Behavioral, Neural, and Molecular Mechanisms of Conditioned Mate Preference: The Role of Opioids and First Experiences of Sexual Reward

Although mechanisms of mate preference are thought to be relatively hard-wired, experience with appetitive and consummatory sexual reward has been shown to condition preferences for partner related cues and even objects that predict sexual reward. Here, we reviewed evidence from laboratory species and humans on sexually conditioned place, partner, and ejaculatory preferences in males and females, as well as the neurochemical, molecular, and epigenetic mechanisms putatively responsible. From a comprehensive review of the available data, we concluded that opioid transmission at μ opioid receptors forms the basis of sexual pleasure and reward, which then sensitizes dopamine, oxytocin, and vasopressin systems responsible for attention, arousal, and bonding, leading to cortical activation that creates awareness of attraction and desire. First experiences with sexual reward states follow a pattern of sexual imprinting, during which partner- and/or object-related cues become crystallized by conditioning into idiosyncratic “types” that are found sexually attractive and arousing. These mechanisms tie reward and reproduction together, blending proximate and ultimate causality in the maintenance of variability within a species.

First sexual experiences determine the development of conditioned ejaculatory preference in male rats

We have shown previously that male rats develop a conditioned ejaculatory preference (CEP) for females scented with a neutral odor like almond or lemon that is paired with the male's post-ejaculatory reward state during their first and subsequent early sexual experiences. However, preexposing males to the neutral odor alone prior to its pairing with sexual reward results in latent inhibition. Here, we examined the phenomenon of unconditioned stimulus (US) preexposure, in which male rats were preexposed to the ejaculatory reward state either one or five times with scented (ScF) versus unscented (UnScF) females prior to multiple ejaculatory trials with females in the opposite condition (e.g., ScF preexposure received 10 subsequent ejaculatory trials with UnScF, whereas UnScF preexposure received 10 subsequent ejaculatory trials with ScF). As before, mate and partner preference was evaluated in an open field where each male had access to two females, one ScF and the other UnScF. Males that underwent five trials of preexposure did not display a CEP for either female. Conversely, males preexposed once to a ScF, and later trained with UnScF developed a preference for the latter, whereas males preexposed once to the UnScF, and then trained with ScF did not show a preference for any of the females. Subsequent exposure to the odor cue alone revealed different patterns of brain activation in areas related to sexual behavior that depended on the animal's group membership. Altogether, these findings demonstrate the pivotal role of first sexual experiences in the establishment of future sexual partner preference in the male rat, and suggest an innate preference for estrous odors over neutral odors that can become conditioned subsequently as predictors of sexual reward.

Effect of CS preexposure on the conditioned ejaculatory preference of the male rat: behavioral analyses and neural correlates

Early experiences with sexual reward play a pivotal role in the formation of sexual behavior and partner preference. Associations of salient partner cues, or even neutral cues on a partner, with sexual reward states are a product of Pavlovian learning. However, the extent to which first experiences that associate a neutral stimulus with no immediate consequence, and how that association may affect subsequent associability after being paired with a sexual reward state after copulation to ejaculation, remains unclear. To address this question, sexually naïve males were preexposed over one or five trials to almond scented gauze pads prior to training during which half of the males were trained 10 times with scented receptive females, and the other half with unscented receptive females. A final test of partner preference was conducted in a large open field containing two sexually receptive females, one scented and the other unscented. Males developed a conditioned ejaculatory preference for the type of female they were trained with, except when they were preexposed five times to the odor and then trained with females bearing the same odor, indicating a significant CS preexposure effect. One CS preexposure was not sufficient to inhibit subsequent conditioning. Exposure to the scent before perfusion for inmunohistochemistry, revealed different patterns of brain activation in brain areas previously associated with the development of partner preference, like the medial preoptic area, ventral tegmental area, nucleus accumbens, basolateral amygdala, among others, depending on group membership. Thus, CS preexposure results in a subsequent impairment of the association that links the odor cue to sexual reward and preference. This highlights the impact of the first sexual experiences in future partner preference.

