Editorial

doi:10.1016/j.bbr.2009.02.003

Behavioural Brain Research

Volume 200, Issue 2, 25 June 2009, Pages 237-238

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Cited by (5)

Phylogenesis of mammal sexuality. Analysis of the evolution of proximal factors
2017, Sexologies
L’objectif de cet article est d’identifier précisément les facteurs à l’origine de l’évolution de la sexualité humaine. Les analyses présentées concernent principalement l’évolution des facteurs, proximaux, qui contrôlent la copulation hétérosexuelle prototypique des mammifères. Les données ont été recueillies à partir d’une revue de la littérature qui concerne l’évolution des facteurs neurobiologiques du comportement sexuel mammalien. Plusieurs études, en biologie, en génétique et en neurosciences, ont mis en évidence que certains de ces facteurs sont modifiés ou altérés au cours de l’évolution. Chez les primates, les circuits olfactifs sont altérés, les activités sexuelles se dissocient des cycles hormonaux (la reproduction et le comportement sexuel deviennent indépendants), le réflexe copulatoire de la lordose n’est plus fonctionnel, et le développement du cortex est majeur chez l’être humain. Pour ces raisons, l’analyse des données disponibles suggère que : (1) la dynamique du comportement sexuel a significativement évolué à partir des primates anthropoïdes ; (2) la dynamique fonctionnelle de la copulation hétérosexuelle est très probablement désorganisée ; (3) la dynamique comportementale qui émerge chez les hominidés – à partir des facteurs encore existants de la copulation hétérosexuelle – correspond vraisemblablement à une dynamique de recherche des récompenses érotiques, au moyen de la stimulation des zones érogènes ; et (4) chez l’être humain, en raison du développement majeur de la cognition, la sexualité est structurée par les représentations culturelles.
The aim of this article is to make a precise identification of the factors involved in the evolution of human sexuality. The analyses presented concern mainly the evolution of proximal factors that govern prototypical heterosexual copulation in mammals. The data was collected from a review of the literature concerning the evolution of neurobiological factors of sexual behaviour in mammals. Several studies, in biology, genetics and neurosciences, have shown that some of these factors have changed over the course of evolution. In primates, the olfactory circuits are impaired, sexual activities are dissociated from hormone cycles (reproduction and sexual behavior have become independent one from the other), the lordotic mating reflex is no longer functional and the cortex is highly developed in human beings. For these reasons, the analysis of available data suggests that: (1) the dynamics of sexual behaviour has significantly evolved from the anthropoid primates; (2) the functional dynamic of heterosexual copulation is very probably disorganized; (3) the behavioural dynamics that emerge with the hominidae – from factors that still exist in heterosexual copulation – would seem to be based on a quest for erotic reward, by stimulation of the erogenous zones; and (4) in humans, due to the extensive cognitive development, sexuality is structured by cultural representations.
Phylogenesis of mammal sexuality. Analysis of the evolution of proximal factors
2017, Sexologies
Citation Excerpt :
A general evolutionary trend can be observed: chemically-mediated senses (smell and taste), which are so fundamental in animals (Brennan and Zufall, 2006; Wyatt, 2009), lose their importance in primates (Liman, 2006; Swaney and Keverne, 2009). Pheromones are involved in numerous functions (Keller and Bakker, 2009), such as partner evaluation (Hurst, 2009), heterosexual orientation (Martinez-Ricos et al., 2008; Roberts et al., 2010; Stowers et al., 2002; but also see Pankevich et al., 2006; and Kimchi et al., 2007), the forming of attachment between copulation partners (Young and Wang, 2004) and sexual conditioning (Lanuza et al., 2008). An impairment in pheromone detection capacity leads to an impairment in these functions, the extent of which will vary depending on the number of genes that have changed into pseudogenes in each species.
The aim of this article is to make a precise identification of the factors involved in the evolution of human sexuality. The analyses presented concern mainly the evolution of proximal factors that govern prototypical heterosexual copulation in mammals. The data was collected from a review of the literature concerning the evolution of neurobiological factors of sexual behaviour in mammals. Several studies, in biology, genetics and neurosciences, have shown that some of these factors have changed over the course of evolution. In primates, the olfactory circuits are impaired, sexual activities are dissociated from hormone cycles (reproduction and sexual behavior have become independent one from the other), the lordotic mating reflex is no longer functional and the cortex is highly developed in human beings. For these reasons, the analysis of available data suggests that: (1) the dynamics of sexual behaviour has significantly evolved from the anthropoid primates; (2) the functional dynamic of heterosexual copulation is very probably disorganized; (3) the behavioural dynamics that emerge with the hominidae – from factors that still exist in heterosexual copulation – would seem to be based on a quest for erotic reward, by stimulation of the erogenous zones; and (4) in humans, due to the extensive cognitive development, sexuality is structured by cultural representations.
Sexual orientation or sexual preferences?
2017, Sexologies
L’objectif de cet article est d’identifier, chez les mammifères et l’être humain, les processus neurobiologiques de l’orientation sexuelle et de la formation des préférences sexuelles, puis d’évaluer leur importance respective. Les données ont été recueillies à partir d’une revue de la littérature qui concerne la neurobiologie de l’orientation et des préférences sexuelles. Chez les mammifères non primates (rongeurs, canidés, félidés, bovidés, équidés…), il existe différents types de processus et de situations à l’origine de la formation de préférences pour certains partenaires. Il existe également des processus neurobiologiques qui sont spécifiquement organisés pour l’orientation hétérosexuelle, et qui seraient, principalement, les circuits olfactifs qui détectent et traitent les phéromones sexuelles. Mais chez les hominidés (orangs-outans, gorilles, chimpanzés, bonobos, humains), les gènes des récepteurs aux phéromones sont altérés, diminuant ainsi l’importance fonctionnelle de ces processus de l’orientation sexuelle. Par contre, les processus à l’origine des préférences sexuelles deviennent plus importants. Pour ces raisons, chez l’être humain, les processus olfactifs altérés et les phéromones sexuelles n’auraient plus qu’une influence secondaire, et seraient combinés avec plusieurs autres facteurs (gènes, hormones, conditionnements, préférences sexuelles, émotions, processus cognitifs, contexte culturel). L’importance relative de chacun de ces facteurs dépendrait à la fois de caractéristiques physiologiques individuelles, du vécu singulier et des caractéristiques du contexte socioculturel. Cette combinaison complexe de plusieurs facteurs en interactions (incluant l’activité résiduelle des processus olfactifs de l’orientation sexuelle) serait à l’origine du développement de préférences sexuelles, propres à chaque personne.
