Adolescence, stress reactivity and ovarian hormones: investigating the neuroendocrine mechanisms underpinning anxiety-like behaviour in a rodent species

Supervisors: Gillian Brown, Javier Tello

Project Description:
During adolescence, the stress hormone axis undergoes significant maturational changes, which result in sex differences in physiological stress reactivity and behavioural responses to stressors in adulthood (Brown & Spencer, 2013). Gonadal hormones produced by the ovaries and testes (e.g. estrogen and testosterone) are thought to play an important role in the development of the stress hormone system during adolescence (Bale & Epperson, 2015). However, the exact neuroendocrine mechanisms involved in the development of sex differences in physiological and behavioural responses to stress are not fully understood. Recent research has suggested that exposure to estrogen during adolescence influences neural development in the amygdala (Poling & Kauffman, 2013). Understanding the link between adolescent ovarian hormones, stress reactivity and amygdala development will potentially increase our understanding of sex differences in susceptibility to anxiety and mood disorders in human beings, which emerge during the adolescent period.

The aim of this project is to examine the long-term effects of experimentally manipulating ovarian hormone levels during adolescence on behavioural development, stress physiology, brain development and sexual maturation in female Norway rats (Rattus norvegicus). Ovarian hormone levels can be manipulated using pharmacological and surgical techniques in this species, and the effects on behaviour, circulating hormone levels, brain function, and physical development, including markers of pubertal development, will be examined. The PhD project will provide the student with a broad range of practical skills, including recording and measuring behaviour and cognition, taking anatomical measurements, performing ELISA hormone assays, and conducting immunohistological procedures and other laboratory-based techniques. The student will also gain experience in data management, statistical techniques, presenting research at conferences and writing up manuscripts for publication.

The School of Psychology & Neuroscience has an excellent research environment, with a large and active community of postgraduate research students. Postgraduate students are provided with a comprehensive training programme within the School, which is further supported by the University’s GRADSkills programme. The progress of postgraduate students is supported by the team of supervisors and by the School’s Postgraduate Tutor. Opportunities for networking with researchers from other disciplines and institutions are provided by the University’s Institute of Behavioural and Neural Sciences (IBANS), the Scottish Universities Psychology Postgraduate Research Training (SUPPORT) programme and the Scottish Neuroscience Group, and postgraduate students present their research at national and international conferences. The School and the University are fully committed to promoting equality, diversity and inclusion, as demonstrated by their Athena SWAN bronze awards.

References:

Bale TL & Epperson CN. 2015. Sex differences and stress across the lifespan. Nature Neuroscience 18: 1413-1420.

Brown GR & Spencer KA. 2013. Steroid hormones, stress and the adolescent brain: a comparative perspective. Neuroscience 249, 115-128.

Poling MC & Kauffman AS. 2013. Organizational and activational effects of sex steroids on kisspeptin neuron development. Frontiers in Neuroendocrinology 34: 3-17.

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