Showing papers by "Pavel M. Balaban published in 2015"
TL;DR: The intracellular pH drop that occurs within an extended region of the amputated tail of the Xenopus laevis tadpole before it begins to regenerate is revealed for the first time.
69 citations
TL;DR: Results suggest that the Helix homolog of PKMζ might be involved in post-induction maintenance of long-term changes in the nervous system of the terrestrial snail.
Abstract: 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 PKMζ. 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 homologue of PKMζ was confirmed with transcriptomics. We have demonstrated in behavioral experiments that contextual fear memory disappeared under a blockade of PKMζ with a selective peptide blocker of PKMζ (ZIP), but not with scrambled ZIP. If ZIP was combined with a “reminder” (20 min in noxious context), no impairment of the long-term contextual memory was observed. In electrophysiological experiments we investigated whether PKMζ takes part in the maintenance of long-term facilitation (LTF) in the neural circuit mediating tentacle withdrawal. LTF of excitatory synaptic inputs to premotor interneurons was induced by high-frequency nerve stimulation combined with serotonin bath applications and lasted at least four hours. We found that bath application of 2x10-6 M ZIP at the 90th min after the tetanization reduced the EPSP amplitude to the non-tetanized EPSP values. Applications of the scrambled ZIP peptide at a similar time and concentration didn't affect the EPSP amplitudes. In order to test whether effects of ZIP are specific to the synapses, we performed experiments with LTF of somatic membrane responses to local glutamate applications. It was shown earlier that serotonin application in such an "artificial synapse" condition elicits LTF of responses to glutamate. It was found that ZIP had no effect on LTF in these conditions, which may be explained by the very low concentration of PKMζ molecules in somata of these identified neurons, as evidenced by immunochemistry. Obtained results suggest that the Helix homologue of PKMζ might be involved in post-induction maintenance of long-term changes in the snail.
22 citations
TL;DR: A round-table discussion on central pattern generators was held on November 21, 2012 as part of the Fifth All-Russian Conference on Animal Behavior in Moscow, discussing the mechanisms of the organization and rearrangement of pattern-generating neuron ensembles and the possibility that structures of the central pattern generator type have a role in controlling non-motor brain functions.
Abstract: A central pattern generator (CPG) is defined as a set of neurons whose members work together to generate organized motor output activity. A round-table discussion on central pattern generators was held on November 21, 2012 as part of the Fifth All-Russian Conference on Animal Behavior in Moscow. The main topics of discussion were: 1) the mechanisms of the organization and rearrangement of pattern-generating neuron ensembles; 2) the possibility that structures of the central pattern generator type have a role in controlling non-motor brain functions; and 3) the evolutionary and ontogenetic aspects of central pattern generators.
11 citations
TL;DR: Anionic channelrhodopsin slow ChloC could be considered as an effective optogenetic tool capable in response to light stimulation to inhibit the generation of action potentials in the neuron.
Abstract: Anionic channelrhodopsin slow ChloC was expressed in the culture of nerve cells and in vivo in mouse brain. We demonstrated ability of slow ChloC to suppress effectively the activity of the neuron in response to the illumination with the visible light. It has been shown for a first time that slow ChloC works equally efficiently in both neuronal culture and in the whole brain being expressed in vivo. Thus, slow ChloC could be considered as an effective optogenetic tool capable in response to light stimulation to inhibit the generation of action potentials in the neuron.
6 citations
TL;DR: Use of voltage-sensitive dyes (VSD) is the only of the small number of currently available methods which combines high spatial resolution with the ability to record ultrafast signals (<0.1 msec) in real time with a high signal:noise ratio.
Abstract: Studies of the electrical activity and plasticity of neural networks, individual nerve cells, and their subcellular compartments are now impractical without using optical methods to visualize functional signals which allow electrical events to be recorded both in many neurons simultaneously and in individual dendrites and axons and provide for linking these data to precise morphological images. Use of voltage-sensitive dyes (VSD) is the only of the small number of currently available methods which combines high spatial resolution with the ability to record ultrafast signals (<0.1 msec) in real time with a high signal:noise ratio. Significant progress in applying VSD has been made in the last decade, particularly in analysis of the occurrence and encoding of electrical signals in dendrites and axons, and has resulted from improvements in the method associated with using the best dyes in combination with sequential improvements in apparatus and optical instruments. This has allowed the method to demonstrate its value and effectiveness and advance from purely technical areas to the arsenal of major equipment in the world’s leading laboratories working at the frontiers of cell biology and neurophysiology.
6 citations
TL;DR: The bases of the organization of ubiquitin-dependent protein degradation of proteins in proteasomes are reviewed and its role in synaptic plasticity and consolidation, reconsolidation, and the extinction of memory is reviewed.
Abstract: Synaptic plasticity is considered as a basis of learning and memory and, in its turn, is associated with the reconstruction of molecular complexes in the preand postsynaptic parts. One of the means of this reconstruction is ubiquitin-dependent degradation of proteins in proteasomes, which leads to local elimination of preliminarily defined proteins–targets strictly within a certain time period in order to subsequently modify molecular complexes, such as postsynaptic density, the presynaptic apparatus of neuromediator release, and the receptor apparatus of preand postsynaptic membranes. Here, we review the bases of the organization of ubiquitin-dependent protein degradation of proteins in proteasomes and its role in synaptic plasticity and consolidation, reconsolidation, and the extinction of memory. In addition, one section is focused on the analysis of novel data on the mechanisms of the regulation of ubiquitin-dependent protein degradation, because knowledge on the mechanisms of regulation helps one to better understand how the process of protein degradation interacts with other intracellular processes in the cell.
3 citations
TL;DR: The atypical protein kinase Cζ is present in the snail CNS, while in the CNS neuropil it is predominantly located in varicosities, which is the location of the major zones of synaptic contacts.
Abstract: The distribution of the atypical protein kinase Cζ in the nervous system of the adult and juvenile terrestrial snail Helix aspersa L. was studied immunocytochemically. Immunoreactive (IR) elements were detected in all CNS ganglia. The pattern of immunoreactivity included cytoplasmic staining of many CNS neurons, fibers in the CNS tracts and nerves, and ultrathin fibers and single varicosities inside the ganglia neuropil, which is the location of the major zones of synaptic contacts. The primary neurites and their proximal branches were not immunoreactive. The relatively low immunoreactivity of the fibers did not correspond to the presence of numerous Cζ-IR cell bodies. In the juvenile CNS, the IR neuropil was better developed than in the adult CNS, while immunoreactivity was practically absent in the cell bodies. We conclude that the atypical protein kinase Cζ is present in the snail CNS, while in the CNS neuropil it is predominantly located in varicosities.
2 citations