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Showing papers on "Cuneate nucleus published in 2010"


Journal ArticleDOI
TL;DR: A significant reduction in the expression of 5- HT(1A)R, 5-HT(1B) R, and 5-ht(2A) R in multiple respiratory-related nuclei at P12 is consistent with reduced serotonergic transmission during the critical period, thereby rendering the animals less able to respond adequately to ventilatory distress.

73 citations


Journal ArticleDOI
TL;DR: These patterns reflect a dynamic remodeling of NMDA receptor subunit composition during postnatal development, with a distinct reduction of NR2A expression during the critical period (P12), just as NR1 did in various respiratory nuclei.

46 citations


Journal ArticleDOI
01 Jan 2010-Pain
TL;DR: In this paper, the authors examined the relationship between astrocyte activation in the cuneate nucleus (CN) and behavioral hypersensitivity after chronic constriction injury (CCI) of the median nerve.
Abstract: In this study, we examined the relationship between astrocyte activation in the cuneate nucleus (CN) and behavioral hypersensitivity after chronic constriction injury (CCI) of the median nerve. In addition, we also examined the effects of pre-emptive treatment with a number of drugs on astrocyte activation and hypersensitivity development in this model. Using immunohistochemistry and immunoblotting, little glial fibrillary acidic protein (GFAP; an astrocyte marker) immunoreactivity was detected in the CN of the normal rats. As early as 3 days after CCI, there was a significant increase in GFAP immunoreactivity in the lesion side of CN, and this reached a maximum at 7 days, and was followed by a decline. Counting of GFAP-immunoreactive astrocytes revealed that astrocytic hypertrophy, but not proliferation, contributes to increased GFAP immunoreactivity. Furthermore, microinjection of the glial activation inhibitor, fluorocitrate, into the CN at 3 days after CCI attenuated injury-induced behavioral hypersensitivity in a dose-dependent manner. These results suggest that median nerve injury-induced astrocytic activation in the CN modulated the development of behavioral hypersensitivity. Animals received MK-801 (glutamate N-methyl-d-aspartate (NMDA) receptor antagonist), clonidine (alpha(2)-adrenoreceptor agonist), tetrodotoxin (TTX, sodium channel blocker) or lidocaine (local anesthetic) 30 min prior to median nerve CCI. Pre-treatment with MK-801, TTX, and 2% lidocaine, but not clonidine, attenuated GFAP immunoreactivity and behavioral hypersensitivity following median nerve injury. In conclusion, suppressing reactions to injury, such as the generation of ectopic discharges and activation of NMDA receptors, can decrease astrocyte activation in the CN and attenuate neuropathic pain sensations.

39 citations


Journal ArticleDOI
TL;DR: The data suggest that the rvCN–mvCM network is functionally related to joints rather than to single muscles producing an overall potentiation of proprioceptive feedback from a moving forelimb joint while inhibiting, through GABAergic and glycinergic interneurons, deep muscular feedback from other forelimB joints.
Abstract: Medial lemniscal activity decreases before and during movement, suggesting prethalamic modulation, but the underlying mechanisms are largely unknown. Here we studied the mechanisms underlying proprioceptive transmission at the midventral cuneate nucleus (mvCN) of anesthetized cats using standard extracellular recordings combined with electrical stimulation and microiontophoresis. Dual simultaneous recordings from mvCN and rostroventral cuneate (rvCN) proprioceptive neurons demonstrated that microstimulation through the rvCN recording electrode induced dual effects on mvCN projection cells: potentiation when both neurons had excitatory receptive fields in muscles acting at the same joint, and inhibition when rvCN and mvCN cells had receptive fields located in different joints. GABA and/or glycine consistently abolished mvCN spontaneous and sensory-evoked activity, an effect reversed by bicuculline and strychnine, respectively; and immunohistochemistry data revealed that cells possessing strychnine-sensitive glycine receptors were uniformly distributed throughout the cuneate nucleus. It was also found that proprioceptive mvCN projection cells sent ipsilateral collaterals to the nucleus reticularis gigantocellularis and the mesencephalic locomotor region, and had slower antidromic conduction speeds than cutaneous fibers from the more dorsally located cluster region. The data suggest that (1) the rvCN-mvCM network is functionally related to joints rather than to single muscles producing an overall potentiation of proprioceptive feedback from a moving forelimb joint while inhibiting, through GABAergic and glycinergic interneurons, deep muscular feedback from other forelimb joints; and (2) mvCN projection cells collateralizing to or through the ipsilateral reticular formation allow for bilateral spreading of ascending proprioceptive feedback information.

36 citations


Journal ArticleDOI
TL;DR: The present results point to GABA transport in the gracile nucleus as a putative therapeutic target against abnormal sensory perceptions related to neuropathic pain.

25 citations


Journal ArticleDOI
TL;DR: The results suggest that in diabetes, MNT induced NPY expression via the reduction of NT-3, and electrical stimulation of the injured median nerve evoked the release of NPY and accordingly more c-Fos-LI cells were identified in the CN.

3 citations


01 Jan 2010
TL;DR: It is suggested that the cuneate nucleus acts as filter for its input sensory signal, applying a differentiating and phase-lead effect on the transmitted signal, which are interesting features of a control system, and could help understand how the body can attain such a high degree of precision in its movements.
Abstract: The body shows impressive control capabilities in terms of the speed and the precision with which movements can be carried out under a wide variety of circumstances. The cerebellum and brainstem nuclei, including the cuneate nucleus, are believed to play a crucial role in this control. If these control mechanisms can be unveiled, this could yield important insights in not only medicine and neurophysiology, but could also control theory in general, which could then potentially be applied in a variety of industry-based control applications. In this thesis system identification and modeling of one subsystem is considered: the cuneate nucleus. The aim of this project is to create a quantitative model for control of a network of neurons in this structure and to create a detailed single-cell model of the cuneate neuron. A two-pronged approach is used to study the function of this structure. First a black-box like system identification using Matlab with experimental data as in- and output signals is considered. Then, building on a previously developed Scicos neuron model, a detailed neuron model of one cuneate neuron is developed, incorporating many aspects of recently described cellular neurophysiology. Our findings suggest that the cuneate nucleus acts as filter for its input sensory signal, applying a differentiating and phase-lead effect on the transmitted signal. These are interesting features of a control system, and could help understand how the body can attain such a high degree of precision in its movements. (Less)

3 citations


Journal ArticleDOI
TL;DR: The results indicate that the cuneate nucleus neurons play a relatively minor role in transmission of cardiac nociceptive information in comparison to upper thoracic spinal neurons.

3 citations