Cortico spinal

Figure 1.8 Some basic neuronal systems. The three different brain areas shown (I, II and III) are hypothetical but could correspond to cortex, brainstem and cord while the neurons and pathways are intended to represent broad generalisations rather than recognisable tracts. A represents large neurons which have long axons that pass directly from one brain region to another, as in the cortico spinal or cortico striatal tracts. Such axons have a restricted influence often only synapsing on one or a few distal neurons. B are smaller inter or intrinsic neurons that have their cell bodies, axons and terminals in the same brain area. They can occur in any region and control (depress or sensitise) adjacent neurons. C are neurons that cluster in specific nuclei and although their axons can form distinct pathways their influence is a modulating one, often on numerous neurons rather than directly controlling activity, as with A . Each type of neuron and system uses neurotransmitters with properties that facilitate their role...

In most cases, hepatic myelopathy will develop after several episodes of HE. For unknown reasons, most patients described are men. Imaging of the spinal cord by MRI or myelography reveals normal results, as does the examination of CSF. The main pathological finding in HM is demyelination of the cortico-spinal tracts predominantly in the lower part of the cervical and the thoracic spinal cord. Occasionally demyelination has also been found in the ventral pyramidal tracts and in the posterior columns and spinocerebellar tracts (Campellone et al., 1996, Weissenbom et al., 2003). 

Mat Safri N., Murayama N., Igasaki X, Hayashida Y. (2006) Effects of Visual Stimulation on Cortico-Spinal Coherence During Isometric Hand Contraction in Humans. Int. J. of Psychophysiol 61 88-293... 

Glutamatergic neurons are widely distributed throughout the entire brain. Most glutamatergic neurons are so-called projection neurons their axon projects into distant brain regions. Prominent glutamatergic pathways are the connections between different regions of the cerebral cortex (cortico-cortical projections), the connections between thalamus and cortex, and the projections from cortex to striatum (extrapyramidal pathway) and from cortex to brain stem/spinal chord (pyramidal pathway). 

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