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Biomedical subjects

L Angyán

Publications and source records attributed to L Angyán.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Does physical education has a place in medical training?].

This paper makes a few remarks on the importance of physical education in medical curriculum. Data are presented to show the physical fitness profile of medical students. Regular physical activity is important to promote their health oriented behaviour. Moreover, the sport offers a number of improvements in the university life. It is also emphasized that elementary sports physiology is necessary for all practitioners dealing with public health problems.

Curriculum↗
PubMed1991

Substantia nigra stimulation and blood pressure effects of locally applied kainic acid.

Cardiovascular response to electrical stimulation of the substantia nigra were studied in awake, unrestrained cats. Significant increases in the arterial blood pressure, heart rate and respiratory rate appeared simultaneously with the somatomotor effects of stimulation. Twenty-four hours after local microinjection of kainic acid into the site of stimulation the blood pressure responses to stimulation were reduced by 70%, while the changes in heart rate and respiratory rate effects were not statistically significant. Intense somatomotor effects appeared about 30 min after the injection. However, the animal recovered much of its behavioural functions within five hours. It is concluded that the substantia nigra, besides its somatomotor functions, has a role in regulation of blood pressure.

Animals↗
PubMed1989

Role of the substantia nigra in the behavioural-cardiovascular integration in the cat.

Electrical stimulation of the substantia nigra elicited complex patterns of response composed of somatomotor and circulatory changes. Increase in blood pressure associated with acceleration in heart rate was consistently produced by substantia nigra stimulation both in conscious and in anaesthetized cats. The respiration was either accelerated or arrested by the stimulation. Also self-stimulation of the substantia nigra elicited pressor responses. Electrical stimulation of the nucleus of the tractus solitarius paired with self-stimulation of the substantia nigra, produced regular changes in the lever-pressing rate for self-stimulation. It is suggested that the substantia nigra is probably involved in the neural mechanisms coupling the circulatory changes with the somatomotor responses.

Animals↗
PubMed1989

Effects of stimulus parameters on cardiovascular responses to medullary stimulation in the cat.

The results of this study indicated that when stimulus intensity, pulse frequency and train duration were varied the basic topography of the cardiovascular responses to medullary stimulation did not change, but was merely increased or diminished in magnitude. Pressor responses were usually obtained in conscious cats, and also narcosis produced reversal effect on rare occasions. It is suggested that the reversal in cardiovascular responses is probably locus specific, and the medullary loci yielding reversal effect are more limited than those eliciting consequently pressor responses.

Anesthesia↗
PubMed1988

Electrically elicited cardiovascular and respiratory responses from the nucleus tractus solitarii in unrestrained cats.

Heart rate, arterial blood pressure and respiratory rate responses to electrical stimulation of the nucleus tractus solitarii (NTS) were studied in unanaesthetized freely moving cats. Complex cardiovascular response patterns, mainly pressor responses, were obtained from stimulation of the portion of the NTS rostral to the obex. No significant difference was observed between the effects produced by stimulation of the NTS on the right and on the left side. These results indicate that the rostral portion of the NTS also plays a role in the cardiovascular control, and a functional asymmetry between the two sides does not exist at the level of the NTS.

Animals↗
PubMed1987

Behavioural and cardiovascular responses to electrical stimulation of the medulla oblongata of the cat.

Effects of stimulation of the nucleus tractus solitarii, the dorsal motor nucleus of the vagus, the nucleus reticularis paramedianus, and the nucleus cuneatus were studied in free-moving cats. Stimulation of the medullary nuclei that are known to be involved in the central nervous control of cardiovascular functions might activate preprogrammed motor responses such as licking and sniffing, and induce complex behavioural response patterns such as sleep or flight reaction. Moreover, both lever-pressing for rewarding brain stimulation, and eating in food deprived cats might be modulated by these stimulations. In a shuttle box the cats showed no tendency toward shuttling during stimulation, except the stimulation of the nucleus reticularis paramedianus which produced aversion. The cardiovascular and respiratory effects varied parallel with the behavioural responses. It is concluded that the medullary nuclei related to visceral functions are capable of affecting somatomotor behaviour either directly on the motor system, or by inducing complex response patterns in which somatomotor and visceral responses are integrated.

Animals↗
PubMed1985

Behavioural responses to electrical stimulation of the nucleus of the tractus solitarius of the cat.

