Recent developments in neurochemical imaging in schizophrenia: an update.

The advent of neurochemical brain imaging methods has provided an opportunity to study the neurochemistry of the human brain in normal and abnormal development. The aim of this article is to provide an update on recent major developments in neurochemical imaging in schizophrenia research. In this concise review, we discuss the major findings on three neurotransmitters, namely dopamine, serotonin and glutamate. The most promising radioligand for D(2)/D(3) neuroreceptor imaging is the agonist [(11)C]PHNO, with higher in vivo affinity for D(3) than D(2) receptors, which can be used to measure amphetamine-induced release of dopamine, and therefore a potential model of dopaminergic alterations in schizophrenia. Recent development of selective radiotracers allow imaging of the serotonin transporter (SERT) using positron emission tomography (PET) with selective tracers such as [(11)C]DASB. Additionally, the glutamatergic hypothesis has evolved from theory to phase III clinical trials of newer agents with novel mechanisms. With the development of newer radioligands and the in vivo application of magnetic resonance spectroscopy (MRS) at relatively high magnetic field strengths, there is ample scope for further neuroimaging advances.