Sex: The Altered State of Consciousness

1. Sex: The Altered State of Consciousness COGS 175, June 5th 2006 Part I: Cody Frew, Rachel Jaffe, Rajiv Rao Part II: Katie Frehafer, Dan Hoag, Josh Kirsch, Brian Waldberg

2. Topic Outline • Group I • Intro - Cody, Rachel, Rajiv • Neurochemicals - Rachel • Arousal Pathways - Rajiv • Hormones / Baseline States - Cody • Group II • Pheromones / Attraction - Josh • Biological Changes - Katie • Sexual Abnormalities - Brian • Masochism – Dan Hoag • Conclusion – Josh, Katie, Brian, Dan

3. Warning: contains explicit material

4. Introduction • Is sex an altered state of consciousness? • Yes… • Many changes take place during sexual arousal and intercourse that deviate from the normal waking state of consciousness. • Neurochemical changes • Hormonal changes • Changes in brain activation • Changes in the biological state of the body • Social behavior and interactions that are limited to sexual states

5. Neurochemicals of Sex • Neurotransmitters and Neuropeptides involved in sexual function • Nitric Oxide (NO) • Serotonin (5-HT) • Dopamine (DA) • Epinephrine • Norepinephrine (NE) • Opioids • Acetylcholine (Ach) • Histamine • γ-Aminobutyric Acid (GABA)

6. Nitric Oxide (NO) • Key factor in production of penile/clitoral vasocongestion and tumescence. • Sexual stimulation  NO production  Guanylate Cyclase • Guanosine Triphosphitase (via Guanylate Cyclase)  cGMP • cGMP: relaxation of smooth muscles genital arteries resulting in increased blood flow to those areas. • cGMP is metabolized by cyclic nucleotide phosphodiesterase isoenzymes. • As long as stimulation continues, metabolic degradation is balanced by production and arousal is maintained.

7. Serotonin (5-HT) • Selective Serotonin Reuptake Inhibitors (SSRIs) effects 5-HT activity and causes sexual side effects. • Increased 5-HT causes decreased libido. • 5-HT2 receptor stimulation impairs sexual functioning. • 5-HT1a receptor stimulation facilitates sexual functioning. • 95% of 5-HT receptors are located in the periphery of the body. • Peripheral 5-HT acts on: • smooth muscle vasodilation/vasoconstriction, including the smooth muscle of the genitals. • peripheral nerve functions, including those of the sexual organs.

8. Dopamine (DA) • DA facilitates male sexual behavior • D1 and D2 receptor agonists increase sexual activity and induces erection. • Common DA agonists: Apomorphine and L-Dopa • Moderate doses of cocaine, which blocks the reuptake of DA, can increase sexual pleasure, but also inhibit sexual behavior in the withdrawal phase.

9. Epinephrine • Adrenergic activity has a role in maintaining the penis in a flaccid state and reducing swelling. • Blockade of the α1-adrenergic receptors produces erection. • Adrenergic agonists, like Ephedrine, increase vaginal pulse amplitudes in response to erotic stimuli. • Adrenergic system activates when sexual arousal begins, and epinephrine increases until its peak at orgasm.

10. Norepinephrine (NE) • Blood plasma levels of NE increase during sexual activity. • NE levels positively correlate with arousal, peaking at orgasm and then returning to baseline. • NE levels return to baseline within minutes for males, while it can take up to 23 hours for females.

11. Opioids • Role in sexual function is studied by looking at: • Endogenous opioids (endorphins, enkephalins, dynorphins). • Narcotics (opiates) • Abuse of opiates leads to sexual difficulties. • Opioid anatogonists (naloxone and naltrexone) used to treat erectile dysfunction. • Exact role of endogenous opioids in normal sexual functioning is unclear, but levels are thought to increase during sexual activity.

12. Acetylcholine (Ach) • Ach is involved in the sexual function of males much more than females. • Ach stimulates the cholinergic receptors in the penile tissue to act as a key factor in producing erection. • Penile erection is controlled by the Ach levels in the CNS, regardless of cholinergic receptors in the periphery.

13. Histamine • Histamine antagonists tied to loss in libido. • Due to decrease in uptake of testosterone. • Administering histamine counters some cases of impotence. • Possible action on H2 and H3 receptors.

14. γ-Aminobutyric Acid (GABA) • Effects only studied in male rats • Inhibits sexual behavior (mounting, intermitting, erection, ejaculation) • Possibly correlates to GABA effects in human sexual function.

15. Arousal Pathways • Connectivity in the Brainstem and Spinal Cord • Neurological Substrates Involved in Sexual Activity and Arousal

17. Arousal Pathways • Connectivity in the Brainstem and Spinal Cord: • The Nucleus Paragigantocellularis → lumbosacral spinal cord of both males and females. • lumbosacral spinal cord → ascending reticular activating system. • The Raphe Nuclei (5-HT) → lumbosacral spinal cord • Magnus and Parapyramidal regions → lumbosacral spinal cord • Locus Ceruleus (NE) → lumbosacral spinal cord

18. Arousal Pathways • Connectivity in the Brainstem and Spinal Cord (continued): • Further evidence shows that the Periaqueductal Grey Area of the midbrain acts as a relay center for sexually relevant stimuli.

