Dopamine D3 agonists into the substantia nigra aggravate cataplexy but do not modify sleep [corrected].
We have recently demonstrated that local perfusion of dopaminergic D2/D3 agonists into the ventral tegmental area (VTA) significantly aggravates cataplexy and increases sleep in narcoleptic Dobermans. We further assessed the roles of the mesostriatal dopaminergic system and found that local perfusion of quinpirole and 7-OH-DPAT into the substantia nigra (SN) significantly aggravated cataplexy, while perfusion of a D2/D3 antagonist significantly reduced cataplexy. Neither a D1 agonist nor a D1 antagonist modified cataplexy. SN perfusion of quinpirole did not significantly modify sleep, while VTA perfusion significantly increased the drowsy state. Although autoregulation of the VTA and SN dopaminergic neurons are involved in the regulation of cataplexy, both structures have distinct roles for the regulation of sleep.
Honda
K
K
Sleep Disorders Center, Department of Psychiatry and Behavioral Science, Stanford University, School of Medicine, Palo Alto, CA 94304, USA.
Riehl
J
J
Mignot
E
E
Nishino
S
S
D000818:Animals; D001143:Arousal / Q000187:drug effects; D001381:Azepines / Q000494:pharmacology; D002385:Cataplexy / Q000139:chemically induced* / Q000503:physiopathology; D004285:Dogs; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D004569:Electroencephalography / Q000187:drug effects; D004576:Electromyography / Q000187:drug effects; D004585:Electrooculography / Q000187:drug effects; D008845:Microinjections; D009290:Narcolepsy / Q000503:physiopathology; D017448:Receptors, Dopamine D2 / Q000819:agonists*; D050637:Receptors, Dopamine D3; D012890:Sleep / Q000187:drug effects*; D013378:Substantia Nigra / Q000033:anatomy & histology / Q000502:physiology*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D001381:Azepines; D018491:Dopamine Agonists; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013764:Tetrahydronaphthalenes; C024763:talipexole; C031349:7-hydroxy-2-N,N-dipropylaminotetralin