Synaptic release of zinc from brain slices: factors governing release, imaging, and accurate calculation of concentration.
Cerebrocortical neurons that store and release zinc synaptically are widely recognized as critical in maintenance of cortical excitability and in certain forms of brain injury and disease. Through the last 20 years, this synaptic release has been observed directly or indirectly and reported in more than a score of publications from over a dozen laboratories in eight countries. However, the concentration of zinc released synaptically has not been established with final certainty. In the present work we have considered six aspects of the methods for studying release that can affect the magnitude of zinc release, the imaging of the release, and the calculated concentration of released zinc. We present original data on four of the issues and review published data on two others. We show that common errors can cause up to a 3000-fold underestimation of the concentration of released zinc. The results should help bring consistency to the study of synaptic release of zinc.
Frederickson
Christopher J
CJ
NeuroBioTex Inc., Galveston, TX 77550, USA. c.j.frederickson@neurobiotex.com
Giblin
Leonard J
LJ
Balaji
Rengarajan V
RV
Rengarajan
Balaji
B
Masalha
Rafik
R
Frederickson
Cathleen J
CJ
Zeng
Yaping
Y
Lopez
Emilio Varea
EV
Koh
Jae-Young
JY
Chorin
Udi
U
Besser
Limor
L
Hershfinkel
Michal
M
Li
Yang
Y
Thompson
Richard B
RB
Krezel
Artur
A
D000818:Animals; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D004396:Coloring Agents; D018891:Dentate Gyrus / Q000254:growth & development / Q000378:metabolism; D003952:Diagnostic Imaging; D004492:Edetic Acid / Q000494:pharmacology; D005260:Female; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D019599:Mossy Fibers, Hippocampal / Q000737:chemistry / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011083:Polycyclic Compounds; D011247:Pregnancy; D011725:Pyridines; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology*; D013572:Synaptic Vesicles / Q000187:drug effects / Q000378:metabolism; D013696:Temperature; D015032:Zinc / Q000378:metabolism*
D004396:Coloring Agents; C451182:FluoZin-3; D005456:Fluorescent Dyes; D011083:Polycyclic Compounds; D011725:Pyridines; C462061:ZnAF-2; D004492:Edetic Acid; D015032:Zinc