Use this URL to cite or link to this record in EThOS:
Title: Neurocognitive phenotypes and endophenotypes of horse behaviour
Author: Roberts, Kirsty
ISNI:       0000 0004 7968 8310
Awarding Body: Coventry University in association with the Royal Agricultural University
Current Institution: Coventry University
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
The horse is utilised worldwide in both competition and leisure pursuits, both of which depend on appropriate behavioural output from the animal. Due to the key role that the central nervous system plays in cognition and motor control it is surprising therefore that very little research has been directed at the neuromodulatory systems governing behaviour in this species. The overarching aim of this investigation was to address the aforementioned dearth in current knowledge with a specific focus on dopamine due to 1) its critical role in temperament and behavioural control and 2) the existence of behavioural probing strategies which enable non-invasive investigation. In addition, horses demonstrate alterations to dopaminergic mechanisms leading to pathologies such as pituitary pars intermedia dysfunction (PPID) and behavioural abnormalities such as stereotypic behaviour. As such, the work reported herein forms an initial step in the development of predictive endophenotypes which will enable these conditions to be managed in their early stages of development. Four studies were conducted, the first of which correlated spontaneous eye blink rate as an inferred measure of dopamine (iDopamine) with a temperament questionnaire data derived from 100 horses. The temperament traits 'anxiety' and 'docility' were found to correlate positively (rs(97)=0.202, p=0.04) and negatively (rs(97)=-0.215, p=0.032) with iDopamine respectively. To determine whether iDopamine influenced cortical or striatal functioning, study 2 focussed on the development of a novel, fully-automated operant system capable of conducting a 3 choice serial reaction time task (3-CSRTT) akin to rodent models. The 3-CSRTT was then applied to non-symptomatic High, Medium and Low iDopamine horses (study 3), revealing that High iDopamine horses performed significantly more impulsive (F(2,24)=7.774, p=0.002) and compulsive (F(2,24)=8.167, p=0.002) responses compared to Low and Medium iDopamine equivalents. The fourth and final study identified a genetic component to iDopamine, as there was a lack of the GG genotype at the dopamine receptor 4 (DRD4) 292A locus in the Medium iDopamine group. Overall there is clear scope in future to test the behavioural and genetic markers identified in this investigation as candidate endophenotypes for conditions featuring dopamine dysfunction.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available