TY - JOUR
T1 - Functional magnetic resonance spectroscopy in patients with schizophrenia and bipolar affective disorder
T2 - Glutamate dynamics in the anterior cingulate cortex during a working memory task
AU - Jelen, Luke A.
AU - King, Sinead
AU - Horne, Charlotte M.
AU - Lythgoe, David J.
AU - Young, Allan H.
AU - Stone, James M.
PY - 2019/12
Y1 - 2019/12
N2 - The glutamate system is implicated in the pathophysiology of schizophrenia and mood disorders. Using functional magnetic resonance spectroscopy (
1H-fMRS), it is possible to monitor glutamate dynamically in activated brain areas and may give a closer estimate of glutamatergic neurotransmission than standard magnetic resonance spectroscopy. 14 patients with schizophrenia, 15 patients with bipolar disorder II (BPII) and 14 healthy volunteers underwent a 15 min N-back task in a 48s block design during
1H-fMRS acquisition. Data from the first, second and third 16s group of 8 spectra for each block were analysed to measure levels of glutamate and Glx (glutamate + glutamine), scaled to total creatine (TCr), across averaged 0-back and 2-back conditions. A 6 × 3 repeated-measures analysis of variance (rmANOVA) demonstrated a significant main effect of time for Glx/TCr (P = 0.022). There was a significant increase in Glu/TCr (P = 0.004) and Glx/TCr (P < 0.001) between the final spectra of the 0-back and first spectra of the 2-back condition in the healthy control group only. 2 × 2 rmANOVA revealed a significant time by group interaction for Glx/TCr (P = 0.019) across the 0-back condition, with levels reducing in healthy controls and increasing in the schizophrenia group. While healthy volunteers showed significant increases in glutamatergic measures between task conditions, the lack of such a response in patients with schizophrenia and BPII may reflect deficits in glutamatergic neurotransmission. Abnormal increases during periods of relatively low executive load, without the same dynamic modulation as healthy volunteers with increasing task difficulty, further suggests underlying abnormalities of glutamatergic neurotransmission in schizophrenia.
AB - The glutamate system is implicated in the pathophysiology of schizophrenia and mood disorders. Using functional magnetic resonance spectroscopy (
1H-fMRS), it is possible to monitor glutamate dynamically in activated brain areas and may give a closer estimate of glutamatergic neurotransmission than standard magnetic resonance spectroscopy. 14 patients with schizophrenia, 15 patients with bipolar disorder II (BPII) and 14 healthy volunteers underwent a 15 min N-back task in a 48s block design during
1H-fMRS acquisition. Data from the first, second and third 16s group of 8 spectra for each block were analysed to measure levels of glutamate and Glx (glutamate + glutamine), scaled to total creatine (TCr), across averaged 0-back and 2-back conditions. A 6 × 3 repeated-measures analysis of variance (rmANOVA) demonstrated a significant main effect of time for Glx/TCr (P = 0.022). There was a significant increase in Glu/TCr (P = 0.004) and Glx/TCr (P < 0.001) between the final spectra of the 0-back and first spectra of the 2-back condition in the healthy control group only. 2 × 2 rmANOVA revealed a significant time by group interaction for Glx/TCr (P = 0.019) across the 0-back condition, with levels reducing in healthy controls and increasing in the schizophrenia group. While healthy volunteers showed significant increases in glutamatergic measures between task conditions, the lack of such a response in patients with schizophrenia and BPII may reflect deficits in glutamatergic neurotransmission. Abnormal increases during periods of relatively low executive load, without the same dynamic modulation as healthy volunteers with increasing task difficulty, further suggests underlying abnormalities of glutamatergic neurotransmission in schizophrenia.
KW - Bipolar affective disorder
KW - Functional magnetic resonance spectroscopy
KW - Glutamate
KW - Glx
KW - H-fMRS
KW - Schizophrenia
UR - http://www.scopus.com/inward/record.url?scp=85058422930&partnerID=8YFLogxK
U2 - 10.1016/j.euroneuro.2018.12.005
DO - 10.1016/j.euroneuro.2018.12.005
M3 - Article
C2 - 30558824
SN - 0924-977X
VL - 29
SP - 222
EP - 234
JO - European Neuropsychopharmacology
JF - European Neuropsychopharmacology
IS - 2
ER -
