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When I researched I found different reason for this, the popular ones are

1) white matter is mylinated .this reason was given in reference books and this website

while others say

2)cell body concentration causes grayish appearance ,as in brain the cell body is concentrated outside. As mentioned in this .i.e cell body orientation.

also my teacher agrees with 2nd one, that the nissls granules contribute to the grayish appearance.orientation causes the effect of gray matter and white matter

I feel 1st reason to be more appropriate as there are billions of it couldn't be arranged as depicted in the second reason.

kindly help me out to choose the accurate one, with appropriate reason of-course!

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  • $\begingroup$ so whats is your question ? :) Just teasing you but kindly i higly doubt you will get anything more than just comment on it. $\endgroup$ – L.Diago Oct 5 '18 at 17:25
  • $\begingroup$ why is that true ? $\endgroup$ – Chemist Oct 5 '18 at 17:30
  • $\begingroup$ man i just say that this type of question is rather fit to the chat room rather posted like that. In my opinion SE its about sharing information not discuss like that. Still i hope that somebody try give you proper answer not jus opinion. $\endgroup$ – L.Diago Oct 5 '18 at 17:34
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    $\begingroup$ @L.Diago the question is clear and definitely answerable, you just might not be familiar with it if you haven't worked with gross specimens. $\endgroup$ – De Novo Oct 5 '18 at 19:10
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    $\begingroup$ You are right that was the reason of my special interest to this question so thank you man. :) $\endgroup$ – L.Diago Oct 5 '18 at 19:18
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The terms gray and white matter relate to their color in gross specimens (i.e., not microscopic specimens) that have been formalin fixed. Nissl granules describe a microscopic structure, the rough endoplasmic reticulum, and aren't directly related to the color of gross specimens. Here's an example of a frontal cross section from a University of Utah slide set:

enter image description here

You'll see it's generally a tannish-yellow (at least on my monitor, this image is a pretty good representation of what it looks like in person), but there are lighter "white" parts in the white matter areas, and darker "gray" parts in the cortex.

A live, or a recently deceased and not formalin fixed brain has different qualities, including color and consistency.

The color of the formalin fixed tissue is an artifact of the process of fixing, so it's not necessarily accurate to describe the gray color as something inherent to the cells in the gray matter, but generally yes, the whiter color in the white matter of formalin fixed brain is because of the high lipid concentration. The grayer color of the gray matter is because of the lower lipid concentration. This lovely old JBC article from 1929 discusses some of these issues, mostly regarding white matter in response to staining after fixation, but also gray and white matter before staining.

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  • $\begingroup$ Nice answer but i still dont see that answer to question what exacly makes gray matter gray ? :) $\endgroup$ – L.Diago Oct 5 '18 at 17:39
  • $\begingroup$ @L.Diago "the grayer color of the gray matter is because of the lower lipid concentration." $\endgroup$ – De Novo Oct 5 '18 at 17:40
  • $\begingroup$ I know, actually i am trying to give you constructiv criticism. But the other part was about the fact what makes gray matter gray (i am not telling that your answer is bad but he put on tabel something about nissle substance ) $\endgroup$ – L.Diago Oct 5 '18 at 17:42
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    $\begingroup$ @Marzipanherz myelin $\endgroup$ – De Novo Oct 6 '18 at 20:13
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    $\begingroup$ @sudhanvab plasma membranes are not opaque. The intracellular contents of a tissue are typically what give that tissue a characteristic color. $\endgroup$ – De Novo Oct 9 '18 at 19:43

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