Cerebellar GABAergic correlates of cognition-mediated verbal fluency in physiology and schizophrenia.
OBJECTIVE
Defective cerebellar GABAergic inhibitory control may participate to the cognitive impairments seen in SZ. We tested the prediction of a model for the relationship between cerebellar GABA concentration and the associative/executive processes required by verbal fluency in patients with schizophrenia (SZ) and matched healthy controls (HC).


METHOD
Magnetic resonance spectroscopy of GABA was performed using a 3 Tesla scanner and verbal fluency assessed by the Controlled Word (WFT) and Semantic (SFT) Fluency tests. Cerebellar GABA measurements were obtained using the MEGA-PRESS acquisition sequence. Linear correlations between cerebellar GABA levels and the WFT, SFT score were performed to test differences between correlation coefficients of SZ and HC. Quantile regressions between GABA levels and the WFT score were performed.


RESULTS
Higher cerebellar GABA concentration was associated in SZ with lower phonemic fluency and reduced number of switches among subcategories as opposed to what observed in HC (with higher cerebellar GABA associated with higher number of words and phonemic switches). GABA levels explained phonemic fluency in SZ performing above the group mean.


CONCLUSION
Studying cerebellar GABA provides a valid heuristic to explore the molecular mechanisms of SZ. This is crucial for developing pharmacological treatments to improve cognition and functional recovery in SZ.
['Piras|F|F|', 'Piras|F|F|', 'Banaj|N|N|', 'Ciullo|V|V|', 'Vecchio|D|D|', 'Edden|R A E|RAE|', 'Spalletta|G|G|0000-0002-7432-4249']
D000328:Adult D016022:Case-Control Studies D002531:Cerebellum D003071:Cognition D056344:Executive Function D005260:Female D059330:GABAergic Neurons D006801:Humans D007806:Language Disorders D008279:Magnetic Resonance Imaging D008297:Male D012559:Schizophrenia D014705:Verbal Behavior
verbal fluency schizophrenia cognition GABA magnetic resonance spectroscopy cerebellum