Functional topography of respiratory, cardiovascular and pontine-wave responses to glutamate microstimulation of the pedunculopontine tegmentum of the rat.
Functionally distinct areas were mapped within the pedunculopontine tegmentum (PPT) of 42 ketamine/xylazine anesthetized rats using local stimulation by glutamate microinjection (10 mM, 5-12 nl). Functional responses were classified as: (1) apnea; (2) tachypnea; (3) hypertension (HTN); (4) sinus tachycardia; (5) genioglossus electromyogram activation or (6) pontine-waves (p-waves) activation.We found that short latency apneas were predominantly elicited by stimulation in the lateral portion of the PPT, in close proximity to cholinergic neurons. Tachypneic responses were elicited from ventral regions of the PPT and HTN predominated in the ventral portion of the antero-medial PPT. We observed sinus tachycardia after stimulation of the most ventral part of the medial PPT at the boundary with nucleus reticularis pontis oralis, whereas p-waves were registered predominantly following stimulation in the dorso-caudal portion of the PPT. Genioglossus EMG activation was evoked from the medial PPT. Our results support the existence of the functionally distinct areas within the PPT affecting respiration, cardiovascular function, EEG and genioglossus EMG.
Topchiy
Irina
I
Center for Narcolepsy, Sleep and Health Research, M/C 802, University of Illinois at Chicago, 845 South Damen Ave, Chicago, IL 60612, USA. itopchiy@uic.edu
Waxman
Jonathan
J
Radulovacki
Miodrag
M
Carley
David W
DW
D000818:Animals; D001049:Apnea / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects; D001931:Brain Mapping; D002318:Cardiovascular Diseases / Q000139:chemically induced; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004576:Electromyography / Q000379:methods; D018698:Glutamic Acid / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008845:Microinjections / Q000379:methods; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D045042:Pedunculopontine Tegmental Nucleus / Q000187:drug effects* / Q000502:physiology; D011149:Pons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D012119:Respiration / Q000187:drug effects*; D012893:Sleep Wake Disorders / Q000139:chemically induced
D018698:Glutamic Acid; D009252:NADPH Dehydrogenase