Fig. 3.

Diagrammatic summary of main pathways involved in GLP1 signalling in the brain. PI3K, phosphoinositide-3-kinase; PDK, 3-phosphoinositide-dependent protein kinase; Akt, protein kinase B (PKB), plays a key role in activating downstream regulators of cell metabolism, proliferation and survival; GSK3β, glycogen synthase kinase 3, downstream mediator involved in IDE inactivation, leading to an increase in α synuclein expression, which aggregate into amyloid fibres; FOXO1, Forkhead box O1, involved in maintaining the mitochondrial electron transport chain for ATP generation and fatty acid oxidation, preventing oxidative stress; NFκB, nuclear factor κB regulates microglial activation and the expression of inflammatory mediators such as IL1β and TNFα; cAMP, cyclic AMP, activated by binding of GLP1 to GLP1 receptor; PKA, protein kinase A, activates downstream processes via MAPK pathway; MAPK, mitogen-activated protein kinase, modulates downstream protein kinases involved in regulating cell proliferation, differentiation and apoptosis, maintaining neuronal growth and survival.