You are very clear in your descriptions but I still do not see the
arrangement that seems to be vexing you. There are many large cells
deep to the granular layer but I am uncertain of what they are.
However, I will ask an expert or two tomorrow.
Kal
On Wed, 24 Feb 2010 23:09:30 -0800 (PST), "Peter H."
<pjwholm from yahoo.es> wrote:
>On 24 feb, 23:57, Kalman Rubinson <k... from earthlink.net> wrote:
>> On Wed, 24 Feb 2010 09:33:28 -0800 (PST), "Peter H."
>>>>>>>>>>>> <pjwh... from yahoo.es> wrote:
>> >On 24 feb, 00:15, Kalman Rubinson <k... from earthlink.net> wrote:
>> >> >*2: See Macaca Mulatta, Nissl, horizontal, histo, whole-brain,
>> >> >section 0205 hemisphere at bottom inhttp://brainmaps.org>>>> >> I do not see what you are describing. This section looks perfectly
>> >> normal to me and comparable to standard descriptions.
>>>> >> Kal
>>>> >Wish there were coordinates I could point to, but being things as they
>> >are I will just have to describe the situation:
>>>> > Magnify section 0205 until the scale bar measures at most 184
>> >micrometers. Below the Vermis on this section, the posterior margin of
>> >the molecular layer of the bottom hemisphere forms a "U" leaning to
>> >the right, the right arm of which points to the plexus choroideus on
>> >the top right of it and is fatter than the left one. The inside of
>> >this U, which represents the outside of the molecular layer, you will
>> >see lined with Purkinje cells. And on the right side of this right arm
>> >you will see fairly large cells (diam. ca. 23 microns), which due to
>> >their size I interpret to be neurons and not Glia, nearly touching the
>> >molecular layer.
>>>> >Alternatively, in section 0254 of this series you can see what
>> >doubtlessly are the deep nuclei approaching the molecular layer on its
>> >inside to a distance of about 400 microns.
>>>> I do see those large cells in both 205 and 254 but these seem to be in
>> the white matter adjacent to the granular layer while the normal
>> pattern of the molecular/Purkinje/granular layers remains intact and
>> external.
>>>> Kal- Ocultar texto de la cita -
>>>> - Mostrar texto de la cita -
>>The granular layer is supposed to be on the same side of the molecular
>layer as are the Purkinje cells. But those large neurons in 205 to
>which I was referring myself are on the opposite side of the molecular
>layer from where the Purkinje cells are. And besides that, only in
>205, but not in 254, can these neurons opposite to the Purkinje side
>really be seen to be adjacent to the molecular layer. So it seems like
>we are talking about different cells here. I wish there were
>coordinates.
>>Furthermore, what you should have written is that " the normal pattern
>of the molecular/Purkinje/granular layers remains intact *but is*
>external". Because according to Niewenhuys and apparently everybody
>else "These layers are, passing from superficial to deep, the cell-
>poor molecular layer, the monolayered Purkinje layer and the granular
>layer." (see my first article). I repeat: The molecular layer
>supposedly is on the outside (towards the surface), below it
>supposedly comes the thin Purkinje layer, and below that supposedly
>comes the granular layer. And that would mean that the Purkinje cells
>were on the internal side of the molecular layer - and not on its
>external side, where they really appear to be. Or not?
>>And this is really the crucial point here: If the Purkinje and
>granular layers were on the inside of the molecular layer, then there
>would be no problem of understanding how the Purkinje cell axons reach
>the deep nuclei and how the Mossy Fibers reach the Granule cells. But
>these layers appears to be (?are!) on the outside (or external side)
>of the molecular layer, and thus the molecular layer is situated in
>between the Purkinje layer and the deep nuclei. Hence my problem.
>>Hope I have made myself clear this time.
>>Peter
