1. Introduction to Biopsychology [PSB 4002] Professor Josh Herrington DM 249 305-348-1230 Jherr033@fiu.edu website: dpblab.fiu.edu

2. Human Sexual and Reproductive Behavior humans are non-seasonal breeders human females are concealed ovulators sex is not only for reproduction

3. Hormonal Mechanisms At the onset of puberty, the hypothalamus begins to release bursts of gonadotropin releasing hormone, (GRH) Which stimulates the pituitary to secrete luteinizing hormone (LH) and follicle stimulating hormone (FSH). These hormones stimulate the gonads to release estradiol or testosterone.

4. Estradiol& Testosterone Estradiolcauses breast development, growth of body hair, broadening of the hips, etc. Testosterone causes lowering of the voice, hair and beard growth, muscle development, broadening of the shoulders, etc.

6. Female Reproductive Cycle A strong example of the role of negative feedback (a self-regulatory process in which a system’s output fees back to the input part of the system, thereby reversing the directon of change of the output). Last week, we talked about another example, the HPA axis negative feeback loop GRH -> ACTH ->Glucocorticoids -> GRH, etc.

7. Female Reproductive Cycle Hypothalamus (GRH)  Pituitary (FSH and LH)  Gonads (ovaries) FSH acts on the ovary to stimulate the growth of the follicle, which contains the egg or ovum. As the follicle grows it secretes estrogen.

8. Female Reproductive Cycle (cont.) This estrogen feeds back to the pituitary, inhibiting it from sending out more FSH. Estrogen also stimulates the pituitary to release LH, which causes the walls of the follicle to break, releasing the egg (ovulation). After the release of the egg, the follicle tissue becomes the corpus luteum.

9. Female Reproductive Cycle (cont.) LH causes the corpus luteum to secrete progesterone. Progesterone increases blood supply to the uterus wall, preparing it for egg implantation. Progestrone also feeds back to the pituitary, inhibiting the secretion of LH

10. Female Reproductive Cycle (cont.) If fertilization does not occur, the corpus luteum shrinks, progesterone decreases, the uterine lining is gradually expelled in menstruation, and the cycle begins again.

12. H > P > G axis -Puberty -Sexual and Reproductive Behavior -Menopause

13. menopause

14. andropaus e

15. Midterm #2 will be on Wednesday, Feb 27th Sample study questions and powerpoint slides will be posted by Wed, Feb 20th. Covers information from Chapters 7, 10, 11, 12, 13, 17, & 19

16. Rhythms Daily rhythms affect your: – pulse rate and blood pressure, – blood sugar level, – body temperature, – gland secretions, – salt secretion by the kidneys – cell growth, etc. These biological changes are called circadian rhythms, changes that occur daily.

17. Rhythms The hypothalamus is the “control center” for coordinating bodily processes with the outside world. In the front part of the hypothalamus is a specialized group of nerve cells called the suprachiasmatic nuclei (or SCN).

18. Rhythms Linked by a track to the retina of the eye, which picks up light and dark signals from the environment. This system influences hormone secretion, particularly from the pineal gland. The pineal gland secretes melatonin, which is typically secreted between 11 pm and 7 am and suppressed during the day.

19. Rhythms

20. Zeitgebers External cues or “time-givers” are known as zeitgebers. – Examples include cycles of light and dark, watches and clocks, mealtimes and social routines, bedtimes, etc. Sunday, November 06

21. Zeitgebers The power of zeitgebers to affect how we feel can be seen in the phenomenon of jet lag and in our responses to shift-work.

22. Sleep and Waking

23. What is sleep? An activeprocess Characterized by: – an increased threshold for stimulus detection – limited behavior – particular neuronal activity patterns

24. Who sleeps? most animal species all mammals

25. Why do we sleep? We will spend approximately one-third of our lives sleeping and yet we do not know why Three main theories: – homeostasis – inactivity/safety – neural plasticity/ memory formation Likely more than one theory is correct

26. Sleep Sleep is an active process of the nervous system, involving systems in the: – brain stem, – the reticular activating system, – the raphe nuclei (secretes serotonin), – the locus coeruleus(secretes norepinephrine) – and of course, the rest of the CNS as well.

27. Brain Waves During Wakefulness Alert: beta activity – Low amplitude – High frequency Drowsy: alpha activity – Increased amplitude – Decreased frequency

28. Stages of Sleep Not one state, but a dynamic, orderly, rhythmic succession of states, each with its own unique properties: – Stage 1: daydreaming, reveries (1-10 min or so) – Stage 2: sound sleep (40-60% of total sleep time) – Stage 3: deep sleep (5-10% of sleep time) – Stage 4: deepest sleep (15-30% of sleep time) – REM sleep: every 90 min or so, 4-5 times a night

29. Stages of Sleep NREM – Stage 1 – Stage 2 – Stage 3 – Stage 4 REM

30. Non-REM Sleep With each successive stage – the amplitude of brain waves increases – the frequency of brain waves decreases – and the threshold for waking increases Lower metabolism – Oxygen consumption falls to 45% in stage 4 Activity of sympathetic nervous system decreases Activity of parasympathetic nervous system increases Sensory information from the external world inhibited at the level of the thalamus

31. REM Sleep Occurs every 60 to 90 minutes after 80 to 100 minutes of sleep onset; lasts 5 to 30 minutes. “Paradoxical sleep”: brain activity as great as, or greater than, during periods of wakefulness. – metabolism similar to waking levels Motor neurons inhibited – but not the muscles responsible for eye movements, thus the name REM sleep

32. Brain Mechanisms Involved in Sleep and Waking Hypothalamus: – Anterior activity promotes sleep – Posterior activity promotes waking – Suprachiasmatic nucleus: generates circadian rhythm Triggers melatonin release

33. Sleep Throughout the Lifespan With increasing age, humans – sleep less – have a decreased percentage of REM sleep Sleep links to the circadian rhythm at 6 to 12 weeks of age in most infants Precocial species do not have as high a percentage of REM sleep when young as do altricialspecies

34. Newborns sleep about 16 hr/day, 8 hr are spent in REM sleep

35. Can we learn while we sleep? No: in adulthood, sensory information is blocked at the level of the thalamus. Newborns can learn while sleeping – Rudimentary thalamocortical connections in early infancy result in imperfect blocking of sensory information.

36. Why do we dream? Many theories but no definitive answer: – We dream to organize the day’s information – Activation-synthesis: dreaming is the subjective awareness of neural events – Epiphenomenon: dreaming is a byproduct with no function

37. Sleep and Health 40 million Americans have chronic sleep problems. Sleep problems include: – insomnia. – narcolepsy. – sleep apnea. Too much (more than 9 hours) or too little (less than 4 hours) of sleep over time can be bad for your health.