Thomas P. O'Neill

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Recent evidence suggests an important role for the median preoptic nucleus (MnPO) in cardiovascular responses evoked by angiotension II (ANG II). We therefore planned to determine whether selective inactivation of this nucleus would produce deficits in pressor responsiveness to centrally administered ANG II and carbachol. Chronic disruption of MnPO by(More)
Dextromethorphan is a widely used antitussive agent, also showing increased recreational abuse. Dextromethorphan and its metabolite dextrorphan are non-competitive antagonists at the N-methyl-d-aspartate (NMDA) receptor ion channel. Single doses of some NMDA receptor antagonists produce neuropathologic changes in neurons of the retrosplenial/posterior(More)
When norepinephrine was applied microiontophoretically to certain neurons in the pontine reticular formation of rats, it produced an increase in neuronal firing like that produced by noxious stimulation. Previous studies have shown that both noxious stimulus- and norepinephrine-evoked increases in neuronal firing are mediated by alpha-adrenoceptors. These(More)
Acetylcholine (ACh) and norepinephrine (NE) have been identified previously as putative nociceptive neurotransmitters in the mesencephalic reticular formation (MRF) of the rat because they frequently mimic the change in neuronal firing (usually an increase) evoked by a noxious stimulus (NS). The purpose of this study was to determine if 1.) morphine (M)(More)
Norepinephrine (NE) may be a neurotransmitter in a nociceptive pathway in the mesencephalic reticular formation (MRF) of the rat. When NE is applied microiontophoretically to certain neurons in rat MRF, it produces a change in neuronal firing rate similar to that produced by a noxious stimulus (foot pinch) in these neurons. If NE is a neurotransmitter(More)
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