Cerebral ageing-the role of insulin and insulin-like growth factor signalling: A review

Figure 1 Insulin and insulin-like growth factor signalling pathways-a simplified outline as based on ref. [77]. Low affinity binding between insulin and IGF-1R, and IGF-1 and IR, and IGF-2 and IR is represented by dashed lines. ACh: Acetylcholine; ERK: Extracellular signal-related kinase; GRB: Growth factor receptor-bound protein; IGF-1: Insulin-like growth factor 1; IR: Insulin receptor; IGF-1R: IGF-1 receptor; mTOR: Mammalian target of rapamycin; PLC: Phospholipase C; PKC: Protein kinase C; PI3K: Phosphoinositide 3-kinase; Ras: Signalling proteins involved in cell proliferation (name derived from rat sarcoma).