A simple and rapid enzyme-linked immunosorbent assay (ELISA) has been devel
oped to provide an alternative to cell counting to detect increases in cell
survival in primary neuronal cultures. This sensitive assay has the advant
age of being less time consuming and labour intensive than cell counting, c
an be used to quantify cell survival and is more accurate than estimation m
ethods of counting. The ELISA uses an antibody raised to GAP-43, a growth-a
ssociated protein which is strongly expressed by developing and regeneratin
g neurones. The effects of nerve growth factor (NGF), neurotrophin-3 (NT-3)
and brain-derived neurotrophic factor (BDNF) on GAP-43 immunoreactivity in
dissociated primary cultures of rat and chick dorsal root ganglia have bee
n compared to results obtained by cell counting. Data show that human NGF p
roduced the greatest increase in GAP-43-immunoreactive neurones in both spe
cies; this increase in immunoreactivity correlated well with the increased
survival shown by cell count data. Results prove that the ELISA can also be
used to accurately detect small changes in cell survival as seen with NT-3
and BDNF, or potentiation of the effects obtained with the trophic factor
NT-3. In conclusion, this ELISA may be a useful tool to detect neurotrophic
effects of unknown agents or novel neurotrophins. (C) 1999 Published by El
sevier Science B.V. All rights reserved.