I am assuming that not only do you need BDNF, you need to make sure the precursor BDNF does not hang around. Lets get some human testing.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035883
Background
Neurons
extend their dendrites and axons to build functional neural circuits,
which are regulated by both positive and negative signals during
development. Brain-derived neurotrophic factor (BDNF) is a positive
regulator for neurite outgrowth and neuronal survival but the functions
of its precursor (proBDNF) are less characterized.
Methodology/Principal Findings
Here
we show that proBDNF collapses neurite outgrowth in murine dorsal root
ganglion (DRG) neurons and cortical neurons by activating RhoA via the
p75 neurotrophin receptor (p75NTR). We demonstrated that the receptor
proteins for proBDNF, p75NTR and sortilin, were highly expressed in
cultured DRG or cortical neurons. ProBDNF caused a dramatic neurite
collapse in a dose-dependent manner and this effect was about 500 fold
more potent than myelin-associated glycoprotein. Neutralization of
endogenous proBDNF by using antibodies enhanced neurite outgrowth
in vitro and
in vivo, but this effect was lost in p75NTR
−/− mice. The neurite outgrowth of cortical neurons from p75NTR deficient (p75NTR
−/−)
mice was insensitive to proBDNF. There was a time-dependent reduction
of length and number of filopodia in response to proBDNF which was
accompanied with a polarized RhoA activation in growth cones. Moreover,
proBDNF treatment of cortical neurons resulted in a time-dependent
activation of RhoA but not Cdc42 and the effect was absent in p75NTR
−/− neurons. Rho kinase (ROCK) and the collapsin response mediator protein-2 (CRMP-2) were also involved in the proBDNF action.
Conclusions
proBDNF
has an opposing role in neurite outgrowth to that of mature BDNF. Our
observations suggest that proBDNF collapses neurites outgrowth and
filopodial growth cones by activating RhoA through the p75NTR signaling
pathway.
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