CADENCE - Neuroinformatics Tool for Supervised Calcium Events Detection.

CADENCE is an open Python 3-written neuroinformatics tool with Qt6 graphic user interface for supervised calcium events detection. In neuronal ensembles recording during calcium imaging experiments, the output of instruments such as Celena X, Zeiss LSM 5 Live confocal microscope and Miniscope is a movie showing flashing cells somata. There are few pipelines to convert video to relative fluorescence ΔF/F, from simplest ImageJ plugins to sophisticated tools like MiniAn (Dong et al.

Overexpression of KCNN4 channels in principal neurons produces an anti-seizure effect without reducing their coding ability.

Gene therapy offers a potential alternative to the surgical treatment of epilepsy, which affects millions of people and is pharmacoresistant in ~30% of cases. Aimed at reducing the excitability of principal neurons, the engineered expression of K channels has been proposed as a treatment due to the outstanding ability of K channels to hyperpolarize neurons. However, the effects of K channel overexpression on cell physiology remain to be investigated.

Bidirectional regulation by "star forces": Ionotropic astrocyte's optical stimulation suppresses synaptic plasticity, metabotropic one strikes back.

The role of astrocytes in modulating synaptic plasticity is an important question that until recently was not addressed due to limitations of previously existing technology. In the present study, we took an advantage of optogenetics to specifically activate astrocytes in hippocampal slices in order to study effects on synaptic function. Using the AAV-based delivery strategy, we expressed the ionotropic channelrhodopsin-2 (ChR2) or the metabotropic Gq-coupled Opto-a1AR opsins specifically in hippocampal astrocytes to compare different modalities of astrocyte activation.

Sodium butyrate as a selective cognitive enhancer for weak or impaired memory.

Several recent studies showed that memory can be modulated by manipulating chromatin modifications using histone deacetylase (HDAC) inhibitors during memory formation, consolidation, and reconsolidation. We used a context fear conditioning paradigm with minimal non-painful current as a reinforcement, what elicited alertness to the context and freezing during tests in rats. Such paradigm resulted in a relatively weak memory in significant part of the rats.

Immediate-Early Genes Detection in the CNS of Terrestrial Snail.

In the present work, using in situ hybridization, we studied the expression patterns of three molluscan homologs of vertebrate immediate-early genes C/EBP, c-Fos, and c-Jun in the central nervous system (CNS) of terrestrial gastropod snail Helix. The molluscan C/EBP gene was described in literature, while c-Fos and c-Jun were studied in terrestrial snails for the first time. Localization of the expression was traced in normal conditions, and in preparations physiologically activated using stimulation of suboesophageal ganglia nerves.

Distinct Heterosynaptic Plasticity in Fast Spiking and Non-Fast-Spiking Inhibitory Neurons in Rat Visual Cortex.

Inhibition in neuronal networks of the neocortex serves a multitude of functions, such as balancing excitation and structuring neuronal activity in space and time. Plasticity of inhibition is mediated by changes at both inhibitory synapses, as well as excitatory synapses on inhibitory neurons. Using slices from visual cortex of young male rats, we describe a novel form of plasticity of excitatory synapses on inhibitory neurons, weight-dependent heterosynaptic plasticity.

Experiments with Snails Add to Our Knowledge about the Role of aPKC Subfamily Kinases in Learning.

Protein kinase Mζ is considered important for memory formation and maintenance in different species, including invertebrates. PKMζ participates in multiple molecular pathways in neurons, regulating translation initiation rate, AMPA receptors turnover, synaptic scaffolding assembly, and other processes. Here, for the first time, we established the sequence of mRNA encoding PKMζ homolog in land snail .

Thermogenetic stimulation of single neocortical pyramidal neurons transfected with TRPV1-L channels.

Thermogenetics is a promising innovative neurostimulation technique, which enables robust activation of single neurons using thermosensitive cation channels and IR stimulation. The main advantage of IR stimulation compared to conventional visible light optogenetics is the depth of penetration (up to millimeters). Due to physiological limitations, thermogenetic molecular tools for mammalian brain stimulation remain poorly developed.

A BK channel-mediated feedback pathway links single-synapse activity with action potential sharpening in repetitive firing.

Action potential shape is a major determinant of synaptic transmission, and mechanisms of spike tuning are therefore of key functional significance. We demonstrate that synaptic activity itself modulates future spikes in the same neuron via a rapid feedback pathway. Using Ca imaging and targeted uncaging approaches in layer 5 neocortical pyramidal neurons, we show that the single spike-evoked Ca rise occurring in one proximal bouton or first node of Ranvier drives a significant sharpening of subsequent action potentials recorded at the soma.

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.

Nitric Oxide Upregulates Proteasomal Protein Degradation in Neurons.

Nitric oxide (NO) is involved in many neuronal functions such as neuromodulation and intracellular signaling. Recent studies have demonstrated that nitric oxide is involved in regulation of proteasomal protein degradation. However, its role in neuronal protein degradation still remains unclear.

Homolog of protein kinase Mζ maintains context aversive memory and underlying long-term facilitation in terrestrial snail Helix.

It has been shown that a variety of long-term memories in different regions of the brain and in different species are quickly erased by local inhibition of protein kinase Mζ (PKMζ), a persistently active protein kinase. Using antibodies to mammalian PKMζ, we describe in the present study the localization of immunoreactive molecules in the nervous system of the terrestrial snail Helix lucorum. Presence of a homolog of PKMζ was confirmed with transcriptomics.

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.).

Biolistic delivery of voltage-sensitive dyes for fast recording of membrane potential changes in individual neurons in rat brain slices.

Optical recording of membrane potential changes with fast voltage-sensitive dyes (VSDs) in neurons is one of the very few available methods for studying the generation and propagation of electrical signals to the distant compartments of excitable cells. The more lipophilic is the VSD, the better signal-to-noise ratio of the optical signal can be achieved. At present there are no effective ways to deliver water-insoluble dyes into the membranes of live cells.

Neural control of olfaction and tentacle movements by serotonin and dopamine in terrestrial snail.

We investigated the role of serotonin (5HT) and dopamine (DA) in the regulation of olfactory system function and odor-evoked tentacle movements in the snail Helix. Preparations of the posterior tentacle (including sensory pad, tentacular ganglion and olfactory nerve) or central ganglia with attached posterior tentacles were exposed to cineole odorant and the evoked responses were affected by prior application of 5HT or DA or their precursors 5-hydroxytryptophan (5HTP) and L: -DOPA, respectively. 5HT applications decreased cineole-evoked responses recorded in the olfactory nerve and hyperpolarized the identified tentacle retractor muscle motoneuron MtC3, while DA applications led to the opposite changes.

Functional changes in the snail statocyst system elicited by microgravity.

Background: The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations.

Methodology/principal Findings: In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.