Adenosine inhibition of mesopontine cholinergic neurons: implications for EEG arousal.
Increased discharge activity of mesopontine cholinergic neurons participates in the production of electroencephalographic (EEG) arousal; such arousal diminishes as a function of the duration of prior wakefulness or of brain hyperthermia. Whole-cell and extracellular recordings in a brainstem slice show that mesopontine cholinergic neurons are under the tonic inhibitory control of endogenous adenosine, a neuromodulator released during brain metabolism. This inhibitory tone is mediated postsynaptically by an inwardly rectifying potassium conductance and by an inhibition of the hyperpolarization-activated current. These data provide a coupling mechanism linking neuronal control of EEG arousal with the effects of prior wakefulness, brain hyperthermia, and the use of the adenosine receptor blockers caffeine and theophylline.
Rainnie
D G
DG
Department of Psychiatry, Harvard University, Brockton, MA.
Grunze
H C
HC
McCarley
R W
RW
Greene
R W
RW
D000241:Adenosine / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D004553:Electric Conductivity; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials; D009474:Neurons / Q000502:physiology*; D010275:Parasympathetic Nervous System / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D051381:Rats
D000241:Adenosine; D011188:Potassium; D002118:Calcium