Thrombin through its receptor PAR-1 plays an important role in the peripheral nervous system. PAR-1 is located at the microvilli of Schwann cells at the node of Ranvier, and thrombin is generated by the coagulation system on these glial structures. In the present study, we examined the link between neuronal activity and modulation of thrombin generation by glial Schwann cells. Thrombin activity was assessed in sciatic nerves in reaction to high KCl as a model of neuronal activity. We demonstrated a significant transient effect of high KCL on thrombin activity (F(5, 20) = 42.65, p < 0.0001, by ANOVA) compared to normal KCl levels. Since the sciatic nerve includes components of axons and Schwann cell myelin sheath, we continued to investigate the effect of high KCl on a Schwannoma cell line as a model for nodal Schwann cell microvilli. We demonstrated a transient decrease in thrombin activity in response to high extracellular KCl (F(1, 18) = 9.56, p = 0.0063). The major neuronal inhibitor of thrombin is PN-1, and we therefore measured the effect of high KCL on PN-1 immunofluorescence intensity. We found significantly higher PN-1 staining intensity 3 min after the application of high KCL in comparison to cells exposed to high KCL for 7 min and to cells in regular KCL (F(2, 102) = 8.4737, p < 0.0004), and this effect may explain the changes in thrombin activity. The present results support an interaction between neuronal activity and the coagulation pathway as a novel mechanism for neuron-glia crosstalk at the node of Ranvier.
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http://dx.doi.org/10.1007/s12031-019-01265-4 | DOI Listing |
Elife
January 2025
Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
The inferior colliculus (IC) has traditionally been regarded as an important relay in the auditory pathway, primarily involved in relaying auditory information from the brainstem to the thalamus. However, this study uncovers the multifaceted role of the IC in bridging auditory processing, sensory prediction, and reward prediction. Through extracellular recordings in monkeys engaged in a sound duration-based deviation detection task, we observed a 'climbing effect' in neuronal firing rates, indicative of an enhanced response over sound sequences linked to sensory prediction rather than reward anticipation.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
Theoretical neuroscientists and machine learning researchers have proposed a variety of learning rules to enable artificial neural networks to effectively perform both supervised and unsupervised learning tasks. It is not always clear, however, how these theoretically-derived rules relate to biological mechanisms of plasticity in the brain, or how these different rules might be mechanistically implemented in different contexts and brain regions. This study shows that the calcium control hypothesis, which relates synaptic plasticity in the brain to the calcium concentration ([Ca2+]) in dendritic spines, can produce a diverse array of learning rules.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Institut für Physiologie II, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Jena 07740, Germany.
In mammals, the four subunit isoforms HCN1-4 assemble to form functional homotetrameric and heterotetrameric hyperpolarization-activated cyclic nucleotide-modulated (HCN) ion channels. Despite the outstanding relevance of HCN channels for organisms, including generating electrical rhythmicity in cardiac pacemaker cells and diverse types of brain neurons, key channel properties are still elusive. In particular, the unitary conductance, of HCN channels is highly controversial.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Kavli Institute for Systems Neuroscience and Centre for Algorithms in the Cortex, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Persistent homology applied to the activity of grid cells in the Medial Entorhinal Cortex suggests that this activity lies on a toroidal manifold. By analyzing real data and a simple model, we show that neural oscillations play a key role in the appearance of this toroidal topology. To quantitatively monitor how changes in spike trains influence the topology of the data, we first define a robust measure for the degree of toroidality of a dataset.
View Article and Find Full Text PDFElife
January 2025
Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.
The mushroom body (MB) is the center for associative learning in insects. In , intersectional split-GAL4 drivers and electron microscopy (EM) connectomes have laid the foundation for precise interrogation of the MB neural circuits. However, investigation of many cell types upstream and downstream of the MB has been hindered due to lack of specific driver lines.
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