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The effect of cortical spreading depression, a proposed initiating event for migraine pain, on cortical blood flow (laser Doppler method) and on the spontaneous firing rate and stimulus-evoked responses of trigemino-cervical neurons with craniovascular input was studied in 17 neurons in 8 cats anesthetized with chloralose. Cortical spreading depression,(More)
A method is described for fabrication of 7-barrelled microiontophoresis electrodes with a center barrel of platinum-coated tungsten. The electrodes require a minimum of expensive apparatus and can be fabricated in an hour or two. The electrodes have low recording impedance (typically 100 k omega and low resistance iontophoresis barrels (typically 20-50 M(More)
OBJECTIVES To review conjectured modes of action of migraine triggers and to present a new hypothesis about them. BACKGROUND Migraine attacks are initiated in many migraineurs by a variety of "triggers," although in some patients no external trigger can be identified. Many triggers provoke attacks with such a short latency that only some kind of neural(More)
Changes in cortical blood flow and cerebrovascular activity occurring during and after cortical spreading depression (CSD) were studied in alpha-chloralose-urethan-anesthetized cats. CSD was induced by superficial cortical pinprick, and laser-Doppler velocimetry (LDV) was used to measure cerebral blood flow (CBFLD). CSD resulted in a wave of cortical(More)
Stimulation of the trigeminal nerve or ganglion in the cat caused a frequency-dependent reduction in carotid vascular resistance. Systemic arterial blood pressure (SABP) decreased at low frequencies (0.2 to 5 sec-1) and increased at higher frequencies, thus increasing carotid blood flow at the higher frequencies. The effect on resistance was predominantly(More)
The superior sagittal sinus (SSS) and the trigeminal ganglion (Vg) of anesthetized cats were stimulated electrically and field potentials in the upper cervical spinal cord and regional cerebral blood flow were recorded. Stimulation of the entire ganglion produced smaller field potential changes in two regions (medioventral area (MVA); dorsolateral area(More)
This report examines the effect of the transient receptor potential vanilloid 1 receptor antagonist SB-705498 on neurotransmission and inflammation-induced sensitisation in the trigeminovascular sensory system. A single-neuron electrophysiological animal model for neurovascular head pain was used to evaluate dural and facial noxious inputs and the effects(More)
AIM To use an animal model to test whether migraine pain arises peripherally or centrally. METHODS We monitored the spontaneous and evoked activity of second-order trigeminovascular neurons in rats to test whether traffic increased following a potential migraine trigger (cortical spreading depression, CSD) and by what mechanism any such change was(More)
The dorsal raphe nucleus (DRN) and surrounding midbrain of 16 anaesthetized monkeys were stimulated electrically, and carotid blood flows were measured with electromagnetic flow probes. Stimulation of the DRN caused a frequency-dependent decrease (vasodilatation) in both internal and external carotid vascular resistance, which was abolished in both(More)