Faculty Opinions recommendation of Preferential and bidirectional labeling of the rubrospinal tract with adenovirus-GFP for monitoring normal and injured axons.

The somatotopic inputs into red nucleus (RN) neurons have been studied with special reference to their level of projection in the spinal cord. As inputs we employed either volleys in predominantly cutaneous nerves of forelimb and hindlimb or cutaneous mechanoreceptor discharges evoked by taps to footpads of forelimb and hindlimb. There has been physiological confirmation of the anatomical findings that RD neurons projecting to the lumbar cord are located in the ventrolateral zone of the pars magnocellularis, whereas in the dorsomedial zone are RN neurons with cervical but not lumbar projection. Somatotopically there was found to be a differentiation of input to RN neurons according as they projected to the lumbar or only to the cervical cord. This finding was presented in the form both of tables and of somatotopic maps. As expected, this discrimination was more restrictive for the more selective inputs from pad taps than for nerve inputs. Nevertheless, forelimb inputs often had a considerable excitatory and inhibitory action on lumbar-projecting RN neurons, and vice versa for cervical-projecting neurons. There were two notable somatotopic findings that suggest specificities of connectivities. First, despite the large convergence of IP neurons onto RN neurons (about 50-fold), the degree of somatotopic discrimination was about the same for interpositus and RN neurons with two testing procedures: between inputs from forelimb and hindlimb; and between inputs from pads on one foot. Second, although there was in the interpositus nucleus a considerable topographical admixture of neurons with dominant forelimb or hindlimb inputs, the axonal projections of these neurons were apparently unscrambled on the way to the target RN neurons, so as to deliver the somatotopic specificities observed for two classes of RN neurons; those projecting down the spinal cord beyond L2 level, and those projecting to C2 but not L2. Finally, there is a general discussion of motor control with reference to the pathway; pars intermedia of anterior lobe of cerebellum leads to interpositus nucleus leads to red nucleus leads to rubrospinal tract leads to spinal motoneurons.

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An investigation into the potential for activity-dependent regeneration of the rubrospinal tract after spinal cord injury

European Journal of Neuroscience ◽

10.1111/j.1460-9568.2005.04514.x ◽

2005 ◽

Vol 22 (12) ◽

pp. 3025-3035 ◽

Cited By ~ 11

Author(s):

Philip J. Harvey ◽

Joey Grochmal ◽

Wolfram Tetzlaff ◽

Tessa Gordon ◽

David J. Bennett

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Rubrospinal Tract ◽

Cord Injury ◽

Activity Dependent

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Human Connectome-Based Tractographic Atlas of the Brainstem Connections and Surgical Approaches

Neurosurgery ◽

10.1227/neu.0000000000001224 ◽

2016 ◽

Vol 79 (3) ◽

pp. 437-455 ◽

Cited By ~ 47

Author(s):

Antonio Meola ◽

Fang-Cheng Yeh ◽

Wendy Fellows-Mayle ◽

Jared Weed ◽

Juan C. Fernandez-Miranda

Keyword(s):

Spatial Resolution ◽

Diffusion Mri ◽

Diffusion Tensor ◽

Population Based ◽

Medial Longitudinal Fasciculus ◽

Surgical Approaches ◽

Medial Lemniscus ◽

Spinothalamic Tract ◽

Rubrospinal Tract ◽

Human Connectome Project

Abstract BACKGROUND The brainstem is one of the most challenging areas for the neurosurgeon because of the limited space between gray matter nuclei and white matter pathways. Diffusion tensor imaging-based tractography has been used to study the brainstem structure, but the angular and spatial resolution could be improved further with advanced diffusion magnetic resonance imaging (MRI). OBJECTIVE To construct a high-angular/spatial resolution, wide-population-based, comprehensive tractography atlas that presents an anatomical review of the surgical approaches to the brainstem. METHODS We applied advanced diffusion MRI fiber tractography to a population-based atlas constructed with data from a total of 488 subjects from the Human Connectome Project-488. Five formalin-fixed brains were studied for surgical landmarks. Luxol Fast Blue-stained histological sections were used to validate the results of tractography RESULTS We acquired the tractography of the major brainstem pathways and validated them with histological analysis. The pathways included the cerebellar peduncles, corticospinal tract, corticopontine tracts, medial lemniscus, lateral lemniscus, spinothalamic tract, rubrospinal tract, central tegmental tract, medial longitudinal fasciculus, and dorsal longitudinal fasciculus. Then, the reconstructed 3-dimensional brainstem structure was sectioned at the level of classic surgical approaches, namely supracollicular, infracollicular, lateral mesencephalic, perioculomotor, peritrigeminal, anterolateral (to the medulla), and retro-olivary approaches. CONCLUSION The advanced diffusion MRI fiber tracking is a powerful tool to explore the brainstem neuroanatomy and to achieve a better understanding of surgical approaches.

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