Pathological decision-making in addiction
Prise de décision pathologique dans l'addiction

Selected publications

• Probing the decision-making mechanisms underlying choice between drug and nondrug rewards in rats. Youna Vandaele, Magalie Lenoir, Caroline Vouillac-Mendoza, Karine Guillem, Serge H Ahmed. eLife. 2021-04-26. 10
• Loss of resistance to punishment of cocaine use after prior experience. Audrey Durand, Paul Girardeau, Luana Freese, Serge H. Ahmed. Preprint bioRxiv. 2020-07-26.
• Reorganization of Theta Phase-Locking in the Orbitofrontal Cortex Drives Cocaine Choice Under the Influence. Karine Guillem, Serge H Ahmed. Sci Rep. 2020-05-15. 10 (1) : 8041.
• Pharmacokinetics trumps pharmacodynamics during cocaine choice: a reconciliation with the dopamine hypothesis of addiction. Ludivine Canchy, Paul Girardeau, Audrey Durand, Caroline Vouillac-Mendoza, Serge H. Ahmed. Preprint biorxiv. 2020-05-22.
• Relapse to cocaine use persists following extinction of drug-primed craving. Paul Girardeau, Sylvia Navailles, Audrey Durand, Caroline Vouillac-Mendoza, Karine Guillem, Serge H. Ahmed. Neuropharmacology. 2019-06-01.
• A neuronal population code for resemblance between drug and nondrug reward outcomes in the orbitofrontal cortex. Karine Guillem, Serge H. Ahmed. Brain Struct Funct. 2018-12-11.
• A transdiagnostic dimensional approach towards a neuropsychological assessment for addiction: an international Delphi consensus study. Murat Yücel, Erin Oldenhof, Serge H. Ahmed, David Belin, Joel Billieux, Henrietta Bowden-Jones, Adrian Carter, Samuel R. Chamberlain, Luke Clark, Jason Connor, Mark Daglish, Geert Dom, Pinhas Dannon, Theodora Duka, Maria Jose Fernandez-Serrano, Matt Field, Ingmar Franken, Rita Z. Goldstein, Raul Gonzalez, Anna E. Goudriaan, Jon E. Grant, Matthew J. Gullo, Robert Hester, David C. Hodgins, Bernard Le Foll, Rico S. C. Lee, Anne Lingford-Hughes, Valentina Lorenzetti, Scott J. Moeller, Marcus R. Munafò, Brian Odlaug, Marc N. Potenza, Rebecca Segrave, Zsuzsika Sjoerds, Nadia Solowij, Wim van den Brink, Ruth J. van Holst, Valerie Voon, Reinout Wiers, Leonardo F. Fontenelle, Antonio Verdejo-Garcia. Addiction. 2018-10-05.
• Pre-trial cocaine biases choice toward cocaine through suppression of the nondrug option. Luana Freese, Audrey Durand, Karine Guillem, Serge H. Ahmed. Pharmacology Biochemistry and Behavior. 2018-07-01.
• Individual decision-making in the causal pathway to addiction: contributions and limitations of rodent models.. Serge H. Ahmed. Pharmacology Biochemistry and Behavior. 2018-01-01. 164 : 22-31.
• Misdeed of the need: towards computational accounts of transition to addiction.. Mehdi Keramati, Serge H Ahmed, Boris S Gutkin. Current Opinion in Neurobiology. 2017-10-01. 46 : 142-153.
• Incubation of Accumbal Neuronal Reactivity to Cocaine Cues During Abstinence Predicts Individual Vulnerability to Relapse.. Karine Guillem, Serge H Ahmed. Neuropsychopharmacology. 2017-09-18. 43 (5) : 1059-1065.
• Neuronal representation of individual heroin choices in the orbitofrontal cortex. Karine Guillem, Viridiana Brenot, Audrey Durand, Serge H. Ahmed. Addiction Biology. 2017-07-13. 23 (3) : 880-888.
• Preference for Cocaine is Represented in the Orbitofrontal Cortex by an Increased Proportion of Cocaine Use-Coding Neurons.. Karine Guillem, Serge H. Ahmed. Cereb. Cortex. 2017-01-04.
• Cocaine addiction as a homeostatic reinforcement learning disorder.. Mehdi Keramati, Audrey Durand, Paul Girardeau, Boris Gutkin, Serge H. Ahmed. Psychological Review. 2017-01-01. 124 (2) : 130-153.
