Showing papers on "Cuneate nucleus published in 2016"
TL;DR: This is the first study to demonstrate that nAChR subunits are affected following pre- into post-natal SE and that they simultaneously coincided with changes in apoptotic expression.
Abstract: Infants exposed to cigarette smoked during pregnancy into infancy have increased respiratory and cardiac abnormalities. Nicotine, the major neurotoxic component of cigarette smoke, induces its actions by binding to nicotinic acetylcholine receptors (nAChR), with one downstream effect being increased apoptosis. Using a pre- into post- natal cigarette smoke exposure mouse model (SE), we studied the immunohistochemical expression of nAChR subunits α2, α3, α4, α5, α7, α9, β1 and β2 and two markers of apoptosis, active caspase-3 and TUNEL, in seven nuclei of the medulla and facial nucleus of the pons in male mice. Pups of dams exposed to two cigarettes (nicotine ≤1.2mg, CO ≤15mg) twice daily for six weeks prior to mating, during gestation and lactation (n=5; SE), were compared to pups exposed to air under the same condition (n=5; SHAM) at P20. Results showed that the hypoglossal nucleus had increased α3, α4, α7, α9, Casp-3 and TUNEL, dorsal motor nucleus of the vagus had increased α3, α5, α7, β1 and Casp-3, nucleus of the solitary tract had increased α3 but decreased α4, α5, β1 and apoptosis, cuneate nucleus had increased α3, β2 and Casp- 3, but decreased α5, nucleus of the spinal trigeminal tract had increased α3, α7, β1, lateral reticular nucleus had decreased β1, inferior olivary nucleus had increased β1 but decreased apoptosis, and the facial had increased α2, α3 and α7. This is the first study to demonstrate that nAChR subunits are affected following pre- into post-natal SE and that they simultaneously coincided with changes in apoptotic expression.
31 citations
TL;DR: Unexpectedly, the intrinsic connections within area 3b hand cortex were more widespread after incomplete dorsal column lesions (DCLs) than after a complete DCL, and these changes in connections may contribute to the reactivation process after injuries.
Abstract: A complete unilateral lesion of the dorsal column somatosensory pathway in the upper cervical spinal cord deactivates neurons in the hand region in contralateral somatosensory cortex (areas 3b and 1). Over weeks to months of recovery, parts of the hand region become reactivated by touch on the hand or face. To determine whether changes in cortical connections potentially contribute to this reactivation, we injected tracers into electrophysiologically identified locations in cortex of area 3b representing the reactivated hand and normally activated face in adult squirrel monkeys. Our results indicated that even when only partially reactivated, most of the expected connections of area 3b remained intact. These intact connections include the majority of intrinsic connections within area 3b; feedback connections from area 1, secondary somatosensory cortex (S2), parietal ventral area (PV), and other cortical areas; and thalamic inputs from the ventroposterior lateral nucleus (VPL). In addition, tracer injections in the reactivated hand region of area 3b labeled more neurons in the face and shoulder regions of area 3b than in normal monkeys, and injections in the face region of area 3b labeled more neurons in the hand region. Unexpectedly, the intrinsic connections within area 3b hand cortex were more widespread after incomplete dorsal column lesions (DCLs) than after a complete DCL. Although these additional connections were limited, these changes in connections may contribute to the reactivation process after injuries. J. Comp. Neurol. 524:1494-1526, 2016. © 2015 Wiley Periodicals, Inc.
26 citations
TL;DR: The extensive expression of CTR in the medulla suggests that CTR may be involved in a wider range of functions than currently appreciated.
Abstract: The calcitonin receptor (CTR) is relevant to three hormonal systems: amylin, calcitonin, and calcitonin gene-related peptide (CGRP). Receptors for amylin and calcitonin are targets for treating obesity, diabetes, and bone disorders. CGRP receptors represent a target for pain and migraine. Amylin receptors (AMY) are a heterodimer formed by the coexpression of CTR with receptor activity-modifying proteins (RAMPs). CTR with RAMP1 responds potently to both amylin and CGRP. The brain stem is a major site of action for circulating amylin and is a rich site of CGRP binding. This study aimed to enhance our understanding of these hormone systems by mapping CTR expression in the human brain stem, specifically the medulla oblongata. Widespread CTR-like immunoreactivity was observed throughout the medulla. Dense CTR staining was noted in several discrete nuclei, including the nucleus of the solitary tract, the hypoglossal nucleus, the cuneate nucleus, spinal trigeminal nucleus, the gracile nucleus, and the inferior olivary nucleus. CTR staining was also observed in the area postrema, the lateral reticular nucleus, and the pyramidal tract. The extensive expression of CTR in the medulla suggests that CTR may be involved in a wider range of functions than currently appreciated.
