Use this URL to cite or link to this record in EThOS:
Title: Behavioural, neurochemical and neuroanatomical analysis of stop-signal task performance in rats
Author: Bari, A.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2011
Availability of Full Text:
Full text unavailable from EThOS.
Please contact the current institution’s library for further details.
Chapter 1 introduces the concept of response inhibition, while Chapter 2 describes the rodent version of the SST. Chapter 3 clarifies the interpretation of SST variables and their relevance as measures of impulsivity and attention. In Chapter 4, testing various classes of pharmacological agents suggested that noradrenaline (NA) is primarily implicated in ‘stopping’, whereas dopamine (DA) is more involved in optimizing ‘go’ performance. In Chapter 5, inactivation of the dorso-medial (dmPFC) and orbitofrontal cortex impaired stop and go processes, respectively, while enhancing NA transmission in either area speeded SSRT. Within dmPFC, inactivation of the anterior cingulated cortex disrupted action cancellation, whereas silencing the prelimbic cortex impaired action restraint. Infusion of specific pharmacological agents in dmPFC revealed that NA improves stopping performance by modulating sustained attention, the monitoring of performance and stimulus detection, effects that were mediated by α1, α2 and β-adrenoceptors, respectively. Moreover, forebrain NA depletion impaired SSRT only when the attentional demand of the task was increased, whereas dmPFC-lesioned animals were impaired under all load conditions. In Chapter 6, I show that the atypical stimulant modafinil improves inhibitory processes at least in part via α1 noradrenergic receptors located in dmPFC. It is concluded that NA neurotransmission in dmPFC aids response inhibition by increased sustained attention and by facilitating attentional and behavioural shifts. Overall, this Thesis has helped to define the neural and neurochemical basis of inhibitory response control, through the study of pharmacological effects of relevance to human clinical conditions such as attention deficit/hyperactivity disorder.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available