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Biomedical subjects

M Cabanac

Publications and source records attributed to M Cabanac.

At least 19 recordsLinked to original sources
PubMed1992

Ingestive/aversive response of rats to sweet stimuli. Influence of glucose, oil, and casein hydrolyzate gastric loads.

Facial consummatory responses reflecting ingestive and aversive perceptions were studied and quantified in rats chronically implanted with gastric and oral catheters. A gustatory stimulus of 50 microliters of 0.6 mol.l-1 sucrose was injected into the mouth every 5 min during 90 min. At time zero, one of seven loads was injected into the stomach. These consisted of, 5 ml of water, or 5 ml solution containing 1 g glucose, 3 g glucose, 1 g casein hydrolyzate, 3 g casein hydrolyzate, or of oil 0.6 ml, or 1.4 ml. The typical ingestive facial consummatory responses in response to sweet stimuli were observed prior to all gastric loads, and also after the water load. On the other hand, the consummatory responses to sweet stimuli turned aversive after all three high-calorie gastric loads. The magnitude of this decrease in palatability (negative alliesthesia) was similar after glucose, casein hydrolyzate, and oil. The reversal of the consummatory responses from ingestive to aversive did not reach the threshold of statistical significance after the three low-calorie gastric loads. These results would tend to show that the intestinal signal for alimentary alliesthesia is nonspecific.

Animals↗
PubMed1992

Acute, but not chronic, exercise lowers the body weight set-point in male rats.

The influence of muscular training on overall energy balance and body weight is not clear. A group of male rats was trained to feed every day from 1000 to 1200. Then the intersect of regression line of food hoarded during meal time vs. body weight with the X-axis was measured. Finally, the rats were trained to run 1 h every day on a motor-driven treadmill. When the training took place in the morning, just before the hoarding session, the mean intersect was significantly lowered from control (497 +/- 18 g to 433 +/- 9 g). When the training took place in the afternoon, after the hoarding session, the mean intersect was not significantly different (504 +/- 21 g) from control. Food intake during the hoarding sessions was affected neither by body weight changes nor by muscular exercise. These results suggest that the set-point for body weight regulation is acutely lowered just after muscular exercise, but is not influenced by chronic training.

Animals↗
PubMed1992

Duodenal preabsorptive origin of gustatory alliesthesia in rats.

Facial consummatory responses reflecting ingestive and aversive perceptions were studied and quantified in rats chronically implanted with gastric, duodenal, and oral catheters. A gustatory stimulus of 50 microliters of 1.75 mol/l sucrose was injected into the mouth every 5 min for 65 min. At time 0, 0.5 ml containing 0.3 g glucose was injected into the stomach or into the duodenum. Typical ingestive facial consummatory responses were observed in response to sweet stimuli prior to the load. Aversive consummatory responses were observed in response to sweet stimuli after the glucose duodenal load (negative alliesthesia). The gastric load of glucose was not followed by negative alliesthesia in response to sweet oral stimuli. In the last part of the experiment the rats were vagotomized. When the rats were subjected again to the same gustatory sessions, the duodenal load was followed by weak and delayed negative alliesthesia in response to sweet stimuli. These results in rats parallel results obtained in human subjects and reinforce the hypothesis of the existence of a duodenal preabsorptive signal for alimentary alliesthesia. They also suggest that the vagus nerve plays a part in the perception of satiety.

Absorption↗
PubMed1979

Sensory pleasure.

In response to a stimulus, a sensation is tridimensional: qualitative, quantitative, and affective. The affective part of sensation, pleasure or displeasure, depends on the qualities of the stimulus. Within a narrow range of intensity, chemical, thermal, and mechanical stimuli are able to arouse pleasure. In addition, pleasure depends on the internal state of the subject. This is easily observed in the case of temperature: pleasure is aroused by a warm stimulus in a hypothermic subject and by a cold stimulus in a hyperthermic subject. This property of a given stimulus to arouse pleasure or displeasure according to the internal state of the subject is termed alliethesia. Alliesthesia is also produced by chemical and mechanical stimuli. Acquired preferences or aversions for alimentary stimuli represent a case of alliesthesia. In the same way, the capacity of any indifferent stimulus to become rewarding, or punishing, by association with some reward or punishment, is also a case of alliethesia. In all cases, pleasure is a sign of a stimulus useful to the subject; displeasure a sign of danger. Usefulness and danger are judged by the central nervous system with reference to homeostasis and the set point of the implied regulation. Pleasure and displeasure thus appear to motivate useful behaviors.

Animals↗
PubMed1979

Natural selective cooling of the human brain: evidence of its occurrence and magnitude.

1. The technique of perceptual rating of thermal stimuli was used, in eight human subjects immersed in warm water, in order to appreciate whether they were hypo-, normo- or hyperthermic. Oesophageal, tympanic and forehead skin temperatures were recorded, as also was the temperature of the skin above the angularis oculi vein. Once the subjects gave clearly hyperthermic ratings, one arm was exposed to a 6 m/s wind. After 5--10 min the arm was re-immersed and the face was fanned. 2. Fanning of the arm resulted in lowering of body core temperature. However ratings of thermal stimuli remained hyperthermic. 3. Face fanning decreased forehead skin, angularis oculi vein and tympanic temperatures. Hyperthermic ratings were replaced by normothermic ratings, although oesophageal temperature continued to rise. 4. The upper limit of oesophageal temperature for normothermic ratings was 37.o6 +/- 0.09 degrees C during the control period without fanning. This temperature rose to 37.91 +/- 0.09 degrees C during facial ventilation. 5. These results suggest a selective cerebral cooling due to venous blood returning from facial skin via the ophthalmic vein to the cavernous sinus, where a cooling of arterial blood ascending to the brain can take place.

