Se. Zerby et Ag. Ewing, ELECTROCHEMICAL MONITORING OF INDIVIDUAL EXOCYTOTIC EVENTS FROM THE VARICOSITIES OF DIFFERENTIATED PC12 CELLS, Brain research, 712(1), 1996, pp. 1-10
Rat pheochromocytoma (PC12) cells have been used as a model of develop
ing neurons to study exocytosis during differentiation. Upon treatment
with nerve growth factor, PC12 cells become more neuronal-like. Using
amperometric detection at carbon fiber microelectrodes, time-resolved
exocytosis of electroactive catecholamines can be observed. The site
of exocytosis has been compared for differentiated and undifferentiate
d cells. Upon differentiation, cells release catecholamines primarily
from varicosities along their neurites with no release from the cell b
ody. In addition, the mean vesicular content is not significantly alte
red upon differentiation although it appears that the distribution of
vesicle content becomes more narrow. The number of release events obse
rved also decreases as the cells become more neuronal in character. It
is possible that the smaller range of vesicle dopamine content and th
e decreased number of release events observed after differentiation ar
e a result of the relocation of the site of exocytosis.