


Vol 54, No 6 (2018)
- Year: 2018
- Articles: 13
- URL: https://journal-vniispk.ru/0022-0930/issue/view/9697
Comparative and Ontogenic Biochemistry
Biochemical Aspects of Hydroquinone Impact on Motor Activity in Newborn Rats
Abstract
The effects of hydroquinone (200 mg/kg) on spontaneous periodic motor activity (SPMA) and a number of biochemical markers were studied in 116-day-old rats. According to Laborit (1965), the mechanism of hydroquinone action is based on inhibition of the pentose phosphate pathway in excitable structures. Herein, we confirmed that intraperitoneal injection of hydroquinone drastically changes the SPMA pattern, inducing uninterrupted intense motor activity. To test the metabolic, redox and anticholinergic hypotheses, various feasible targets of hydroquinone were addressed. The experimental results revealed age-related changes in a number of biochemical markers. In erythrocytes (RBC), hydroquinone induced a slight increase in lactate and pyruvate levels but did not affect the glucose level, nor did it inhibit the activity of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PDH) in vitro. Hydroquinone did not affect significantly RBS levels of reduced and oxidised glutathione (GSH and GSSG) and different types of hemoglobin as well as plasma levels of malonic dialdehyde (MDA). High doses of hydroquinone inhibited RBC acetylcholinesterase (AChE) in vitro. However, blockade of central and peripheral muscarinic and nicotinic acetylcholine receptors, induced both before and after hydroquinone injection, did not prevent SPMA potentiation and changes in its pattern. Thus, our results cast doubt both on the metabolic hypothesis of the hydroquinone action and the physiological relevance of its anticholinesterase effect to enhancing motor activity. The tasks for further investigation in this direction are outlined.



Semi-Synthetic Ecdysteroids and Their Impact on Reproduction in the Domestic Fly Musca domestica Strains
Abstract
We report the experimental evaluation of the impact of 10 modified 20-hydroxyecdysone derivatives on the duration and efficacy of domestic fly imaginal reproduction in the strains with an increased (Sh gen) and decreased (L gen) lifespan. A scoring method is proposed to comparatively analyze the impact of the compounds on imaginal reproduction.



Comparative and Ontogenic Physiology
Effects of Hypoxia or Dexamethasone at Different Gestation Periods on Fear Conditioning in Adult Rats
Abstract
We report here the long-term effects of deep hypobaric hypoxia or dexamethasone administration (0.8 mg/kg) endured at the early prenatal period of gestation (days 14–16 or 17–19) on contextual and cued fear conditioning in postnatal ontogenesis of male rats. Fear responses conditioned to a context or a cue (tone) were comparatively evaluated in the male offspring of rats exposed to hypoxia or injected with dexamethasone at different gestational ages. Hypoxic exposures at any period of early prenatal ontogenesis were found to entail no statistically significant differences in the offspring relative to control. During contextual fear conditioning or extinction, the freezing time increased relative to control in animals born to females that were injected with dexamethasone on gestational days 17–19. In an analogous test on fear conditioning to a tone, the freezing time decreased relative to control in rats born to females injected with dexamethasone on gestational days 14–16 and increased in those whose mothers were injected with dexamethasone on days 17–19. We suggest that effects induced by dexamethasone administration at both gestation periods were mainly due to the involvement of the amygdala nuclei. The effect of dexamethasone on contextual fear conditioning, which seems to be due to functional changes in the hippocampus, was only detected upon its injection on gestational days 17–19.



Role of the GluR2 Subunit of AMPA Receptors in Associative Learning in the Honeybee Apis mellifera L.
Abstract
In the honeybee, we discovered (1) the presence of the AMPA-like receptors containing the GluR2 subunit in neurons (Kenyon cells) of the mushroom bodies responsible for olfactory learning, (2) the involvement of the GluR2 subunit in the short-term memory formation during a single training session; (3) a similarity to mammals in the regulation of functional activity of the AMPA-like receptor GluR2 subunit.



