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. 2012 Oct 5;7(28):2165–2175. doi: 10.3969/j.issn.1673-5374.2012.028.001

Figure 4.

Figure 4

Effect of neutralization of (1) NGF, (2) BDNF, (3) GDNF and (4) NT-3 on neurite counts in either (A) small or (B) large dissociated DRG neurons incubated with or without EG-conditioned medium.

DRG: Dorsal root ganglion; EG: enteric glia; NGF: nerve growth factor; BDNF: brain-derived neurotrophic factor; GDNF: glial cell line-derived neurotrophic factor; NT-3: neurotrophin-3.

(A) Average neurite counts (± SEM) in small DRG neurons plotted over time. (B) Average neurite counts (± SEM) in large DRG neurons plotted over time. Diamonds (–CDN/+aB) represent counts taken from DRG neurons incubated in standard neurobasal medium with neutralizing antibodies. Crosses (–CDN/–aB) represent counts taken from DRG neurons incubated in standard neurobasal medium without neutralizing antibodies. Triangles (+CDN/+aB) represent counts taken from DRG neurons incubated in EG-conditioned medium with neutralizing antibodies. Squares (+CDN/–aB) represent counts taken from DRG neurons incubated in EG-conditioned medium without antibodies.

(1) In both small and large neurons, the addition of anti-NGF neutralizing antibody to EG-conditioned medium resulted in a lowered neurite count compared with that seen in control (bP < 0.01 at days 1 and 3).

(2) Neutralizing antibody to BDNF had no effect on neurite count in small DRG neurons cultured in either conditioned or unconditioned medium, nor did the antibody affect neurite count relative to baseline (A). The antibody had a markedly different effect in large DRG neurons. Neurite count in neurons cultured in conditioned medium was significantly higher than those cultured in conditioned medium with antibody on both day 1 (aP < 0.001) and day 3 (bP < 0.01) (B).

(3) The effect of GDNF antibody on small and large DRG neurons cultured in EG-conditioned medium was not fully clear until three days after baseline count, at which time there was a significant difference (small: cP < 0.05; large: bP < 0.01) in neurite counts of the EG-conditioned medium treatment groups.

(4) In small neurons, anti-NT-3 neutralizing antibody had no significant effect on neurite count in neurons cultured in EG-conditioned medium (A). In large neurons, it resulted in a decrease in the absolute neurite count (bP < 0.01; B) by day 3.

Neurite counts were analyzed with the Kruskal-Wallis test to determine whether at least two groups at the same time point were different. When it was determined that at least two groups were different, pairwise comparisons were conducted using the Mann-Whitney U test with the Bonferroni correction applied.