Understanding the behavioral aspects of cyber sexual grooming

Law enforcement agencies worldwide are concerned about cyber sexual grooming (CSG), particularly because of its potential to increasingly become transnational and global. The Internet medium facilitates CSG, where predators can draw children into a façade relationship through systematic grooming, inappropriate sexual advances and manipulation, for the purpose of sexual victimization. This article discusses four main issues. First, it discusses the definition of CSG and its inadequacies. Second, it reviews the behavioral characteristics of CSG perpetrators and victims, exposing the prevailing myths that offenders are violent paedophiles and strangers to their victims. Third, it illustrates how the CSG process unfolds through five different psychological and behavioral stages. Finally, recommendations are provided for caregivers, schools, law enforcement authorities, and adolescents to remain proactive in the prevention of and intervention in CSG.

Conditioned inhibition of social approach in male Japanese quail (Coturnix japonica) using visual exposure to a female

Male Japanese quail (Coturnix japonica) learned to approach lights that predicted visual exposure to a female quail and showed significantly less approach to lights that predicted the absence of a female quail. Following discrimination training, subjects were given transfer summation tests in which a stimulus positively correlated with female exposure (CS +) was presented alone, simultaneously with a novel stimulus, and simultaneously with a stimulus negatively correlated with female exposure (CS -). Approach to the CS + was lower when the CS + and CS - were presented together than when the CS + was presented alone or when the CS + was presented with a novel stimulus. These findings demonstrate conditioned inhibition of sexual conditioned approach in Japanese quail.

Somatosensory conditioning of sexual arousal and copulatory behavior in the male rat: a model of fetish development

Previous studies have established that neutral olfactory cues associated with sexual reward or inhibition become conditioned stimuli that direct male or female rats toward or away from potential sex partners bearing the cue. Here we examined the ability of a somatosensory cue to exert stimulus control over sexual arousal and copulation in male rats. In the first experiment, two groups of sexually naïve male rats had their first copulatory experiences with receptive females in bilevel chambers with or without a rodent jacket. On a final copulatory test, half of the rats in each group were tested with the jacket on or off. Rats trained and tested without the jacket copulated normally, as did rats trained and tested with the jacket on, and rats trained without the jacket but tested with the jacket on. However, significantly fewer rats trained with the jacket on but tested with the jacket off copulated to ejaculation, and those that did made significantly fewer anticipatory level changes and had fewer significantly longer mount, intromission, and ejaculatory latencies, and fewer ejaculations. In the second experiment, one group of sexually naïve males was given differential conditioning trials in bilevel chambers to associate the jacket on with sexual reward (copulation to ejaculation with a sexually receptive female) and the jacket off with sexual inhibition (thwarted copulatory attempts with a sexually nonreceptive female). A second group had the opposite order of association. A final test with receptive females was made for all males with the jacket on. Males trained to associate the jacket with excitation displayed normal copulation whereas males trained to associate the jacket with inhibition displayed significantly fewer anticipatory level changes and ejaculations, and had significantly longer ejaculation latencies. Thus, somatosensory cues can signal sexual excitation or inhibition in male rats depending on the conditioning history.

Who, what, where, when (and maybe even why)? How the experience of sexual reward connects sexual desire, preference, and performance

