nerve-to-nerve coherent inspiratory oscillation generated in the brainstem is already functional early in life.
authors.affiliation: Biologie Fonctionnelle du Neurone, Institut Alfred Fessard, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
authors.forename: F
authors.initials: F
authors.lastname: Kato
authors.forename: M P
authors.initials: MP
authors.lastname: Morin-Surun
authors.forename: M
authors.initials: M
authors.lastname: Denavit-Saubié
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002415:Cats; D003391:Cranial Nerves / Q000502:physiology*; D003714:Denervation; D004594:Electrophysiology; D005154:Facial Nerve / Q000502:physiology; D005930:Glossopharyngeal Nerve / Q000502:physiology; D007002:Hypoglossal Nerve / Q000502:physiology; D008526:Medulla Oblongata / Q000166:cytology* / Q000502:physiology; D010477:Perfusion; D010507:Periodicity; D011149:Pons / Q000601:surgery; D012119:Respiration / Q000502:physiology*; D013696:Temperature; D014630:Vagus Nerve / Q000502:physiology