Dopaminergic regulation of cerebral cortical microcirculation.
Functional variations in cerebral cortical activity are accompanied by local changes in blood flow, but the mechanisms underlying this physiological coupling are not well understood. Here we report that dopamine, a neurotransmitter normally associated with neuromodulatory actions, may directly affect local cortical blood flow. Using light and electron-microscopic immunocytochemistry, we show that dopaminergic axons innervate the intraparenchymal microvessels. We also provide evidence in an in vitro slice preparation that dopamine produces vasomotor responses in the cortical vasculature. These anatomical and physiological observations reveal a previously unknown source of regulation of the microvasculature by dopamine. The findings may be relevant to the mechanisms underlying changes in blood flow observed in circulatory and neuropsychiatric disorders.
Krimer
L S
LS
Section of Neurobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Muly
E C
EC
Williams
G V
GV
Goldman-Rakic
P S
PS
D000818:Animals; D001369:Axons / Q000502:physiology; D001808:Blood Vessels / Q000187:drug effects / Q000294:innervation; D002540:Cerebral Cortex / Q000098:blood supply*; D004298:Dopamine / Q000494:pharmacology / Q000502:physiology*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008253:Macaca mulatta; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology*; D008854:Microscopy, Electron; D009411:Nerve Endings / Q000378:metabolism / Q000648:ultrastructure; D014666:Vasomotor System / Q000187:drug effects
D004298:Dopamine