QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, January 4, 2006, 26(1):158-168; doi:10.1523/JNEUROSCI.2064-05.2006

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Olypher, A. V. Articles by Fenton, A. A. Search for Related Content PubMed PubMed Citation Articles by Olypher, A. V. Articles by Fenton, A. A.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Cognitive Disorganization in Hippocampus: A Physiological Model of the Disorganization in Psychosis

Andrey V. Olypher,^1 * Daniel Klement,^1 * and André A. Fenton^1,2

¹Institute of Physiology, Academy of Sciences of the Czech Republic, 14220 Prague, Czech Republic, and ²Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Brooklyn, New York 11203

Cognitive coordination refers to processes that organize the timing of activity among neurons without altering individual discharge properties. Coordinating processes allow neural networks to coactivate related representations and prevent the coactivation of unrelated representations. Impaired cognitive coordination, also called cognitive disorganization, is hypothesized to be the core deficit in the disorganized syndrome of schizophrenia (Phillips and Silverstein, 2003), a condition characterized by hallucinations, disorganization, and thought disorder. This disorganization hypothesis is based on the observation that schizophrenic subjects are impaired at segregating relevant and irrelevant stimuli and selectively using associations between relevant cues. We report that injecting the neural activity blocker tetrodotoxin (TTX) into one hippocampus persistently coactivated pyramidal cells in the uninjected hippocampus that initially discharged independently. In accord with the definition of cognitive disorganization, pyramidal cell firing rates only changed for 15 min and did not accompany the coactivation. The TTX-induced coactivity was maximal at gamma periods, consistent with altered gamma oscillations and disorganization in schizophrenia. A network model confirmed that increasing the coupling of weakly associated cells impairs the selective activation and inhibition of stored spatial representations. This TTX-induced cognitive disorganization correctly predicted that the same TTX injection selectively impaired the ability of rats to segregate relevant associations among distal spatial stimuli from irrelevant local stimuli (Wesierska et al., 2005). The TTX-induced coactivity of hippocampal pyramidal cell discharge has construct and predictive validity as a physiological model of psychosis-related disorganization.

Key words: cognitive coordination; cognitive disorganization; reversible lesion; dynamic grouping; parasitic attractor; schizophrenia

---

Received Sep 24, 2004; revised November 7, 2005; accepted November 7, 2005.

This article has been cited by other articles:

				J. Zhong, S.-C. Chuang, R. Bianchi, W. Zhao, H. Lee, A. A. Fenton, R. K. S. Wong, and H. Tiedge BC1 Regulation of Metabotropic Glutamate Receptor-Mediated Neuronal Excitability J. Neurosci., August 12, 2009; 29(32): 9977 - 9986. [Abstract] [Full Text] [PDF]

				T. D. Perera, S. Park, and Y. Nemirovskaya Cognitive Role of Neurogenesis in Depression and Antidepressant Treatment Neuroscientist, August 1, 2008; 14(4): 326 - 338. [Abstract] [PDF]

				S. M. Silverstein Measuring Specific, Rather than Generalized, Cognitive Deficits and Maximizing Between-Group Effect Size in Studies of Cognition and Cognitive Change Schizophr Bull, July 1, 2008; 34(4): 645 - 655. [Abstract] [Full Text] [PDF]

				W. I. Colon-Cesario, M. M. Martinez-Montemayor, S. Morales, J. Felix, J. Cruz, M. Adorno, L. Pereira, N. Colon, C. S. Maldonado-Vlaar, and S. Pena de Ortiz Knockdown of Nurr1 in the rat hippocampus: Implications to spatial discrimination learning and memory Learn. Mem., November 1, 2006; 13(6): 734 - 744. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help