Sexual behaviour

Central/Tertiary structures The fish olfactory bulb is a fourlayered structure much as in higher vertebrates. Within the 2nd layer, the first synapse for olfactory input is on the dendrites of the mitral cells (MC). About 1000 ORN axons converge on one MC, a ratio similar to mammals. The MC output, from cells at various levels, leads into several glomeruli and receives (inhibitory) input from granule cells. The latter also innervate a distinct cell type in the MC layer of teleosts — the ruffed cells (RC), with which they have reciprocal synapses [Fig. 2.18(a)] both relay cells send ascending fibres to forebrain centres (Kosaka and Hama, 1982). The RC are unlike the MC since they are not stimulated by the ORNs directly. Their interactions (Chap. 5) may contribute to the processing of pheromonal stimuli (Zippel, 2000). The main bulbar pathways project to several nuclei in the forebrain via two ipsilateral tracts, the lateral and medial [Fig. 2.18(b)], the latter mediates sexual behaviour and the former probably other behaviours (Hara,... 

Macrides F., Johnson P.A. and Schneider S.P. (1977). Responses of the male golden hamster to vaginal secretion and dimethyl disulfide attraction versus sexual behaviour. Behav Biol 20, 377-386. 

Meredith M., Marques D.M., 0 Connell R.J. and Stem F.L. (1980). Vomeronasal pump significance for hamster sexual behaviour. Science 207, 1224-1245. 

Wood, R,I, and Coolen, L.M. (1997) Integration of chemosensory and hormonal cues is essential for sexual behaviour in the male Syrian hamster role of the medial amygdaloid nucleus, Neuroscience 78, 1027-35. 

The Company Questionnaire Study A Nation-Wide (UK) Survey of Female Sexual Behaviour... 

In March 1989, in collaboration with Mark Beilis and Company Magazine, I carried out a nation-wide questionnaire survey of female sexual behaviour. The questions asked (Beilis et al. 1989), the characteristics of the nearly 4000 respondents (Baker et al. 1989), and many of the analyses (Beilis and Baker 1990, Baker and Beilis 1993b, 1995 ) have been published elsewhere and need not be described further here. 

An initial widespread scepticism over fluctuating asymmetry has had to be re-appraised in the light of many demonstrations (e.g. for insects, birds, and humans) that symmetry is associated with various facets of sexual behaviour. Almost universally, for a whole range of animals, it has been found that males who are more symmetrical are faster,... 

As Sperm Competition Theory is applied to more and more organisms, its early promise as a paradigm for the understanding of sexual behaviour has been maintained. I suggest that human sexuality is no exception. As I hope this paper continues to show, there are few aspects of human copulation, masturbation and infidelity that have not been shaped during evolution, at least in part, by the threat of sperm competition. 

ACSF. (1992). AIDS and sexual behaviour in France. Nature, London 360,407-409. 

Ford, C. S. and Beach, F. A. (1952). Patterns of Sexual Behaviour. London Eyre Spottiswoode. 

Thornhill, R. and Gangestad, S. W. (1994). Fluctuating asymmetry and human sexual behaviour. Psychological Science 5, 297-302. 

SEXUAL BEHAVIOURS IN MELANESIAN SOCIETIES—EVOLUTIONARY MODELS ... 

Taha SA, Ageel AM, Islam MW, GInawl OT. (1995). Effect of (-)-cathinone, a psychoactive alkaloid from khat (Catha edulis Forsk.) and caffeine on sexual behaviour in rats. Pharmacol Res. 31(5) 299-303. 

Pheromones are volatile chemicals that allow communication between individuals via air or water, over a distance which can be quite long. That is, one individual animal produces and emits a chemical that changes the biochemistry and physiology of another member of the same species. This can result in changes in social or sexual behaviour. The pheromones are known more generally as smells or scents. Communication via pheromones is well... 

Effects in the adult In the adult, testosterone maintains spermatogenesis. It also influences sexual interest, arousal and behaviour. Nonetheless, although testosterone plays a role in sexual behaviour, social, environmental and emotional factors are also important. Indeed, neither testosterone in the male nor oestradiol in the female is essential for sexual interactions in humans. 

Dorsal raphe Main serotonin (5-HT)-containing neurons that project through the brain. Other raphe neurons project down the spinal cord where they act as a gating mechanism for pain perception from the periphery. Main activity is in the regulation of mood, anxiety, sexual behaviour, sleep. 

Physiological/ Pathological Effects Anxiety, depression Appetite, aggression Pain, sexual behaviour 7 Appetite, anxiety Mood V asoconstriction Appetite ... 

Sexual behaviour 5-HTia agonists both facilitate and inhibit sexual behaviour in male rats 5-HTig agonists inhibit sexual behaviour in the male but facilitate this behaviour in the female rat... 

Alkaloids take part in the life processes of some invertebrates as pheromones, inducers of sexual behaviour, and in reproduction. A case study of quinolizidine alkaloids and population changes proved that these alkaloids occur in all legume species studied but not, however, in all individuals. The distribution and frequency changes of alkaloidal and non-alkaloidal plants in populations is a direct expression of natural selection natural hybridization and micro-evolution can be considered as an evidence of current evolutionary responses by ecological and genetic systems. 

---