Respiratory pattern modulation by the pedunculopontine tegmental nucleus.
This study demonstrates respiratory modulation caused by stimulation of the pedunculopontine tegmental nucleus (PPT), a structure not classically included in the pontine respiratory neuronal network. The long-lasting increase in variability of respiratory parameters following glutamate microinjection into PPT in anesthetized, spontaneously breathing Sprague Dawley rats was more pronounced under ketamine than nembutal anesthesia. The induced respiratory perturbations were characterized by intermittent apneas and increased variability of expiratory (TE) and total (TT) breath durations in all animals. Although the baseline spontaneous breathing patterns (mean values of all respiratory parameters and their variabilities) were equivalent under ketamine and nembutal anesthesia, different anesthetic agents did affect respiratory responses to PPT stimulation by glutamate in terms of latency, duration, and structure. We conclude that glutamatergic stimulation of PPT has a significant impact on the brainstem respiratory pattern generator.
Saponjic
Jasna
J
Department of Medicine, Section of Respiratory and Critical Care Medicine, University of Illinois at Chicago, 840 South Wood Street, Chicago, IL 60612-7323, USA.
Radulovacki
Miodrag
M
Carley
David W
DW
D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000379:methods; D018698:Glutamic Acid / Q000494:pharmacology; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007649:Ketamine / Q000494:pharmacology; D008297:Male; D045042:Pedunculopontine Tegmental Nucleus / Q000187:drug effects / Q000502:physiology*; D010424:Pentobarbital / Q000494:pharmacology; D011149:Pons / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects; D013997:Time Factors
D006993:Hypnotics and Sedatives; D018698:Glutamic Acid; D007649:Ketamine; D010424:Pentobarbital