Lingual Mechanoreceptive Information II

1982 ◽  
Vol 25 (3) ◽  
pp. 357-363
Author(s):  
James P. Bowman

The extent to which the known trigeminothalamic projections are related to afferents from specific peripheral branches of the trigeminal nerve is not clearly revealed by degeneration studies involving lesions of the various trigeminal nuclei. This study examines the ascending projections related to the lingual branch of the trigeminal nerve using the evoked-potential technique in pentobarbital anesthetized rhesus monkeys. The distribution of potentials within the medulla, pons, and midbrain was determined by recording with macroelectrodes following single-pulse stimulation of the lingual nerve. Results show that two pathways from the main sensory nucleus convey lingual nerve information to the thalamic ventral posteromedial nucleus: an ipsilateral projection which in position corresponds to the dorsal trigeminal tract, and a larger contralateral projection which in position corresponds to the crossed ventral trigeminal tract, or trigeminal lemniscus. Additionally, the spinal trigeminal nucleus contributes fibers of lingual nerve origin to the contralateral medial lemniscus. The role of low-threshold mechanoreceptive information in lingual sensorimotor activity is discussed in relation to current concepts of somatosensory system function.

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Sasitorn Siritho ◽  
Wadchara Pumpradit ◽  
Wiboon Suriyajakryuththana ◽  
Krit Pongpirul

A 43-year-old female presented with severe sharp stabbing right-sided periorbital and retroorbital area headache, dull-aching unilateral jaw pain, eyelid swelling, ptosis, and tearing of the right eye but no rash. The pain episodes lasted five minutes to one hour and occurred 10–15 times per day with unremitting milder pain between the attacks. She later developed an erythematous maculopapular rash over the right forehead and therefore was treated with antivirals. MRI performed one month after the onset revealed small hypersignal-T2 in the right dorsolateral mid-pons and from the right dorsolateral aspect of the pontomedullary region to the right dorsolateral aspect of the upper cervical cord, along the course of the principal sensory nucleus and spinal nucleus of the right trigeminal nerve. No definite contrast enhancement of the right brain stem/upper cervical cord was seen. Orbital imaging showed no abnormality of bilateral optic nerves/chiasm, extraocular muscles, and globes. Slight enhancement of the right V1, V2, and the cisterna right trigeminal nerve was detected. Our findings support the hypothesis of direct involvement by virus theory, reflecting rostral viral transmission along the gasserian ganglion to the trigeminal nuclei at brainstem and caudal spreading along the descending tract of CN V.


2019 ◽  
Author(s):  
Ana Rita Ribeiro Gomes ◽  
Etienne Olivier ◽  
Herbert P. Killackey ◽  
Pascale Giroud ◽  
Michel Berland ◽  
...  

AbstractPerturbation of the developmental refinement of the corticospinal pathway leads to motor disorders. In non-primates developmental refinement is well documented, however in primates invasive investigations of the developing corticospinal pathway have been confined to neonatal and postnatal stages when refinement is relatively modest.Here, we investigated the developmental changes in the distribution of corticospinal projection neurons in cynomolgus monkey. Injections of retrograde tracer at the cervical levels of the spinal cord at embryonic day (E) 95 and E105 show that (i) areal distribution of back-labeled neurons is more extensive than in the neonate and dense labeling is found in prefrontal, limbic, temporal and occipital cortex; (ii) distributions of contra- and ipsilateral projecting corticospinal neurons are comparable in terms of location and numbers of labeled neurons, in contrast to the adult where the contralateral projection is an order of magnitude higher than the ipsilateral projection. Findings from one largely restricted injection suggest a hitherto unsuspected early innervation of the gray matter.In the fetus there was in addition dense labeling in the central nucleus of the amygdala, the hypothalamus, the subthalamic nucleus and the adjacent region of the zona incerta, subcortical structures with only minor projections in the adult control.


