Isolectin-IB 4 as a vascular stain for the study of adult neurogenesis.

It has been proposed that new neurons in the adult brain might preferentially develop in the immediate vicinity of existing vasculature, an area that has been referred to as a "vascular niche". The most common method for identifying neurons that arise as the result of mitotic activity is to label them with the thymidine analogue bromodeoxyuridine (BrdU), and a nuclear marker for mature neurons (NeuN). Unfortunately, commercially available forms of NeuN and the vasculature stain, RECA-1, are incompatible, as both antibodies are raised in the same species. This technical limitation has impeded the analysis of the relationship between new neurons and existing vasculature. In the present work we show that Isolectin-IB 4, a 114 k Da protein isolated from the seeds of the African legume, Griffonia simplicifolia, can be used to identify vasculature in conjunction with both NeuN and BrdU immunohistochemistry. Isolectin-IB 4 serves as an easy to use and robust marker for obtaining spatial information regarding the proximity of new neurons to vasculature in the mammalian brain.