Hyppocampus

The authors studied C14-leucine and S35-methionine incorporation into the brain tissue homogenates and protein from different parts of the brain of rats subjected to intrauterine hypoxia. Depression of protein synthesis in certain brain structures, particularly in the hyppocampus was observed alongside with the stimulation of the amino acid incorporation into proteins of the other parts of the brain. Changes of the amino acid penetration into tissue homogenates fialed to correlate with the rate of their incorporation into proteins in separate structures of the brain...

The paper contains some results of a neuropsychological study of memory in 32 patients with tumors of the temporal lobe. The authors distinguished syndromes of disturbed speech memory (mainly--auditory-verbal) in tumors of the medial, posterior and, to a less degree, frontal areas of the left temporal lobe. In tumors of the right temporal lobe changes of memory were less expressed and had prevalently a visual-image character. An involvement into the process of the hyppocampus leads to a model nonspecific drop of short-time memory, while the expansion of the tumor towards the diencephalo-mesencephalic structures--to a formation of the Korsakoff syndrome...

In acute experiments on cats anesthetized with nembutal and chloralose the projections of different parts of orbito-frontal cortex, basal temporal cortex and hippocampus to hypothalamic nuclei were studied by focal potential recording. It was found that the proreal gyrus has local projections into the latero-dorsal parts of the preoptical region, rostral parts of the forebrain medial bundle, lateral and posterior hypothalamus with mammilary bodies. The orbital gyrus is projected mainly into latero-dorsal parts of the forebrain medial bundle, latero-ventral part of the preoptical region, and the region of lateral and latero-dorsal hypothalamic nuclei...

The author compared the protein composition of the brain structures (premotor zone of the cortex, CA3 are of the hyppocampus, the caudate nucleus, the frontal lobe of the cerebellum) in rats by electrophoresis in the continuous gradient of polyacrylamide gel pores in capillaries. The method used proved to possess a much greater resolving capacity in comparison with electrophoresis in the homogeneous gel concentration; no differences could be revealed in the protein composition of the brain structures under study...

The content of 5-methylcytosine (m5C) in DNA of different cow organs is found to decrease in ontogenesis. No other age changes were found in DNA structure and molecular population (GC content, the content of different in the length and the base composition pyrimidine clusters, hyperchromicity value etc.). It is suggested that the age tissue-specific decrease of the m5C content is due to a decrease of the level of DNA methylation, which takes place in heart, kidneys, spleen and brain DNAs and is not observed in lungs...

The transplacental action of nitrosoethylurea (NEU) was studied in organic cultures of the embryonic rat brain tissue (the hyppocampus region). The brain tissue proved to be highly sensitive to NEU. This was expressed in a greater survival of the experimental cultures in comparison with the control and in the appearance of epithelial proliferations of the vascular plexus resembling, in individual cases, adenomas. The amount of morphological changes observed in the experiment depended on the carcinogen dose.

Slices of the rat hyppocampus (CA2 region) were incubated in blood plasma, and the content of Na and K in them, and also distribution of these elements in the extra- and intracellular space (by the inulin method) after hydrocortisone (HC) administration was investigated. Special morphological studies had shown that the first slices embraced the dense neuron cell bodies layer; the next slices (deeper ones) had much less neurons. A single dose of HC given 3 hours before the experiment in doses of 1 and 5 mg per 100 g of body weight caused a decrease of intracellular Na concentration and an increase of intracellular K in the first slices; the transmembrane distribution coefficient was elevated for both ions...

A comparative study of the protein composition of the brain structures of rats (premotor area of the cortex, the CA3 region of the hyppocampus, the caudate nucleus, the frontal area of the cerebellum) was carried out by the method of disc electrophoresis in the micro- and macroscale. Protein zones were identified by their relative electrophoretic mobility calculated according to the mobility of the "marker" protein (trypsin inhibitor from soya beans). Both methods revealed no significant differences in the composition of the electrophoretic separation of the brain proteins pointed to the greater resolving capacity of the micromethod...

Chronic experiments on rabbits which had electrodes implanted into the hypothalamus, amygdalar area and hyppocampus have shown that electrostimulation of these brain structures which brought about different emotional and behavioral reactions during preliminary test produces a distinct modulating effect on the vestibular (rotatory and post-rotatory) nystagmus and labyrinthine posture-tonic reflexes.

Experiments on rabbits demonstrated that local electrocoagulation of the dorsal hyppocampus portions by means of the implanted electrodes caused reduction of the complementary and lysozyme activity of the blood serum, inhibited the development of Arthus' skin allergic-reaction, decreased the intensity of systemic anaphylaxis to the blood serum antigens, this being accompanied by a relative fall of the precipitating antibodies titres and a reduction of the vagus response of the heart to adrenaline.

The authors studied the influence of a single intraperitoneal administration of corticosterone to rats on the content of serotonin, 5-hydroxyindolacetic acid (5-HIAA), serotonin turnover in the hypothalamus, mesencephalon, dorsal hyppocampus, frontal and parietal cortex. In a dose of 1 mg per 1 kg of body weight corticosterone increased the content and the turnover of serotonin in the hypothalamus and the mesencephalon 30 min after its administration. 120 min after the administration of the hormone the content of serotonin was restored to control values...