The effects of a glycine antagonist (strychnine) on cortically induced rhythmical jaw movements in the anesthetized guinea pig.
We have investigated the effects of systemic administration of a glycine antagonist, strychnine, on rhythmical jaw movements (RJMs) induced by repetitive stimulation of the masticatory area of the guinea pig cerebral cortex. It was found that after strychnine administration (0.4 mg/kg), the frequency of the cortically induced RJMs was minimally affected, whereas the burst durations of the digastric EMG during the jaw opening phase of the RJM cycle were dramatically increased. These data suggest that the neuronal network (central pattern generator (CPG)) which is responsible for the production of rhythmical jaw movements is not critically dependent upon glycine for the genesis of the basic oscillatory rhythm. On the other hand, glycine synapses are involved with the neuronal mechanisms which are responsible for controlling the burst durations of the digastric muscle during the jaw opening phase of each rhythmic jaw movement cycle.
Chandler
S H
SH
Nielsen
S A
SA
Goldberg
L J
LJ
D000818:Animals; D004576:Electromyography; D005998:Glycine / Q000502:physiology*; D006168:Guinea Pigs; D008409:Mastication; D008410:Masticatory Muscles / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D010507:Periodicity; D013331:Strychnine / Q000494:pharmacology*; D009435:Synaptic Transmission; D014278:Trigeminal Nuclei / Q000502:physiology*
D013331:Strychnine; D005998:Glycine