• Qu’apporte la neurobiologie aux addictions ?. Magalie Lenoir, Florence Noble. La Presse Médicale. 2016-12-01. 45 (12) : 1096-1101.
• Erratum to: Review of the nutritional benefits and risks related to intense sweeteners.. Olivier Bruyère, Serge H. Ahmed, Catherine Atlan, Jacques Belegaud, Murielle Bortolotti, Marie-Chantal Canivenc-Lavier, Sybil Charrière, Jean-Philippe Girardet, Sabine Houdart, Esther Kalonji, Perrine Nadaud, Fabienne Rajas, Gérard Slama, Irène Margaritis. Arch Public Health. 2015-10-23. 73 (1)
• Review of the nutritional benefits and risks related to intense sweeteners.. Olivier Bruyère, Serge H. Ahmed, Catherine Atlan, Jacques Belegaud, Murielle Bortolotti, Marie-Chantal Canivenc-Lavier, Sybil Charrière, Jean-Philippe Girardet, Sabine Houdart, Esther Kalonji, Perrine Nadaud, Fabienne Rajas, Gérard Slama, Irène Margaritis. Arch Public Health. 2015-10-01. 73 (1)
• Rats quit nicotine for a sweet reward following an extensive history of nicotine use.. Carmen Huynh, Justine Fam, Serge H. Ahmed, Kelly J. Clemens. Addiction Biology. 2015-09-16. 22 (1) : 142-151.
• Choosing under the influence: A drug-specific mechanism by which the setting controls drug choices in rats. Youna Vandaele, Lauriane Cantin, Fuschia Serre, Caroline Vouillac-Mendoza, Serge H Ahmed. Neuropsychopharmacol. 2015-07-01. 41 (2) : 646-657.
• The opioid receptors as targets for drug abuse medication. Florence Noble, Magalie Lenoir, Nicolas Marie. Br J Pharmacol. 2015-06-26. 172 (16) : 3964-3979.
• Sex differences in conditioned nicotine reward are age-specific. Magalie Lenoir, Amy K. Starosciak, Jennifer Ledon, Caitlin Booth, Elena Zakharova, Dean Wade, Beatrice Vignoli, Sari Izenwasser. Pharmacology Biochemistry and Behavior. 2015-05-01. 132 : 56-62.
• Alternative models of addiction.. Hanna Pickard, Serge H. Ahmed, Bennett Foddy. Front. Psychiatry. 2015-02-13. 6
• Abstinence from cocaine and sucrose self-administration reveals altered mesocorticolimbic circuit connectivity by resting state MRI.. Hanbing Lu, Qihong Zou, Svetlana Chefer, Thomas J. Ross, D. Bruce Vaupel, Karine Guillem, William P. Rea, Yihong Yang, Laura L. Peoples, Elliot A. Stein. Brain Connectivity. 2014-09-01. 4 (7) : 499-510.
• Escalation of cocaine intake and incubation of cocaine seeking are correlated with dissociable neuronal processes in different accumbens subregions.. Karine Guillem, Serge H. Ahmed, Laura L. Peoples. Biological Psychiatry. 2014-07-01. 76 (1) : 31-39.
• Coordinated Recruitment of Cortical-Subcortical Circuits and Ascending Dopamine and Serotonin Neurons During Inhibitory Control of Cocaine Seeking in Rats.. Sylvia Navailles, Karine Guillem, Caroline Vouillac-Mendoza, Serge H. Ahmed. Cereb. Cortex. 2014-05-28. 25 (9) : 3167-3181.
• A redescription of data does not count as a general theory.. Serge H. Ahmed. Psychopharmacology. 2014-05-27. 231 (19) : 3909-3910.
• Drug versus sweet reward: greater attraction to and preference for sweet versus drug cues.. Heather B. Madsen, Serge H. Ahmed. Addiction Biology. 2014-03-07. 20 (3) : 433-444.
• Intravenous nicotine injection induces rapid, experience-dependent sensitization of glutamate release in the ventral tegmental area and nucleus accumbens. Magalie Lenoir, Eugene A. Kiyatkin. J. Neurochem.. 2013-10-21. 127 (4) : 541-551.
