Journal: The Journal of Neuroscience

Article Title: Local and Target-Derived Brain-Derived Neurotrophic Factor Exert Opposing Effects on the Dendritic Arborization of Retinal Ganglion CellsIn Vivo

doi: 10.1523/jneurosci.22-17-07639.2002

Figure Lengend Snippet: Figure 1. Altering endogenous retinal and tectal BDNF levels in vivo. Diagrams representing a transverse view of a Xenopus tadpole brain and eye illustrate experimental procedures (see Materials and Methods). RGCs are depicted in red, relative endogenous BDNF expression levels (Cohen-Cory et al., 1996) are depicted in blue, and exogenously applied factors are depicted in green. A, Effects of altered tectal neurotrophins on RGC dendritic arborization. Control, anti-BDNF, or BDNF-treated green fluorescent microspheres were injected into the stage 38 tadpole tectum. At stage 42, RGCs were retrogradely labeled by injecting rhodamine–dextran in the contralateral tectum. At stage 45, dendritic morphologies of double-labeled RGCs were evaluated. A low-power view of a tadpole eye shows green fluorescent microspheres retrogradely transported to the retinal ganglion cell layer, where a rhodamine–dextran-labeled RGC soma can also be visualized (lines denote lens and eye periphery). Scale bar, 50 m. A single-plane, high-power view of a stage 45 retina reveals a rhodamine–dextran-labeled RGC with internalized green fluorescent microspheres. Scale bar, 5 m. B, Effects of altered retinal neurotrophins on RGC dendritic arborization. Control, anti-BDNF, or BDNF-treated microspheres were injected into the stage 38 tadpole retina, and then RGCs were retrogradely labeled at stage 42. The low-power view shows rhodamine–dextran-labeled RGCs and green fluorescent microspheres restricted within the tadpole eye. Scale bar, 200 m. The single-plane, high-power view of a stage 45 retina reveals the morphology of a rhodamine– dextran-labeled RGC surrounded by green fluorescent microspheres. Scale bar, 5 m. C, Effects of altered retinal neurotrophins on RGC axonal arborization in the tectum. Control, anti-BDNF, or BDNF-treated microspheres were injected into the stage 43 tadpole retina, and the morphology of DiI- or YFP-labeled RGC axon arbors was visualized 24 and 48 hr later. Confocal microscope images of a control RGC axon at 0 and 24 hr demonstrate normal RGC axon arborization dynamics. Scale bar, 20 m.

Article Snippet: Recombinant human BDNF (rhBDNF) was kindly provided by Amgen (Thousand Oaks, CA), recombinant human neurotrophin-4 (NT-4) was generously provided by Genentech (South San Francisco, CA), and anti-rhBDNF neutralizing antibody (mouse IgG1) was obtained from R & D Systems (Minneapolis, MN).

Techniques: In Vivo, Expressing, Control, Injection, Labeling, Microscopy

Journal: The Journal of Neuroscience

Article Title: Local and Target-Derived Brain-Derived Neurotrophic Factor Exert Opposing Effects on the Dendritic Arborization of Retinal Ganglion CellsIn Vivo

doi: 10.1523/jneurosci.22-17-07639.2002

Figure Lengend Snippet: Figure 2. Tectal BDNF retrogradely enhances RGC dendritic arborization. To determine whether tectal BDNF influences RGC dendritic arborization within the retina, tadpoles received tectal injections of microspheres treated with control, BDNF, or anti-BDNF function-blocking antibodies. Microsphere-containing neurons colabeled with rhodamine–dextran were analyzed morphologically (Fig. 1A). A, Image reconstructions of two rhodamine-labeled RGCs with simple and complex dendritic arbors illustrate differences in dendritic arbor morphologies. B, Images of RGC dendritic arbors reveal that increasing tectal BDNF enhances RGC dendritic arborization, whereas neutralizing endogenous tectal BDNF with function-blocking antibodies reduces RGC dendritic arborization. C, Quantitative analysis reveals that primary dendrite number, branch tip number, branch tips per primary dendrite, and overall dendritic length were significantly enhanced by increasing tectal BDNF and reduced by injecting anti-BDNF into the optic tectum. Scale bar, 5 m. Error bars indicate SEM. p 0.05; p 0.01; p 0.001.

Article Snippet: Recombinant human BDNF (rhBDNF) was kindly provided by Amgen (Thousand Oaks, CA), recombinant human neurotrophin-4 (NT-4) was generously provided by Genentech (South San Francisco, CA), and anti-rhBDNF neutralizing antibody (mouse IgG1) was obtained from R & D Systems (Minneapolis, MN).

