I understand that the Area Postrema was a site where there was increased penetrability of the blood brain barrier. I am not sure, but thought I had come across additional sites of increased penetrability last year in my reading. Are there other sites where there is increased permeability of the BBB?
In pondering an answer to this question, I immediately thought of the illustrious Dr. John Donahue, consummate neurologist, neuropathologist, and neuroanatomist. I posed the question to him and got the following response:
| Dr. John Donahue, Brown University, Providence, RI |
"Not increased permability of the BBB. NO BBB! Area postrema is one of the circumventricular organs, areas in the brain that lack a BBB. Being the vomiting center, it is imperative that it lacks a BBB so that it can sample the systemic circulation. Being in the medulla, it is the only circumventricular organ that is adjacent to the fourth ventricle; all of the others are adjacent to the third. It is the only paired circumventricular organ; all of the others are single and midline. The other circumventricular organs are subfornical organ, organum vasculosum of the lamina terminalis, median eminence, posterior pituitary gland, subcommissural organ, and pineal gland."
There you have it!

Comments
To add a comment to the original post, click here.
You must be signed in to post a comment.
Sign in nowhttp://plato.stanford.edu/entries/pineal-gland/
--Douglas C Miller, posting as "anonymous" after multiple failures of known passwords to work with this blog's access system
Do not know about the indusium griseum.
DCM, anonymous as far as google is concerned.