Developmental Effects of Cortisol on the Stress Response and Behaviour in Zebrafish

The objective of the study was to determine whether maternal stress affects early development in zebrafish (Danio rerio). The hypothesis was that maternal stress will lead to excess cortisol deposition in the embryos, and this will compromise the larval stress response and locomotor activity. Maternal stress and the attendant rise in cortisol levels led to excess cortisol deposition, but only transiently in the embryos. This was kept in check by cortisol-induced stimulation of 11βHSD2, a cortisol-degrading enzyme, in the ovarian follicles. Excess embryo cortisol content disrupted the larval stress response, locomotor activity, and was anxiolytic. These phenotypes corresponded with increased region-specific neurogenesis. Post-hatch elevation in cortisol levels by waterborne exposure, mimicking a stress response, increased locomotor activity but did not impact anxiety behaviour. Overall, maternal stress alters larval stress and behavioural phenotypes, underpinning a distinct developmental effect associated with elevated zygotic cortisol content in zebrafish.

Name thesis:degree_name

Master of Science (MSc)

Discipline thesis:degree_discipline

Biological Sciences

Grantor dc:publisher.institution

Graduate Studies

Year dc:date.issued

2015

Author dc:creator

• Best, Carol

Advisor dc:contributor.advisor

• Vijayan, Mathilakath M.

• Animal Physiology

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

eng

DOI

http://dx.doi.org/10.11575/PRISM/25631

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:11023/2518