Temporomandibular joint ganglion-induced external auditory canal obstruction associated with osteoarthritis: a case report.

Ganglions are pseudocysts that develop from part of the joint capsule or tendon sheath and are filled with synovial fluid. In this report, we describe a case of external auditory canal obstruction caused by a temporomandibular joint (TMJ) ganglion that was thought to be related to osteoarthritis. A 62-year-old man with the chief complaint of swelling of the anterior wall of the left external auditory canal underwent cystectomy at the Department of Otorhinolaryngology.

Preservation of masseter muscle until the end stage in the SOD1G93A mouse model for ALS.

Amyotrophic lateral sclerosis (ALS) progressively impairs motor neurons, leading to muscle weakness and loss of voluntary muscle control. This study compared the effects of SOD1 mutation on masticatory and limb muscles from disease onset to death in ALS model mice. Notably, limb muscles begin to atrophy soon after ALS-like phenotype appear, whereas masticatory muscles maintain their volume and function in later stages.

Bone microstructural characteristics or positional changes of condyle head affect short-term condyle head resorption after orthognathic surgery.

Condylar resorption occurs in some cases after orthognathic surgery, and the risk factors associated with postoperative condylar head resorption have been extensively described. Nevertheless, even in cases with a combination of risk factors, postoperative condylar resorption may not appear. This study analyzed the microstructure and three-dimensional positional change of the condylar bone via imaging in patients who have undergone bimaxillary orthognathic surgery to determine whether the microstructure or condylar position differs between patients with and without postoperative condylar resorption.

Current Status and Molecular Mechanisms of Resistance to Immunotherapy in Oral Malignant Melanoma.

Immune checkpoint inhibitors (ICIs), including anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and anti-programmed death-1 (PD-1) antibodies, have initiated a new era in the treatment of malignant melanoma. ICIs can be used in various settings, including first-line, adjuvant, and neo-adjuvant therapy. In the scope of this review, we examined clinical studies utilizing ICIs in the context of treating oral mucosal melanoma, a rare disease, albeit with an extremely poor prognosis, with a specific focus on unraveling the intricate web of resistance mechanisms.

Analysis of Feeding Behavior Characteristics in the Cu/Zn Superoxide Dismutase 1 (SOD1) SOD1G93A Mice Model for Amyotrophic Lateral Sclerosis (ALS).

Amyotrophic lateral sclerosis (ALS) is a progressive disease affecting upper and lower motor neurons. Feeding disorders are observed in patients with ALS. The mastication movements and their systemic effects in patients with ALS with feeding disorders remain unclear.

Membrane excitabilities in neonatal rat mesencephalic trigeminal neurons under dietary zinc deficiency.

Purpose: The present study aimed to evaluate the effects of zinc deprivation on the properties of membrane and spike-discharge features of mesencephalic trigeminal neurons (MTNs), which are important sensory neurons for oral-motor reflexes and rhythmical jaw movements.

Methods: Neonatal Sprague Dawley rats (P10-12) were distributed equally into a normal diet group and a zinc-deficient diet (ZD) group. Whole cell patch-clamp recordings were obtained from MTNs from coronal brain slices.

Persistent sodium conductance contributes to orexin-A-mediated modulation of membrane excitability in neonatal rat mesencephalic V neurons.

Orexins are multifunctional hypothalamic neuropeptides that participate in the stimulation of feeding behavior and energy expenditure. However, little is known about their neuromodulatory effects in lower brainstem effector regions, including in the trigeminal neuronal system. The aim of this study was to examine the effects of orexin-A (Ox-A) on the membrane properties of mesencephalic trigeminal (Mes V) neurons that are critically involved in the generation and control of rhythmical oral motor activities.

Orexins modulate membrane excitability in rat trigeminal motoneurons.

Orexins (Oxs) are multifunctional neuropeptides, secreted from the lateral hypothalamus, that stimulate feeding behavior and energy expenditure. In this study, the direct effects of Oxs on the membrane properties of trigeminal motoneurons (TMNs) were examined, which critically participate in the genesis of rhythmical oral motor activities underlying suckling and mastication. Sprague-Dawley rats (3-6 day-old) were used to obtain whole-cell patch-clamp recordings from TMNs.

Neuropeptide Y modulates membrane excitability in neonatal rat mesencephalic V neurons.

Neuropeptide Y (NPY) is one of a number of neuropeptides with powerful orexigenic effects. Intracerebroventricular administration of NPY induces increases in food intake and alters feeding rate. Besides it role in feeding behavior, NPY also has significant effects on neuronal systems related to other spontaneous behaviors such as rearing and grooming.

Circuit-Specific Early Impairment of Proprioceptive Sensory Neurons in the SOD1 Mouse Model for ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons degenerate, resulting in muscle atrophy, paralysis, and fatality. Studies using mouse models of ALS indicate a protracted period of disease development with progressive motor neuron pathology, evident as early as embryonic and postnatal stages. Key missing information includes concomitant alterations in the sensorimotor circuit essential for normal development and function of the neuromuscular system.

Resurgent Na+ Current Offers Noise Modulation in Bursting Neurons.

Neurons utilize bursts of action potentials as an efficient and reliable way to encode information. It is likely that the intrinsic membrane properties of neurons involved in burst generation may also participate in preserving its temporal features. Here we examined the contribution of the persistent and resurgent components of voltage-gated Na+ currents in modulating the burst discharge in sensory neurons.

Serotonergic modulation of slow inward rectification in mesencephalic trigeminal neurons.

Inward rectification in response to membrane hyperpolarization is a prominent feature of mesencephalic trigeminal (Mes V) neurons and the hyperpolarization-activated inward current (I), as the basis of this property, regulates the spike discharge characteristics and input frequency preference (resonance) in these neurons, suggesting that I modulation is an important regulator of oral motor activity. To examine a possible contribution of serotonin (5-HT) to the modulation of I activation characteristics, in the present study, we investigated the modulatory effects of 5-HT receptor activation on I in postnatal day (P) 2-12 rat Mes V neurons by whole-cell patch-clamp recording. Bath application of 5-HT suppressed the I-dependent voltage sag and I conductance, but induced only a modest shift in the voltage dependence of I activation.

Development of resurgent and persistent sodium currents in mesencephalic trigeminal neurons.

Sodium channels play multiple roles in the formation of neural membrane properties in mesencephalic trigeminal (Mes V) neurons and in other neural systems. Mes V neurons exhibit conditional robust high-frequency spike discharges. As previously reported, resurgent and persistent sodium currents (I and I , respectively) may carry small currents at subthreshold voltages that contribute to generation of spike firing.