Effects of dopamine receptor blockade on cerebral blood flow response to somatosensory stimulation in the unanesthetized rat.
Local cerebral blood flow (CBF) was determined in 30 cerebral structures, including four structures of the whisker-to-barrel cortex sensory pathway, by the quantitative autoradiographic [(14)C]iodoantipyrine method during unilateral vibrissal stimulation in rats administered 0.1 or 1.0 mg/kg haloperidol or its control vehicle intravenously. The low dose of haloperidol had no significant effects on resting CBF or its enhancement by vibrissal stimulation. By standard t tests, the high dose statistically significantly lowered baseline CBF in frontal and visual cortex, hippocampus, dentate gyrus, inferior olive, cerebellar cortex, and the ventral posteromedial (VPM) thalamic nucleus on the unstimulated side, and raised baseline CBF in the lateral habenula; however, these changes lost statistical significance after Bonferroni correction for multiple comparisons. Neither dose had any effects on the increases in CBF evoked by vibrissal stimulation in the principal sensory trigeminal nucleus and barrel cortex, but the higher dose statistically significantly enhanced the percent increases in CBF due to the sensory stimulation in the spinal trigeminal nucleus and VPM thalamic nucleus. These results do not support a role for direct dopaminergic vasoactive mechanisms in the increases in CBF associated with neuronal functional activation.
Esaki
Takanori
T
Laboratory of Cerebral Metabolism, National Institute of Mental Health/NIH, Building 36, 36 Convent Drive, Bethesda, MD 20892-4030, USA.
Itoh
Yoshiaki
Y
Shimoji
Kazuaki
K
Cook
Michelle
M
Jehle
Jane
J
Sokoloff
Louis
L
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002375:Catalepsy / Q000139:chemically induced / Q000523:psychology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects*; D013003:Somatosensory Cortex / Q000502:physiology*; D014738:Vibrissae / Q000294:innervation / Q000502:physiology*
D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D006220:Haloperidol