Sexual behaviour development

Disorders of adult personality and behaviour (ICD 10 codes F60-F69), mental retardation (ICD 10 codes F70-F79), disorders of psychological development (ICD 10 codes F80-F89), behavioural and emotional disorders with onset usually occurring in childhood and adolescence (ICD 10 codes F90-F98) and unspecified mental disorder (ICD 10 code F99) are all often non-specific and/or cannot be treated with conventional psychopharmacological medicaments. For example, disorders of sexual behaviour have been treated with hormone therapies or antagonists and hyperkinetic disorders and other disruptive behaviour disorders in children have been treated with stimulants such as methylphenidate (Ritalin ). 

The corpus luteum arises from the ruptured follicle and secretes progesterone, which has an important role in the estrous or menstrual cycle. Luteal progesterone is also required to maintain early pregnancy in most mammalian species, including humans (Csapo Pulkkinen, 1978). Therefore, establishment and maintenance of normal corpora luteaare essential for normal reproductive function. However, with the exception of evaluations to establish their presence or absence, these structures are not evaluated in routine testing. Increased rates of follicular atresia and oocyte toxicity may lead to premature menopause in humans. Altered follicular development, failure to ovulate or altered corpus luteum formation and function can disrupt cyclicity, reduce fertility and interfere with normal sexual behaviour. Therefore, significant increases in the rate of follicular atresia, evidence of oocyte toxicity, interference with ovulation or altered corpus luteum formation or function should be considered adverse effects. 

The butyrophenones and diphenylbutylpiperidines differ from the phenothia-zines and thioxanthines in that they are not tricyclic structures. The first butyrophenone to be developed was haloperidol, and this is the most widely used, potent neuroleptic. Unlike many of the phenothiazines, these neuroleptics largely lack antihistaminic, anticholinergic and adrenolytic activity they are also non-sedative in therapeutic doses. Their potent antidopaminergic activity renders them likely to cause extrapyramidal side effects. Of the various butyrophenones shown in Figure 11.10, benperidol has been selectively used to suppress asocial sexual behaviour. 

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. 

Jenner s speckled monster (smallpox) has been defeated, but AIDS will be with us for many years to come. While smallpox was eradicated by means of a worldwide vaccination campaign, prevention of acquired immune deficiency syndrome or AIDS will require new drugs and more careful sexual behaviour. Both diseases do share a common feature - they are caused by Nature s most successful parasites - the viruses. In the developed world, it is not uncommon for a person to survive to a ripe old age without experiencing a serious bacterial infection or contracting one of the many forms of cancer. They will, however, have suffered from the effects of numerous viral infections of the respiratory tract, i.e., colds and flu, and most probably, from the common childhood virus-inflicted disease of chicken pox. It is unlikely that any of these afflictions will have been life-threatening, but they will have caused many days to be lost from school or work. In other words, the morbidity due to the common viral diseases is high, but the mortality is low. 

It is known that the brain is one of the most sensitive sites of action of steroids in utero, and recently there have been suggestions that EDs may affect normal brain development and behaviour. For example, it has been alleged that in utero exposure to polychlorinated biphenyl compounds (PCBs) resulted in adverse effects on neurologic and intellectual function (memory and attention) in young children born to women who had eaten PCB contaminated fish in the USA." It has also been speculated that exposure to environmental pollutants with steroidal activity may be infinencing human sexual development and sexually controlled behavioiir." ... 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

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). 

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