[The comparative characteristics of the work capacity of adult and older rats under positive and negative emotional reinforcement]. / Sravnitel'naia kharakteristika rabotosposobnosti vzroslykh i starykh krys pri polozhitel'nom i otritsatel'nom émotsional'nom podkreplenii.

Age-dependent characteristics of motor activity during self-stimulation and active avoidance of stimulation of the hypothalamus were studied in rats. Capacity for work of the adult rats was found to be higher than that of the old ones during the positive as well as the negative emotional reinforcement. Age-dependent differences of the capacity for work were more expressed during the negative emotional reinforcement being connected with relatively fast destruction of motivational behaviour in the old animals.

[Age-related features of the working capacity of rats during positive emotional reinforcement by hypothalamic self-stimulation]. / Vozrastnye osobennosti rabotosposobnosti krys pri polozhitel'nom émotsional'nom podkreplenii samorazdrazheniem gipotalamusa.

Some age-related peculiarities found in rats striving for hypothalamic self-stimulation: (1) the capacity in old rats decreased more rapidly during fatique than in adult ones; (2) some old but not adult animals died after hard physical work; (3) some old rats "working" for a longer time have done greater work, than adult ones.

[Emotional manifestations in the electrical stimulation of the hypothalamic nuclei in adult and old rats]. / Emotsional'nye proiavleniia pri élektricheskom razdrazhenii iader gipotalamusa u vzroslykh i starykh krys.

In experiments on adult (9-10 months) and old (24-26 months) white Wistar rats behavioural manifestations under electrical stimulation of the ventromedial hypothalamus nucleus and self-stimulation (SS) of the lateral hypothalamic region were studied. It has been found that with age electrical thresholds of negative emotional manifestations decrease with invariable SS thresholds. In old rats, in comparison with the adult ones, SS frequency is lower, maximum SS proceeds at lower currents, the range of currents capable to evoke an intensive SS is narrower, SS motivational component is less expressed. The obtained data testify that in old rats there exist neurophysiological preconditions for prevailing of negative emotional manifestations.

[Age characteristics of the development of a reserpine model of parkinsonism in rats]. / Vozrastnye osobennosti razvitiia rezerpinovoi modeli parkinsonizma u krys.

The studies were performed on 9-month- and 26-month-old rats. Electrodes were implanted into the nucleus caudatus, globus pallidus and substantia nigra. It has been found that with ageing the greatest decrease in the background electrical activity was found in n. caudatus and the least in globus pallidus. Old rats showed the signs of relative extrapyramidal insufficiency, i. e. hypokinesia and enhanced tremor. Due to 7-day reserpine administration the adult animals developed a marked hypokinesia, while the old rats showed an enhanced tremor. The author has found qualitative age-dependent differences in the changes of the electrical activity of the structures in question, as well as the interdependence between the initial electrical activity of n. caudatus of old rats and their death following reserpine administration.

[Effect of electric stimulation of the hypothalamus on the transcription activity of chromatin in the rat liver during aging]. / Vliianie élektrostimuliatsii gipotalamusa na sostav i transkriptsionnuiu aktivnost' khromatina pecheni krys pri starenii.

Age-dependent peculiarities of electric stimulation of hypothalamus were studied by means of estimation of active/inactive liver chromatin fractions, protein/DNA ratio in the latters, level of incorporation of 14C-orotic acid in total RNA and in chromatin RNA fractions. Electric stimulation of hypothalamus in adult rats led to an increase in the relative content of active chromatin fraction and in the rate of the labelled precursor incorporation into both chromatin fractions. In old animals the stimulation did not cause any redistribution of chromatin fractions and did not affect the rate of the labelled precursor incorporation into RNA. These data showed that hypothalamic control of the chromatin status was altered during ageing.

[Effect of electrostimulation of the hypothalamus on protein biosynthesis in organs of adult and aged rats]. / Vliianie élektrostimuliatsii gipotalamusa na biosintez belka v raznykh organakh vzroslykh i starykh krys.

The effect of hypothalamus electrical stimulation on total protein biosynthesis was studied in skeletal muscle, heart, liver, adrenal cortex and thyroid gland of adult rats. In adult animals hypothalamus stimulation provokes a pronounced increase in 3H-leucine incorporation into total protein of all tissues, as well as into liver chromatin proteins. No significant changes were observed in protein biosynthesis when hypothalamus of old rats was stimulated. This can serve as evidence of age-related decrease in the ability of the hypothalamus to stimulate protein synthesis in peripheral tissues.

[Changes in the kallikrein-kinin system of the blood following hypothalamo-hypophyseal stimulation of animals of different ages]. / Izmeneniia kallikrein-kininovoi sistemy krovi pri gipotalamo-gipofizarnoi stimuliatsii u zhivotnykh raznogo vozrasta.

Changes occurring in the formation and synthesis of kinins become irregular with ageing: the content of kallikreinogenes decreases, the activity of kininase and inhibitors of trypsin falls, and total blood activity of hydrolysis of ethyl--N--benzoil--L--arginine ether rises. Stimulation of the hypothalamus causes an obvious activation of the kalikrein--kinin system in adult animals: the contents of kallikreinogenes and kininogenes fall, the kallikrein activity sharply increases, whereas the kininase activity decreases. Both single and repeated administrations of vasopressin induce the same shifts of kallikrein--kinin system as the stimulation of hypothalamus. On repeated administrations of vasopressin the kininase activity rises.