Scaling the high latitudes: evolution, diversification, and dispersal of Coryphella nudibranchs across the Northern Hemisphere.

Nudibranch molluscs Coryphella are widely distributed and species-rich gastropod group lacking fossil record and displaying a complex distribution across both Southern and Northern hemispheres. In this paper we provide a detailed review of the morphology, ecology, and distribution of Coryphella, estimation of divergence times between species, an ancestral area reconstruction, and a population analysis of widely distributed trans-Arctic species Coryphella verrucosa to investigate the evolution, phylogeographic patterns and reconstruct possible historical routes of oceanic dispersal. The inclusion of a larger sample size and five molecular markers has revealed a complex evolutionary history of Coryphella, shaped by transgression, vicariance, and dietary shifts, and overall driven by the pervasive effect of glacial cycles.

Panmixia and local endemism: a revision of the species complex with a description of new species.

Species of the genus Eubranchus Forbes, 1838 (Mollusca: Gastropoda: Nudibranchia) are common faunistic elements of boreal benthic ecosystems, associated with hydroid communities. Recent studies have suggested that the widely distributed trans-Arctic E. rupium (Møller, 1842) constitutes a complex of at least three candidate species, but the detailed taxonomy of the complex remains unresolved.

Intranasal Administration of GRP78 Protein (HSPA5) Confers Neuroprotection in a Lactacystin-Induced Rat Model of Parkinson's Disease.

The accumulation of misfolded and aggregated α-synuclein can trigger endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), leading to apoptotic cell death in patients with Parkinson's disease (PD). As the major ER chaperone, glucose-regulated protein 78 (GRP78/BiP/HSPA5) plays a key role in UPR regulation. GRP78 overexpression can modulate the UPR, block apoptosis, and promote the survival of nigral dopamine neurons in a rat model of α-synuclein pathology.

Aquaporin-4 and Parkinson's Disease.

The water-selective channel aquaporin-4 (AQP4) is implicated in water homeostasis and the functioning of the glymphatic system, which eliminates various metabolites from the brain tissue, including amyloidogenic proteins. Misfolding of the α-synuclein protein and its post-translational modifications play a crucial role in the development of Parkinson's disease (PD) and other synucleopathies, leading to the formation of cytotoxic oligomers and aggregates that cause neurodegeneration. Human and animal studies have shown an interconnection between AQP4 dysfunction and α-synuclein accumulation; however, the specific role of AQP4 in these mechanisms remains unclear.

Helminths of three species of White Sea fishes.

Parasitic fauna of the White Sea cod, Gadus morhua marisalbi; the navaga, Eleginus nawaga; and the shorthorn sculpin, Myoxocephalus scorpius, in the White Sea was repeatedly studied, but no large-scale parasitological surveys have been made in the recent three decades. To fill this gap, we conducted a survey of the helminths of these three fish species at the White Sea Biological Station (Karelia, Russia) of the Lomonosov Moscow State University in August 2021. The navaga (50 specimens studied) was found to be infected with 13 species of helminths; the White Sea cod (50 specimens), with 12 species; and the shorthorn sculpin (21 specimens), with 13 species.

[Chronic sleep restriction in rats leads to a weakening of compensatory reactions in response to acute sleep deprivation].

Objective: To identify features in the compensatory mechanisms of sleep regulation in response to acute sleep deprivation after chronic sleep restriction in rats.

Material And Methods: Male Wistar rats 7-8 months old underwent 5-day sleep restriction: 3 h of sleep deprivation and 1 h of sleep opportunity repeating throughout each day. Six-hour acute total sleep deprivation was performed at the beginning of daylight hours on the 3rd day after sleep restriction.

Morphological Organization of Cerata in the Nudibranch Pteraeolidia semperi (Gastropoda, Nudibranchia).

The morphology of cerata and cnidosacs were studied in the nudibranch mollusk Pteraeolidia semperi (Bergh, 1870). Fine tubules arise from the gastrodermal channel of the digestive gland and contain cells with symbiotic algae (zooxanthellae). The cnidosac stores large kleptocnides.

Nematocyst sequestration within the family Fionidae (Gastropoda: Nudibranchia) considering ecological properties and evolution.