Although sexual behavior is controlled by hormonal and neurochemical actions in the brain, sexual experience induces a degree of plasticity that allows animals to form instrumental and Pavlovian associations that predict sexual outcomes, thereby directing the strength of sexual responding. This review describes how experience with sexual reward strengthens the development of sexual behavior and induces sexually-conditioned place and partner preferences in rats. In both male and female rats, early sexual experience with partners scented with a neutral or even noxious odor induces a preference for scented partners in subsequent choice tests. Those preferences can also be induced by injections of morphine or oxytocin paired with a male rat's first exposure to scented females, indicating that pharmacological activation of opioid or oxytocin receptors can "stand in" for the sexual reward-related neurochemical processes normally activated by sexual stimulation. Conversely, conditioned place or partner preferences can be blocked by the opioid receptor antagonist naloxone. A somatosensory cue (a rodent jacket) paired with sexual reward comes to elicit sexual arousal in male rats, such that paired rats with the jacket off show dramatic copulatory deficits. We propose that endogenous opioid activation forms the basis of sexual reward, which also sensitizes hypothalamic and mesolimbic dopamine systems in the presence of cues that predict sexual reward. Those systems act to focus attention on, and activate goal-directed behavior toward, reward-related stimuli. Thus, a critical period exists during an individual's early sexual experience that creates a "love map" or Gestalt of features, movements, feelings, and interpersonal interactions associated with sexual reward.

Conditioned sexual arousal in a nonhuman primate

Conditioning of sexual arousal has been demonstrated in several species from fish to humans but has not been demonstrated in nonhuman primates. Controversy exists over whether nonhuman primates produce pheromones that arouse sexual behavior. Although common marmosets copulate throughout the ovarian cycle and during pregnancy, males exhibit behavioral signs of arousal, demonstrate increased neural activation of anterior hypothalamus and medial preoptic area, and have an increase in serum testosterone after exposure to odors of novel ovulating females suggestive of a sexually arousing pheromone. Males also have increased androgens prior to their mate's ovulation. However, males presented with odors of ovulating females demonstrate activation of many other brain areas associated with motivation, memory, and decision making. In this study, we demonstrate that male marmosets can be conditioned to a novel, arbitrary odor (lemon) with observation of erections, and increased exploration of the location where they previously experienced a receptive female, and increased scratching in post-conditioning test without a female present. This conditioned response was demonstrated up to a week after the end of conditioning trials, a much longer lasting effect of conditioning than reported in studies of other species. These results further suggest that odors of ovulating females are not pheromones, strictly speaking and that marmoset males may learn specific characteristics of odors of females providing a possible basis for mate identification.

Has dopamine a physiological role in the control of sexual behavior? A critical review of the evidence

The role of dopaminergic systems in the control of sexual behavior has been a subject of study for at least 40 years. Not surprisingly, reviews of the area have been published at variable intervals. However, the earlier reviews have been summaries of published research rather than a critical analysis of it. They have focused upon the conclusions presented in the original research papers rather than on evaluating the reliability and functional significance of the data reported to support these conclusions. During the last few years, important new knowledge concerning dopaminergic systems and their behavioral functions as well as the possible role of these systems in sexual behavior has been obtained. For the first time, it is now possible to integrate the data obtained in studies of sexual behavior into the wider context of general dopaminergic functions. To make this possible, we first present an analysis of the nature and organization of sexual behavior followed by a summary of current knowledge about the brain structures of crucial importance for this behavior. We then proceed with a description of the dopaminergic systems within or projecting to these structures. Whenever possible, we also try to include data on the electrophysiological actions of dopamine. Thereafter, we proceed with analyses of pharmacological data and release studies, both in males and in females. Consistently throughout this discussion, we make an effort to distinguish pharmacological effects on sexual behavior from a possible physiological role of dopamine. By pharmacological effects, we mean here drug-induced alterations in behavior that are not the result of the normal actions of synaptically released dopamine in the untreated animal. The conclusion of this endeavor is that pharmacological effects of dopaminergic drugs are variable in both males and females, independently of whether the drugs are administered systemically or intracerebrally. We conclude that the pharmacological data basically reinforce the notion that dopamine is important for motor functions and general arousal. These actions could, in fact, explain most of the effects seen on sexual behavior. Studies of dopamine release, in both males and females, have focused on the nucleus accumbens, a structure with at most a marginal importance for sexual behavior. Since accumbens dopamine release is associated with all kinds of events, aversive as well as appetitive, it can have no specific effect on sexual behavior but promotes arousal and activation of non-specific motor patterns. Preoptic and paraventricular nucleus release of dopamine may have some relationship to mechanisms of ejaculation or to the neuroendocrine consequences of sexual activity or they can be related to other autonomic processes associated with copulation. There is no compelling indication in existing experimental data that dopamine is of any particular importance for sexual motivation. There is experimental evidence showing that it is of no importance for sexual reward.

