Experiments on anesthetized rats were performed using local chemical exclusion of neurons with kainic acid to study the relative roles of the rostral, intermediate, and caudal parts of the nucleus ambiguus in the mechanisms controlling respiration. The characteristics of the respiratory rhythm and pattern responses to chemical exclusion of different parts of this nucleus were observed. In particular, sequential exclusion of the left and right rostral parts of the nucleus ambiguus reproducibly induced significant decreases in the respiration rate and respiratory volume in the first minutes; in 83% of experiments, there was also irreversible respiratory arrest. Exclusion of symmetrical intermediate parts of the nucleus ambiguus was followed by bradypnea and decreases in pulmonary ventilation, the greatest respiratory effects being noted only after injection of kainic acid into the second symmetrical area, irreversible respiratory arrest being seen in 50% of cases. Exclusion of symmetrical caudal areas of the nucleus ambiguus resulted only in small decreases in respiratory frequency without significant changes in respiratory volume and gave rise to the smallest incidence of respiratory arrest, i.e., 33%.
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Curr Biol
January 2025
Department of Neuroscience, Physiology & Pharmacology, UCL, Gower Street, London WC1E 6BT, UK. Electronic address:
Animals construct diverse behavioral repertoires by moving a limited number of body parts with varied kinematics and patterns of coordination. There is evidence that distinct movements can be generated by changes in activity dynamics within a common pool of motoneurons or by selectively engaging specific subsets of motoneurons in a task-dependent manner. However, in most cases, we have an incomplete understanding of the patterns of motoneuron activity that generate distinct actions and of how upstream premotor circuits select and assemble such motor programs.
View Article and Find Full Text PDFNeuroscience
January 2025
Department of Molecular Anatomy, School of Medicine University of the Ryukyus, Uehara, 207, Nishihara, Okinawa 903-0213, Japan.
The subiculum is a main output part of the hippocampal formation and important for learning and memory. According to connection studies, the distal and proximal regions of the subiculum project to the brain regions related to the spatial and emotional memories, respectively. Our previous morphological studies indicated that the ventral subiculum (vSub) consists of two regions, the distal subiculum (Sub1) and the proximal subiculum (Sub2), while the dorsal subiculum (dSub) seemed to comprise only one region (Sub1).
View Article and Find Full Text PDFVavilovskii Zhurnal Genet Selektsii
November 2024
Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
We present a series of articles proving the existence of a previously unknown mechanism of interaction between hematopoietic stem cells and extracellular double-stranded DNA (and, in particular, double-stranded DNA of the peripheral bloodstream), which explains the possibility of emergence and fixation of genetic information contained in double-stranded DNA of extracellular origin in hematopoietic stem cells. The concept of the possibility of stochastic or targeted changes in the genome of hematopoietic stem cells is formulated based on the discovery of new, previously unknown biological properties of poorly differentiated hematopoietic precursors. The main provisions of the concept are as follows.
View Article and Find Full Text PDFProteins
December 2024
Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia.
Hydrogen-deuterium exchange mass spectrometry (HDX-MS) approach has become a valuable analytical complement to traditional methods. HDX-MS allows the identification of dynamic surfaces in proteins. We have shown that the introduction of various mutations into the amino acid sequence of whale apomyoglobin (apoMb) leads to a change in the number of exchangeable hydrogen atoms, which is associated with a change in its compactness in the native-like condition.
View Article and Find Full Text PDFAnal Chem
December 2024
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Street S., Lanzhou, Gansu 730000, China.
The advancement in fluorescent probe technology for visualizing nuclear morphology and nucleic acid distribution in live cells and has attracted considerable interest within the biomedical research community, as it offers invaluable insights into cellular dynamics across various physiological and pathological contexts. In this study, we present a novel two-photon nucleus-imaging fluorescent probe called Nu-red, which is a typical donor(D)-π-acceptor(A) rotor composed of the donor (dihydroquinoline) and acceptor (pyridiniumylpentadienitrile) parts linked by a single bond. This probe offers several advantages, including long-wavelength excitation and emission (λ/λ = 610/664 nm), favorable quantum yields (1.
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