title: Tremulous jaw movements in rats: a model of parkinsonian tremor.
abstract: Several pharmacological and neurochemical conditions in rats induce 'vacuous' or 'tremulous' jaw movements. Although the clinical significance of these movements has been a subject of some debate, considerable evidence indicates that the non-directed, chewing-like movements induced by cholinomimetics, dopamine antagonists and dopamine depletions have many of the characteristics of parkinsonian tremor. These movements occur within the 3-7 Hz peak frequency range that is characteristic of parkinsonian tremor. Tremulous jaw movements are induced by many of the conditions that are associated with parkinsonism, and suppressed by several different antiparkinsonian drugs, including scopolamine, benztropine, L-DOPA, apomorphine, bromocriptine, amantadine and clozapine. Striatal cholinergic and dopaminergic mechanisms are involved in the generation of tremulous jaw movements, and substantia nigra pars reticulata appears to be a major basal ganglia output region through which the jaw movements are regulated. Future research on the neurochemical and anatomical characteristics of tremulous jaw movements could yield important insights into the brain mechanisms that generate tremulous movements.
authors.affiliation: Department of Psychology, University of Connecticut, Storrs 06269-1020, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Salamone
authors.forename: A J
authors.initials: AJ
authors.lastname: Mayorga
authors.forename: J T
authors.initials: JT
authors.lastname: Trevitt
authors.forename: M S
authors.initials: MS
authors.lastname: Cousins
authors.forename: A
authors.initials: A
authors.lastname: Conlan
authors.forename: A
authors.initials: A
authors.lastname: Nawab
mesh_terms: D000818:Animals; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001479:Basal Ganglia / Q000033:anatomy & histology / Q000502:physiology; D018680:Cholinergic Antagonists / Q000627:therapeutic use; D018491:Dopamine Agonists / Q000627:therapeutic use; D006801:Humans; D007571:Jaw Diseases / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D009434:Neural Pathways; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D051381:Rats; D014202:Tremor / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; D018680:Cholinergic Antagonists; D018491:Dopamine Agonists