Effect of Photobiomodulation by Red and Infrared Laser Radiation on Motility of Paramecium caudatum
Abstract
To evaluate the effects of photobiomodulation, we used laser devices with wavelengths of 662 nm (ALOD-01; Alcom Medica, Russia) and 808 nm (ALPH-01 Diolan; NPP VOLO, Russia) and an energy density of 1–15 J/cm2. The experiments were carried out on the infusoria Paramecium caudatum (Alveolata: Ciliophora: Oligohymenophora: Peniculia). The results were evaluated before as well as 5, 10, 30, 60 min and 24 h after irradiation. 5 min after exposure to red light (662 nm), motor activity of P. caudatum increased vs. control and then decreased within 60 minutes. 24 h after irradiation at an energy density of 15 J/cm2, the speed of P. caudatum was 52% of the initial (73% in the control) (p < 0.05). Immediately since exposure to infrared radiation (808 nm) and during the first hour, motor activity tended to decrease. 24 h later, the speed decrement was significantly less than in the control. The data obtained indicate that changes in the functional state of P. caudatum arise immediately after irradiation and persist for a long time, leading either to an increased (808 nm) or a decreased (662 nm) resistance at the same values of a radiation energy density. The peculiarities of the P. caudatum response to red vs. infrared radiation appear to be due to the differences between primary photoacceptors and appropriate signaling pathways, which come into action immediately upon their excitation.



Kinetic and Thermodynamic Characteristics of Lactate Dehydrogenase in Skeletal Muscles of Homeo- and Heterothermic Animals at Low Body Temperatures
Abstract
Kinetic and thermodynamic characteristics of lactate dehydrogenase (LDG) in skeletal muscles were analyzed in homeothermic animals (rats) under deep (20°C) artificial hypothermia and in heterothermic animals (ground squirrels) under natural hypothermia (hibernation). It was found that, despite different etiology of hypothermic states, changes in some LDG parameters both in homeo- and heterothermic animals at low body temperatures are unidirectional: the catalytic efficiency decreases, the optimum point on the concentration curve shifts towards higher concentrations, efficient activation energies and Ki values increase. At the same time, multidirectional changes in LDG Vmax and KM values as well as the degree of their manifestation in rats versus ground squirrels at low body temperatures indicate that the mechanisms, which regulate activity of this enzyme in animals with diverse strategies of thermal adaptation, are quite different.



Morphological Basics for Evolution of Functions
Intersegmental Thoracic Descending Interneurons in the Cockroach Periplaneta americana
Abstract
The number, location and morphology of intersegmental descending interneurons, which connect pro- and mesothoracic ganglia with the matathoracic ganglion in the cockroach Periplaneta americana, were investigated herein using a retrograde nickel chloride tracing through one of the connectives that link meso- and metathoracic ganglia. The bodies of stained neurons were aggregated into clusters lying ether ipsilaterally or contralaterally to the axon through which the dye was delivered. Differences in size, architecture and dendrite ramification of ipsi- and contralateral neurons were described. Ipsilateral neurons ramified also ipsilaterally, whereas contralateral neurons formed ramifications on the both sides of the ganglion. The data obtained suggest that adjustment of the walking pattern generator by sensory input from legs is mainly achieved through ipsilateral descending neurons, while adaptation to the environment and brain commands is accomplished through contralateral neurons.



Short Communications
Adaptation of Different Types of Neurons in the Midbrain Auditory Center to Sound Pulse Sequences



Age-Related Features of Resistance of the Nigrostriatal System under Proteasome Dysfunction in Rats



Altered Expression of Glucocorticoid Receptors in the Rat Hippocampus after Perinatal Hypoxia and Its Correction by a GABA Derivative



The Sleep–Wake Cycle and Molecular Chaperones: New Evidence in Support of the Hypothesis of the Critical Function of Paradoxical Sleep



Magnetoreception in the Retina of the Domestic Pigeon Columbia livia: a Retinographic Search



Peculiarities of Emotional Behavior of Aged Rats in Preclinical Parkinson’s Disease Model