Preclinical models of sexual desire: conceptual and behavioral analyses

The epidemiology, etiology and proposed treatments for the sexual desire disorders are briefly reviewed before turning to an analysis of preclinical models. We suggest that the concept of sexual desire in the human is equivalent to sexual motivation as employed in the scientific literature. Many animal tests for sexual motivation have been described over the years. Most of them are based on the evaluation of the rate or speed of performing learned operant responses. These are not ideal measures for inferring the intensity of sexual motivation. We present a test for sexual incentive motivation, which has been used in male and female rats. No learning is involved, and the test is rather insensitive to variations in ambulatory activity and it does not employ rate measures. A procedure that recently has attracted much attention, paced-mating behavior in the female, does not seem to be as useful as could be expected. In fact, it does not appear to be superior to tests for sexual receptivity (lordosis). The lack of established, clinically efficient treatments for sexual desire disorders makes it difficult to evaluate if any model has predictive validity. However, the model proposed here may be isomorphic and homologous to the human condition.

Unconditioned sexual incentive motivation in the male Norway rat (Rattus norvegicus)

Sexual incentive motivation was evaluated in a procedure consisting of a large open field where incentive animals were confined behind wire mesh openings. When sexually inexperienced male rats (Rattus norvegicus) were exposed to the receptive female-male incentives, they spent more time close to the female. If the incentives were receptive female-nonreceptive female, the receptive female was preferred. However, when the alternatives were nonreceptive female-male, no preference was obtained. Castration abolished preference for the receptive female, and treatment with testosterone propionate restored it. Estradiol plus oil is as efficient as estradiol plus progesterone for giving the ovariectomized female incentive properties. The living female can be replaced with female odor. Sexual experience did not have any long-term effects on the female's incentive value, but immediately preceding limited sexual activity enhanced it

Extinction of conditioned sexual responses in male Japanese quail (Coturnix japonica): role of species-typical cues

The authors examined how a conditioned stimulus (CS) that included species-typical cues affected the acquisition and extinction of conditioned sexual responses in male quail (Coturnix japonica). Some subjects were conditioned with a CS that supported sexual responses and included a taxidermic head of a female quail. Others were conditioned with a similar CS that lacked species-typical cues. Pairing the CSs with access to live females increased CS-directed behavior, with the head CS eliciting significantly more responding than the no-head CS. Responding to the head CS persisted during the 42-day, 126-trial extinction phase; responses to the no-head CS extinguished. Responding declined when the cues were removed or the subjects were sexually satiated. Possible functions and mechanisms of these effects are discussed.

Conditioning and sexual behavior: a review

Sexual behavior is directed by a sophisticated interplay between steroid hormone actions in the brain that give rise to sexual arousability and experience with sexual reward that gives rise to expectations of competent sexual activity, sexual desire, arousal, and performance. Sexual experience allows animals to form instrumental associations between internal or external stimuli and behaviors that lead to different sexual rewards. Furthermore, Pavlovian associations between internal and external stimuli allow animals to predict sexual outcomes. These two types of learning build upon instinctual mechanisms to create distinctive, and seemingly "automated," patterns of sexual response. This article reviews the literature on conditioning and sexual behavior with a particular emphasis on incentive sequences of sexual behavior that move animals from distal to proximal with regard to sexual stimuli during appetitive phases of behavior and ultimately result in copulatory interaction and mating during consummatory phases of behavior. Accordingly, the role of learning in sexual excitement, in behaviors that bring about the opportunity to mate, in courtship and solicitation displays, in sexual arousal and copulatory behaviors, in sexual partner preferences, and the short- and long-term influence of copulatory experience on sexual and reproductive function is examined. Although hormone actions set the stage for sexual activity by generating the ability of animals to become sexually excited and aroused, it is each animal's unique experience with sexual behavior and sexual reward that molds the strength of responses made toward sexual incentives.

