Abstract
Formation of an axon is the first morphological evidence of neuronal polarization, visible as a profound outgrowth of the axon compared with sibling neurites. One unsolved question on the mechanism of axon formation is the role of axon outgrowth in axon specification. This question was difficult to assess, because neurons freely extend their neurites in a conventional culture. Here, we leveraged surface nano/micro-modification techniques to fabricate a template substrate for constraining neurite lengths of cultured neurons. Using the template, we asked (i) Do neurons polarize even if all neurites cannot grow sufficiently long? (ii) Would the neurite be fated to become an axon if only one was allowed to grow long? A pattern with symmetrical short paths (20 μm) was used to address the former question, and an asymmetrical pattern with one path extended to 100 μm for the latter. Axon formation was evaluated by tau-1/MAP2 immunostaining and live-cell imaging of constitutively-active kinesin-1. We found that (1) neurons cannot polarize when extension of all neurites is restricted and that (2) when only a single neurite is permitted to grow long, neurons polarize and the longest neurite becomes the axon. These results provide clear evidence that axon outgrowth is required for its specification. Axon formation: no growth, no specification One unsolved question on the mechanism of axon formation by cultured neurons was the role of axon outgrowth in axon specification. Using micropatterned surfaces to extrinsically regulate lengths of individual neurites, we show that differential outgrowth of a future axon is required for axon specification. The results presented here provide clear evidence that an axon cannot be specified without sufficient outgrowth.
| Original language | English |
|---|---|
| Pages (from-to) | 904-910 |
| Number of pages | 7 |
| Journal | Journal of Neurochemistry |
| Volume | 123 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2012 Dec |
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Keywords
- hippocampal neuron
- kinesin
- live-cell imaging
- micropatterned surface
- neuronal polarization
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience
Cite this
Differential neurite outgrowth is required for axon specification by cultured hippocampal neurons. / Yamamoto, Hideaki; Demura, Takanori; Morita, Mayu; Banker, Gary A.; Tanii, Takashi; Nakamura, Shun.
In: Journal of Neurochemistry, Vol. 123, No. 6, 12.2012, p. 904-910.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Differential neurite outgrowth is required for axon specification by cultured hippocampal neurons
AU - Yamamoto, Hideaki
AU - Demura, Takanori
AU - Morita, Mayu
AU - Banker, Gary A.
AU - Tanii, Takashi
AU - Nakamura, Shun
PY - 2012/12
Y1 - 2012/12
N2 - Formation of an axon is the first morphological evidence of neuronal polarization, visible as a profound outgrowth of the axon compared with sibling neurites. One unsolved question on the mechanism of axon formation is the role of axon outgrowth in axon specification. This question was difficult to assess, because neurons freely extend their neurites in a conventional culture. Here, we leveraged surface nano/micro-modification techniques to fabricate a template substrate for constraining neurite lengths of cultured neurons. Using the template, we asked (i) Do neurons polarize even if all neurites cannot grow sufficiently long? (ii) Would the neurite be fated to become an axon if only one was allowed to grow long? A pattern with symmetrical short paths (20 μm) was used to address the former question, and an asymmetrical pattern with one path extended to 100 μm for the latter. Axon formation was evaluated by tau-1/MAP2 immunostaining and live-cell imaging of constitutively-active kinesin-1. We found that (1) neurons cannot polarize when extension of all neurites is restricted and that (2) when only a single neurite is permitted to grow long, neurons polarize and the longest neurite becomes the axon. These results provide clear evidence that axon outgrowth is required for its specification. Axon formation: no growth, no specification One unsolved question on the mechanism of axon formation by cultured neurons was the role of axon outgrowth in axon specification. Using micropatterned surfaces to extrinsically regulate lengths of individual neurites, we show that differential outgrowth of a future axon is required for axon specification. The results presented here provide clear evidence that an axon cannot be specified without sufficient outgrowth.
AB - Formation of an axon is the first morphological evidence of neuronal polarization, visible as a profound outgrowth of the axon compared with sibling neurites. One unsolved question on the mechanism of axon formation is the role of axon outgrowth in axon specification. This question was difficult to assess, because neurons freely extend their neurites in a conventional culture. Here, we leveraged surface nano/micro-modification techniques to fabricate a template substrate for constraining neurite lengths of cultured neurons. Using the template, we asked (i) Do neurons polarize even if all neurites cannot grow sufficiently long? (ii) Would the neurite be fated to become an axon if only one was allowed to grow long? A pattern with symmetrical short paths (20 μm) was used to address the former question, and an asymmetrical pattern with one path extended to 100 μm for the latter. Axon formation was evaluated by tau-1/MAP2 immunostaining and live-cell imaging of constitutively-active kinesin-1. We found that (1) neurons cannot polarize when extension of all neurites is restricted and that (2) when only a single neurite is permitted to grow long, neurons polarize and the longest neurite becomes the axon. These results provide clear evidence that axon outgrowth is required for its specification. Axon formation: no growth, no specification One unsolved question on the mechanism of axon formation by cultured neurons was the role of axon outgrowth in axon specification. Using micropatterned surfaces to extrinsically regulate lengths of individual neurites, we show that differential outgrowth of a future axon is required for axon specification. The results presented here provide clear evidence that an axon cannot be specified without sufficient outgrowth.
KW - hippocampal neuron
KW - kinesin
KW - live-cell imaging
KW - micropatterned surface
KW - neuronal polarization
UR - http://www.scopus.com/inward/record.url?scp=84870607892&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84870607892&partnerID=8YFLogxK
U2 - 10.1111/jnc.12001
DO - 10.1111/jnc.12001
M3 - Article
C2 - 22928776
AN - SCOPUS:84870607892
VL - 123
SP - 904
EP - 910
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 6
ER -