Features of the formation of conditioned secretory reflexes in response to the stimulation of different areas of the caudate nucleus of the dog

Properties were studied of elaboration of conditioned alimentary secretory reflexes to threshold electric stimulation of the caudate nucleus in dogs. The rate of formation of such a reflex and its magnitude were considerably lower than in reflexes elaborated to distant stimuli. Latencies were longer; dynamics of conditioned and unconditioned secretory reactions was similar to that of reflexes to a weak stimulus--light. The motor component of the conditioned alimentary reaction, as a rule, was absent. Characteristics were revealed of formation of alimentary reflexes to stimulation of the dorsal and ventral parts of the head and body of the caudate nucleus.     

Comparative ultrastructural characteristics of the anterior lobe of the hypophysis, thyroid and gonads in mammals during aging

Ultrastructural changes in certain types of adenocytes of old rats, guinea pigs, rabbits and dogs are characterized by specific peculiarities. However, the direction of these changes mainly coincides. The somatotropic function of rats, guinea pigs and rabbits is suppressed, lactotrophic and corticotrophic cells being activated with aging. The phenomenon of the overstrain of gonadotrophic and thyrotrophic cells is registered. Dystrophic changes in the peripheral glands are observed.     

The hormonal indices of the reactivity of the central links in the hypothalamo-hypophyseal-adrenocortical system of rats during postnatal ontogeny]

Radioimmunological assay has been made of the amount of ACTH in the adenohypophysis and blood plasma in adult male rats as well as in 1, 3, 5, 7, and 20 days old rat puppies 30 minutes after a surgical stress, i. e. cutting the skin at the back of the body. Reliable increase of ACTH level was originally observed in 7-day puppies, whereas in younger animals surgical stress resulted in the decrease of ACTH in the blood. Changes in vasopressin content of the blood and hypophysis exhibit significant variations, but on the whole mainly the decrease was observed in younger animals together with the increase from the 5-7th day of postnatal development of rats. Accumulation of vasopressin was noted in the median eminence after surgical stress in younger animals. The data obtained suggest that the early period of development of the hypothalamo-hypophyseal-adrenocortical system is characterized rather by paradoxal reaction than by non-reactivity, which may be associated with poor neurohormonal transport in the outer zone of the median eminence.     

Distribution of catecholamines in the median eminence of rats following adrenalectomy]

Distribution of adrenergic and peptidergic nerve fibers in rat median eminence was studied three weeks after bilateral adrenalectomy. Fluorescence intensity in the external zone and in some of the nerve cell-bodies proved to be increased in the nucleus arcuatus. There were many nerve fibers with a bright fluorescence in the internal zone. A great number of the peptidergic nerve fibers appeared in the external zone. Reactions in the rostral, medial and caudal regions of the median eminence differed and were described.     

Membrane Lipids and Osmolytes Composition of Xerohalophilic Fungus Aspergillus penicillioides during Growth on High NaCl and Glycerol Media

Microbiology - Aspergillus penicillioides may be both xerophilic and halophilic. To study whether there is a difference in the mechanisms of adaptation to low water activity and high NaCl...     

The population structure of rural settlements of Sakha Republic (Yakutia): ethnic, sex, and age composition and vital statistics

The genetic demographic structure of 12 rural populations from eight uluses of Sakha Republic (Yakutia) has been analyzed. The ethnic, sex, and age composition of the population and the reproductive parameters of women that have completed and have not completed the reproductive period are reported. Crow's indices have been estimated in representatives of three indigenous ethnic groups (Yakuts, Evens, and Evenks).