Aeolid nudibranchs are well-known for their ability to incorporate cnidarian nematocysts and use them for defense; this process is tightly linked with the feeding preferences of molluscs. As many nudibranch groups show signs of ecology-based adaptive radiation, studies of prey-based defensive mechanisms can provide valuable insight into details of nudibranch evolutionary history. The main goal of this study is to test the correlation of ecological traits, feeding mechanisms, and prey preferences with cnidosac fine morphology and to pinpoint the phylogenetic value of these traits.

The first report of a parasitic 'turbellarian' from a cephalopod mollusc, with description of gen. nov., sp. nov. (Platyhelminthes: Fecampiida: Notenteridae).

Parasitic 'turbellarians' are known from various animals such as echinoderms, crustaceans, annelids, bivalve and gastropod molluscs. So far, however, no 'turbellarians' have been reported from cephalopods. In this paper we report a parasitic 'turbellarian' from the giant Antarctic octopus, .

Chaperone Hsp70 (HSPA1) Is Involved in the Molecular Mechanisms of Sleep Cycle Integration.

The molecular mechanisms of sleep cycle integration at the beginning and the end of the inactive period are not clear. Sleep cycles with a predominance of deep slow-wave sleep (SWS) seem to be associated with accelerated protein synthesis in the brain. The inducible Hsp70 chaperone corrects protein conformational changes and has protective properties.

The First Discovery of Pogonophora (Annelida, Siboglinidae) in the East Siberian Sea Coincides with the Areas of Methane Seeps.

Pogonophora or siboglinid tubeworms (Annelida, Siboglinidae) have been found in the East Siberian Sea for the first time. On the basis of the results of molecular phylogenetic analysis, the found specimens are presumably assigned to the genus Oligobrachia. The stations where the siboglinid tubeworms have been found are located in the area of methane seeps.

A comparison of food sources of nudibranch mollusks at different depths off the Kuril Islands using fatty acid trophic markers.

Gastropod molluscs such as nudibranchs are important members of deep-sea benthic ecosystems. However, data on the trophic ecology and feeding specialization of these animals are limited to date. The method of fatty acid trophic markers (FATM) was applied to determine the dietary preferences of nudibranchs off the Kuril Islands.

Preventive Administration of the Heat Shock Protein Hsp70 Relieves Endotoxemia-Induced Febrile Reaction in Pigeons ( ) and Rats.

The stress-inducible 70 kDa heat shock protein (Hsp70) can exert a protective effect on endotoxemia and sepsis due to its ability to interact with immune cells and modulate the immune response. However, it remains unknown whether Hsp70 is able to relieve endotoxemia-induced fever. We carried out a comparative study of the effects of preventive administration of the human recombinant Hsp70 (HSPA1A) on lipopolysaccharide (LPS)-induced endotoxemia in pigeons and rats with preimplanted electrodes and thermistors for recording the thermoregulation parameters (brain temperature, peripheral vasomotor reaction, muscular contractile activity).

[Modeling of chronic sleep restriction for translational studies].

Objective: To develop of a chronic sleep restriction model in rats by repeated sleep deprivation using an orbital shaker and to determine whether this model leads to disturbances in sleep homeostatic mechanisms.

Material And Methods: Male Wistar rats (7-8 months old) underwent sleep restriction for five consecutive days: 3 h of sleep deprivation and 1 h of sleep opportunity repeating throughout each day. Polysomnograms were recorded telemetrically throughout the day before sleep restriction (baseline), on the 1st, 3rd, 5th day of sleep restriction and 2 days after the end of sleep restriction (recovery period).

General and fine structure of Aeolidia papillosa cnidosacs (Gastropoda: Nudibranchia).

Nudibranch mollusks (Gastropoda: Heterobranchia) are widely known for their ability to incorporate some active biochemical compounds of their prey, or even organelles and symbionts of the prey, which assured biological success of this group. At the same time, the process of nematocysts obtaining and incorporation into specific structures called cnidosacs by cladobranch mollusks remain poorly studied. This highlights a necessity of additional ultrastructural studies of cnidosac and adjacent organs in various aeolid mollusks using modern microscopic methods as they may provide new insight into the cnidosac diversity and fine-scale dynamics of nematocysts sequestration process.

Functional morphology and post-larval development of the buccal complex in Eubranchus rupium (Nudibranchia: Aeolidida: Fionidae).

