Grey matter

The spinal cord is classically divided into white and grey matter (Fig. 21.2). The grey matter can be organised into ten different laminae, which run continuously along the entire length of the spinal cord. Within a given section of a spinal cord, each lamina can be seen as a layer of functionally distinct cells. Laminae I to VI comprise the dorsal horn, laminae VII to IX the ventral horn, and lamina X is the substantia grisea centralis which surrounds the central canal. 

Attwell, D. and Laughlin, S. B. An energy budget for signaling in the grey matter of the brain. J. Cereb. Blood Flow Metab. 21 1133-1145, 2001. 

Velakoulis, D., Wood, S. J., Smith, D. J. et al. Increased duration of illness is associated with reduced volume in right medial temporal/anterior cingulate grey matter in patients with chronic schizophrenia. Schizophr Res. 57 43-49, 2002. 

All dead within 17 min cyanide concentrations postmortem, in mg/kg FW, were 3.3 in blood, 1.5 in plasma, 1.6 in serum, 1.4 in cerebrospinal fluid, 0.9 in brain grey matter, and 1.0 in brain white matter... 

G. Gratton, P. M. Corbaliis, E. Cho, M. Fabiani, and D. Hood. Shades of grey matter non-invasive optical images of human brain responses during visual stimulation. Psychophysiology, 32 505-509, 1995. 

Divalent mercury in rats has been reported to poorly penetrate the blood-brain barrier [23], However, there is an impairment of the blood-brain barrier within hours after mercury treatment [24, 25], By means of autoradiographic techniques, it was demonstrated [26] that after a single intravenous injection of labelled mercuric chloride, large portions of the radioactive mercury were detected in the cerebellar grey matter, area postrema, hypothalamus and areas near the lateral ventricle of mice. 

The density of cerebral capillaries, especially in the cortical grey matter, is very high with mean distances of 40 /xm. The capillary network has a total length of 600-650 km, the mean velocity of the blood flow is below 0.1 cm/s, and the luminal surface extends to 15-30 m2. Thus the blood-brain barrier represents an important surface for potential drug delivery besides gut (30CM100 m2), lung (70-120 m2), or skin (1.8 m2) [24-26, 33-37],... 

Bergquist J, Vona MJ, Stiller CO, O Connor WT, Falkenberg T, et al. 1996. Capillary electrophoresis with laser-induced fluorescence detection a sensitive method for monitoring extracellular concentrations of amino acids in the periaqueductal grey matter. J Neurosci Methods 65( 1) 33-42. 

Figure 14.4 Different types of glial cells. Astrocytes connect capillaries and neurones. Fibrous astrocytes, with less branching and more filamentous processes, occur mainly in white matter while protoplasmic astrocytes are located principally in the grey matter. Oligodendrocytes form the myelin sheath by wrapping themselves around axons. The connection between the myelin sheath and the oligodendrocyte is permanent and provides material for the myelin sheath. Microgliocytes (microglia) are the phagocytes of the nervous system. The ciliated ependymal cells line the cavities of the central nervous system.

GABA is one of the most widely distributed transmitters in the brain and it has been calculated that it occurs in over 40% of all s)mapses. Nevertheless, its distribution is quite heterogeneous, with the highest concentrations being present in the basal ganglia, followed by the hypothalamus, the periaqueductal grey matter and the hippocampus approximately equal concentrations are present in the cortex, amygdala and... 

Moore, G.J., Bebchuk, J.M., Wilds, I.B., Chen, G., and Manji, H.K. (2000a) Lithium-induced increase in human brain grey matter. Lancet 356 1241-1242. 

Shah, P.J., Ebmeier, K.P., Glabus, M.F., and Goodwin GM (1998) Cortical grey matter reductions associated with treatment-resistant chronic unipolar depression. Controlled magnetic resonance imaging study. Br J Psychiatry 172 527-532. 

Woermann, EG., van Elst, L.T., Koepp, M.J., Free, S.L., Thompson, P.J., Trimble, M.R., and Duncan, J.S. (2000) Reduction of frontal neocortical grey matter associated with affective aggression in patients with temporal lobe epilepsy an objective voxel by voxel analysis of automatically segmented MRI. / Neurol Neurosurg Psychiatry 68 162-169. 

Blessed G, Tomlinson BE, Roth M The association between quantitative measures of dementia and senile change in the cerebral grey matter of elderly subjects. Br J Psychiatry 144 797-811, 1968... 

Cerebral grey matter i PCr/Pi Migraine, during interictal period 152... 

Using a large laser ablation chamber, commercially available from CETAC Technologies, we quantitatively analyzed the Cu distribution in a 20 p,m thin section of the whole human hemisphere (110 mm x 65 mm). The quantitative Cu distribution of part of the human hemisphere is presented in Figure 9.40. A layered structure of cortex was found with higher metal concentration in the grey matter compared to the white matter. 

The anatomy of the brain and spinal column is very complex. The outer, most visible portion of the brain is known as the cerebrum. The cerebrum accounts for about 80% of the mass of the brain. Covered with a layer of grey matter known as the cerebral cortex, the cerebrum is divided into two hemispheres -left and right. 

Recent measurements of aluminum concentrations in human tissues for estimation of exposures are primarily limited to bone and brain tissues (Nieboer et al. 1995). Background levels of aluminum in bone are in the order of 1-3 g/g (ppm, dry weight). These authors also reported that background aluminum levels in brain tissues (primarily grey matter) of healthy individuals typically ranges from 1 to 3 g/g (ppm, dry weight) or <0.5 g/g (wet weight). 

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