Sex differences in the brain and behaviour: activational and organisational effects of steroid hormones during puberty. (360G-Wellcome-078405_Z_05_Z)

The aim of this project is to investigate both activational and organisationaleffects of steroid hormones on novelty-seeking behaviour using a rodent model,with particular emphasis on the hormonal changes that accompany puberty. The research will involve manipulating hormone levels during puberty in male and female rats and examining short-term and long-term effects on sex differences in novelty-seeking, using well-established behavioural tests such as the elevated plus-maze and open-field. The proposed research will test the hypothesis that differential exposure to steroid hormones during puberty directs the development of brain and behaviour along male-typical or female-typical pathways by influencing brain development. The dopamine neurotransmitter system is an important brain system that is involved in modulating the rewarding effects of novelty and that undergoes considerable re-organisation during puberty. The effects of pubertal hormone manipulation on the developing dopamine system will be investigated by studying the development of sex differences in novelty-seeking behaviour and also through the administration of psychostimulants, such as d-amphetamine. As the dopaminesystem plays a role in the rewarding effects of drugs of abuse, as well as being involved in novelty-seeking behaviour, this research has implications for our understanding of sex differences in drug addiction in human beings.