• Neurobiology of addiction versus drug use driven by lack of choice.. Serge H Ahmed, Magalie Lenoir, Karine Guillem. Current Opinion in Neurobiology. 2013-08-01. 23 (4) : 581-587.
• Sugar addiction: pushing the drug-sugar analogy to the limit.. Serge H. Ahmed, Karine Guillem, Youna Vandaele. Current Opinion in Clinical Nutrition and Metabolic Care. 2013-07-01. 16 (4) : 434-439.
• A choice-based screening method for compulsive drug users in rats.. Magalie Lenoir, Eric Augier, Caroline Vouillac, Serge H. Ahmed. Current Protocols in Neuroscience. 2013-07-01. 64 (1) : 9.44.1-9.44.17.
• Levodopa gains psychostimulant-like properties after nigral dopaminergic loss.. Michel Engeln, Stefania Fasano, Serge H. Ahmed, Martine Cador, Veerle Baekelandt, Erwan Bezard, Pierre-Olivier Fernagut. Ann Neurol.. 2013-07-01. 74 (1) : 140-144.
• Rapid sensitization of physiological, neuronal, and locomotor effects of nicotine: critical role of peripheral drug actions.. M. Lenoir, J. S. Tang, A. S. Woods, E. A. Kiyatkin. Journal of Neuroscience. 2013-06-12. 33 (24) : 9937-9949.
• Physiological Fluctuations in Brain Temperature as a Factor Affecting Electrochemical Evaluations of Extracellular Glutamate and Glucose in Behavioral Experiments. Eugene A. Kiyatkin, Ken T. Wakabayashi, Magalie Lenoir. ACS Chem. Neurosci.. 2013-03-14. 4 (5) : 652-665.
• Dorsolateral caudate nucleus differentiates cocaine from natural reward-associated contextual cues.. H.-S. Liu, S. Chefer, H. Lu, K. Guillem, W. Rea, P. Kurup, Y. Yang, L. Peoples, E. A. Stein. Proceedings of the National Academy of Sciences. 2013-02-19. 110 (10) : 4093-4098.
• Discriminative inhibitory control of cocaine seeking involves the prelimbic prefrontal cortex.. Claudia Mihindou, Karine Guillem, Sylvia Navailles, Caroline Vouillac, Serge H. Ahmed. Biological Psychiatry. 2013-02-01. 73 (3) : 271-279.
• Extended heroin access increases heroin choices over a potent nondrug alternative. Magalie Lenoir, Lauriane Cantin, Nathalie Vanhille, Fuschia Serre, Serge H Ahmed. Neuropsychopharmacol. 2013-01-15. 38 (7) : 1209-1220.
• Reinforcing properties of Pramipexole in normal and parkinsonian rats.. Michel Engeln, Serge H. Ahmed, Caroline Vouillac, François Tison, Erwan Bezard, Pierre-Olivier Fernagut. Neurobiology of Disease. 2013-01-01. 49 : 79-86.
• Animal studies of addictive behavior.. L. J. M. J. Vanderschuren, S. H. Ahmed. Cold Spring Harbor Perspectives in Medicine. 2012-12-18. 3 (4) : a011932-a011932.
• Rapid fluctuations in extracellular brain glucose levels induced by natural arousing stimuli and intravenous cocaine: fueling the brain during neural activation. Eugene A. Kiyatkin, Magalie Lenoir. Journal of Neurophysiology. 2012-09-15. 108 (6) : 1669-1684.
• fMRI response in the medial prefrontal cortex predicts cocaine but not sucrose self-administration history.. Hanbing Lu, Svetlana Chefer, Pradeep K. Kurup, Karine Guillem, D. Bruce Vaupel, Thomas J. Ross, Anna Moore, Yihong Yang, Laura L. Peoples, Elliot A. Stein. NeuroImage. 2012-09-01. 62 (3) : 1857-1866.
• The science of making drug-addicted animals.. S.H. Ahmed. Neuroscience. 2012-06-01. 211 : 107-125.
• Sugars, addiction and obesity. S. H. Ahmed. Obes. 2012-02-03. 7 (1) : 3-9.
• Toward an evolutionary basis for resilience to drug addiction.. Serge H. Ahmed. Behav Brain Sci. 2011-11-10. 34 (06) : 310-311.
