Human and animal models of information processing in schizophrenia

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HUMANAND ANIM?&MXXXSOFINFORMATION FRCEESSINGINmzoHIRENIA

David L. EQ-aff, M.D.

Department of Psy&iatry, M-003; University of California, San Diego: Ia Jolla, CA 92093

mmanardanimlmodel studiesofattentionand infonnationpmcessing canhelpustounderstand the neur&iological basis of s&izo@renia. SirlcethetimeofKraepelinandBleuler,ithasbeenclearthat schizopbrenicpatients~~dysfunctionsininformati~processing. In recentyears,wehaveametounderstard thattheseprecise,time-linked dysfunctions occur inthetimerangeofuptoseveralhundred millisecombafterstimulusintak. Thistimerangeisalso characteristic oftheteqoral course of action of momamineqic neurons thatallowsustolinkattentionalarddopamine theories of schizo@mmia.

Theseprinciples are illustratedbystudies of sensorimotmgatingofthe startleresponseandP50ERPresponsesin~z~cpatientsandin animals. Specifically, schizophrenic patients show a failure of Central nervous system inhibition and a diminution of sensory gating that is ampatiblewiththeories of sensory overload inschizophrenia. Theoretically, such inhibitory failure leads to stimulus inurdation, cognitive fragmentation, and the typical signs and syqtcms of schizophrenia.

Humanpsyd~o@mrmacologicandanimalmodel studiesallowustoun%rsb& how regionally specific and systemic rleumchemi~andneuroaMtcanicdl mani~ations (e.g., incrms4 nucleus accmbens dqamine)altertiese attentional mechanisms. wec!analsoexamine the effects of antipsychotic medications onthese functions. Wecancreateand examinemodelsof information prccess ing functions and thus obtain a relatively specific ideaoftheCNSchangesthatmayhave functional importance inthegrcup ofs&izophrenias. Newhumanandanimalmdeldatawillbedismss4 thatal1mustobetterunderstand the functional significance of mumkmmitter alterations and interactions (e.g., dopamine, m) inschizophrenia.