Migration to neurospheres and expression of chemokine receptors of RS-MSCs and SR-MSCs. (A) Migration of RS-MSCs (•) and SR-MSCs (▴) in response to neurospheres. Migration was followed by fluorimetry of underside of opaque inserts in the transwells. Data are expressed as mean and range of 2 values. (B) RT-PCR assays of total RNA for chemokine receptors. Lane 1: RS-MSCs. Lane 2: SR-MSCs. Lane 3: Unsorted MSCs.