Cuneate nucleus

About: Cuneate nucleus is a research topic. Over the lifetime, 614 publications have been published within this topic receiving 24859 citations. The topic is also known as: cuneate nucleus of spinal cord.

Intravascular large B-cell lymphoma affecting multiple cranial nerves: A histopathological study.

Abstract: Intravascular large B-cell lymphoma (IVLBCL) is a rare form of lymphomas with poor prognosis, characterized by atypical lymphocytes selectively growing within the lumen of small or medium-sized vessels. Here, we report a case of intracerebral IVLBCL in a 54-year-old man who died three months after symptom onset. The diagnosis was made by postmortem pathological examination, based on the identification of multiple ischemic lesions, with small or medium-sized vessels filled with malignant B-cells, in the cerebral hemispheres, cerebellum, midbrain, and medulla oblongata, including the external cuneate nucleus and trigeminal spinal tract nucleus. Apart from necrotic lesions, specific histopathological search for occluded vessels in the other brain stem structures permitted identification of significant involvement of the cuneate nucleus, solitary tract nucleus, hypoglossal nucleus, and inferior olivary complex. Small vessels affected by IVLBCL were also found in the trunks of the oculomotor, trigeminal, glossopharyngeal, vagal, and hypoglossal nerves. These histopathological findings were consistent with some cranial nerve symptoms/signs ascertained during hospitalization, such as diplopia, dysphonia, and asymmetry/hypomotility of the palatal veil. The case study presented here reports novel insights on radiological, anatomical, and clinical correlations of the IVLBCL, including the possible involvement of nuclei and trunks of multiple cranial nerves. The reported findings may help clinicians in the early identification of this rapidly progressive disease that can be easily misdiagnosed, through integrated neuroradiological, neurological and neuropathological approaches.

The synaptic relationships between the primary afferent terminals and the cuneo-thalamic relay neurons in the rat cuneate nucleus.

Abstract: In order to establish the synaptic relationship between the primary afferent terminals and the cuneothalamic relay neurons in the cuneate nucleus, the combined retrograde transport of horseradish peroxidase (HRP) and experimental degeneration have been applied in the young adult albino rats. 10 to 30% HRP was injected contralaterally (0.5 microliter) in the ventrobasal thalamic nucleus and multiple dorsal rhizotomies (C5 to T1) in the cervicothoracic dorsal roots were performed on the side ipsilateral to the cuneate nucleus. The results showed that: The cuneo-thalamic relay (CTN) neurons were the major neuronal type of the nucleus. More than 55% of neurons have been labelled. These neurons were 18-30 micron X 15-25 micron in sizes. They distributed in the whole rostrocaudal extent of the nucleus, particularly dense in the middle portion. The cells varied from round, oval, spindle to multipolar in shapes. They were rich in cytoplasmic organelles and had well-developed roughed endoplasmic reticulum. Their nucleus was either centrally or eccentrically located and was rather regular. The HRP-positive granules were randomly distribute in the perikaryon, dendrites and initial segment of the axons; At least three types of the experimental degeneration of the primary afferent terminals (PAT) were observed in the cuneate nucleus two to three days after dorsal rhizotomy, namely, electron-dense, granular and neurofilamentous. These PAT were mostly large and contained round vesicles. They were commonly found within synaptic complex, in which they were presynaptic to dendrites of various sizes, and were themselves postsynaptic to smaller axon terminals containing flattened vesicles. Degenerating PAT forming isolated synapses were less commonly seen; The PAT in the synaptic complex were directly presynaptic to the dendrites originating from the CTN neurons. The dendrites forming PAT-CTN synases were of large and medium-sized. The PAT did not form direct axo-somatic synapses with the somata of CTN or of any other cell types in the cuneate nucleus.

A Realistic Computational Model of the Local Circuitry of the Cuneate Nucleus

Abstract: Intracellular recordings obtained under cutaneous and lemniscal stimulation show that the afferent fibers can establish excitatory and inhibitory synaptic connections with cuneothalamic neurons [5]. In addition, distinct types of recurrent collaterals with the capability of either exciting or inhibiting both cuneothalamic neurons and interneurons were also discovered [6]. With these data we have generated hypothesis about which circuits are implicated and also developed realistic computational models to test the hypothesis and study the cuneate properties [17,18]. The results show that the cuneate could perform spatial and temporal filtering and therefore detect dynamic edges.