Morphology of the inner ear of mammals in ontogeny

In both phylogenesis and ontogenesis, the inner ear is formed first as a core, which, phylogenetically, is the most ancient part of the peripheral region of the auditory system. Along with the development of the inner ear, other links of different evolutionary ages (the auricle is a phylogenetically young link) begin to form in the peripheral auditory system.     

Levels of acute phase proteins remain stable after ischemic stroke

Background  

Inflammation and inflammatory biomarkers play an important role in atherosclerosis and cardiovascular disease. Little information is available, however, on time course of serum markers of inflammation after stroke.     

Comparative Analysis of Vestibular System Development in Various Groups of Mammals Living under Different Environmental Conditions

We have conducted for the first time a comparative study of the prenatal development of the vestibular system in representatives of pinnipeds (Phocidae, Otariidae, Odobenidae) and cetaceans (Odontoceti, Mysticeti) in comparison with terrestrial mammals. This allowed us to perform a detailed study of the structural organization of the inner ear in species with different ecological specialization, to find out adaptive aspects and stages of the formation of cochlear and vestibular structures in each of the studied species, and to correlate it with the properties of the environment. Studies on early embryogenesis of the labyrinth in cetaceans and pinnipeds, which represent a special direction in the evolution of placentates, give a significant contribution to the solution of the problem of the evolutionary origin of the labyrinth in the mammals studied. Sensory systems clearly demonstrate the scope of evolutionary and adaptive transformations, which appear in mammals during the transition from the terrestrial to the aquatic mode of life. At the same time, these results may provide help in understanding the general trends of the development of structure and function of the inner ear in mammals as a whole.     

Selective depression of dopamine-induced depolarization by morphine and enkephalins in snail neurons

Morphine, met-enkephalin, and leu-enkephalin in a concentration of 1×10^?5 M depress rapidly and reversibly the amplitude of depolarization induced by dopamine application toHelix pomatia neurons; the effect is naloxone-dependent. The amplitudes of dopamine-induced hyperpolarization and also of the depolarization and hyperpolarization responses to acetylcholine application are unchanged under these circumstances. The hypothesis of blocking of chemosensitive sodium channels by enkephalins is discussed. It is suggested that this hypothesis is true for high concentrations of morphine and enkephalins (1×10^?4 to 1×10^?3 M). In lower concentrations (1×10^?5 M) morphine and enkephalins lead to modulation of the reponses to the action of neurotransmitters, evidently through their influence on the cyclic nucleotide system.     

Abolition of the inhibitory effect of antibodies against S-100 proteins on the calcium current of molluscan neurons after intracellular injection of EGTA

A two-electrode voltage clamp method was used to study Ca inward current (ICa) in unidentified isolated snail neurons. Extracellular administration of antibodies against S-100 proteins (AS-100) produces a reversible inhibition of ICa in a dose-dependent and time-dependent manner. Intracellular injection of EGTA with the help of 10nA 5-10 min microiontophoresis through a multibarrel microelectrode evoked a weak increase in the amplitude of the ICa before AS-100 application and a complete abolition of the inhibitory effect of AS-100 on the ICa. The data obtained suggest that AS-100 application results in an increase in the intracellular Ca concentration and Ca-dependent inactivation of Ca-channels.