Posterior cingulate gyrus metabolic changes in chronic schizophrenia with generalized cognitive deficits.
N-Methyl-d-aspartate (NMDA) receptor antagonists are known to induce schizophrenia-like psychotic symptoms and cognitive deficits in humans, and have been shown to cause neuronal damage in the posterior cingulate gyrus (PCG) of rodents. Patients with chronic schizophrenia exhibit generalized cognitive deficits, but it remains unclear whether or not the PCG is related to their cognitive dysfunction. To determine what biochemical changes may occur in the PCG of patients with chronic schizophrenia, and to ascertain whether or not such abnormalities may be related to the incidence of cognitive deficits, we obtained cognitive scores and proton magnetic resonance spectra (MRS) from the PCG and the left and right medial temporal lobes (MTL) of 19 patients with schizophrenia and 18 age- and sex-matched normal healthy controls. Compared to the normal controls, the patients with chronic schizophrenia showed significantly worse cognitive performance on verbal and visual memory tests, verbal fluency tests, and the Trail Making Test. The ratio of N-acetylaspartate to creatine and phosphocreatine (NAA/Cr) in the PCG of the patients was significantly lower than that of the controls. Moreover, the NAA/Cr in the PCG of the healthy controls exhibited age-related decline, whereas in the patients with schizophrenia, the corresponding values were consistently low, regardless of age. These findings are thus in accord with current speculation about neuronal dysfunction in the PCG based on the NMDA hypofunction hypothesis regarding the pathophysiology of chronic schizophrenia.
Department of Psychiatry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan. eiji@faculty.chiba-u.jp
Eiji
E
Shimizu
Kenji
K
Hashimoto
Shigehiro
S
Ochi
Goro
G
Fukami
Mihisa
M
Fujisaki
Kaori
K
Koike
Naoe
N
Okamura
Shintaro
S
Ohgake
Hiroki
H
Koizumi
Daisuke
D
Matsuzawa
Lin
L
Zhang
Hiroyuki
H
Watanabe
Michiko
M
Nakazato
Naoyuki
N
Shinoda
Naoya
N
Komatsu
Fuminori
F
Morita
Masaomi
M
Iyo
D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D010054:Brief Psychiatric Rating Scale; D002908:Chronic Disease; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010725:Phosphocreatine / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012559:Schizophrenia / Q000453:epidemiology* / Q000378:metabolism* / Q000503:physiopathology; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000378:metabolism / Q000503:physiopathology; D014888:Wechsler Scales
D016194:Receptors, N-Methyl-D-Aspartate; D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate