Here is an image from a letter to the editor (which i didn’t read thoroughly but was just looking closely at the freeze fracture of tight junction encircling a desmosome) and saw what I had seen in the transmission micrographs of thin sections: that is…. a small ring around the desmosome which i called the annulus which is restrictive and different than the intercellular space nearby.   This particular freeze fracture micrograph (original found here)  by Yasuo Kitajima shows it clearly, yet is it not marked. I don’t know what the function is but clearly a “no fly zone” surrounds the desmosome. Top micrograph untouched, bottom micrograph with bar marker and blue dotted lines showing part of the annulus. It is kind of nice that this particular desmosome is approximately what the literature suggests in terms of number of nm for the diameter.

so, next question is what are the semiregularly raised areas…?