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Vol 476, No 1 (2017)

Physiology

β-Adrenergic stimulation induces pro-arrhythmic activity in the caval vein myocardial tissue

Ivanova A.D., Kuzmin V.S., Rosenshtraukh L.V.

Abstract

Electrical activity of the right superior vena cava (SVC) is considered as a source of the atrial fibrillation. We have shown that bioelectrical properties of the SVC myocardium differ from those of the working atrial myocardium. Electrically evoked action potential duration in SVC is significantly shorter, the resting membrane potential in both stimulated and quiescent SVC preparations is significantly more positive than in atria. Activation of β-adrenoreceptors in SVC myocardium leads to a series of action potentials, and this process depends on protein kinase A. Probably, β-adrenergic stimulation enhances SVC arrhythmogenesis in vivo.

Doklady Biological Sciences. 2017;476(1):183-187
pages 183-187 views

Impairment of non-associative learning in a rat experimental model of preclinical stage of Parkinson’s disease

Abdurasulova I.N., Ekimova I.V., Matsulevich A.V., Gazizova A.R., Klimenko V.M., Pastukhov Y.F.

Abstract

An experimental model of the preclinical stage of Parkinson’s disease was induced by double intranasal administration of the proteasome inhibitor lactacystin. The results demonstrated signs of cognitive impairments expressed as impaired non-associative learning. This was related to degeneration of one-third of dopaminergic neurons in the ventral tegmental area of the midbrain and their axons in the dorsolateral prefrontal cortex. Impairment of non-associative learning may be an early non-motor marker of Parkinson’s disease indicating the start of neurodegenerative processes in the dopaminergic mesocortical system of the brain.

Doklady Biological Sciences. 2017;476(1):188-190
pages 188-190 views

General Biology

The role of circadian rhythm and environmental factors in the regulation of sea urchin spawning

Zhadan P.M., Vaschenko M.A., Ryazanov S.D.

Abstract

Simultaneous video recording of the sea urchin spawning behavior and recording of environmental factors enabled us to found synergism of the effects of circadian rhythm and phytoplankton on the spawning activity of the sea urchin Strongylocentrotus intermedius (Agassiz, 1864).

Doklady Biological Sciences. 2017;476(1):191-195
pages 191-195 views

The structure of cnidosacs in nudibranch mollusc Aeolidia papillosa (Linnaeus, 1761) and presumable mechanism of nematocysts release

Vorobyeva O.A., Ekimova I.A., Malakhov V.V.

Abstract

The structure of cnidosacs in nudibranch mollusc Aeolidida papillosa (Linnaeus, 1761) before and after the discharging of kleptocnidae has been studied. In the apical zone of the cnidosac, the basal laminae of epidermis and gastrodermis are interrupted, and the muscle layers of the cnidosac and the epidermis are absent. We suggest the formation of a temporary channel during the discharging of the cnidosac. Through this channel, nematocysts move from the cnidosac to the cnidopore, which forms on the top of the ceras.

Doklady Biological Sciences. 2017;476(1):196-199
pages 196-199 views

Recent decrease in carbon sink to Russian forests

Zamolodchikov D.G., Grabovskii V.I., Shulyak P.P., Chestnykh O.V.

Abstract

Regional Evaluation of Carbon Budget of Forests (RECBF), was used to study the dynamics of carbon balance in Russian forests in 1988–2015. The carbon sink (excess of absorption over losses) to forests was minimal in 1988. Since the first half of the 1990s, its increase has started. This increase was associated with the reduction of logging volume in connection with socioeconomic reforms. Since 2008, the carbon sink was gradually reduced due to increasing losses in logging operations, forest fires, and decreased carbon absorption.

Doklady Biological Sciences. 2017;476(1):200-202
pages 200-202 views

Cell Biology

Involvement of the p38 MAPK signaling cascade in stress response of RAW 264.7 macrophages

Novoselova E.G., Glushkova O.V., Khrenov M.O., Parfenyuk S.B., Lunin S.M., Vinogradova E.V., Novoselova T.V., Fesenko E.E.

Abstract

The role of the p38 MAPK signaling cascade was studied in stress response of RAW 264.7 macrophages to extremely low-intensity centimeter microwaves. Irradiation stimulated production of a number of cytokines (IL-1, IL-6, TNF-α, INF-γ and IL-10), as well as induced activation of the signaling cascades NF- κB and p38 MAPK, and enhanced expression of Hsp72 heat shock protein. In the presence of the cascade p38 MAPK inhibitor (p38 MAP kinase inhibitor XI), the stimulating effects of electromagnetic waves were abrogated either completely (for NF-κB and Hsp72) or partially (for p38 MAPK and cytokines). The results obtained are indicative of a high sensitivity of the signaling cascade p38 MAPK to the effect of low-intensity physical fields.

Doklady Biological Sciences. 2017;476(1):203-205
pages 203-205 views