Neostriatal stimulation activates tongue-protruder muscle, but not tongue-retractor or facial muscles: an electrical and chemical microstimulation study in rats.
Whether electrical microstimulation of a rat's striatal jaw region (SJR) in fact induced tongue or facial muscle activity in addition to jaw muscle activity was tested. Microstimulation of SJR-evoked EMG activity in a jaw-opener (anterior digastricus) and tongue-protruder (genioglossus). No activity was evoked in jaw-closers (temporalis or masseter), tongue-retractor (hyoglossus) or in facial muscles. In addition, the EMG effect could still be induced after extensive ablation of the neocortex; it was reproduced by microinjection of 50 mM kainic acid into SJR. The effective sites were histologically localized to a small central striatal region adjoining the anterior commissure. These findings may be of considerable value in understanding the striatal mechanism of orolingual dyskinesia involving involuntary jaw and tongue movements.
Department of Oral Neuroscience, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan.
Y
Y
Yanase
N
N
Amano
T
T
Satoda
Y
Y
Masuda
S
S
Kawagishi
K
K
Yoshino
D000818:Animals; D002541:Cerebral Decortication; D004558:Electric Stimulation; D004576:Electromyography; D005152:Facial Muscles / Q000502:physiology*; D007608:Kainic Acid / Q000008:administration & dosage; D008297:Male; D008410:Masticatory Muscles / Q000502:physiology*; D008839:Microelectrodes; D008845:Microinjections; D017072:Neostriatum / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013268:Stimulation, Chemical; D014059:Tongue / Q000502:physiology*
D007608:Kainic Acid