William P. Norman

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Our purpose was to determine the central vagal sites for regulating changes in lower esophageal sphincter (LES) pressure in the cat. Injection of the retrograde tracer, horseradish peroxidase, into the LES resulted in labeling of cells in the dorsal motor nucleus of the vagus (DMV), with the largest number of cells appearing in two areas, one area rostral(More)
The purpose of our study was to determine whether clonidine exerts its centrally mediated hypotensive action at three sites that influence arterial pressure located in the medulla, specifically associated with the intermediate area of the ventrolateral medulla. The "intermediate area" lies approximately 1.5 mm caudal to the border of the trapezoid body(More)
We previously demonstrated that GABA and muscimol administered either into the cisterna magna or the fourth ventricle to chloralose-anesthetized cats cause respiratory depression, hypotension, and bradycardia. Injection of these substances into the lateral and third ventricles had no effect. In order to localize the site of action, muscimol and GABA were(More)
The purpose of the present study was to determine whether blockade of excitatory amino acid receptors at the ventrolateral nucleus of the tractus solitarius would influence respiratory activity. This was done by microinjecting excitatory amino acid receptor antagonists into the ventrolateral nucleus of the tractus solitarius of alpha-chloralose-anesthetized(More)
The purpose of our study was to determine the localization of sites within the dorsal motor nucleus of the vagus (DMV) of the cat that when stimulated would increase gastric motility. To do this, two types of experiments were performed. First, the retrograde tracer fast blue was injected into the antrum and pylorus, and labeled neurons in the DMV were(More)
In this study, the distribution of neurons containing the adrenaline-synthesizing enzyme phenylethanolamine-N-methyltransferase (PNMT) was mapped in the medulla of the cat. Data from recent studies in the rat suggest that the anatomical structure responsible for cardiorespiratory changes that occur following application of neurotransmitters and drugs to(More)
The purpose of this study was to identify the projections from the brain to the phrenic motor nucleus in the cat by employing a retrogradely-transported fluorescent dye. Propidium iodide was iontophoresed into the phrenic motor nucleus which is located in the fourth, fifth and sixth segments of the cervical spinal cord. Retrogradely-labeled cell bodies were(More)
To identify hindbrain sites that influence gastric motility, we administered multiple injections of horseradish peroxidase into the anterior surface of the antrum near the lesser curvature in 3 cats, and used light microscopy to identify horseradish peroxidase-positive neurons in the hindbrain. Retrogradely labeled neurons were found evenly distributed on(More)
The purposes of the present study were to: (1) characterize the GABAergic input to vasodepressor neurons in the caudal ventrolateral medulla of the cat, and (2) define more precisely the anatomical localization of these neurons in this species. This was done by microinjecting GABA receptor antagonists and agonists, and a negative allosteric modulator of the(More)