Techniques: Control, Blocking Assay, Labeling

Journal: The Journal of Neuroscience

Article Title: Local and Target-Derived Brain-Derived Neurotrophic Factor Exert Opposing Effects on the Dendritic Arborization of Retinal Ganglion CellsIn Vivo

doi: 10.1523/jneurosci.22-17-07639.2002

Figure Lengend Snippet: Figure 4. Retinal BDNF inhibits RGC den- dritic arborization in a dose-dependent man- ner. To determine whether RGCs are sensi- tive to the concentration of BDNF in the retina, Xenopus retinas were microinjected with 1–100 ng/l BDNF or control micro- spheres at the onset of dendritic arborization. Quantitative measures of dendritic arbor morphology revealed a dose-dependent re- sponse to BDNF. The highest concentration of BDNF most dramatically decreased pri- mary dendrite number, branch tip number, tips per dendrite, and dendrite length versus control. Error bars indicate SEM. p 0.05; p 0.01; p 0.001.

Article Snippet: Recombinant human BDNF (rhBDNF) was kindly provided by Amgen (Thousand Oaks, CA), recombinant human neurotrophin-4 (NT-4) was generously provided by Genentech (South San Francisco, CA), and anti-rhBDNF neutralizing antibody (mouse IgG1) was obtained from R & D Systems (Minneapolis, MN).

Techniques: Concentration Assay, Control

Journal: The Journal of Neuroscience

Article Title: Local and Target-Derived Brain-Derived Neurotrophic Factor Exert Opposing Effects on the Dendritic Arborization of Retinal Ganglion CellsIn Vivo

doi: 10.1523/jneurosci.22-17-07639.2002

Figure Lengend Snippet: Figure 5. RGC dendritic arborization is temporally sensitive to increased reti- nal BDNF levels. To determine whether RGCs were sensitive to enhanced retinal BDNF in a stage-dependent manner, control or BDNF-treated microspheres were injected into Xenopus retinas at stage 38 or 42. A, The morphology of RGC dendritic arbors revealed a stage- dependent response to increased retinal BDNF levels. B–C, Quantitative analy- sis of dendritic differentiation indicates that earlier exposure to exogenous BDNF (stages 38–45) inhibited den- dritic arborization more dramatically than later exposure to BDNF (stages 42–45). Primary dendrite number as well as dendritic branching was signifi- cantly decreased by altering retinal BDNF starting at stage 38 (B), whereas altering retinal BDNF levels from stage 42 onward (C) selectively reduced den- dritic branching without affecting pri- mary dendrite number. Error bars indi- cate SEM. p 0.05; p 0.001. Scale bar, 10 m.

Article Snippet: Recombinant human BDNF (rhBDNF) was kindly provided by Amgen (Thousand Oaks, CA), recombinant human neurotrophin-4 (NT-4) was generously provided by Genentech (South San Francisco, CA), and anti-rhBDNF neutralizing antibody (mouse IgG1) was obtained from R & D Systems (Minneapolis, MN).

Techniques: Control, Injection

Journal: The Journal of Neuroscience

Article Title: Local and Target-Derived Brain-Derived Neurotrophic Factor Exert Opposing Effects on the Dendritic Arborization of Retinal Ganglion CellsIn Vivo

doi: 10.1523/jneurosci.22-17-07639.2002

Figure Lengend Snippet: Figure 6. RGC axon arbor complexity is unaffected by retinal BDNF levels. To deter- mine whether retinal BDNF influences RGC axon arborization at a distance, tadpoles were intraocularly injected with control, BDNF-, or anti-BDNF-treated microspheres, and the re- sulting changes in RGC axon arbor dynamics were compared with tectally applied BDNF (Cohen-Cory and Fraser, 1995; Lom and Co- hen-Cory, 1999). A, Individual RGC axon ar- bor morphologies of control, retinal BDNF, and tectal BDNF at 0 and 24 hr after treat- ment demonstrate that only tectally applied BDNF significantly alters RGC axon ar- borization. B, C, Altering retinal BDNF lev- els had no significant effects on RGC axon arbor complexity as measured by the in- crease in total branch number (B) and total arbor length (C) 24 and 48 hr after treatment ( p 0.05). Error bars indicate SEM. Scale bar, 20 m.

Article Snippet: Recombinant human BDNF (rhBDNF) was kindly provided by Amgen (Thousand Oaks, CA), recombinant human neurotrophin-4 (NT-4) was generously provided by Genentech (South San Francisco, CA), and anti-rhBDNF neutralizing antibody (mouse IgG1) was obtained from R & D Systems (Minneapolis, MN).

Techniques: Injection, Control