FGF14 isoforms are widely expressed in a number of brain regions during development, and expressed in more focal fashion in adult brain [281]. FGF14 lacks signal sequences and may thus play intracellular roles that include interactions with ion channels and intracellular signal transducing proteins [282]. The FGF14 gene is a candidate to play roles in control of midbrain dopamine neurons, based on mouse strain comparison studies [283, 284]. FGF14 expression is upregulated by methylphenidate [285]. FGF14 knockout mice display substantial alterations in learning and aspects of long term potentiation [286]. Humans with FGF14 mutations also display cognitive changes [121]. While we are aware of no small molecule FGF14 agonists or antagonists, such development might well benefit from the substantial progress in producing small molecule peptidomimetics in other fields.