Precontact 50-kHz vocalizations in male rats during acquisition of sexual experience

50-kHz ultrasonic vocalizations emitted by male rats during a 5-min period before introduction of a female (precontact vocalizations [PVs]) were analyzed in the context of acquisition of sexual experience. Changes in the main copulatory parameters and their N-methyl-D-aspartate (NMDA) receptor dependence, the role of contact with either anestrous or estrous females, and conditioning to odor and background cues were also investigated. Mount latency (ML) and intromission latency (IL) decreased after the 1st copulatory session, but ejaculation latency (EL) changed significantly only starting from the 4th session onward. The number of PVs gradually increased during the first 3-4 sessions. Blocking of NMDA receptors affected PVs and EL but not ML or IL. After a 5-month break in copulatory sessions, ML remained unchanged, whereas EL increased and the number of PVs decreased significantly. PVs were most robustly elevated by contact with estrous females. Exposure to background cues resulted in a linear decrease in number of PVs during 10 subsequent sessions without exposure to a female. The results suggest that, in the course of acquisition of a sexual experience, PVs reflect a learning process that depends on a rewarding value of sociosexual contact.

Sexual motivation--an inquiry into events determining the occurrence of sexual behavior

For the individual engaged in it, sexual behavior has no finality or purpose other than its own execution. Data are presented showing that the execution of sexual reflexes can promote learning, i.e. it functions as reinforcement. Furthermore, positive affect is generated. Based on these principles, a model of sexual motivation has been elaborated. The conceptual framework is the incentive motivation theory previously proposed by Bindra D, A motivational view of learning, performance, and behavior modification, Psychol Rev 1974: 81:199-213; A Theory of Intelligent Behavior, New York: Wiley, 1976; How adaptive behavior is produced: a perceptual-motivational alternative to response reinforcement, Behav Brain Sci 1978; 1:41-52. Although the model is intended for application to most mammals, the rat is used as example. Essentially, sexual approach behaviors are activated by appropriate incentives (conditioned in the male, unconditioned in the female). Approach is, in the inexperienced male, followed by the execution of copulatory reflexes as a consequence of accidentally obtained tactile stimulation of the perineal region. In the female, copulatory acts are activated by tactile stimulation of the flanks and hinds provided by the mounting male. The role of conditioning for the execution of copulatory reflexes and for the acquisition of incentive value of neutral stimuli is analyzed. It is also shown that the incentive properties of sexual acts are not substantially different from those of other incentives. Sexual exhaustion is suggested to be either a case of negative alliesthesia or of stimulus habituation and the Coolidge effect is, in consequence, an example of dishabituation. Studies in women and men support this proposal. It is emphasized that sexual behavior is best understood as being entirely mechanistic albeit not deterministic.

Mating-induced expression of c-fos in the male Syrian hamster brain: role of experience, pheromones, and ejaculations

