20. Sexual dimorphism and behaviour II Flashcards
(24 cards)
What is the primary purpose of complex songs produced by male songbirds?
Territory establishment and mate attraction
What are the three distinct phases of song learning in songbirds?
- Sensory period
- Sensorimotor period
- Crystallization period
Which brain regions show sexual dimorphism in song learning pathways in male songbirds?
- Area X
- HVC
- RA
What hormone stimulates the growth of brain regions involved in song production in male songbirds?
Testosterone
What unique reproductive strategy do some species of whiptail lizards exhibit?
Parthenogenetic reproduction (all-female)
What hormonal state influences behavioral roles in whiptail lizards?
Hormonal state
What is the role of estrogen in female whiptail lizards?
Displays female receptive behaviors
What does the SRY gene on the Y chromosome trigger?
Male development
What are the two hormones produced during male development?
- Testosterone
- Anti-Müllerian hormone
What are the two products testosterone can be converted into?
- Estradiol
- Dihydrotestosterone (DHT)
What is the prevalence of XYY syndrome?
1 in 1,000
What is Klinefelter syndrome characterized by?
XXY, male with some female secondary characteristics
What hormonal disorder leads to excess testosterone due to 21-hydroxylase deficiency?
Congenital adrenal hyperplasia
True or False: Steroid hormones are hydrophilic and cannot pass through cell membranes.
False
What are the two mechanisms through which steroid hormones act?
- Membrane effects
- Nuclear receptor effects
What receptors are key in multiple brain regions for steroid hormone signaling?
- Estrogen receptors α and β
- Androgen receptors
What is the default brain development pattern in rodents?
Female
What hormone is responsible for masculinizing the brain in male rodents?
Estradiol
What prevents estradiol from entering brain cells in female rodents?
Alpha-fetoprotein
What effect does high-dose estradiol have on female rodents when administered perinatally?
Masculinizes their brains and adult behaviors
What are some effects of hormones on neural development and plasticity?
- Dendritic branching
- Spine density
- Synaptic transmission
- Long-term potentiation
What is Onuf’s nucleus and its characteristic in males?
Larger in males
What regulates sexual development and function in the neuroendocrine system?
Hypothalamic-pituitary-gonadal axis
What hormone triggers LH and FSH release from the pituitary?
Gonadotropin-releasing hormone
