This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Cassaday, H. J. Articles by Marsden, C. A. Search for Related Content PubMed PubMed Citation Articles by Cassaday, H. J. Articles by Marsden, C. A. Social Bookmarking                         What's this?

Serotonergic depletion increases conditioned suppression to background stimuli in the rat

School of Psychology, University of Nottingham, University Park, Nottingham NG7 2RD UK;; helen.cassaday{at}nottingham.ac.uk

C. S. Shilliam

C. A. Marsden

School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham, UK

Dark Agouti rats were lesioned by intra-ventricular injection of 5,7-dihydroxytryptamine (DHT) and, 2 weeks later, learning was tested in a conditioned suppression of drinking procedure. Lesioned and vehicle-injected control rats were conditioned with a discrete stimulus (tone or light conditioned stimulus, CS) twice paired with footshock (unconditioned stimulus), with or without a 30-s trace interval between theseevents to produce strong and weak learning conditions (a trace conditioning effect). During this conditioning session, the alternate stimulus (light or tone) was presented continuously in the background. Since the 5,7-DHT lesion also reduced the baseline licking response in the experimental chambers, we used drinkingc during the first minute, when this non-specific effect was minimal, as the dependent variable. We tested conditioning to target CS and to the alternative experimental background stimulus in exactly the same way in the same rats. We found that a level of serotonergic depletion without any intrinsic action on the trace conditioning effect nevertheless increased conditioning to the alternative background stimulus, irrespective of trace interval or stimulus modality. Thus, for both light and tone stimuli, the effect of serotonergic depletion depended only on the discrete target versus diffuse background role of the stimulus in use. These findings have implications for the modification of human cognition by serotonergic drugs.

Key Words: classical conditioning • rat • serotonin depletion

Journal of Psychopharmacology, Vol. 15, No. 2, 83-92 (2001)
DOI: 10.1177/026988110101500204


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				R.R. Horsley and H. J. Cassaday Methylphenidate can reduce selectivity in associative learning in an aversive trace conditioning task J Psychopharmacol, July 1, 2007; 21(5): 492 - 500. [Abstract] [PDF]

				C. Norman and H. J. Cassaday Amphetamine increases aversive conditioning to diffuse contextual stimuli and to a discrete trace stimulus when conditioned at higher footshock intensity J Psychopharmacol, January 1, 2003; 17(1): 67 - 76. [Abstract] [PDF]