Excitatory and inhibitory effects on respiration of L-glutamate microinjected superficially into the ventral aspects of the medulla oblongata in cat.
L-Glutamate (4-40 nmol) was microinjected at superficial depths beneath the ventral surface of the medulla oblongata in cats. Injections (100-300 microns beneath the surface) made rostromedial to the hypoglossal nerve, less than 1.5 mm lateral to the pyramidal tract, caused stimulation of phrenic nerve activity. Injections (100-500 microns beneath the surface) up to 1 mm further lateral caused a marked increase in arterial pressure and depression of phrenic nerve activity. These findings support the existence of two cell groups in the ventral medulla that are involved in regulation of respiration; when activated, one (medial group) causes facilitation and the other (lateral group) inhibition of respiration.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D005971:Glutamates / Q000008:administration & dosage / Q000494:pharmacology*; D018698:Glutamic Acid; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology; D012119:Respiration / Q000187:drug effects*
D005971:Glutamates; D018698:Glutamic Acid