[Effect of glial cell metabolism on respiratory rhythmical discharge activity in neonatal rat medulla oblongata slices].
OBJECTIVE
To explore the role of glial cell metabolism in the generation and regulation of central respiratory rhythm.


METHODS
The medulla oblongata slices (600-700 microm) containing the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets retained from 12 neonatal (0-3 days) Sprague-Dawley rats were prepared and perfused with modified Kreb's solution (MKS). Upon recording of respiratory rhythmical discharge activity (RRDA) of the rootlets of the hypoglossal nerve, the brain slices were treated with glial cell metabolism antagonist L-methionine sulfoximine (L-MSO, 50 micromol/L) for 20 min followed by application of glial cell metabolism agonist L-glutamine (L-GLN, 30 micromol/L) for 20 min, or with L-MSO for 20 min with additional L-GLN for 20 min. The changes in the RRDA of the rootlets of the hypoglossal nerve in response to the treatments were recorded.


RESULTS
L-MSO prolonged the respiratory cycle (RC) and expiratory time (TE), and reduced the integral amplitude (IA) and the inspiratory time (TI) in the brain slices. L-GLN induced a significant decrease in RC and TE, but IA and TI showed no obvious variations. The effect of L-MSO on the respiratory rhythm was reversed by the application of L-GLN.


CONCLUSIONS
Glial cell metabolism may play an important role in the modulation of RRDA in neonatal rat brainstem.
Fang
Fang
F
Department of Physiology, Southern Medical University, Guangdong, Guangzhou 510515, China. fancyf1118@sina.com
Jiao
Yong-gang
YG
Li
Guo-cai
GC
Wu
Zhong-hai
ZH
D000818:Animals; D000831:Animals, Newborn; D005973:Glutamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008526:Medulla Oblongata / Q000378:metabolism / Q000502:physiology*; D008717:Methionine Sulfoximine / Q000494:pharmacology; D009457:Neuroglia / Q000378:metabolism*; D010507:Periodicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration
D005973:Glutamine; D008717:Methionine Sulfoximine