H+-sensitivity of cultured neurons from the dorsomedial and ventrolateral medulla of neonate rats.
The H+-sensitivity of neonate rat cultured neurons derived from the dorsomedial medulla (DMM) containing the nucleus tractus solitarii and the ventrolateral medulla (VLM) was determined by H+-sensitive fluorescent probe BCECF-AM and immunohistochemical methods. Against an extracellular pH as low as 7.2-7.3, H+-sensitivity was verified in 2.6% of the DMM neurons (46/ 1800) and 2.1% of the VLM neurons (38/1800). This H+-sensitive neurons of the DMM were immunoreactive to glutamate (52.4%) and glutamic acid decarboxylase (GAD) (28.6%), while those of the VLM were immunoreactive to glutamate (66.7%) and GAD (33.3%). There was no immunoreactivity to tyrosine hydroxylase, phenylethanolamine-N-methyltransferase or choline acetyltransferase in the H+-sensitive neurons are present in the DMM and VLM besides the ventral medullary surface, the site of the central chemoreceptors.
Department of Physiology, Gunma University School of Medicine, Maebashi-shi, Japan.
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S
Sugama
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Okada
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H
Jingu
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M
Miura
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D002628:Chemoreceptor Cells / Q000502:physiology; D005110:Extracellular Space / Q000378:metabolism; D005452:Fluoresceins; D018698:Glutamic Acid / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011522:Protons; D051381:Rats; D017208:Rats, Wistar; D017552:Solitary Nucleus / Q000166:cytology* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D005452:Fluoresceins; D011522:Protons; C057433:2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid