In article <3edr24$opq at mserv1.dl.ac.uk>,
un691cs at genius.embnet.dkfz-heidelberg.de says...
>>>hello,
>i need some info. Do astrocytes express any of the following substances ?
>Or could you point me towards a review which additional info ?
>some of these factors are neurotransmitters, so this makes me wonder:
>vip, tph,somatostatin, subst. P, cck,neuropept. Y, CGRP, LIF,
>enkaphilin.
>>thanks in advance,
>>clemens, heidelberg
> Generally, only nerve cells (neurons) are involve in nerotransmitter
secretion-signalling. Signalling is the function of neurons. Astrocytes
are involve in many other functions-mostly in the maintenance of the blood
brain barrier. It has been postulated that astrocytes are involve in the
policing of excess K+ ions due to the constant firing of brain neurons. The
permeability of astrocytes allows for uptake of Cl- ions thereby maintaining
electrical neutrality. Astrocytes are considered as the third major class
of glial cell, which are the most numourous, and at the same time the most
enigmatic.
Their end-feet, formed on the surface of the nerve, brain and spinal cord,
giving rise to the glial membrane (or limiting sheath) that surrounds the
central nervous system as a protective covering. Moreover, astrocytes are
involve in the clean-up of the surrounding brain region and spinal cord.
Take a look at Newman, E. A. 1986. High Potassium conductance in
astrocyte endfeet Science 233:453-454. for mor information.
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________________________________________
Johnny Sandaire
PhD Candidate
Behavioral Neuroscience/
Neuropsychopharmacology
Boston University School of Medicine
jsandair at acs.bu.edu
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