• Drug specificity in extended access cocaine and heroin self-administration.. Magalie Lenoir, Karyn Guillem, George F. Koob, Serge H. Ahmed. Addiction Biology. 2011-10-13. 17 (6) : 964-976.
• Diazepam promotes choice of abstinence in cocaine self-administering rats.. Eric Augier, Caroline Vouillac, Serge H. Ahmed. Addiction Biology. 2011-09-28. 17 (2) : 378-391.
• Acute effects of nicotine amplify accumbal neural responses during nicotine-taking behavior and nicotine-paired environmental cues.. Karine Guillem, Laura L. Peoples. PLoS ONE. 2011-09-22. 6 (9) : e24049.
• Preclinical validation of a novel cocaine exposure therapy for relapse prevention.. Claudia Mihindou, Caroline Vouillac, George F. Koob, Serge H. Ahmed. Biological Psychiatry. 2011-09-01. 70 (6) : 593-598.
• Nicotinic acetylcholine receptor β2 subunits in the medial prefrontal cortex control attention.. K. Guillem, B. Bloem, R. B. Poorthuis, M. Loos, A. B. Smit, U. Maskos, S. Spijker, H. D. Mansvelder. Science. 2011-08-11. 333 (6044) : 888-891.
• Critical Role of Peripheral Actions of Intravenous Nicotine in Mediating Its Central Effects. Magalie Lenoir, Eugene A Kiyatkin. Neuropsychopharmacol. 2011-06-08. 36 (10) : 2125-2138.
• Intravenous saline injection as an interoceptive signal in rats. Eugene A. Kiyatkin, Magalie Lenoir. Psychopharmacology. 2011-04-15. 217 (3) : 387-396.
• Cracking the molecular code of cocaine addiction.. S. H. Ahmed, P. J. Kenny. ILAR Journal. 2011-01-01. 52 (3) : 309-320.
• Validation crisis in animal models of drug addiction: beyond non-disordered drug use toward drug addiction.. Serge H. Ahmed. Neuroscience & Biobehavioral Reviews. 2010-11-01. 35 (2) : 172-184.
• Cocaine is low on the value ladder of rats: Possible evidence for resilience to addiction. Lauriane Cantin, Magalie Lenoir, Eric Augier, Nathalie Vanhille, Sarah Dubreucq, Fuschia Serre, Caroline Vouillac, Serge H. Ahmed. PLoS ONE. 2010-07-28. 5 (7) : e11592.
• Varenicline effects on cocaine self administration and reinstatement behavior.. Karine Guillem, Laura L. Peoples. Behavioural Pharmacology. 2010-03-01. 21 (2) : 96-103.
• Sugar overconsumption during adolescence selectively alters motivation and reward function in adult rats.. Leandro F. Vendruscolo, Aliou B. Gueye, Muriel Darnaudéry, Serge H. Ahmed, Martine Cador. PLoS ONE. 2010-02-19. 5 (2) : e9296.
• Progressive and lasting amplification of accumbal nicotine-seeking neural signals.. K. Guillem, L. L. Peoples. Journal of Neuroscience. 2010-01-06. 30 (1) : 276-286.
• Orbitofrontal and insular cortex: neural responses to cocaine-associated cues and cocaine self-administration.. Karine Guillem, Alexxai V. Kravitz, David E. Moorman, Laura L. Peoples. Synapse. 2010-01-01. 64 (1) : 1-13.
• Risk-prone individuals prefer the wrong options on a rat version of the Iowa Gambling Task.. Marion Rivalan, Serge H. Ahmed, Françoise Dellu-Hagedorn. Biological Psychiatry. 2009-10-01. 66 (8) : 743-749.
• Voluntary nicotine consumption triggers in vivo potentiation of cortical excitatory drives to midbrain dopaminergic neurons.. S. Caille, K. Guillem, M. Cador, O. Manzoni, F. Georges. Journal of Neuroscience. 2009-08-19. 29 (33) : 10410-10415.
• Computational approaches to the neurobiology of drug addiction.. S. H. Ahmed, M. Graupner, B. Gutkin. Pharmacopsychiatry. 2009-05-01. 42 (S 01) : S144-S152.
• Monoamine oxidase inhibition dramatically prolongs the duration of nicotine withdrawal-induced place aversion.. Karine Guillem, Caroline Vouillac, George F. Koob, Martine Cador, Luis Stinus. Biological Psychiatry. 2008-01-01. 63 (2) : 158-163.
