Activity of the rat pontomedullary reticular neurons related to rhythmical jaw movements.
Electrical stimulation of the cerebral peduncle or oral mechanical or chemical stimulation induced rhythmical jaw movements (RJM) in the anesthetized rat. Extracellular recording was made from the pontomedullary reticular neurons in relation to RJM. The RJM-related activity was classified to a tonic, a transient and a phase-dependent rhythmical activities (116, 92 and 45 neurons, respectively). We found that the neurons showing the phase-dependent activities discharged exclusively or almost exclusively during RJM without responding to at least one of three kinds of RJM-inducing stimulation. Fourteen neurons were activated by all kinds of RJM-inducing stimulation and majority of them showed weak or no change in activity during RJM, although some showed the transient or the rhythmical activity during RJM. We propose that the phase-dependent rhythmical activity is necessary to generate RJM since any stimulation-induced RJM was reversibly blocked by microinjection of lidocaine or glutamate receptor blocking agents into the brainstem site concentrated by this type of neurons. No other type of activity was observed exclusively during RJM.
Ohta
M
M
Department of Oral Physiology, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
Sasamoto
K
K
Kishikawa
N
N
Kuraoka
N
N
D000818:Animals; D001933:Brain Stem / Q000187:drug effects / Q000502:physiology; D004558:Electric Stimulation; D018698:Glutamic Acid / Q000494:pharmacology; D007568:Jaw / Q000294:innervation / Q000502:physiology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology; D009068:Movement / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011149:Pons / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D018698:Glutamic Acid