SynGAP1 is a complex protein with several functions that may be regulated temporally via complex isoforms.[8] A well-documented function of SynGAP1 involves NMDA receptor-mediated synaptic plasticity and membrane insertion of AMPA receptors through the suppression of upstream signaling pathways. However, SynGAP1 has also been shown to function cooperatively with Unc51.1 in axon formation. One way SynGAP1 affects these processes is through the MAP kinase signaling pathway by attenuation of Ras signalling. However, alternative splicing and multiple translational start sites have been shown to cause opposing effects, illustrating the importance of multiple functional domains that reside within the c- and n-termini. For example, the expression of an α1 or α2 c-terminal variant of SynGAP1 will either increase or decrease synaptic strength, respectively. Overall, SynGAP1 is essential for development and survival, which is evident as knockout mice die perinatally.