The Journal of Neuroscience, September 1, 2001, 21(17):6802-6809
Agrin Differentially Regulates the Rates of Axonal and Dendritic
Elongation in Cultured Hippocampal Neurons
Kristina B.
Mantych and
Adriana
Ferreira
Institute for Neuroscience and Department of Cell and Molecular
Biology, Northwestern University Medical School, Chicago, Illinois
60611
In the present study, we examined the role of agrin in axonal and
dendritic elongation in central neurons. Dissociated hippocampal neurons were grown in the presence of either recombinant agrin or
antisense oligonucleotides designed to block agrin expression. Our
results indicate that agrin differentially regulates axonal and
dendritic growth. Recombinant agrin decreased the rate of elongation of
main axons but induced the formation of axonal branches. On the other
hand, agrin induced both dendritic elongation and dendritic branching.
Conversely, cultured hippocampal neurons depleted of agrin extended
longer, nonbranched axons and shorter dendrites when compared with
controls. These changes in the rates of neurite elongation and
branching were paralleled by changes in the composition of the
cytoskeleton. In the presence of agrin, there was an upregulation of
the expression of microtubule-associated proteins MAP1B, MAP2, and tau.
In contrast, a downregulation of the expression of these MAPs was
detected in agrin-depleted cells. Taken collectively, these results
suggest an important role for agrin as a trigger of the transcription
of neuro-specific genes involved in neurite elongation and branching in
central neurons.
Key words:
agrin; neurite outgrowth; microtubule-associated
proteins; CREB; antisense oligonucleotides; axons and
dendrites
Copyright © 2001 Society for Neuroscience 0270-6474/01/21176802-08$05.00/0
Previous Article | Next Article