This study was designed to investigate the effects of pheromonal cues and specific behaviors within the male copulatory sequence on c-fos expression in the medial nucleus of the amygdala (Me), the bed nucleus of the stria terminalis (BNST), and the medial preoptic area (MPOA) of the Syrian hamster brain. Sexually experienced male hamsters were placed into clean testing arenas and were either: 1) left alone as handled controls; 2) exposed to female hamster vaginal secretion (FHVS) on cotton swabs; or mated to various end points of copulation with a sexually receptive female: 3) five intromissions, 4) one ejaculation, 5) five ejaculations, or 6) long intromissions, A seventh group of sexually naive control males 7) was left alone in the arena. The brains of these males were compared to those of the sexually experienced controls to determine whether exposure to cues associated with prior sexual experience could alter c-fos expression. In males exposed only to FHVS, Fos immunoreactivity (Fos-ir) increased within the posterodorsal Me, the anterodorsal part of the posteromedial BNST, and the magnocellular medial preoptic nucleus (MPNmag). Following one ejaculation, Fos-ir increased within the caudal posterodorsal Me, the dorsolateral MPOA, and the paraventricular nucleus of the hypothalamus. After multiple ejaculations, additional labeling was observed within the posteroventral part of the posteromedial BNST, the medial preoptic nucleus (MPN), the central tegmental field, and in cell clusters of the caudal posterodorsal Me and rostral posteromedial BNST. Fos-ir also increased within the posterodorsal Me, MPN, and MPNmag in sexually experienced control males exposed to the empty test chamber compared to sexually naive males exposed to an identical chamber. These results demonstrate that the mating-induced pattern of neuronal activation in sexually experienced males is dependent upon multiple factors, including prior sexual experience in the testing environment, investigation of FHVS, and the number of ejaculations achieved.

Involvement of mesolimbic dopamine neurons in sexual behaviors: implications for the neurobiology of motivation

Mesencephalic dopamine-containing neurons that innervate limbic regions, notably nucleus accumbens, are thought to be involved in the control of a variety of species-typical behaviors such as male copulatory behavior, feeding and drinking as well as of behaviors reinforced by many drugs abused by humans. While it is generally agreed that these neurons are an important link in the brain circuitry that mediates these behaviors, their precise function remains a source of conjecture. The present article reviews evidence implicating the mesoaccumbens dopamine projection in sexual behaviors and discusses some of the issues that have contributed to the uncertainty over the exact role of this system in these and other species typical behaviors. This review also describes approaches we have been using in an attempt to address these issues and summarizes recent findings we believe provide important insights into mesoaccumbens dopamine function and the neurobiology of motivation.

Context conditioning: positive reinforcing effects of various food-related stimuli

Rats were subjected to context preference tests to investigate the degree to which various manipulations involving food stimuli can be used to appetitively condition contextual cues. One manipulation consisted of placing hungry rats in a context that contained food that they could consume. A second one involved exposure to a context containing food that could only be seen and smelled, without consumption being possible. A third type of manipulation consisted of exposing animals to a context after the consumption of a small meal in the home cage. Finally, hungry, control subjects were merely exposed to a context containing an empty food tray. Preference for the context was only enhanced after the first type of manipulation, indicating that the actual consummatory act constitutes the major source of reinforcement in the present procedure. Olfactory and visual food cues, as well as postingestional aftereffects in isolation, did not function as reinforces.

Male rats classified as copulators and noncopulators respond differentially on the hot plate test

Sexually naive male rats that fail to copulate with a sexually receptive female (noncopulators) have been shown to be less responsive to a variety of environmental stimuli in comparison to rats that do engage in copulation (copulators). In this experiment, it was found that noncopulators were less responsive than copulators to noxious thermal stimulation as determined by their latency to paw lick on a 50 degrees C hot plate. Pain sensitivity was not influenced in either noncopulators or copulators by exposure to a sexually receptive female. These results add to the list of differences between copulators and noncopulators.