The objective of this article is to identify in humans and mammals in general the neurobiological processes for sexual orientation and the development of sexual preferences, and to assess the importance of each. The data was collected from a review of the literature concerning the neurobiology of sexual orientation and preferences. In non-primate mammals (rodents, caninae, felidae, bovidae, equidae, etc.), there are several different types of process and situation involved in the development of preferences for certain partners over others. There are also neurobiological processes that are specifically arranged for heterosexual orientation; mainly the olfactory circuits that detect and process sexual pheromones. But in hominids (orang-utans, gorillas, chimpanzees, bonobos, humans), the pheromone receptor genes are impaired, thus reducing the functional importance of these sexual orientation processes. However, the processes underpinning sexual preferences are more important. This is why, in human beings, the impaired olfactory processes and sexual pheromones only have a secondary influence, and are combined with several other factors (genes, hormones, conditioning, sexual preferences, emotions, cognitive processes, cultural context). The relative importance of each of these factors is dependent both on individual physiological characteristics, personal experience and aspects of the sociocultural environment. This complex combination of several interacting factors (including the residual activity of the olfactory processes for sexual orientation) is thought to be the at the origin of development of sexual preferences, different for each individual.
Heterogeneous electrophysiological and morphological properties of neurons in the mouse medial amygdala in vitro
2012, Brain Research
Citation Excerpt :
The term pheromone (Gk. Pherein, to carry; horman, to excite or to stimulate) was originally proposed by Karlsson and Butenandt (1959) and Karlsson and Luscher (1959) to describe substances that are secreted by an individual and received by another individual of the same species in which they elicit a specific reaction, e.g., a definite behavior (Johnston and Mueller, 1990; Keller and Bakker, 2009). Although the identity of mammalian pheromones is poorly understood, some compounds with pheromonal activity have been purified from complex mixtures such as urine (Hagino-Yamagishi et al., 2001) and anogenital gland secretions.
Neurons in the medial nucleus of the amygdala (MeA) play a key role in the innate maternal, reproductive, defensive, and social behaviors. However, it is unclear how activation of the vomeronasal system leads to the behavioral outputs that are associated with pheromones. Here, we characterized the electrophysiological and morphological properties of MeA neurons using whole-cell recordings in mice slice preparations. Biocytin labeling revealed that MeA neurons possessed bipolar to multipolar cell bodies and dendritic fields covering projection areas from the accessory olfactory bulb. In 70% of recorded MeA neurons, monosynaptic excitatory postsynaptic currents (EPSCs) were evoked from the accessory olfactory bulb afferent in which the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate component was dominant and was rarely followed by the N-methyl-d-aspartic acid component. Norepinephrine increased the frequency of spontaneous inhibitory postsynaptic currents in some neurons, whereas α-methyl-5-hydroxytryptamine increased spontaneous EPSCs in other neurons. Morphologically and physiologically, heterogeneous MeA neurons appear likely to produce multiplex outputs of instinctive behaviors.
The main and accessory olfactory systems of female mice are activated differentially by dominant versus subordinate male urinary odors
2011, Brain Research
Citation Excerpt :
In rodent species, body odors provide essential information about the sex, social and reproductive status of conspecifics (Brown, 1979). They induce hormonal changes and play a key role in mate recognition and partner preferences (reviewed in Bakker, 2003; Keller and Bakker, 2009; Keller et al., 2009). For instance, male urinary pheromones induce sexual maturation (Lombardi and Vandenbergh, 1977) and pregnancy block (Bruce, 1959; Lloyd-Thomas and Keverne, 1982) in female mice.
Previous studies have shown that female preferences for male pheromones depend on the female's reproductive condition and the dominance status of the male. However, it is unknown which olfactory system detects the odors that result in a preference for a dominant male. Therefore, in the present study, we asked whether dominant versus subordinate male urinary odors differentially activate the main and accessory olfactory systems in female (C57Bl/6j) mice by monitoring the induction of the immediate early gene, c-fos. A more robust induction of Fos was observed in female mice which had direct nasal contact with dominant male urinary odors in four specific segments of the accessory olfactory system, i.e., the posteroventral part of the medial amygdala, the bed nucleus of the stria terminalis, the medial part of the preoptic nucleus and the ventrolateral part of the ventromedial hypothalamus, compared to females that were exposed to subordinate male urine. This greater activation of the accessory olfactory pathway by dominant male urine suggests that there are differences in the nonvolatile components of dominant versus subordinate male urine that are detected by the vomeronasal organ. By contrast, subordinate male urinary odors induced a greater activation in the piriform cortex which is part of the main olfactory system, suggesting that female mice discriminate between dominant and subordinate male urine using their main olfactory system as well.

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