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.
Yanase
Y
Y
Department of Oral Neuroscience, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan.
Amano
N
N
Satoda
T
T
Masuda
Y
Y
Kawagishi
S
S
Yoshino
K
K
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