Mostec#1 Amacrine: Recursive dendritic spines -

#1

The Mostec #1 Amacrine cell has a diffusely layered  thorny dendritic pattern with branches that have many local expansions.
I know that there are still a lot of amacrine cell types that are not or little characterized. Any idea about this one?
I see a  peculiar feature along the Mostec#1 Amacrine’s dendrites, which may be accidental but worthwhile to keep an eye on:
in the outher third (mostly) of the dendrites some of the dendritic spines establish recurrent loops
- back to themselves or to the main dendrite (see examples in image).
This is not too frequent but striking. Perhaps it is just a occasional “necessity” due to microarchitectural interaction.
While certain dopaminergic amacrines establish “synaptic rings” around other amacrine cell bodies,
these “rings” here are smaller, enclosing other dendrites and of course it’s not clear whether they are sites of synaptic interaction.
Still, it would be nice to tag the distribution of these “rings” (by a color, for example) and check their orientation and relative IPL postion.
A further option would be to trace some of these enclosed dendrites to see whether they belong to the same (type of ) cells.


 

#2

You would have to also trace dendrites that are only partially enclosed (by one of the protrusions that looks like a hooked finger) in order to characterize the distinction between the two (or lack thereof).