Zebrafish embryos expressed integrin αVβ3 at 48 hpf but not at 24 hpf. (A) The 48-hpf zebrafish embryos were fixed and incubated with the LM609 antibody. LM609 immunoreactivity was revealed using a rhodamine-labeled fluorescent secondary antibody and preparations were examined using confocal imaging. At 48 hpf, LM609 immunoreactivity specifically labeled cells along the dorsal spinal cord (asterisks), the location of Rohon-Beard cells (RBs). LM609 also labeled cells in the ventral spinal cord (arrowheads), consistent with the location of motoneurons. (B) In contrast, 24-hpf embryos did not display LM609 immunoreactivity, consistent with an absence of integrin αVβ3 expression at 24 hpf. (C) Pre-incubation of LM609 with 50 μg/ml αVβ3 protein blocked immunoreactivity in 48 hpf embryos, indicating that the labeling was specific for αVβ3. (D) Tg(isl3:GFP) transgenic zebrafish embryos expressed green fluorescent protein (GFP) in RBs under control of the islet3 promoter. (E) LM609 immunoreactivity was present in dorsal cells. (F) GFP and LM609 immunoreactivity colocalized in RB soma and axon tracts. Scale bars: 200 μm (A-C); 20 μm (D, E, F).

T4 increases sodium current in caudal primary motoneurons. (A-C) Tg(hb9:GFP) transgenic embryos were incubated with the αVβ3 antibody LM609. The 48-hpf Tg(hb9:GFP) transgenics displayed LM609 immunoreactivity in dorsal (asterisks) and ventral cells (arrowheads). The ventral immunoreactivity for LM609 colocalized with green fluorescent protein (GFP) in primary motoneurons (C, arrowheads). Images are oriented with dorsal neurons and ventral neurons in the upper left and lower right corners, respectively. Scale bar: 50 μm. (D, E) Caudal primary motoneuron (CaP) INa was recorded for 5 minutes (+ Time) either in the absence (D) or presence of T4 (E). Each trace shows current in response to a -10 mV depolarizing stimulus. (F) At 50 to 55 hpf, zebrafish CaPs showed rapid increases in INa amplitude in response to acute application of T4. The 30 nM T4 application significantly increased CaP INa (n = 5; P < 0.01) compared to controls (n = 5).

Acknowledgments
This image is the copyrighted work of the attributed author or publisher, and ZFIN has permission only to display this image to its users. Additional permissions should be obtained from the applicable author or publisher of the image. Full text @ Neural Dev.