It is presumed that the unusual central location of mesencephalic trigeminal neurons is a specialization that allows them to receive synaptic input. However, relatively few synaptic terminals were observed on the somata of mesencephalic trigeminal neurons in macaque monkeys via electron microscopy. This leaves the question of dendritic synaptic terminals open. Unlike the pseudounipolar neurons found in the trigeminal ganglion, some mesencephalic trigeminal neurons have been reported to be multipolar cells exhibiting a number of dendritic processes in non-primate species. To examine whether this morphological feature was also present in macaque monkeys, we retrogradely filled these cells with biotinylated dextran amine by injecting it into the trigeminal nerve entry zone. A portion of the mesencephalic trigeminal neurons exhibited short, poorly branched, dendritic processes. They also exhibited very fine, short processes believed to be somatic spines. Thus, primate trigeminal mesencephalic neurons appear to have specializations aimed at increasing the membrane surface area available for synaptic input.
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Cureus
December 2024
Internal Medicine, Unidade Local de Saúde da Região de Aveiro, Aveiro, PRT.
Schwannomas (SCs) are benign tumors composed of neoplastic Schwann cells and are relatively uncommon intracranially. Although these tumors are frequently associated with neurofibromatosis type 2 (NF2), they may also arise idiopathically, and their pathogenesis remains poorly understood. A 70-year-old Caucasian man presented with a two-month history of vertigo, gait imbalance, and decreased visual acuity in the left eye accompanied by photophobia, nausea, vomiting, and occasional headaches.
View Article and Find Full Text PDFFront Cell Neurosci
November 2024
State Key Laboratory of Oral and Maxillofacial Reconstruction and Regneration, Department of General Dentistry and Emergency, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
The overactivity of the masticatory muscles (bruxism or teeth clenching) is associated with stress exposure, and often leading to consistent muscle pain. However, the neural mechanism underlining it is not fully understood. The central amygdala (CeA), which is linked to stress-induced behaviors and physical reactions, projects directly to the mesencephalic trigeminal nucleus (Vme), which is crucial for oral-motor coordination.
View Article and Find Full Text PDFbioRxiv
November 2024
Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
J Headache Pain
November 2024
Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
Background: Post-traumatic headache (PTH) is a common comorbid symptom affecting at least one-third of patients with mild traumatic brain injury (mTBI). While neuroinflammation is known to contribute to the development of PTH, the cellular mechanisms in the trigeminal system crucial for understanding the pathogenesis of PTH remain unclear.
Methods: A non-invasive repetitive mTBI (4 times with a 24-h interval) was induced in male mice and effect of mTBI was tested on either bregma or pre-bregma position on the head.
Transl Psychiatry
October 2024
Research Group Experimental Oto-rhino-laryngology, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, 3000, Belgium.
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