24 citations
TL;DR: Median nerve injury-induced CN glial ERK activation modulated the development of behavioral hypersensitivity and allopregnanolone significantly diminished CN p-ERK levels, glial activation, proinflammatory cytokines, and behavioral hypers sensitivity after CCI.
Abstract: Background:Mechanisms underlying neuropathic pain relief by the neurosteroid allopregnanolone remain uncertain. We investigated if allopregnanolone attenuates glial extracellular signal-regulated kinase (ERK) activation in the cuneate nucleus (CN) concomitant with neuropathic pain relief in median n
13 citations
TL;DR: The distribution of FtMt which the authors found in the monkey brainstem implies possible involvement of Ftmt in several physiological mechanisms, especially in the catecholaminergic neurons, and the possibility of significant involvement in neurodegenerative disease.
13 citations
01 Aug 2016
TL;DR: In this paper, two rhesus macaques were implanted with microelectrode arrays providing chronic access to the cuneate nucleus (CN) and trained on an active touch oddity task to detect vibrotactile stimuli.
Abstract: The sense of touch and proprioception are critical to movement control. After spinal cord injury, these senses may be restored with direct, electrical microstimulation of the brain as part of a complete sensorimotor neuroprosthesis. The present study was designed to test, in part, the hypothesis that the cuneate nucleus (CN) of the brainstem is a suitable site to encode somatosensory information. Two rhesus macaques were implanted with microelectrode arrays providing chronic access to the CN. The monkeys were trained on an active touch oddity task to detect vibrotactile stimuli. When the vibrotactile stimuli were replaced with electrical stimuli delivered to the CN, initial detection probabilities were near chance. Detection performance improved over time, reaching a plateau after about 10 daily sessions. At plateau performance, the monkeys exhibited detection probabilities that were 68–80% higher than the chance probability. Finally, detection probability was quantified as a function of stimulus amplitude. The resulting psychometric curve showed a detection threshold of 45 μΑ for 100-Hz stimulus trains. These behavioral data are the first to show that artificial CN activation is sufficient for perception. The results are consistent with our hypothesis and motivate future tests of the CN as a somatosensory encoding site.
10 citations
TL;DR: Based on the DCN somatotopic map, the GrN sends information to the PAG from the contralateral hindlimb and the tail and the CunN from the Contralateral forelimb, shoulder, neck and ear, which is consistent with earlier electrophysiological and PAG stimulation studies.
5 citations
TL;DR: Although dexterous hand use can be significantly restored in some patients after months of recovery, some patients never fully recover from the injury and may develop painful and nonpainful phantom sensations.
TL;DR: The study nuclei of the midbrain were found to be involved in functionally diverse circuits whose components include the basal ganglia and the cholinergic nature of their neurons was determined.
Abstract: The organization of the projections of the lateral nuclei of the midbrain tegmentum (the peripeduncular and perilemniscal nuclei, the nucleus of the brachium of the posterior colliculus) to the functionally diverse nuclei of the basal ganglia system of the brain was studied in dogs (n = 34) using a method based on the retrograde axonal transport of horseradish peroxidase. The study nuclei of the midbrain were found to be involved in functionally diverse circuits whose components include the basal ganglia. These nuclei innervate the area of the putamen, globus pallidus, cuneate nucleus, and subcuneate nucleus, which on the basis of their predominant connections with the motor or limbic nuclei of the brain are classified as motor or limbic nuclei, as well as the area of the caudate and accumbens nuclei and the compact zone of the pedunculopontine nucleus, which receive projections from functionally diverse structures. Analysis of Nissl-stained frontal sections allowed the topographical anatomy of the individual lateral nuclei of the midbrain tegmentum to be refined. Histochemical reactions for NADPH diaphorase was used to determine the cholinergic nature of their neurons.