• Supply of a nondrug substitute reduces escalated heroin consumption.. Magalie Lenoir, Serge H Ahmed. Neuropsychopharmacol. 2007-10-31. 33 (9) : 2272-2282.
• The simulation of addiction: pharmacological and neurocomputational models of drug self-administration.. Ahmed SH, Bobashev G, Gutkin BS.. Drug and Alcohol Dependence. 2007-10-01. 90 (2-3) : 304-311.
• Intense sweetness surpasses cocaine reward. Magalie Lenoir, Fuschia Serre, Lauriane Cantin, Serge H. Ahmed. PLoS ONE. 2007-08-01. 2 (8) : e698.
• A critical transition in cocaine self-administration: behavioral and neurobiological implications.. Amandine Zittel-Lazarini, Martine Cador, Serge H. Ahmed. Psychopharmacology. 2007-02-21. 192 (3) : 337-346.
• The role of accumbal hypoactivity in cocaine addiction.. L. L. Peoples, A. V. Kravitz, K. Guillem. The Scientific World JOURNAL. 2007-01-01. 7 : 22-45.
• Explaining the escalation of drug use in substance dependence: models and appropriate animal laboratory tests.. Gerald Zernig, Serge H. Ahmed, Rudolf N. Cardinal, Drake Morgan, Elio Acquas, Richard W. Foltin, Paul Vezina, S. Stevens Negus, Jose A. Crespo, Petra Stöckl, Petra Grubinger, Ekkehard Madlung, Christian Haring, Martin Kurz, Alois Saria. Pharmacology. 2007-01-01. 80 (2-3) : 65-119.
• Monoamine oxidase A rather than monoamine oxidase B inhibition increases nicotine reinforcement in rats.. Karine Guillem, Caroline Vouillac, Marc R. Azar, Loren H. Parsons, George F. Koob, Martine Cador, Luis Stinus. European Journal of Neuroscience. 2006-12-01. 24 (12) : 3532-3540.
• Heroin addiction: anticipating the reward of heroin or the agony of withdrawal?. M. Lenoir. Journal of Neuroscience. 2006-09-06. 26 (36) : 9080-9081.
• Heroin-induced reinstatement is specific to compulsive heroin use and dissociable from heroin reward and sensitization.. Magalie Lenoir, Serge H Ahmed. Neuropsychopharmacol. 2006-04-26. 32 (3) : 616-624.
• Imbalance between drug and non-drug reward availability: a major risk factor for addiction.. Serge H. Ahmed. European Journal of Pharmacology. 2005-12-01. 526 (1-3) : 9-20.
• Monoamine oxidase inhibition dramatically increases the motivation to self-administer nicotine in rats.. K. Guillem. Journal of Neuroscience. 2005-09-21. 25 (38) : 8593-8600.
• Gene expression evidence for remodeling of lateral hypothalamic circuitry in cocaine addiction.. S. H. Ahmed, R. Lutjens, L. D. van der Stap, D. Lekic, V. Romano-Spica, M. Morales, G. F. Koob, V. Repunte-Canonigo, P. P. Sanna. Proceedings of the National Academy of Sciences. 2005-08-02. 102 (32) : 11533-11538.
• Dissociation of psychomotor sensitization from compulsive cocaine consumption.. Serge H Ahmed, Martine Cador. Neuropsychopharmacol. 2005-07-20. 31 (3) : 563-571.
• Mesolimbic dopamine drives the diurnal variation in opiate-induced feeding.. M BARBANO, L STINUS, M CADOR, S AHMED. Pharmacology Biochemistry and Behavior. 2005-07-01. 81 (3) : 569-574.
• Transition to drug addiction: a negative reinforcement model based on an allostatic decrease in reward function.. Serge H. Ahmed, George F. Koob. Psychopharmacology. 2005-02-25. 180 (3) : 473-490.
• Neuroscience. Addiction as compulsive reward prediction.. S. H. Ahmed. Science. 2004-12-10. 306 (5703) : 1901-1902.
• Chronic morphine treatment alters N-methyl-D-aspartate receptors in freshly isolated neurons from nucleus accumbens.. G. Martin. Journal of Pharmacology and Experimental Therapeutics. 2004-05-26. 311 (1) : 265-273.