Body Temperature Regulation↗
PubMed1979

Open loop increase in trunk temperature produced by face cooling in working humans.

1. Five human subjects pedalled on a bicyle ergometer for at least two 74 min periods at 10 degrees C ambient temperature. During the first period the subjects cycled for 42 min with face fanning, followed by 32 min with the head thermally insulated. In the second period, this procedure was reversed. Oesophageal (tes), tympanic (Tty), forehead and hand skin temperatures were recorded. In addition, heart rate (H.R.) was counted throughout the experiments, and the technique of perceptual rating of cool and warm stimuli was used in order to appreciate whether the subjects were hypo-, normo-, or hyperthermic. 2. Face fanning resulted in decreased Tty, decreased H.R., mild skin vasoconstriction but increased Tes. 3. Head covering resulted in increased Tty and H.R., while Tes decreased slightly, due to peripheral vasodilatation. 4. When their faces were being fanned so that Tty was low and Tes was high, the subjects gave slightly hypothermic ratings. Ratings were clearly hyperthermic when their heads were covered and Tty was high and Tes was low. 5. The close correlation between vasomotor response and H.R. on the one hand and Tty on the other confirms that this variable is a better approximation of regulated core temperature than Tes. 6. Increase in Tes during face fanning and decrease in Tes during face insulation is new evidence for the possibility of the human brian being cooled during exercise by cool blood returning from the face. 7. We suggest that this selective brain cooling determines the apparent upper resetting of core temperature during exercise while brain temperature remains precisely regulated and constant.

Body Temperature Regulation↗
PubMed1979

Bradycardia during face cooling in man may be produced by selective brain cooling.

In human subjects, bradycardia was produced by immersing the subjects' faces in water at 15 degrees C when they were hyperthermic. When they were hypothermic, the same face cooling produced tachycardia. It is suggested that the difference in cardiac response originates in selective brain cooling during hyperthermia, by venous return from the face to the brain, via ophthalmic veins.

Adult↗
PubMed1978

[Reversal of human ophthalmic vein blood flow : selective cooling of the brain].

Direction of blood flow in angularis oculi veins was recorded in humans. In mild hypothermia, blood flow was weak and directed from brain to face. In hyperthermia, however, blood flowed rapidly in the opposite direction, angularis oculi vein collecting cool facial blood and supplying cavernous sinus. Therefore selective cooling of human brain is possible.

Adult↗
PubMed1977

[Initial assessment of a behavioural therapy anti-tobacco programme (author's transl)].

The principle of behavioural therapy was used in anti-tobacco treatment. An assessment of the first 100 patients is given here. From the beginning of treatment, which was individual and lasted for one week, the subjects, with three exceptions, stopped smoking between the treatment sessions. After treatment was completed, 93 subjects maintained this abstinence for at least 15 days; 74 patients have not started to smoke again, with a follow-up period ranging from 2 to 18 months. The degree of motivation of the patients would seem to be the only parameter related to relapse.

Adult↗
PubMed1977

Thermoregulatory behaviour after repetitive cooling of the preoptic area and of the spinal cord in the rat.

The thermoregulatory behaviour of 6 rats was studied during exposure to cold and warm ambient temperatures after either the preoptic area or the cervical spinal cord had been intermittently cooled for an average of 130 h. The precooled animals worked more for heat in cold environments and for cool air in a warm environment than the control animals. This behaviour, probably due to a decreased ability of the precooled animals to retain heat, suggested that the precooled animals were not fully adapted to cold. 1974) will learn to press a lever to modify their thermal environment, and this paper describes the thermoregulatory behaviour of rats after prolonged cooling of the preoptic area, and of the spinal cord. The thermoregulatory behaviour of cold exposed and cold adapted animals has already been studied in several species (Carlton and Marks, 1958; Laties and Weiss, 1960; Revusky, 1966; balwin and Ingram, 1967).

Adaptation, Physiological↗
PubMed1977

Fever and behavioural temperature regulation in the frog Rana esculenta.

The skin and colonic temperatures were recorded in frogs (Rana esculenta) which had selected a suitable microenvironment in a box filled with 2-3 cm water. The water temperatures ranged from 0 degrees C to + 40 degrees C. Such measurements were performed before and after intraperitoneal injections of killed pathogenic bacteria (M. xenopi and M. range), killed non-pathogenic bacteria (M. aquae II) and 0.9% sterile saline, intraperitoneal injections of blood plasma from frogs pre-injected with killed M. ranae, injections of PGE1 into the brain. The injections of pathogenic bacterial endotoxin caused, after latencies of 5-120 min, higher preferred water temperatures, which produced an average maximum colonic temperature increase of 6.5 degrees C +/- 1.0 degrees C (S.E.) (p less than 0.001). The non-pathogenic bacteria and sterile saline caused no temperature change. Monophasic hyperthermia of shorter latency was caused by injections of blood plasma from frog preinjected with M. ranae. Monophasic hyperthermia of the shortest latency was observed after diencephalic injections of PGE1. Based on their similarity we suggest that ectothermic and endothermic fever have a common phylogenetic origin.

Animals↗