Investigating determinants of yawning in the domestic (Equus caballus) and Przewalski (Equus ferus przewalskii) horses

International audienceYawning is rare in herbivores which therefore may be an interesting group to disentangle the potential function(s) of yawning behaviour. Horses provide the opportunity to compare not only animals living in different conditions but also wild versus domestic species. Here, we tested three hypotheses by observing both domestic and Przewalski horses living in semi-natural conditions: (i) that domestic horses may show an elevated rate of yawning as a result of the domestication process (or as a result of life conditions), (ii) that individuals experiencing a higher level of social stress would yawn more than individuals with lower social stress and (iii) that males would yawn more often than females. The study involved 19 Przewalski horses (PHs) and 16 domestic horses (DHs) of different breeds living in large outdoor enclosures. The results showed that there was no difference between the PH and DH in yawning frequency (YF). PHs exhibited much higher levels of social interactions than DHs. There was a positive correlation between yawning frequency and aggressive behaviours in PHs, especially males, supporting the idea that yawning may be associated with more excitatory/stressful social situations. A correlation was found between yawning frequency and affiliative behaviours in DHs, which supports the potential relationship between yawning and social context. Finally, the entire males, but not castrated males, showed much higher levels of yawning than females in both species. The intensity (rather than the valence) of the interaction may be important in triggering yawning, which could therefore be a displacement activity that helps reduce tension

Premature ejaculation and serotonergic antidepressants-induced delayed ejaculation: the involvement of the serotonergic system

Premature ejaculation has generally been considered a psychosexual disorder with psychogenic aetiology. Although still mainly treated by behavioural therapy, in recent years double-blind studies have indicated the beneficial effects of some of the serotonergic antidepressants (SSRIs) in delaying ejaculation We describe here the neurophysiology and the peripheral neuroanatomy of ejaculation and provide a review of the involvement of serotonin in the central nervous system in relation to serotonergic nuclei and their projections. A. hypothesis of the role of 5-HT1A and 5-HT2C receptors in premature ejaculation is postulated. (C) 1998 Elsevier Science B.V. All rights reserved

The effects of 5HT1agonists on erection in rats in vivo and rabbit corpus cavernosum in vitro

10.1038/sj.ijir.3900848International Journal of Impotence Research144205-212IJIR

Non-hormonal management of vasomotor symptoms

Vasomotor symptoms are the most common indication for the prescription of hormone replacement therapy since it is effective in over 80% of cases. In 1995, 37% of American women took hormone replacement therapy, principally for this purpose. However, following the publication of results from the Women's Health Initiative, as many as half of these women in the US and in the UK and New Zealand discontinued hormone therapy. Discontinuation of estrogen is often accompanied by a return of vasomotor symptoms; however, only a small number (18%) of women report restarting hormone therapy. Alternatives are available, but limited knowledge on etiology and mechanisms of hot flushing represents a major obstacle for the development of new, targeted, non-hormonal treatments, and no current alternatives are as effective as estrogen