The multilevel organismal diversity approach deciphers difficult to distinguish nudibranch species complex.

Species identification is a key procedure for broad-scoped ecological, phylogeographic and evolutionary studies. However, to perform a taxonomic study in the molecular era is a complicated task that has many pitfalls. In the present study we use particular examples of common but difficult to distinguish European species within the genus of Polycera (Nudibranchia, Mollusca) to discuss the general issues of the "cryptic species" problem that has broad biological and interdisciplinary importance and can significantly impede ecological, evolutionary, and other biodiversity-related research.

Adaptive Changes in the Vestibular System of Land Snail to a 30-Day Spaceflight and Readaptation on Return to Earth.

The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight.

Morphological and molecular evidence indicate is a valid species that has priority over (Nudibranchia).

Morphological and molecular data of type material of the nudibranch mollusc Martynov, Sanamyan, Korshunova, 2015 from the Sea of Japan are summarised and compared with those of Ekimova, Schepetov, Chichvarkhina, Chichvarkhin, 2016. The clear conclusion is that the latter is a junior synonym of .

Previous motor activity affects the transition from uncertainty to decision making in snails.

One of the most widely accepted benefits of enhanced physical activity is an improvement in the symptoms of depression, including the facilitation of decision making. Up until now, these effects have been shown in rodents and humans only. Little is known about their evolutionary origin or biological basis, and the underlying cellular mechanisms also remain relatively elusive.

Nitric oxide is necessary for labilization of a consolidated context memory during reconsolidation in terrestrial snails.

Nitric oxide (NO) is known to be involved in associative memory formation. We investigated the influence of blocking NO function on the reconsolidation of context memory in terrestrial snails (Helix lucorum L.).

Impairment of context memory by beta-amyloid peptide in terrestrial snail.

We examined influence of the beta-amyloid peptide (betaAP) (25-35) neurotoxic fragment on Helix lucorum food-aversion learning. Testing with aversively conditioned carrot showed that 2, 5 and 14 days after training the betaAP-injected group responded in a significantly larger number of cases and with a significantly smaller latency than the sham-injected control group. The results demonstrate that the AP partially impairs the learning process.

Effect of beta-amyloid peptide on behavior and synaptic plasticity in terrestrial snail.

A large body of evidence implicates beta-amyloid peptide (betaAP) and other derivatives of the evolutionarily highly conserved amyloid precursor protein (APP) in the pathogenesis of Alzheimer's disease. However, the functional relationship of APP and its proteolytic derivatives to synaptic plasticity is not well known. We demonstrate that 30 min exposure to the 25-35 fragment of betaAP do not markedly change the dynamics of synaptic responses in identified neurons of terrestrial snail while a significant decrease of long-term sensitization was observed after 180 min betaAP bath application.