Table 1.

Effects of recombinant trophic factors on expression of cGMP-gated cationic channels in embryonic cones

Trophic factors, concentration, and number of observations	Response amplitude compared to controls
CNTF (20 ng/ml); n = 27	NS1-a
BDNF (25 ng/ml); n = 13	NS
BDNF (100 ng/ml); n= 11	NS
bFGF (20 ng/ml); n = 15	NS
GDNF (10 ng/ml); n = 25	NS
IGF-1 (20 ng/ml); n = 12	NS
β-neuregulin-1 (10 nm); n = 9	NS
TGFβ1 (1 nm) n = 18	NS

Inside-out patch recordings were made from dissociated E8 chick cones treated with recombinant trophic factors at the indicated concentrations for 12 hr. Responses were evoked by bath application of 100 μm cGMP. Growth factors tested included ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF), basic fibroblast growth factor (bFGF), glial cell line-derived neurotrophic factor (GDNF), insulin-like growth factor-1 (IGF-1), and transforming growth factor-β1. None of these factors produced a statistically significant stimulation of mean response amplitudes compared to controls cultured in the absence of recombinant factors (denoted by NS).

^F1-aIn this experiment, CNTF-treated cells were compared to control cells cultured in the absence of CNTF.