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M Potegal

Publications and source records attributed to M Potegal.

32 records · Page 2Linked to original sources
PubMed1981

Facilitation of muricide in rats by cholinergic stimulation of the lateral hypothalamus.

The effect of cholinergic stimulation of the lateral hypothalamus on muricide in rats was evaluated in two experiments. In Experiment 1, injections of the cholinergic agonist carbachol (5.0-20.0 micrograms) were found to facilitate muricide in rats that spontaneously killed mice. In Experiment 2, rats were induced to kill mice by food deprivation and then stimulated with carbachol (2.5-5.0 micrograms). Facilitation of muricide was found to be coincident with increased scores on a handling difficulty (irritability) scale for the majority of rats. These results suggest that facilitation of muricide by cholinergic stimulation of lateral hypothalamic areas may be related to increases in irritable aggression.

Aggression↗
PubMed1975

Technique for vestibular neurotomy in the rat.

A technique for vestibular neurotomy in the rat has been developed. Removal of the tympanic membrane and ossicles through the external auditory meatus permits access to the auditory bulla. After the pterygopalatine artery has been cauterized, and the electrode may be introduced through the oval widow. The vestibular branch of the VIII nerve can then be cauterized with the electrode without direct visualization.

Animals↗
PubMed1972

The caudate nucleus egocentric localization system.

It is hypothesized that the motor and spatial functions ascribed to the caudate nucleus are actually different aspects of a single system for spatial localization. Within this system movement programs are the code for spatial locations, i.e. the position of any point in space is defined by the head/eye movement necessary to bring that point into focus. This is an egocentric system; points in space are defined solely in terms of their distance and direction from the observer. The experimental finding that caudate lesions in rats impair their performance in an egocentric localization task, but not in another, equally difficult spatial task, demonstrates a caudate role in this system. Since, in an egocentric system, positions in space are defined relative to the observer, every movement of the observer must be accompanied by a compensatory updating of the internal representation of any given point. Studies with Huntington's Chorea patients are consistent with a caudate involvement in this feature of the system also. Electrophysiological experiments with cats indicate that vestibular information, which can be used in the compensatory updating process, is available to the caudate. It is suggested that this system is used by normal animals in delayed response performance.

Animals↗
PubMedDate not supplied

Plasma levels of human neurotensin: methodological and physiological considerations.

The ingestion of a meal high in fat content is known to increase circulating levels of neurotensin (NT) in humans. However, the magnitude of the postprandial rise of NT in the general circulation and its physiological significance have been subject of much debate. The present study examines circulating levels of NT in male volunteers prior to and following each of their three daily meals (ca. 31 g fat/meal). The response observed are also compared to that elicited by the direct instillation of intralipid (ca. 44 g fat) into the duodenum. NT levels were determined by radioimmunoassay of acid/acetone extracted plasma fractionated by high pressure liquid chromatography. Meals caused a significant but modest increase in NT levels, with the largest increment (ca. 4 fmol/ml) occurring after breakfast. In contrast, NT levels increased ca. 20 fmol/ml with intraduodenal instillation of lipid. The meal-stimulated increases in circulating NT measured here are 4- to 5-fold less than those reported by others, the difference most likely reflecting the lesser amount of lipid ingested. Previous studies provided subjects with single meals containing in excess of 120 g of fat; the 30 g of fat ingested by our subjects, ca. 33% of total caloric intake, is near that recommended by the U.S. Senate, Select Committee on Nutritional and Human Needs. These data show that diets with a reasonable fat content have only a modest effect on circulating levels of NT.

Adult↗