MICROINJECTION OF KAINIC ACID INTO THE ROSTRAL VENTROLATERAL MEDULLA CAUSES HYPERTENSION AND RELEASE OF NEUROPEPTIDE Y-LIKE IMMUNOREACTIVITY FROM RABBIT SPINAL CORD

Microinjections of kainic acid were made into the pressor area of the rostral ventrolateral medulla oblongata of anaesthetized rabbits, in the region of the C1 adrenaline-containing neurons. Over the 65 min following the microinjection, there was a significant increase in blood pressure, as well as an increase in the release of neuropeptide Y-like immunoreactivity into the spinal subarachnoid space. These data provide evidence for a functional bulbospinal neuropeptide Y-containing projection which may be responsible for mediating the pressor effects of stimulation of the rostral ventrolateral medulla.