TY - JOUR
T1 - Increased saccadic distractibility in tardive dyskinesia
T2 - Functional evidence for subcortical GABA dysfunction
AU - Thaker, G. K.
AU - Nguyen, J. A.
AU - Tamminga, C. A.
N1 - Funding Information:
From the Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland. B&more, MD. Supprted in part by NIMH Grants R03 MH40441-01a nd MH402 79-03. Address reprint reg~e~ts to Dr. G. K. Thaker, Ma&and Psychiatric Research Center, Department of Psychiatry, IJnive&y of Maryland, P.O. Box 21247,B altimore, MD 21228. Received August 17, 1987; revised February 26, 1988.
PY - 1989/1/1
Y1 - 1989/1/1
N2 - In mammals, GABAergic projections from the substantia nigra reticulata to the superior colliculus provide tonic inhibition to tectal neurons involved in the generation of saccades. Dysfunction of this pathway has been shown to produce saccadic "distractibility" in the experimental monkey. In two oculomotor paradigms, control of saccadic eye movements was tested in chronic schizophrenic patients with (n = 18) and without (n = 16) tardive dyskinesia (TD) and normal controls (n = 8). The three groups were matched by mean age; the TD and non-TD patient groups had similar duration of illness, benztropine and chlorpromazine equivalent doses and educational levels. A twofold increase in saccadic distractibility was observed in TD compared to non-TD schizophrenic patients, and both patient groups demonstrated a greater saccadic distractibility than normals. Furthermore, schizophrenic patients (both with and without TD) showed significantly increased latency for "volitional" saccades compared to the normal controls. These findings may provide further evidence for basal ganglia GABA dysfunction in tardive dyskinesia, as well as demonstrate oculomotor abnormalities in schizophrenic individuals.
AB - In mammals, GABAergic projections from the substantia nigra reticulata to the superior colliculus provide tonic inhibition to tectal neurons involved in the generation of saccades. Dysfunction of this pathway has been shown to produce saccadic "distractibility" in the experimental monkey. In two oculomotor paradigms, control of saccadic eye movements was tested in chronic schizophrenic patients with (n = 18) and without (n = 16) tardive dyskinesia (TD) and normal controls (n = 8). The three groups were matched by mean age; the TD and non-TD patient groups had similar duration of illness, benztropine and chlorpromazine equivalent doses and educational levels. A twofold increase in saccadic distractibility was observed in TD compared to non-TD schizophrenic patients, and both patient groups demonstrated a greater saccadic distractibility than normals. Furthermore, schizophrenic patients (both with and without TD) showed significantly increased latency for "volitional" saccades compared to the normal controls. These findings may provide further evidence for basal ganglia GABA dysfunction in tardive dyskinesia, as well as demonstrate oculomotor abnormalities in schizophrenic individuals.
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U2 - 10.1016/0006-3223(89)90146-7
DO - 10.1016/0006-3223(89)90146-7
M3 - Article
C2 - 2563231
AN - SCOPUS:0024562006
SN - 0006-3223
VL - 25
SP - 49
EP - 59
JO - Biological Psychiatry
JF - Biological Psychiatry
IS - 1
ER -