title: Higher levels of glutamate in the associative-striatum of subjects with prodromal symptoms of schizophrenia and patients with first-episode psychosis.
abstract: The glutamatergic and dopaminergic systems are thought to be involved in the pathophysiology of schizophrenia. Their interaction has been widely documented and may have a role in the neurobiological basis of the disease. The aim of this study was to compare, using proton magnetic resonance spectroscopy ((1)H-MRS), glutamate levels in the precommissural dorsal-caudate (a dopamine-rich region) and the cerebellar cortex (negligible for dopamine) in the following: (1) 18 antipsychotic-naïve subjects with prodromal symptoms and considered to be at ultra high-risk for schizophrenia (UHR), (2) 18 antipsychotic-naïve first- episode psychosis patients (FEP), and (3) 40 age- and sex- matched healthy controls. All subjects underwent a (1)H-MRS study using a 3Tesla scanner. Glutamate levels were quantified and corrected for the proportion of cerebrospinal fluid and percentage of gray matter in the voxel. The UHR and FEP groups showed higher levels of glutamate than controls, without differences between UHR and FEP. In the cerebellum, no differences were seen between the three groups. The higher glutamate level in the precommissural dorsal-caudate and not in the cerebellum of UHR and FEP suggests that a high glutamate level (a) precedes the onset of schizophrenia, and (b) is present in a dopamine-rich region previously implicated in the pathophysiology of schizophrenia.
authors.affiliation: Experimental Psychiatry Laboratory, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Neuropsychiatry Department, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Camilo
authors.initials: C
authors.lastname: de la Fuente-Sandoval
authors.forename: Pablo
authors.initials: P
authors.lastname: León-Ortiz
authors.forename: Rafael
authors.initials: R
authors.lastname: Favila
authors.forename: Sylvana
authors.initials: S
authors.lastname: Stephano
authors.forename: David
authors.initials: D
authors.lastname: Mamo
authors.forename: Jesús
authors.initials: J
authors.lastname: Ramírez-Bermúdez
authors.forename: Ariel
authors.initials: A
authors.lastname: Graff-Guerrero
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002421:Caudate Nucleus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D011618:Psychotic Disorders / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation / Q000502:physiology; D055815:Young Adult
chemical_list: D018698:Glutamic Acid