Effect of chemical stimulation of the dorsal raphe nucleus on cerebral blood flow in rat.
We have previously shown that electrical stimulation of the dorsal raphe nucleus (DRN) can increase or decrease cerebral blood flow (CBF). We now sought to determine whether the CBF responses are mediated by DRN neurons or fibers of passage. In anesthetized rat, the DRN was stimulated chemically (L-glutamate, kainate) and CBF in parietal cortex was measured by laser-Doppler flowmetry. Microinjection of kainate (5 nmol), but not L-glutamate, into DRN increased CBF (28 +/- 22%; P < 0.05). Decreased CBF to DRN stimulation was not observed. We conclude that stimulation of DRN neurons increases CBF.
Underwood
M D
MD
Department of Neuroscience, New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, NY 10032, USA.
Bakalian
M J
MJ
Arango
V
V
Mann
J J
JJ
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D018698:Glutamic Acid / Q000494:pharmacology*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D010296:Parietal Lobe / Q000187:drug effects; D011903:Raphe Nuclei / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013268:Stimulation, Chemical
D018698:Glutamic Acid; D007608:Kainic Acid