Antibodies to β₁ integrins inhibit dendritic growth in rat sympathetic neurons

We have examined the role of integrins in the development of dendrites in embryonic rat sympathetic neurons in vitro. Previous studies have established that exposure to a basement membrane extract (BME) causes these neurons to form dendrites (Lein and Higgins, 1989). The current experiments demonstrate that the dendrite-promoting activity of BME can be markedly inhibited by antibodies directed against the β₁ integrin subunit. Although the specific ∝ integrin sub-unit(s) that mediate the effect of BME on dendritic growth were not identified, it was found that neither the ∝₁, or ∝₄ sub-units, nor RGD-binding integrins were involved to any significant extent. These data suggest that, in addition to their well established role in regulating axonal growth, β₁ integrins also participate in dendritic growth.