Flashcards in Lecture 3 & 4 Deck (20)
How do hormones affect the target cell?
They affect gene expression (gene transcription factors).
What are the three main types of hormones?
Lipids, Peptides/proteins, Amines/others.
What is an example of a lipid hormone?
What are two examples of a peptide/protein hormone?
Vassopressin and Oxytocin.
What is an example of a amine/other hormone?
How can one study hormones? (4)
1. Remove gland, 2. add hormones, 3. measure circulating levels in reference to behavior, 4. block receptors.
Explain the connection between estrogen and female sexual behaviors in mice.
Removing ovaries eliminated female sexual behavior. Injecting estrogen and progesterone, restored behavior.
Why was both estrogen and progesterone needed to restore sexual behaviors in female mice?
Estrogen increases the number of progesterone receptors.
Explain how researchers found the connection between testosterone and aggression and courting behaviors in Red Deer Stags.
Since testes produce testosterone, castrated males did not fight or mate.
What are the two main modes of hormonal action?
Activational and organizational.
What are activational effects?
Short-term, reversible effects that occur in adult organisms.
What are organizational effects?
Long-term, irreversible effects on tissue differentiation and development that can either directly or indirectly influence behavior.
Which hormonal effect occurs mainly during critical or sensitive periods?
Which hormonal effect is asymmetric to the sexes?
What is an example of activational effects? (Mice)
Oxytocin and maternal behavior in mice. Oxytocin injections induce maternal behaviors in pre-maternal mice.
What is an example of activational effects in sheep?
Oxytocin injections caused sheep to accept alien lambs.
Which acts quicker: steroid or peptide hormones?
What is aromatase?
An enzyme that converts testosterone to estradiol.
How does testosterone lead to sexual behaviors?
By being converted to estradiol and exerting effects on estrogen receptors.