Integrins govern cellular adhesion and transmit signals leading to activation of intracellular signaling pathways aimed to prevent apoptosis. Here we report that attachment of oligodendrocytes (OLs) to fibronectin via avss3 integrin receptors rendered the cells more resistant to apoptosis than the cells attached to laminin via a6ss1 integrins. Investigation of molecular mechanisms involved in avss3 integrin-mediated cell survival revealed that ligation of the integrin with fibronectin results in higher expression of activated Lyn kinase. Both in OLs and in the mouse brain, Lyn selectively associates with avss3 integrin, not with avss5 integrin, leading to suppression of acid sphingomyelinase activity and preventing ceramide-mediated apoptosis. In OLs, knockdown of Lyn with siRNA resulted in OL apoptosis with concomitant accumulation of C16-ceramide due to activation of acid sphingomyelinase (ASMase) and sphingomyelin hydrolysis. Knocking down ASMase partially protected OLs from apoptosis. In the brain, ischemia/reperfusion (IR) triggered rearrangements in avss3 integrin/Lyn kinase complex leading to disruption of Lyn kinase-mediated suppression of ASMase activity. Thus, co-immunoprecipitation studies revealed an increased association of avss3 integrin/Lyn kinase complex with ionotropic glutamate receptor subunits, GluR2 and GluR4, after cerebral IR. Sphingolipid analysis of the brain demonstrated significant accumulation of ceramide and sphingomyelin hydrolysis. The data suggest a novel mechanism for regulation of ASMase activity during cell adhesion in which Lyn acts as a key upstream kinase that may play a critical role in cerebral IR injury.