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Biomedical subjects

Iu A Belozertsev

Publications and source records attributed to Iu A Belozertsev.

At least 19 recordsLinked to original sources
PubMed1987

[Changes in the learning ability of epiphysectomized rats].

The experiments on rats have shown changes in the learning ability of animals. The learning of locomotor reactions of escape and avoidance conditioned reflex was accelerated in animals after pinealectomy. Training of rats in U-shaped and 16-door mazes was significantly affected after pinealectomy. The index of reflex retention (1 and 7 days later) was not changed in the operated animals. Epithalamin (0.5 mg/kg for 5 days) selectively facilitated learning of visual and space discrimination.

Adaptation, Physiological↗
PubMed1984

[Relation of the effect of psychostimulants on learning ability to internal and external factors].

It has been shown in rat experiments that the action of psychostimulants on the learning ability of rats in a T-shape maze and Dombrovskaya's maze depends to a greater degree on the problem complexity rather than on its type. The learning ability was enhanced in animals which responded to stress by the manifestations of the avoidance conditioned reflex. Sydnocarb and amphetamine were capable to abolish "passive" responding to stress and to enhance the learning ability. Individual level of the animals' investigative effort affected insignificantly the changes in the learning ability induced by psychostimulants (sydnocarb, amphetamine, caffeine, acephen, piracetam, euclidan).

Amphetamine↗
PubMed1976

[Phenamine sterotypy as a drug-induced model of psychopathology].

Stereotype movements in cats following the administration of bid dosages of phenamine is accompanied by crude disorders of conditioned avoidance with an increase of intrasignal reactions, a weakening of differentiated inhibition and an inhibition of avoidance responses due to low frequency irritation of the caudate nucleus. Caffeine even in large dosages does not possess such properties. Phenamine as in caudectomia decreases the amount of monomodel neurons in the neocortex, as well as group postdischarges in the caudate response of neurons. It is assumed that many indices of phenamine stereotypicity, as a possible model of psychopathology, may be explained by disturbances of the filtering and retention functions of the caudate nucleaus.

Amphetamine↗
PubMedDate not supplied

[Influence of phenamin on the reaction of cortical neurons evoked by stimulation of mesodiencephalic structures].

Experiments set upon 32 cats demonstrated that d, l-amphetamine (1-3 mg/kg, intravenously) augmented the number of responding units, modified the structure of the response and the intensity of the reaction from the sensorimotor (somatosensory) cortex neurones following stimulation of the mesencephalic reticular formation. Weakening of phasical and significant intensification of tonic reactions from the lateral hypothalamus was noted, this being attended by a rise of areactive neurones. A single stimulation of the antero-medial hypothalamus evoked inhibitory responses more often than it did in controls. Its rhythmical stimulation was less frequently accompanied by activation which stressed the inhibitory nature of the cortical response. It is suggested that the action of d, l-amphetamine on the cortex depends not only upon mobilization of brain stem reticular formation, but also on the greater reticulo-hypothalamic interaction, as well as on the direct excitation (stimulation) of the hypothalamic centres.

Amphetamine↗
PubMedDate not supplied

[Effect of caffeine and phenamin on caudate inhibition of aggressive reactions in cats].

In chronic experiments conducted on cats it was shown that caffeine (10--30 mg/kg) failed to change agressive reactions developing in stimulation of the meso- or diencephalic structures. Phenamine (1--3 mg/kg) facilitated the appearance of emotional manifestations and lowered the threshold of the agressive response. Subliminal stimulation of the caudate nucleus in control experiments caused motor tranquilization and depressed the agressive behaviour to a lesser degree when practised against the background of the caffeine action. At the same time, phenamine abolished the influence not only of the threshold, but also of the subliminal stimulation of the caudate nucleus on the spontaneous motor activity and the rage behaviour.

Aggression↗
PubMedDate not supplied

[Comparison of the effect of sidnocarb and other psychostimulants on discrimination and prediction processes in performing conditioned food-procuring reflexes].

In an Y-shaped maze a differentiation of the positive and negative reflex signals given at random in a ratio of 50 to 50 per cent and an active selection of one of two feeding troughs, reinforced at varying frequency (0.1--0.9), were determined. Sydnocarb (10--20 mg/kg) had no influence on the realization of the food-procurement response, but improved the discrimination of the signals. Only small doses of amphetamine (0.5 mg/kg), caffein (20 mg/kg) and acephen (10 mg/kg) also improved the response to conditioned signals. Sydnocarb reduced the number of runs to a rarely reinforced feeding trough and, at the same time, stimulated an active choice of the latter. Amphetamine largely facilitated an active choice of the runs direction. Caffein displayed a tendency to reduce the number of wrong approaches. Acephen hampered an active choice of compartments in the Y-maze without impairing the ability to distinguish the frequency of the feeding troughs reinforcement.

Acoustic Stimulation↗