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Biomedical subjects

S Bernasconi

Publications and source records attributed to S Bernasconi.

At least 271 records · Page 15Linked to original sources
PubMed1977

Role of brain monoamines in the anorectic activity of mazindol and d-amphetamine in the rat.

The interaction of mazindol and d-amphetamine with brain monoamines was studied in rats. At each dose used, both compounds markedly counteracted the decrease of brain noradrenaline induced by 6-hydroxydopamine while only at high doses they did significantly reduce the effect of 6-hydroxydopamine on brain dopamine. Unlike d-amphetamine, mazindol significantly counteracted the decrease of brain serotonin induced by fenfluramine. The anorectic effect of mazindol and of d-amphetamine was markedly reduced by an electrolytic lesion at the level of the ventral noradrenergic bundle but not by an electrolytic lesion of the nucleus raphe medianus. An intrastriatal injection of 6-hydroxydopamine significantly reduced the effect of mazindol but not that of d-amphetamine. The results indicate that both compounds may block noradrenaline uptake in the brain while their effect on dopamine uptake is less evident. Ulike d-amphetamine, mazindol appears to inhibit serotonin uptake also. In addition, the integrity of the noradrenergic neurons in the brain appears to be an important condition for these drugs to exert their anorectic effect.

Animals↗
PubMed1977

Endocrine aspects of trisomy 4p.

The main endocrinological parameters were investigated in two sisters affected with trisomy 4p. Our findings rule out any impairment of the endocrine system in this rare syndrome, even in those cases in which stunting of growth is more pronounced. The marked weight deficit in one of the two patients had no relationship to the chromosomal anomaly; it was determined by the association of a deficit of immunoglobulin with a Giardia Lamblia infestation.

Adolescent↗
PubMed1977

Biochemical and pharmacological studies on amineptine (S 1694) and (+)-amphetamine in the rat.

The pharmacological activities of amineptine (S 1694) and (+)-amphetamine and their interaction with biogenic amines have been examined in rats. The locomotor activity, stereotyped behaviour and hypothermia induced by amineptine were similar to but not as marked as those produced by (+)-amphetamine, and there was little or no anorectic action. Amineptine does not modify the concentrations of brain noradrenaline or acetylcholine which are respectively reduced and increased by (+)-amphetamine. Moreover, amineptine does not affect significantly the decrease of brain noradrenaline induced by an intraventricular injection of 6-hydroxydopamine, an effect significantly antagonized by (+)-amphetamine. On the other hand, like amphetamine, amineptine significantly reduces the effect of 6-hydroxy-dopamine on brain dopamine. Both drugs increase the striatal concentrations of homovanillic acid and show a cross tolerance in this action. Therefore they could act similarly on the striatal dopaminergine system. Amineptine thus appears to be a new type of antidepressant with a brain biochemical profile differing from that of other drugs used in depressive disorders.

Animals↗
PubMed1977

Annual and daily changes in brain serotonin content in differentially housed mice.

The annual and daily variations of brain serotonin and 5-hydroxyindolacetic acid have been studied over a 6-year period in normally grouped and isolated mice. The results obtained indicate that differences exist between normally grouped and isolated animals, especially when referred to the annual changes to which brain serotonin and 5-hydroxyindolacetic acid undergo. The results suggest that the outcome of the experiments on neurochemistry, neuropharmacology and behavior can change according to the month of the year and they can further be modified by differential housing of mice.

Animals↗
PubMed1977

Prolonged isolation and alcohol effect on avoidance learning in two strains of mice.

Prolonged isolation in mice is known to induce several behavioral changes, among which impairment of learning was also reported. On the other hand, alcohol is known to have either stimulant or depressant effects on behavior. Further, alcohol effect is also known to depend on strain-linked characteristics and on emotional ground of animals. Since prolonged isolation may differently change the emotional setting of mice, according to the strain, the behavioral effects of alcohol on avoidance learning, have been studied in two strains of male mice differentially housed. Evidences were obtained that ethanol can either improve or worsen learning performances according to the strain and the housing conditions adopted.

Administration, Oral↗
PubMed1977

Ocular phenotype in partial trisomy 10 q.

A list of the ocular signs of the partial trisomy 10 q, which is drawn up according to the literature, is not satisfactory as almost only the external appearance of the eyes and their adnexa is considered. The authors report the case of a child still living, whose visual function could be evaluated by subjective and objective (electrophysiological) methods.

Abnormalities, Multiple↗
PubMed1976

Antinociceptive action of quipazine: relation to central serotonergic receptor stimulation.

Quipazine, a serotonin receptor stimulant, inhibited the response of rats to painful stimuli in two methods currently used to measure antinociception in these animals: the hot plate and tail compression test. The antinocicptive action was observed with doses ranging from 5 to 20 mg/kg i.p according to the test situation. The effect was significantly antagonized by a pretreatment with methergoline, a potent serotonin antagonist. An electrolytic lesion placed in the nucleus raphe medianus, which produced a marked decrease of serotonin in the forebrain did not, or only slightly, affected the effect of quipazine, depending on the method used to measure antinociception. It is suggested that quipazine can produce antinociceptive action in rats by interacting with a serotonergic mechanism. The action appears to be due mainly to a direct action on postsynaptic serotonin receptors, although a presynaptic component can also contribute to the effect of quipazine.

Analgesia↗
PubMed1976

Psychoactive drug effect on behavioural changes induced by prolonged socio-environmental deprivation in rats.

Several so-called 'non-specific' or 'non-drug' factors are known to interfere with the response to psychotropic drug administration. Animal emotionality has been reported to change the outcome of psychoactive drug administration, so that the response to a stimulant or depressant drug may considerably change according to the baseline state of activity of the central nervous system. Prolonged socio-encironmental deprivation or isolation has been shown to produce in rats three different types of abnormal behaviour which have been tentatively defined as 'friendly', 'indifferent' and 'muricide'. Such unusual changes in rat behaviour are assumed to reflect a series of different emotional changes. The present experiments show that psychoactive drugs can exert a different effect in relation to the different kinds of animal behaviour used in the experiments. The investigation of the properties of psychoactive compounds, as performed in experimental animals showing behavioural alterations, is then suggested as being more fruitful in providing much information closer to the clinical results than that achieved with the experiments performed in normal laboratory animals.

Aggression↗
PubMed1976

The effect of steroid contraceptives on the concentrations of brain monoamines in rats and mice.

The effect of three estrogen-progestin combinations on biogenic amines in discrete brain areas of rats and mice has been investigated. With the exception of a significant decrease of brain 5-hydroxyindolacetic acid in the rats treated for 30 days with the combination norethynodrel + mestranol, no significant changes in the levels of serotonin, noradrenaline or dopamine in the rat brain were found following the administration of the compounds under study. On the other hand, in mice moderate but significant changes in the levels of serotonin, dopamine, noradrenaline and 5-hydroxyindolacetic acid were found in various brain areas depending on the estrogen-progestin combination used. The potential importance of these effects for the contraceptive as well as for some central actions of these compounds is discussed.

Amines↗
PubMed1976

Effect of midbrain raphe lesion on avoidance learning in aggressive mice.

Lesion of the midbrain ventral raphe nucleus greatly improves the avoidance-learning efficiency of normal and isolated-aggressive Albino Swiss mice. Since the lesion of this brain area selectivity lowers the forebrain concentration of 5-hydroxytryptamine (5-HT), implications of the role of brain 5-HT in avoidance-learning acquisition are discussed.

Aggression↗