2005 ◽  
Vol 36 (4) ◽  
pp. 278-284 ◽  
Author(s):  
Hitoshi Mochizuki ◽  
Yoshikazu Ugawa

The recent revival of interest in high-frequency oscillation (HFO) is triggered by getting an opportunity to noninvasively monitor the timing of highly synchronized and rapidly repeating population spikes generated in the human somatosensory system. HFOs could be recorded from brainstem, cuneothalamic relay neurons, thalamus, thalamocortical radiation, thalamocortical terminals and cortex with deep brain or surface electrodes, or with magnetoencephalography. Here we briefly review the HFOs at each level of somatosensory pathways. HFOs recorded at brainstem might be produced by volume conduction from oscillations of the medial lemniscus. Thalamic HFOs at around 1000 Hz frequency would be generated within the somatosensory thalamus. Cortical HFOs would be generated by at least a few different mechanisms, thalamocortical projection terminals, interneurons and pyramidal cells of the primary sensory cortex. HFOs have been studied in several ways: their modulation by arousal changes, movements or drugs, their recovery function, effects of transcranial magnetic stimulation on them and also their changes in patients with various neurological diseases.


2020 ◽  
pp. 10.1212/CPJ.0000000000001013
Author(s):  
Michelle Paff ◽  
Alexandre Boutet ◽  
Jürgen Germann ◽  
Gavin J. B. Elias ◽  
Clement T. Chow ◽  
...  

AbstractIntroduction:Focused ultrasound thalamotomy is an effective treatment for tremor, however, side effects may occur. The purpose of the present study was to investigate the spatial relationship between thalamotomies and specific sensory side effects as well as their functional connectivity with somatosensory cortex and relationship to the medial lemniscus (ML).Methods:Sensory adverse effects were categorized into four groups based on the location of the disturbance: face/mouth/tongue numbness/paresthesia, hand-only paresthesia, hemi-body/limb paresthesia, and dysgeusia. Then, areas of significant risk (ASR) for each category were defined using voxel-wise mass univariate analysis and overlaid on corresponding odds ratio maps. The ASR area associated with the maximum risk was used as a region-of-interest in a normative functional connectome to determine side-effect specific functional connectivity. Finally, each ASR was overlaid on the medial lemniscus derived from normative template.Results:Of 103 patients, 17 developed sensory side effects after thalamotomy persisting 3 months after the procedures. Lesions producing sensory side effects extended posteriorly into the principle sensory nucleus of the thalamus or below the thalamus in the ML. The topography of sensory adverse effects followed the know somatotopy of the ML and the sensory nucleus. Functional connectivity patterns between each sensory-specific thalamic seed and the primary somatosensory areas supported the role of the middle insula in processing of gustatory information and in multisensory integration.Discussion:Distinct regions in the sensory thalamus and its afferent connections rise to specific sensory disturbances. These findings demonstrate the relationship between the sensory thalamus, ML, and bilateral sensory cortical areas.


2006 ◽  
Vol 23 (5) ◽  
pp. 713-719 ◽  
Author(s):  
NORIAKI HOSHINO ◽  
KAZUYA TSURUDOME ◽  
HIDEKI NAKAGAWA ◽  
NOBUYOSHI MATSUMOTO

The nucleus isthmi (NI) of the frog receives input from the ipsilateral optic tectum and projects back to both optic tecta. After ablation of NI, frogs display no visually elicited prey-catching or threat avoidance behavior. Neural mechanisms that underlie the loss of such important behavior have not been solved. Electrophysiological examination of the contralateral isthmotectal projection has proved that it contributes to binocular vision. On the other hand, there are very few physiological investigations of the ipsilateral isthmotectal projection. In this study, current source density (CSD) analysis was applied to contra- and ipsilateral isthmotectal projections. The contralateral projection produced monosynaptic sinks in superficial layers and in layer 8. The results confirmed former findings obtained by single unit recordings. The ipsilateral projection elicited a prominent monosynaptic sink in layer 8. Recipient neurons were located in layers 6–7. These results, combined with those from the former intracellular study, led to the following neuronal circuit. Afferents from the ipsilateral NI inhibit non-efferent pear shaped neurons in the superficial layers, and strongly excite large ganglionic neurons projecting to the descending motor regions. Thus feedback to the output neurons strengthens the visually elicited responses.


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