• A non-invasive gating device for continuous drug delivery that allows control over the timing and duration of spontaneous opiate withdrawal.. M.R Azar, S.H Ahmed, R Lintz, T Gutierrez, L Stinus, G.F Koob. Journal of Neuroscience Methods. 2004-05-01. 135 (1-2) : 129-135.
• Changes in response to a dopamine receptor antagonist in rats with escalating cocaine intake.. Serge H. Ahmed, George F. Koob. Psychopharmacology. 2004-04-01. 172 (4) : 450-454.
• Escalation of cocaine self-administration does not depend on altered cocaine-induced nucleus accumbens dopamine levels.. Serge H. Ahmed, Daniel Lin, George F. Koob, Loren H. Parsons. Journal of Neurochemistry. 2004-02-04. 86 (1) : 102-113.
• Neurobiological mechanisms in the transition from drug use to drug dependence.. George F Koob, Serge H Ahmed, Benjamin Boutrel, Scott A Chen, Paul J Kenny, Athina Markou, Laura E O'Dell, Loren H Parsons, Pietro Paolo Sanna. Neuroscience & Biobehavioral Reviews. 2004-01-01. 27 (8) : 739-749.
• The transition from controlled to compulsive drug use is associated with a loss of sensitization.. Osnat Ben-Shahar, Serge H. Ahmed, George F. Koob, Aaron Ettenberg. Brain Research. 2004-01-01. 995 (1) : 46-54.
• Conditioning and opiate withdrawal.. G. Schulteis, S. H. Ahmed, A. C. Morse, G. F. Koob, B. J. Everitt. Nature. 2000-06-01. 405 (6790) : 1013-1014.
• Persistent increase in the motivation to take heroin in rats with a history of drug escalation.. S Ahmed. Neuropsychopharmacology. 2000-04-01. 22 (4) : 413-421.
• Microinjections of an opiate receptor antagonist into the bed nucleus of the stria terminalis suppress heroin self-administration in dependent rats.. John R. Walker, Serge H. Ahmed, K.Noelle Gracy, George F. Koob. Brain Research. 2000-01-01. 854 (1-2) : 85-92.
• Long-lasting increase in the set point for cocaine self-administration after escalation in rats.. S. H. Ahmed, George F. Koob. Psychopharmacology. 1999-10-04. 146 (3) : 303-312.
• Transition from moderate to excessive drug intake: change in hedonic set point.. S. H. Ahmed. Science. 1998-10-09. 282 (5387) : 298-300.
• Corticotropin-releasing factor receptor blockade enhances conditioned aversive properties of cocaine in rats.. S. C. Heinrichs, Alwin Klaassen, George F. Koob, Gery Schulteis, Serge Ahmed, Errol B. De Souza. Psychopharmacology. 1998-03-23. 136 (3) : 247-255.
• Amphetamine-induced conditioned activity is insensitive to perturbations known to affect pavlovian conditioned responses in rats.. Serge H. Ahmed, Luis Stinus, Martine Cador. Behavioral Neuroscience. 1998-01-01. 112 (5) : 1167-1176.
• Cocaine- but not food-seeking behavior is reinstated by stress after extinction.. S. H. Ahmed, George F. Koob. Psychopharmacology. 1997-08-05. 132 (3) : 289-295.
• Amphetamine-induced conditioned activity does not result from a failure of rats to habituate to novelty.. S. H. Ahmed, P. Oberling, G. Sandner, G. Di Scala. Psychopharmacology. 1996-02-01. 123 (4) : 325-332.
• Amphetamine-induced conditioned activity in rats: comparison with novelty-induced activity and role of the basolateral amygdala.. Serge H. Ahmed, Martine Cador, Michel Le Moal, Luis Stinus. Behavioral Neuroscience. 1995-01-01. 109 (4) : 723-733.
• Social deprivation enhances the vulnerability of male Wistar rats to stressor- and amphetamine-induced behavioral sensitization.. S. H. Ahmed, L. Stinus, M. Le Moal, M. Cador. Psychopharmacology. 1995-01-01. 117 (1) : 116-124.
• Corticotropin-releasing factor induces a place aversion independent of its neuroendocrine role.. M. Cador, S.H. Ahmed, G.F. Koob, M. Le Moal, L. Stinus. Brain Research. 1992-12-01. 597 (2) : 304-309.