Sexual behaviour dimorphism

Most developmental neurotoxicity studies have focused on general impairment of behaviour, but some studies have also found evidence for effects on sexual dimorphic behaviour. Hormones play a central role in central nervous system development, including the sexual differentiation of the brain. Studies on hormones and various endocrine disrupting chemicals (particularly those with estrogenic or antiandrogenic effects) have shown that the developing brain may be susceptible to disturbances in sexual behaviour. Therefore, effects on one sex but not the other should not be dismissed, but must be evaluated in the context of effects on sexual differentiation of the brain. 

Phytoestrogens have also been shown to have behavioural effects in rodents including increases in sexual activity (Patisaul et al, 2001) and a reversal of sex-specific behaviours (Lund et al, 2001 Flynn et al, 2000). In rodents, the sexually dimorphic nucleus of the preoptic area (SDN-POA) is located in the hypothalamic region of the brain. This area of the brain controls... 

Ferkin, M. H., Sorokin, E.S., and Johnston, R.E. (1996) Self-grooming as a sexually dimorphic communicative behaviour in meadow voles, Microtus pennsylvanicus. Anim. Behav. 51, 801-810. 

The existence of sexual dimorphisms in temporal cortex and cerebellum has not been sufficiently investigated to date, as the bulk of animal model research has focused on regions most directly related to reproductive behaviours. However,... 

The Extreme Male Brain theory, in fact, argues that prenatal testosterone exposure is a strong candidate for contributing to sexual dimorphism in human behaviour, including social development, and may represent a risk factor for conditions characterized by social impairments, particularly autism spectrum conditions (reviewed in Knickmeyer and Baron-Cohen, 2006). 

The Role of Oestrogens in Sexually Dimorphic Anatomy and Behaviour... 

While sexually dimorphic expression of oestrogen receptors has been consistently reported in areas related to reproductive behaviour, such as the hypothalamus, evidence of sexually dimorphic oestrogen pathways in areas that are not directly related to reproductive behaviour is much more limited. Recent work by Canonaco et al. (2008) suggests the existence of robust sex differences in the expression of oestrogen receptor (ER) a, ERP and the ER G-protein-coupled receptor 30 (GPR30) in the cerebellum and amygdala of newborn hamsters. 

Sexual dimorphism, of growth hormone temporal pattern, 336-8 Simple periodic behaviour in model for glycolytic oscillations,... 

Heal (1981) has studied sexual dimorphism in Eristalis arbustorum. The females mimic several small, dark bees (mainly mining bees) well. The males less specifically mimic yellow and black Hymenoptera. The sexual dimorphism of pattern also extends to behavior as well. Heal raises the question of whether there may also be unnoticed behavioural differences between mimetic morphs. . . with loci affecting behaviour associated with supergenes for colour pattern. ... 

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