Plasma testosterone concentration in adult male rats following acquisition of copulation-illness associations

Prior research has identified stimuli and procedures that elicit increments in plasma testosterone in copulating male rats. In the present experiment, we demonstrate that associative inhibition of copulatory behaviors in male rats is not correlated with and cannot be attributed to a conditioned suppression of testosterone. Each male rat was paired with an inaccessible estrous female for 7 min and was then given an opportunity to copulate. Two groups received an injection of either lithium chloride (LiCl; 0.3 M, 20 ml/kg, IP) or saline (0.3 M, 20 ml/kg, IP) immediately after each of 11 pairings spaced at 3- to 4-day intervals. A third group received a noncontingent injection of LiCl 24 h after each pairing. After an initial screening for copulatory behaviors, a fourth group received only handling comparable to that received by the other three groups. Rats that received contingent LiCl gradually ceased to copulate; rats that received either noncontingent LiCl or saline remained vigorous copulators. Male rats were returned to their home cages on Trial 12 after 7-min exposure to an inaccessible female. Blood was collected by decapitation 38 min later. Testosterone levels, measured by radioimmunoassay, were significantly higher for saline than for handled control rats. Testosterone levels for handled control rats, however, were comparable to those of copulating and noncopulating rats that had received either noncontingent or contingent LiCl, respectively.

Hypothalamic involvement in sexuality and hostility: comparative psychological aspects

Evidence presented in this article shows the representation of sexual and aggressive behaviors at the level of the hypothalamus to be more prominent than in all other brain areas involved. Indeed, there are good arguments to attribute a central position to the hypothalamus within larger structural systems encompassing the limbic system, where aspects of the behaviors involved can be influenced. So far, however, the arguments are purely descriptive and factual and do not contribute much to answering questions about hypothalamic function: the grounds for and consequences of this massive representation of apparently almost all emotionally relevant social behavioral complexes, so universally established in a diversity of species, still has to be detected. A second and equally important aspect of hypothalamic function obviously has to be related to its central position within various hormonal systems. The present article concentrated on the acute dynamics and behavioral significance of activation of the pituitary-adrenocortical and pituitary-gonadal axes. Evidence indicates that the unconditioned behavioral stimuli or the consequences of behavior, but also stimuli conditioned to emotionally relevant events, may drastically alter hypothalamic hormonal regulation. Most importantly, these hormonal consequences in themselves again seem to determine further behavior and responses in relevant situations. The evidence presented with respect to reward and aversion, associated with alterations of specific hormones of the gonadal axis, may add a new dimension to our understanding of psychoendocrine functions of the hypothalamus (see also Gary, 1975; Leshner et al., 1981; Carey, 1987). Psychologically, such data can be taken as an argument for a more thorough study of the relation between memory processes and emotion (Bower et al., 1981). However fragmentary and incomplete this review may be, it will be clear that hypothalamic substrates and directly related areas, as well as affiliated hormonal mechanisms, play a central role in many of the most complex motivational and emotional syndromes and disorders. The prime idea in this is that the psychological concomitants of hypothalamic (dys)function are as much output as input, and as much the consequences as the cause within related syndromes. Such a view places the hypothalamus at the core of psychological theories of emotion and motivation, which from their most early origin have been heavily set towards hormonal and humoral changes and their relationships with psychological experience.(ABSTRACT TRUNCATED AT 400 WORDS)

Multisensory regulation of maternal behavior and masculine sexual behavior: a revised view

Frank Beach's view of the multisensory regulation in Norway rats of copulation in males (12) and of pup retrieval in females (23) is critically analyzed and revised in terms of Lashley's influence, Beach's other work, and current neurobiological knowledge. Beach's view was that no single sensory stimulus is essential to elicit these behaviors, but that all relevant stimuli available summate in the neocortex; consequently, (a) sexual "arousal" is increased in males, leading to copulation, and (b) the "efficiency," or likelihood, of retrieval is increased in postpartum mothers. The revised view is based on a component analysis in which each of these behaviors consists of a chain of motoric responses elicited by somatosensory stimulation. Distal stimuli emanating from the female or pups induce proximity by provoking orientation, attention and arousal; the meaning of these stimuli is largely learned by conditioned associations during the initial executions of the behavior, although odors may have a prepotent influence for some individuals. Stimuli are integrated in a multisensory manner by both subcortical and neocortical mechanisms. Generalizations concerning the reproductive behavior of other mammalian species are suggested.