Netrin-5 is highly expressed in neurogenic regions of the adult brain.
Mammalian netrin family proteins are involved in targeting of axons, neuronal migration, and angiogenesis and act as repulsive and attractive guidance molecules. Netrin-5 is a new member of the netrin family with homology to the C345C domain of netrin-1. Unlike other netrin proteins, murine netrin-5 consists of two EGF motifs of the laminin V domain (LE) and the C345C domain, but lacks the N-terminal laminin VI domain and one of the three LE motifs. We generated a specific antibody against netrin-5 to investigate its expression pattern in the rodent adult brain. Strong netrin-5 expression was observed in the olfactory bulb (OB), rostral migrate stream (RMS), the subventricular zone (SVZ), and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus, where neurogenesis occurs in the adult brain. In the SVZ and RMS, netrin-5 expression was observed in Mash1-positive transit-amplifying cells and in Doublecortin (DCX)-positive neuroblasts, but not in GFAP-positive astrocytes. In the OB, netrin-5 expression was maintained in neuroblasts, but its level was decreased in NeuN-positive mature neurons. In the hippocampal SGZ, netrin-5 was observed in Mash1-positive cells and in DCX-positive neuroblasts, but not in GFAP-positive astrocytes, suggesting that netrin-5 expression occurs from type 2a to type 3 cells. These data suggest that netrin-5 is produced by both transit-amplifying cells and neuroblasts to control neurogenesis in the adult brain.
Department of Anatomy and Neuroscience, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan.
Satoru
S
Yamagishi
Research Center for Child Mental Development, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan.
Kohei
K
Yamada
Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan.
Masato
M
Sawada
Department of Anatomy and Neuroscience, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan.
Suguru
S
Nakano
Research Center for Child Mental Development, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan ; Department of Psychiatry, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan.
Norio
N
Mori
Department of Developmental and Regenerative Biology, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan.
Kazunobu
K
Sawamoto
Department of Anatomy and Neuroscience, Hamamatsu University School of Medicine Hamamatsu, Shizuoka, Japan.
Kohji
K
Sato
adult neurogenesis; axon guidance; netrin; rostral migratory stream; subgranular zone; subventricular zone