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Excitotoxic lesions of the pedunculopontine tegmental nucleus in rats impair performance on a test of sustained attention

Kozak, Rouba; Bowman, Eric M.; Latimer, Mary P.; Rostron, Claire L. and Winn, Philip (2005). Excitotoxic lesions of the pedunculopontine tegmental nucleus in rats impair performance on a test of sustained attention. Experimental Brain Research, 162(2) pp. 257–264.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1007/s00221-004-2143-3
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Abstract

Recent research has suggested that the pontomesencephalic tegmentum might be an important part of a network underlying sustained attention. The largest structure of the pontomesencephalic tegmentum is the pedunculopontine tegmental nucleus, which has ascending connections to thalamus and with corticostriatal systems. In this experiment we examined the performance of rats following bilateral excitotoxic lesions of the pedunculopontine tegmental nucleus on a test of sustained attention previously used to examine frontal cortical function. After an initial period of darkness, the rats had to attend continuously to a dim stimulus light that would, at unpredictable intervals, become transiently brighter. During this period of increased stimulus brightness the rats could press a lever to obtain a food reward. Rats were trained to a criterion level of performance before lesions were made. After surgery, sham lesioned rats (n=7) resumed accurate responding, with an average successful detection rate of similar to 70%. Pedunculopontine lesioned rats (n=7), however, only achieved a successful detection rate of similar to 40%. When the duration of the bright target stimulus was increased from 1.5 to 4 s, the performance of the pedunculopontine lesioned rats significantly improved. The observation that an increase in brightness duration caused a marked improvement in lesioned rats' performance suggests strongly that the impairment was in attention rather than motor ability or simple sensory processing. These data are taken to be consistent with the hypothesis that the pedunculopontine tegmental nucleus is an important part of a network maintaining attention.

Item Type: Journal Article
ISSN: 0014-4819
Keywords: acetylcholine; ascending reticular activating system; basal forebrain; corticostriatal; executive function; pontomesencephalic tegmentum; thalamus
Academic Unit/Department: Science > Life, Health and Chemical Sciences
Interdisciplinary Research Centre: Biomedical Research Network (BRN)
Item ID: 9372
Depositing User: Claire Rostron
Date Deposited: 27 Sep 2007
Last Modified: 07 Mar 2014 13:34
URI: http://oro.open.ac.uk/id/eprint/9372
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