Electrical stimulation of the region of the nucleus tractus solitarius (NTS) significantly reduced both the lever-pressing rate for substantia nigra self-stimulation and the food-consumption in food-deprived cats. In a shuttle box the cats showed no tendency toward shuttling in response to NTS stimulations with randomly varied stimulus intensities. In contrast with these effects, stimulation to nucleus reticularis paramedianus yielded an aversive effect.

Animals↗
PubMed1984

Effects of electrical stimulation of the nucleus tractus solitarius on self-stimulation behavior.

The electrical stimulation of the nucleus tractus solitarius (NTS) produced profound suppression of self-stimulation (ICSS) in cats. This effect depended on the sequence and side of NTS stimulation, as well as on the stimulus parameters and locus of self-stimulation. The suppressive effect of NTS stimulation on ICSS was not abolished by ipsilateral vagotomy, thus the vagal bradycardia probably is not involved in the suppression of ICSS.

Animals↗
PubMed1984

The effects of feeding and fasting on self-stimulation.

The effects of ad libitum feeding and 72 hr fasting on intracranial electrical self-stimulation behaviour (ICSS) were tested in cats. In contrast to previous studies it was found that the opposite manipulations in food intake, i.e. ad libitum feeding fasting, often induced identical changes in lever-pressing rate even in cases of lateral hypothalamic self-stimulation. Both increase and decrease in lever-pressing rate for ICSS could be observed depending rather on the electrically elicited behaviours than the precise anatomical location of the stimulating electrodes. It is concluded that changes in ICSS induced by food intake and food deprivation are probably secondary to the changes in activity level.

Animals↗
PubMed1981

Interactions between intracranial electrical self-stimulation behavior and cardiovascular responses.

Interactions between electrical self-stimulating behavior, cardiovascular state and reactions were studied in a series of chronically prepared cats. Pressor responses were found to be the most common cardiovascular concomitants of intracranial electrical self-stimulating behavior in cats. The lever-pressing rate for brain stimulation decreased under the effect of both dibenzyline, an adrenergic blocking agent, and local anesthesia of the cervical vago-sympathetic trunk by procaine. Bilateral vagotomy resulted in an acceleration in lever-pressing responses. The depression and the acceleration in the lever-pressing for brain stimulation were associated with an increase and a decrease in pulse pressure, respectively. It is suggested that peripheral autonomic modifications exert a regulatory feedback effect on the rewarding property of brain stimulation.

Adrenergic Fibers↗
PubMed1978

Optimum parameters for substantia nigra self-stimulation as reflected by peripheral autonomic responses.

Lever-pressing rate, arterial blood pressure, heart rate and respiration were continuously recorded during substantia nigra self-stimulation with systematically varied stimulus parameters in cats. During self-stimulation with fixed pulse train duration, the shorter the pulse train duration the higher was the lever-pressing rate. The rate of responding was a curvilinear function of pulse voltage and frequency during self-stimulation, both at fixed pulse train duration and with self-regulation of pulse train duration. Substantia nigra self-stimulation was always associated with peripheral autonomic changes, which were found within a certain range during self-stimulation with the stimulus parameters producing the highest lever-pressing rate. The preferred level of the peripheral functions under study was characterized by an increase up to 150/130--190/160 mm Hg in blood pressure, an increase up to 190--290/min in heart rate, and an increase up to 60--120/min in respiration. It is concluded that the optimum parameters for substantia nigra self-stimulation may be reflected by the preferred level of peripheral autonomic functions. The results support our earlier suggestion that a peripheral feedback mechanism plays an important role in the timing of lever-pressing behaviour.

Animals↗
PubMed1975

Autonomic effects of hypothalamic self-stimulation in the cat.

Respiration, heart rate and arterial blood pressure were recorded continuously during self-stimulation with systematically varied stimulus parameters. Conspicuous autonomic effects were induced by self-stimulation. Acceleration in the respiration and heart rate, and rise in the arterial blood pressure were generally obtained as direct effects of the stimulus train, which were followed by remarkable rebound-like aftereffects. A close relationship was found between the lever-pressing behaviour and the peripheral autonomic effects of self-stimulation. The frequency of self-stimulation increased in parellel with the amplitude of the autonomic responses to a certain level, and the animal stopped self-stimulation whenever the amplitude of the autonomic effects exceeded this level. The results are consistent with the idea that the periopheral autonomic changes can modulate self-stimulation.

Animals↗