19. Arousal Pathways

20. Arousal Pathways • Neurological Substrates Involved in Sexual Activity and Arousal • Hypothalamus • Lesions to the Medial Preoptic area • The Paraventricular Nucleus (PVN) of the hypothalamus shows activation in both sexes during copulation in rats. • Oxytocin precursors released from PVN

21. Arousal Pathways • Neurological Substrates (continued) • Medial Amygdala • Bed Nucleus of Stria Terminalis • EEG studies have shown that right-to-left hemispheric asymmetry occurs during nocturnal penile tumescence.

22. Arousal Pathways • Neurological Substrates (continued) • Right prefrontal cortex activity during the viewing of sexual stimuli. • Bilateral rCBF increases in the inferior temporal cortex, right insula, right inferior frontal cortex, as well as the left anterior cingulate cortex. • Largest rCBF increase occurred in cerebellum

23. Arousal Pathways • Neurological Substrates (continued) • Activation of the mesodiencephalic transition zone, as well as the ventral tegmental area during ejaculation in males. • Activation in midbrain lateral central tegmental field • Zona incerta, subparafascicular nucleus, and the ventroposterior, midline, and intralaminar thalamic nuclei (all to a lesser extent than the ventral tegmental area).

25. Hormones/Baseline states • “Hormone” – Greek for “to activate” • What do hormones have to do with sex and the altered state of consciousness?

26. Hormones/Baselines • Endocrine System • Anatomy: • Adrenal glands • Pituitary gland • Hypothalamus • Testes (male) • Ovaries (female) • Placenta (pregnancy) • Seen in all mammals- Must be important to survival.

27. Hormones/Baselines • What are some of the hormones related to the ASC of sex? • Pituitary hormones • Gonadotropins • Follicle-stimulating hormone (FSH) • Luteinizing hormone (LH) • Prolactin • Oxytocin • Adrenal hormones • Androgens • Estrogens • Steroids

28. Hormones/Baselines • Hormones play a vital role in overall mood, arousal, desire, coitus, and even post-coital behavior • E.g. Oxytocin – the “cuddle” hormone

29. Hormones/Baselines • How do hormones play a role in brain function, sex, and consciousness? • Constant interaction within endocrine system and brain • Hypothalamus Feedback Mechanism • Gn-RH • Gn-IH • Excessive estrogen ↓ sexual desire (both M & F) • Testosterone ↑ sexual desire (both M & F)

30. Hormones/Baselines • Hormone Configurations/Baseline States • Effect on Cognition • higher testosterone levels has been correlated with higher performance on spatial intelligence tasks, but lower performance on verbal intelligence tasks.

31. Hormones/Baselines • Timelines: • Lifetime (male- testosterone):

32. Hormones/Baselines Monthly (female): Daily (male): • Males seem to have higher levels of testosterone in the morning, compared to the rest of the day. Different hormonal states are constructed that serve as baselines for motivation, perception, cognition, and behavior.

33. Hormones/Baselines • Gender Differences • Same chemicals but different: • Amounts • Proportions • Physical anatomy! The Female Brain The Male Brain

34. Hormones/Baselines • Questions… • Who controls sexual behavior? Is it you or your hormones??? • The hypothalamus monitors and helps maintain various hormone levels within the body that is deemed appropriate… but who tells the hypothalamus what is appropriate?!? • Is it possible to moderate your hormones with deliberate conscious thought? • Biofeedback perhaps!

36. Works Cited (Group I) • Arnow, Bruce et. al. “Brain activation and sexual arousal in healthy, heterosexual males” Brain. Vol. 125, No. 5, 1014-1023, May 2002. http://brain.oxfordjournals.org/cgi/content/full/125/5/1014 • Holstege, Gert et. al. “Brain Activation During Male Ejaculation.” The Journal of Neuroscience, October 8, 2003, 23(27):9185-9193 http://www.jneurosci.org/cgi/content/full/23/27/9185 • McKenna, K. “The Brain is the master organ in sexual function: CNS control of male and female sexual function.” Int. J Impot. Res. 1999;11 (suppl 1):S48-S55 • Meston, Cindy et. al. “The Neurobiology of Sexual Function” Arch Gen Psychiatry, Vol. 57. American Medical Association. Nov 2000. http://www.usfca.edu/fac_staff/dever/neurobiologyofsex2.pdf • Fundamental Neuroscience, 2nd edition. Ch. 35, p. 928-933. Ch. 40, p. 1031-1036. Academic Press, San Diego, 2003. • Allgeier, ER, Allgeier, AR.  Sexual Interactions, 5th Edition.  Houghton Mifflin Company, Boston, New York.  2000. • Gangestad S.W., et al. “Women's Preferences for Male Behavioral Displays Change Across the Menstrual Cycle.” Psychological Science, Volume 15, Number 3, March 2004, pp. 203-207(5) • Christiansen, K., & Knussmann, R. “Sex hormones and cognitive functioning in men.“ Neuropsychobiology, 18: 27 - 36. 1987 • Sanders, R. “Brain hormone puts brakes on reproduction.” February 2006. http://www.berkeley.edu/news/media/releases/2006/02/06_hormone.shtml