A wide variety of sexual dimorphisms, structural differences between the sexes, have been described in the brains of many vertebrate species, including humans. In animal models of neural sexual dimorphism, gonadal steroid hormones, specifically androgens, play a crucial role in engendering these differences by masculinizing the nervous system of males. Usually, the androgen must act early in li...

Charles Darwin made numerous seminal contributions to the study of animal behavior over his long career. This essay places these contributions in the context of Darwin's life, showing his long-standing interest in psychological and behavioral issues encompassing all species, including humans. Ten areas are highlighted: natural history; communication; sexual selection and courtship; comparative ...

Sexual behavior is a natural reward for many rodent species, and it often includes chemosensory-directed components. Chemosensory stimuli themselves may also be rewarding. Conditioned place preference (CPP) is one paradigm frequently used to test the rewarding properties of a range of stimuli. Males and females of several rodent species show a CPP for sexual behavior; however, it is currently u...

background:  patients  with  ischemic  heart  disease  (ihd)  may  report  difficulties with  sexual  function  and  marital relationship. however, there is a dearth of studies focusing on the association between these aspects in ihd patients. the present study sought to assess the association between sexual function and marital relationship among ihd patients and also test the effect modificat...

according to iran’s folk medicine, camphor, a crystalline ketone obtained from essential oils of cinnamomum camphora, has both sexual behavior attenuating and enhancing properties. this study examined the effects of camphor on sexual behavior in male rats. twenty four sexually mature male sprague-dawley rats were randomly divided into 4 groups receiving daily i.p. injections of olive oil as veh...

It is well established that steroid hormones regulate sexual behavior in vertebrates via organizational and activational effects. However, whether the organizational/activational paradigm applies more broadly to the sexual behavior of other animals such as insects is not well established. Here we describe the hormonal regulation of a sexual behavior in the seasonally polyphenic butterfly Bicycl...

Lower spinal cord injuries frequently cause sexual dysfunction in men, including erectile dysfunction and an ejaculation disorder. This indicates that the important neural centers for male sexual function are located within the lower spinal cord. It is interesting that the lumbar spinal segments contain several neural circuits, showing a clear sexually dimorphism that, in association with neura...

Drugs of abuse comprise several pharmacological classes, including psychomotor stimulants, such as amphetamine and cocaine, and CNS depressants, such as morphine and alcohol. Few studies have examined the effects of those drugs systematically on human sexual behavior, although substantial clinical and epidemiological literatures suggest that drugs in both classes either inhibit sexual respondin...

Objective: Methamphetamine consumers use can have more efficient practices, be hyperactive, and take sexual risk-taking behaviors. These behaviors are particularly remarkable in homosexuals. Methods: The present study was conducted based on casual-comparative method in the field of descriptive studies. Since 1 March to 25 June 2015, a total of 62 MSM subjects were selected ...