[Abstract Title]. - Society for Neuroscience

migratory response: the class 3 semaphorins (SEMA3A/3F) and vascular endothelial growth
factor A (VEGF). VEGF is a major regulator of vasculogenesis and vascular permeability,
interacting with receptor tyrosine kinases Flt-1 and Flk-1 on endothelial cells. Recent evidence
indicates that VEGF has additional non-vascular functions. In particular, the identification of
NRPs as co-receptors for VEGF, as well as the detection of their receptors on neurons, suggests
that VEGF could act directly on neurons to produce effects such survival and migration. In this
study, the possible interactions between VEGF, blood vessels and the GnRH-system have been
tested. We first visualized the presence of a network of blood vessels along peripherin-positive
olfactory axons and migrating GnRH neurons. In embryonic mice, blood vessels, stained with
lectin IsoB4, were seen around the olfactory placode, the vomeronasal organ, as well as in the
nasal mesenchyme, during the appearance and migration of GnRH neurons. Then, by using RT-
PCR and enzymatic staining of VEGF-LacZ reporter mice, we found that VEGF is abundantly
expressed in the developing olfactory structures. Moreover, FACS-isolated embryonic GFP-
GnRH neurons expressed specific transcripts for VEGF and its receptor Flt-1. We found that
GN11 cells-used as a model of migrating GnRH neurons- also express these molecules and
respond to VEGF. Functionally, we observed that the latter promotes their survival and
stimulates the chemomigration of GN11 cells by activating PI3K and MAPK pathways. Taken
together, these results indicate that GnRH neuron migration and development are modulated by
VEGF signalling, suggesting the existence of a „cross-talk‟ between the vascular and GnRHneuronal
systems.
Disclosures: A. Cariboni , None; C. Ruhrberg, None; S. Rakic, None; K. Davidson, None; E.
Dozio, None; R. Maggi, None; J.G. Parnavelas, None.
Poster
231. Dendrite Growth and Branching: Signaling
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 231.1/B14
Topic: A.04.i. Dendritic growth and branching
Support: Canadian Institutes of Health Reserach FRN:72027622 to FJV and SR
Natural Sciences and Engineering Research Council Doctoral Grant to LAT
Natural Sciences and Engineering Research Council Grant to DAL
Title: Teneurin C-terminal associated peptide (TCAP)-1 reverses the behavioral effects of
chronic restraint stress and induces morphological changes in CA3 hippocampal neurons in rats