Objective: To study the distribution character of the trigeminal sensory afferent fibers in rat's trigeminal sensory root (RxV) and to explore the possibility of selectively injury of the pain afferent fibers.
Methods: The retrograde tracer fluorogold (FG) was injected into trigeminal spinal subnucleus and pontine nucleus respectively. After 7 days survival, the rats were sacrificed and the RxV was removed and sectioned. The distribution of FG at RxV was studied under fluorescent microscope and its character was analyzed.
Results: After being introduced into trigeminal spinal rostral nucleus, the FG could be observed at the lateral portion on the sections of RxV. The fibers were small and concentrated. The interpolaris subnucleus and caudal subnucleus injection group also showed small and concentrated fibers in the lateral portion of RxV, but the distribution area was larger than that of the rostral subnucleus group. While being injected into trigeminal pontine nucleus, the FG positive axons could be found in the ventral, medial and central portion of the RxV cross sections. These fibers were thicker and more scattered compared to those projecting into trigeminal spinal nucleus.
Conclusion: The fibers relating to transporting pain sensory concentrate at a certain area of rat' s RxV, which indicate that selectively injury of the pain afferent fibers of RxV should be possible.
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J Physiol
January 2025
School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK.
C-low threshold mechanoreceptors (C-LTMRs) in animals (termed C-tactile (CT) fibres in humans) are a subgroup of C-fibre primary afferents, which innervate hairy skin and respond to low-threshold punctate indentations and brush stimuli. These afferents respond to gentle touch stimuli and are implicated in mediating pleasant/affective touch. These afferents have traditionally been studied using low-throughput, technically challenging approaches, including microneurography in humans and teased fibre electrophysiology in other mammals.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
Purpose: A relative afferent pupillary defect (RAPD) is a characteristic clinical sign of optic neuritis (ON). Here, we systematically evaluated ultrasound pupillometry (UP) for the detection of an RAPD in patients with ON, including a comparison with infrared video pupillometry (IVP), the gold standard for objective pupillometry.
Materials And Methods: We enrolled 40 patients with acute (n = 9) or past (n = 31) ON (ON+), 31 patients with multiple sclerosis (MS) without prior ON, and 50 healthy controls (HC) in a cross-sectional observational study.
J Clin Gastroenterol
January 2025
Department of Surgery, Oncology and Gastroenterology, University of Padua.
Among the various factors implicated in the pathogenesis of gastroesophageal reflux disease (GERD), visceral hypersensitivity and mucosal resistance have been recently re-evaluated in relation to the increasing phenomenon of proton pump inhibitor failure, particularly in patients with nonerosive reflux disease (NERD). Intensive research has allowed us to understand that noxious substances contained in the refluxate are able to interact with esophageal epithelium and to induce the elicitation of symptoms. The frequent evidence of microscopic esophagitis able to increase the permeability of the mucosa, the proximity of sensory afferent nerve fibers to the esophageal lumen favoring the higher sensitivity to noxious substances and the possible activation of inflammatory pathways interacting with sensory nerve endings are pathophysiological alterations confirming that mucosal resistance is impaired in GERD patients.
View Article and Find Full Text PDFJ Anesth
January 2025
Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
Nat Commun
January 2025
School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK.
The refinement of neural circuits towards mature function is driven during development by patterned spontaneous calcium-dependent electrical activity. In the auditory system, this sensory-independent activity arises in the pre-hearing cochlea and regulates the survival and refinement of the auditory pathway. However, the origin and interplay of calcium signals during cochlear development is unknown in vivo.
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