Schizophrenia is a
neurodevelopmental disorder featuring complex aberrations in the structure, wiring, and chemistry of multiple neuronal systems. The abnormal developmental trajectory of the brain appears to be established during gestation, long before clinical symptoms of the disease appear in early adult life. Many genes are associated with
schizophrenia, however, altered expression of no one gene has been shown to be present in a majority of
schizophrenia patients. How does altered expression of such a variety of genes lead to the complex set of abnormalities observed in the schizophrenic brain? We hypothesize that the
protein products of these genes converge on common neurodevelopmental pathways that affect the development of multiple neural circuits and
neurotransmitter systems. One such neurodevelopmental pathway is Integrative Nuclear FGFR1 Signaling (INFS). INFS integrates diverse neurogenic signals that direct the postmitotic development of embryonic stem cells, neural progenitors and immature neurons, by direct gene reprogramming. Additionally, FGFR1 and its partner
proteins link multiple upstream pathways in which
schizophrenia-linked genes are known to function and interact directly with those genes. A th-fgfr1(tk-) transgenic mouse with impaired
FGF receptor signaling establishes a number of important characteristics that mimic human
schizophrenia - a neurodevelopmental origin, anatomical abnormalities at birth, a delayed onset of behavioral symptoms, deficits across multiple domains of the disorder and symptom improvement with typical and atypical
antipsychotics,
5-HT antagonists, and
nicotinic receptor agonists. Our research suggests that altered
FGF receptor signaling plays a central role in the developmental abnormalities underlying
schizophrenia and that
nicotinic agonists are an effective class of compounds for the treatment of
schizophrenia.