Sex and puberty

Question 1

Why are steriod hormones allowed to cross the BBB?

Answer 1

Because they are lipids, and the BBB are lipophilic (membranes are)

Question 2

Describe the hormonal change during the menstrual cycle.

Answer 2

• peak in estradiol in the late follicular phase (right before the ovulation)
• LH peak during ovulation
• progesterone peak in the luteal phase (after ovulation)
• secondary estradiol peak in luteal phase

Question 3

Describe the neuroendocrinologic pathway releated to puberty.

Answer 3

GnRH (Gonadotrophin releasing hormone) released from hypothalamus –> LH (luteinzing hormone), FSH (follicle stimulating hormone) released from anterior pituitary –> sex hormones (testerone/estradiol + progesterone) released from gonads

Question 4

Where are GnRH neurons distributed, and what are some of them responsive to?

Answer 4

Distributed in many areas of the hypothalamus, some are responsive to estrogens

Question 5

What is puberty?

Answer 5

Primary: changes in reproductivity
Secondary: everything else (body changes)

Question 6

What are the triggers for puberty onset?

Answer 6

We don’t know, but seems to be affected by:
- body weight (starvation –I puberty, but not vice versa)
- genetics
- environment
- circulating steroids

Question 7

How does the feed-back mechanisms differ in males and females?

Answer 7

Males: only negative

Question 8

Which hormone are the first to increase in females?

Answer 8

Estrogen

Question 9

What are kisspeptin?

Answer 9

• A group of small peptides, encoded by Kiss1
• Possible puberty sensor
• Stimulates GnRH release

Question 10

What are sex differences in the brain?

Answer 10

Genetic, but also endocrine (peak of testosterone makes the difference)

Question 11

What NTs are involved in boding behavior?

Answer 11

Vasopressin and oxytocin