The adenosine antagonist theophylline impairs P50 auditory sensory gating in normal subjects

被引:0
作者
Ghisolfi E.S. [1 ,2 ]
Prokopiuk A.S. [1 ]
Becker J. [3 ,4 ]
Ehlers J.A. [4 ]
Belmonte-De-Abreu P. [2 ]
Souza D.O. [1 ]
Lara D.R. [5 ,6 ]
机构
[1] Departamento De Bioquímica, Instituto De Ciências Básicas Da Saúde, UFRGS, Porto Alegre, RS
[2] Departamento De Psiquiatria, Hospital De Clínicas De Porto Alegre, UFRGS, Porto Alegre, RS
[3] Unidade De Neurofisiologia, Universidade Luterana Do Brasil, ULBRA, Canoas, RS
[4] Departamento De Neurologia, HCPA, UFRGS, Porto Alegre, RS
[5] Departamento De Ciências Fisiológicas, Faculdade De Biociências, PUCRS, Porto Alegre, RS
[6] Faculdade De Biociências, PUC-RS, Porto Alegre, RS, 90619-900, Av. Ip. 6681 Pred. 12 A
关键词
Adenosine; Event related potentials; P50; Purinergic system; Schizophrenia; Sensory gating; Theophylline;
D O I
10.1016/S0893-133X(02)00337-8
中图分类号
学科分类号
摘要
In the P50 suppression paradigm, when two auditory stimuli are presented 500 ms apart, the amplitude of the second response (S2), compared with the first (S1), is markedly attenuated in healthy subjects. This is an index of sensory gating. Most schizophrenic patients fail to inhibit the P50 response to the second stimulus, which is assumed to reflect an inhibitory deficit. Adenosine is a neuromodulator with mostly inhibitory activity which is released by physiological stimuli. Since this inhibitory pattern resembles the phenomenon of sensory gating, the contribution of adenosine to P50 suppression was investigated in normal volunteers after treatment with the adenosine antagonist theophylline or placebo. P50 recordings were conducted in thirteen healthy subjects at baseline and 5, 30, 60, and 90 min after oral administration of theophylline (0.66 mg/kg, maximum dose of 500 mg) or placebo in a cross-over design. Baseline results from 17 drug-treated schizophrenic patients were included for comparison. Compared with placebo, theophylline treatment significantly increased P50 ratio (S2/S1) from 0.28 ± 0.03 to 0.82 ± 0.11 at 30 min and 0.61 ± 0.07 at 60 min (mean ± SEM), which were not significantly different from the schizophrenia group (0.74 ± 0.05). The increased P50 ratio by theophylline was due to a combined decrease in S1 and increase in S2 amplitude. The impairment of P50 suppression by theophylline in normal subjects suggests a modulatory role of adenosine in sensory gating, which may be related to P50 suppression deficit in schizophrenia and is in agreement with a hypoadenosinergic model of schizophrenia. © 2002 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.
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页码:629 / 637
页数:8
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[11]  
Deckert J., Nothen M.M., Bryant S.P., Schuffenhauer S., Schofield P.R., Spurr N.K., Propping P., Mapping of the human adenosine A2a receptor gene: Relationship to potential schizophrenia loci on chromosome 22q and exclusion from the CATCH 22 region, Hum Genet, 99, pp. 326-328, (1997)
[12]  
Ferre S., Euler G.V., Johansson B., Fredholm B., Fuxe K., Stimulation of high affinity adenosine A2 receptors decreases the affinity of dopamine D2 receptors in rat striatal membranes, Proc Natl Acad Sci USA, 88, pp. 7238-7241, (1991)
[13]  
Ferre S., Adenosine-dopamine interactions in the ventral striatum: Implications for the treatment of schizophrenia, Psychopharmacology (Berl), 133, pp. 107-120, (1997)
[14]  
Fredholm B.B., Batting K., Holmen J., Nehlig A., Zvartau E., Actions of caffeine in the brain with special reference to factors that contribute to its widespread use, Pharmacol Rev, 51, pp. 83-153, (1999)
[15]  
Freedman R., Adler L.E., Waldo M.C., Pachtman E., Franks R.D., Neurophysiological evidence for a defect in inhibitory pathways in schizophrenia: Comparison of medicated and drug-free patients, Biol Psychiatry, 18, pp. 537-551, (1983)
[16]  
Freedman R., Coon H., Myles-Worsley M., Orr-Urtreger A., Olincy A., Davis A., Polymeropoulos M., Holik J., Hopkins J., Hoff M., Rosenthal J., Waldo M.C., Reimherr F., Wender P., Yaw J., Young D.A., Breese C.R., Adams C., Patterson D., Adler L.E., Kruglyak L., Leonard S., Byerley W., Linkage of a neurophysiological deficit in schizophrenia to a chromosome 15 locus, Proc Natl Acad Sci USA, 94, pp. 587-592, (1997)
[17]  
Freedman R., Adams C.E., Leonard S., The alpha7-nicotinic acetylcholine receptor and the pathology of hippocampal interneurons in schizophrenia, J Chem Neuroanat, 20, pp. 299-306, (2000)
[18]  
Hershman K.M., Freedman R., Bickford P.C., GABAB antagonists diminish the inhibitory gating of auditory response in the rat hippocampus, Neurosci Lett, 190, pp. 133-136, (1995)
[19]  
Hetrick W.P., Sandman C.A., Bunney W.E. Jr., Jin Y., Potkin S.G., White M.H., Gender differences in gating of the auditory evoked potential in normal subjects, Biol Psychiatry, 39, pp. 51-58, (1996)
[20]  
Kafka S.H., Corbett R., Selective adenosine A2A receptor/dopamine D2 receptor interactions in animal models of schizophrenia, Eur J Pharmacol, 295, pp. 147-154, (1996)