Magnetic resonance imaging and spectroscopy in a mouse model of schizophrenia

Preclinical (1)H-MRS neurochemical profiling in neurological and psychiatric disorders

The ongoing development of animal models of neurological and psychiatric disorders in combination with the development of advanced nuclear magnetic resonance (NMR) techniques and instrumentation has led to increased use of in vivo proton NMR spectroscopy ((1)H-MRS) for neurochemical analyses. (1)H-MRS is one of only a few analytical methods that can assay in vivo and longitudinal neurochemical changes associated with neurological and psychiatric diseases, with the added advantage of being a technique that can be utilized in both preclinical and clinical studies. In this review, recent progress in the use of (1)H-MRS to investigate animal models of neurological and psychiatric disorders is summarized with examples from the literature and our own work.

MRI in animal models of psychiatric disorders

Here we describe MRI and (1)H MRS protocols for the investigation of animal models (mainly mice and rats) of psychiatric disorders. The introduction provides general findings from brain imaging studies in patients with psychiatric diseases and refers to general rules regarding the use of animal models in research. The methods section includes a selection of basic 9.4 T MRI and MRS protocols applicable for the investigation of animal models of psychiatric disorders (T1W, T2W, FLAIR, (1)H MRS). The notes section discusses in detail a series of factors that can influence the outcome of the experiment: from animal handling, stress-triggering aspects, and experimental design-related factors to technical aspects that affect T (1) and T (2) measurements.

Antipsychotic drugs dose-dependently suppress the spontaneous hyperactivity of the chakragati mouse

The chakragati (ckr) mouse has been proposed as a model of aspects of schizophrenia. The mice, created serendipitously as a result of a transgenic insertional mutation, exhibit spontaneous circling, hyperactivity, hypertone of the dopamine system, reduced social interactions, enlarged lateral ventricles, deficits in pre-pulse inhibition of acoustic startle and deficits in latent inhibition of conditioned learning. In this study, the dose-dependent effects of antipsychotic drugs (haloperidol, pimozide, risperidone, clozapine, olanzapine, ziprasidone, quetiapine and aripiprazole) on the spontaneous hyperactivity of the mice were investigated. All the antipsychotic drugs tested dose-dependently suppressed spontaneous hyperactivity. Aripriprazole, which is known to be a dopamine D2 receptor partial agonist, exhibited a tri-phasic dose-response, initially suppressing hyperactivity at low doses, having little effect on hyperactivity at intermediate doses, and suppressing activity again at high doses. These data suggest that the spontaneous circling and hyperactivity of the ckr mouse may allow screening of candidate antipsychotic compounds, distinguishing compounds with aripriprazole-like profiles.