Search PubMed⌕ Search

Biomedical subjects

N Dafny

Publications and source records attributed to N Dafny.

At least 163 records · Page 9Linked to original sources
PubMed1979

Effects of cocaine on sensory evoked potentials recorded from hypothalamus and limbic structures.

1. The present investigation was intended to examine the effects of the acute administration of several doses of cocaine on sensory evoked responses of freely moving rats. 2. Each structure and each component of the average sensory evoked potentials were affected by cocaine differently. 3. The changes induced by cocaine differ from those observed following other drug treatments. Therefore, it may be assumed that the changes observed are related directly to cocaine. 4. The present observation demonstrated a greater degree of sensitivity to low doses of cocaine than other types of electrophysiological recordings. In general cocaine in the lower doses (0.25 or 0.5 mg/kg) induced an increase in the sensory amplitude response while in the highest dose (10.0 mg/kg) attenuation of the sensory responses was obtained. 5. We assume that the euphoric effect induced by cocaine is due to the potentiation of sensory input within the limbic-hypothalamic system. In higher doses, the fatality caused by the drug may be due to the depression of the sensory input.

Amygdala↗
PubMed1979

Morphine acute effects on spontaneous multiunit activity recorded simultaneously from medial thalamus and caudate nucleus in freely behaving rats.

Treatment with varying doses of morphine and its antagonist naloxone produced different response patterns in "spontaneous" multiunit discharges recorded from the medial thalamus and caudate nucleus of freely behaving rats previously implanted, stereotaxically, with permanent semimicro-electrodes. The changes in electrical discharges induced by incremental doses of morphine exhibited dose-related patterns, and could be reversed by naloxone. This procedure, testing several incremental doses of a drug, provides a tool with which to identify and classify the specific response patterns induced by morphine. The two structures examined in the present study exhibited four response patterns to the treatments but only one pattern of response was similar in the two nuclei. The medial thalamic units are more sensitive to morphine than those recorded from the caudate nucleus. The present finding, i.e., acute effects of morphine, provides basic information with which to examine the physiological properties underlying the chronic effects of morphine.

Animals↗
PubMed1978

Endocrine control of appetite: gastrointestinal hormonal effects on CNS appetitive structures.

Permanent semi-microelectrodes were implanted in the ventromedial hypothalamus (VMH), lateral hypothalamus (LH), amygdala (AMYG), medial forebrain bundle (MFB), anterior hypothalamus (AH), inferior colliculus (IC), and caudate nucleus (CN). Average evoked responses were recorded simultaneously from the above sites in freely behaving rats before and after administration of pentagastrin (100 microgram/kg), secretin 1 microgram/kg or cholecystokinin octapeptide (CCK-OP) (1 microgram/kg) in search of satiety signal. Gastrin and secretin had little effect while it appears that CCK may perform a regulatory function in a neurohumoral feedback mechanism.

Amygdala↗