title: Impairment on the hippocampal-dependent virtual Morris water task in schizophrenia.
abstract: Traditional neuropsychological tests of visual and verbal memory have been used to evaluate memory deficits in schizophrenia. However, these tests cannot be used in non-human animal research, which is important for the discovery of treatments that will improve cognition and for study of the etiology of schizophrenia. To help bridge the gap between human and non-human animal research on hippocampal function in schizophrenia, this study sought to characterize the behavioral performance exhibited by patients using the Morris water task (MWT). The MWT has been shown in human and non-human animal studies to be hippocampus-dependent. In the virtual MWT, human subjects navigate a computer-generated on-screen environment to escape from the "water" by locating a platform. Patients with schizophrenia and controls performed two versions of the virtual MWT: a hippocampal-dependent hidden-platform version, relying on allocentric navigational abilities, and a non-hippocampal-dependent visible-platform version, relying on cued-navigational abilities. Patients traveled further and took longer to find the hidden platform over training blocks and spent less time in the correct quadrant during a probe trial. There was no deficit in the visible-platform condition. These findings identify a behavioral impairment on a hippocampal-dependent task in schizophrenia and support using the MWT in testing animal models of schizophrenia.
authors.affiliation: The Mental Illness and Neuroscience Discovery (MIND) Institute, 1101 Yale Blvd. NE, Albuquerque, New Mexico 87106, USA. fhanlon@themindinstitute.org
authors.forename: Faith M
authors.initials: FM
authors.lastname: Hanlon
authors.forename: Michael P
authors.initials: MP
authors.lastname: Weisend
authors.forename: Derek A
authors.initials: DA
authors.lastname: Hamilton
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Jones
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Thoma
authors.forename: Mingxiong
authors.initials: M
authors.lastname: Huang
authors.forename: Kimberly
authors.initials: K
authors.lastname: Martin
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Yeo
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Miller
authors.forename: Jose M
authors.initials: JM
authors.lastname: Cañive
mesh_terms: D000328:Adult; D003463:Cues; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000209:etiology; D011581:Psychological Tests; D012559:Schizophrenia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D012720:Severity of Illness Index; D013028:Space Perception / Q000502:physiology; D013037:Spatial Behavior / Q000502:physiology*; D011795:Surveys and Questionnaires; D014584:User-Computer Interface; D014796:Visual Perception / Q000502:physiology