Serial neurochemical measurement of cerebrospinal fluid during the human sexual response cycle.

Recent studies examining the neuroendocrine response pattern underlying the human sexual response cycle revealed transient activation of the sympathoadrenal system and a substantial, long-lasting increase in plasma prolactin concentrations following orgasm in men and women. Prolactin has been discussed as being part of a feedback mechanism that signals centers in the central nervous system, such as the dopaminergic system controlling sexual arousal. To further elucidate the central role of neuropeptides, biogenic monoamines and neurotransmitters in human sexual behavior, a serial cerebrospinal fluid (CSF)-sampling technique was implemented using a previously established experimental paradigm for sexual activity in a laboratory setting. In parallel with peripheral endocrine measures, lumbar CSF was drawn via an indwelling spinal catheter during the sexual response cycle in 10 healthy males and 10 age-matched controls, and analysed for prolactin, oxytocin, biogenic monoamines and/or their metabolites as well as inhibitory and excitatory neurotransmitter concentrations. Parallel to raised peripheral sympathetic activity, norepinephrine also increased in CSF during audiovisual, masturbation-induced sexual arousal and orgasm, and remained elevated for the remainder of the session (F(4,72) = 8.79, P = 0.000). In contrast, none of the other measures, in particular prolactin and dopamine or its metabolites, reflected significant alteration. In conclusion, the human sexual response cycle is characterized by an increase in sympathetic activity in plasma and CSF, and by pronounced secretion of plasma prolactin after orgasm. However, alterations in dopaminergic or peptidergic activity are not found in lumbar CSF, possibly due to local and restricted release in diencephalic and mesencephalic brain regions.

The dental anxiety scale and effects of dental fear on salivary cortisol.

Only a few studies have investigated use of the Dental Anxiety Scale in dental fear-induced neuroendocrine changes. The present study examined 19 female patients, each at two timepoints across an educational and a treatment session within periodontitis therapy. Subjective measures included a visual analogue scale, the STAI State scale, and the Dental Anxiety Scale. Salivary cortisol was measured in parallel across all four timepoints. Although patients were significantly more aroused and anxious prior to the treatment session, salivary cortisol remained unchanged. However, patients with high Dental Anxiety were significantly more aroused and anxious and showed significantly higher salivary cortisol during the educational session than those with low scores on Dental Anxiety. In conclusion, the Dental Anxiety Scale differentiated mean neuroendocrine change between patients scoring low and high for Dental Anxiety and its use as an accurate tool to identify patients with high dental anxiety should be further studied predictively.

Effects of sexual arousal on lymphocyte subset circulation and cytokine production in man.

OBJECTIVE: Sexual arousal and orgasm induce an increase in sympathetic activity as well as in catecholamine and prolactin plasma concentrations. However, the effects of sexual arousal and orgasm on immune functions in man are unknown. Thus, this study investigated the effects of masturbation-induced orgasm on lymphocyte circulation and cytokine production in healthy young males. METHODS: In a crossover design, 11 volunteers completed an experimental condition in which they were asked to masturbate until orgasm and to participate in a control condition without sexual activity. Blood was drawn continuously for determination of endocrine parameters. In addition, leukocyte and lymphocyte subsets were analyzed via flow cytometry, and the production of lipopolysaccharide-induced interleukin 6 and tumor necrosis factor alpha was measured before and then 5 and 45 min after the orgasm. RESULTS: The results confirmed transient increases in adrenaline and prolactin plasma concentrations. Sexual arousal and orgasm increased the absolute number of leukocytes, in particular natural killer cells (CD3-CD16+CD56+), in the peripheral blood. In contrast, T cell (CD3+) and B cell (CD3-CD20+) subpopulations as well as the production of interleukin 6 and tumor necrosins factor alpha remained unaffected by sexual activity. CONCLUSION: These findings demonstrate that components of the innate immune system are activated by sexual arousal and orgasm.

Acute neuroendocrine response to sexual stimulation in sexual offenders.

BACKGROUND: Several pharmacotherapeutic approaches have confirmed the influence of neuroendocrine parameters on sexual desire, function, and fantasies in men; however, the relevance of acute neuroendocrine changes in mediating heightened sexual drive remains unknown. We recently demonstrated that plasma prolactin substantially increases following orgasm in healthy men, suggesting a feedback mechanism for peripheral prolactin in the control of acute sexual arousal. Because prolactin appears to play a regulatory role in acute sexual drive, we initiated this study to see whether sexual offenders with a high sexual drive have a different neuroendocrine response to sexual arousal. This study compares the prolactin response to orgasm of sexual offenders with high sexual drive and that of healthy subjects with average sexual drive. METHODS: From a subject pool of 150 inpatients held because of sexual crimes, we recruited 10 volunteers, based on their high sexual drive according to an intensive, semistructured clinical interview. We defined sexual drive by a short refractory period and strong sexualization, or a high frequency of sexual stimulation. We analyzed the acute psychoneuroendocrine response to sexual arousal and orgasm continuously before, during, and after masturbation-induced orgasm in patients and control subjects. RESULTS: Sexual offenders demonstrated higher sexual desire (P < 0.001) and function (P < 0.001) and a more positively perceived refractory period (P < 0.05). Both groups displayed a prolonged, significant increase in prolactin plasma levels after orgasm (P < 0.001). Sexual offenders did not differ from control subjects in neuroendocrine response to sexual arousal and orgasm. CONCLUSIONS: These data demonstrate that sexual offenders with a high sexual drive do not differ from control subjects in the postorgasmic neuroendocrine response, particularly in prolactin release. This study confirms that factors other than peripheral hormones influence deviant sexual behaviour.

Orgasm-induced prolactin secretion: feedback control of sexual drive?

Recent studies from our laboratory have investigated the hormonal response to various forms of sexual stimulation, including film, masturbation, and coitus in both men and women. This series of studies clearly demonstrated that plasma prolactin (PRL) concentrations are substantially increased for over 1h following orgasm (masturbation and coitus conditions) in both men and women, but unchanged following sexual arousal without orgasm. Here we discuss evidence suggesting that the PRL response to orgasm may play an important role in the control of acute sexual arousal following orgasm. Supporting this position, chronic elevations of PRL (hyperprolactinemia) produce pronounced reductions in animal sexual activity, and significant reduction of libido and gonadal function in both men and women. These data suggest that PRL may represent a peripheral regulatory factor for reproductive function, and/or a feedback mechanism that signals CNS centres controlling sexual arousal and behaviour. Thus, we propose a theoretical model of the role of PRL as a neuroendocrine reproductive reflex.