Nudibranch molluscs represent an interesting model group to study the evolution of feeding apparatus and feeding modes, being characterized by specialized buccal complex in combination with extremely diverse dietary preferences and multiply prey shifts in evolutionary history. However, the plasticity of the buccal complex morphology in response to diet and specific feeding modes remains understudied. Here we study the general morphology and ontogenesis of the buccal complex in Eubranchus rupium (Nudibranchia: Fionidae).

[Age-related differences in sleep disturbances in rat models of preclinical Parkinson's disease].

Objective: To describe the changes in temporal characteristics of sleep-wake cycle, which can serve as non-motor manifestations of an early stage of Parkinson's disease (PD), using the model of preclinical PD in rats of two age groups.

Material And Methods: A prolonged (up to 21 days) model of preclinical PD in middle-aged (7-8 month) and aged (19-20 month) rats was created. The model was based on cumulative inhibition of proteasomal system of the brain caused by intranasal administration of lactacystin, a specific proteasome inhibitor.

A case of nascent speciation: unique polymorphism of gonophores within hydrozoan Sarsia lovenii.

Revealing the mechanisms of life cycle changes is critical for understanding the processes driving hydrozoan evolution. Our analysis of mitochondrial (COI, 16S) and nuclear (ITS1 and ITS2) gene fragments resulted in the discovery of unique polymorphism in the life cycle of Sarsia lovenii from the White Sea. This polymorphic species exhibits two types of gonophores: hydroids produce both free-swimming medusae and attached medusoids (phenotypic polymorphism).

Diet-driven ecological radiation and allopatric speciation result in high species diversity in a temperate-cold water marine genus Dendronotus (Gastropoda: Nudibranchia).

While the majority nudibranch clades are more species rich in the tropics, the genus Dendronotus is mainly represented in Arctic and boreal regions. This distribution pattern remains poorly understood. An integrative approach and novel data provided valuable insights into processes driving Dendronotus radiation and speciation.

[Parkinson's disease and aging.].

Parkinson's disease (PD) is one of the most severe human neurodegenerative diseases that is mainly represented by sporadic form with multifactorial nature and commonly diagnosed in persons over 65 years of age. Current data on molecular mechanisms of PD development and their connection with processes of aging have been given in the review. Mechanisms of conformational control and selective degradation of proteins in the cell, possible trigger factors initiating the cascade of pathological reactions have been analyzed.

[U-133, a heat shock proteins inducer, precludes sleep disturbances in a model of the preclinical stage of Parkinson's disease in aged rats.].

Parkinson's disease (PD) is a chronic progressive neurodegenerative disease, closely associated with aging. It is considered incurable due to both late diagnosis and symptomatic treatment, which is able to alter neither molecular mechanisms of sleep disruption nor the neurodegenerative processes, developing with aging and PD progression. In the present study, we assess the therapeutic potential of a novel chaperone inducer U-133 (acetyl 2,3,7-tris-O-glucoside echinochrome) in the preclinical stage of PD modelled in aged rats by the inhibition of the proteasomal system in the brain.

Drilling in the dorid species Vayssierea cf. elegans (Gastropoda: Nudibranchia): Functional and comparative morphological aspects.

The drilling mode of feeding is known from two clades of Gastropoda: Caenogastropoda and Heterobranchia. However, the level of convergence and parallelism or homology among these two lineages is unclear. The morphology of the buccal complex is well studied for drilling caenogastropods, but poorly known for drilling nudibranchs.

[Signs of anhedonia and destructive changes in the ventral tegmental area of the midbrain in the model of the preclinical Parkinson's disease stage in experiment].

Parkinson's disease (PD) is one of incurable socially significant diseases. Success in the PD treatment is associated with the development of the technology of preclinical diagnosis and neuroprotective treatment of the disease. In the experimental model of the preclinical PD stage in rats created by intranasal administration of the proteasome inhibitor lactacystin, signs of depression as an anhedonia symptom were detected for the first time.

[Study of age changes in compensatory processes on the model of neurodegeneration of nigrostriatal system in rats.].

It is generally accepted that advanced age is the main risk factor for the development and progression of Parkinson's disease (PD). However, data that experimentally confirm the dependence on the age of the rate of neurodegeneration progression and the activity of compensatory processes in the nigrostriatal system in the development of PD are absent in the modern literature. The present study uses a model of neurodegeneration of the nigrostriatal system in rats of different age groups, created by the microinjections of the proteasome inhibitor lactacystin (LC) into the substantia nigra pars compacta (SNpc).