NPB 110A Midterm 2 WIP

Organizational effects

build the system early in development

Activational effects

trigger immediate behavior later in life

Testosterone

has both organizational and activational influences on sexual differentiation

Organizational effect of testosterone

made the HVC and RA area of male birds larger than that of females

What is the RA

song premotor nucleus that receives cholinergic inputs from the basal forebrain

Activational effects of testosterone

What can bird brains do that human brains cant

More gifted in navigating

How is birdsong produced

by a specialized circuit in the brain

Organizational effects of sex hormones

Testosterone enlarges the HVC area of males compared to females who don’t have it as much

What does the HVC do

it is necessary for both learning and production of bird song. affects syllables, order, and duration of trills

What are androgens in birds

DHT and Estradiol

how are RA and HVC regions affected

blocking androgen receptors allowed us to see aspects of song were affected

What’s a trill

type of sound that involved the rapid repetition of a single note or syllable

• fast rhythmic sequence used for communication, mates, and defending territory

how does raising androgen levels affect females

it enlarges the HVC which allows them to sing like male birds

Membrane transport

channels are membrane proteins permeable to certain ions permeable to certain ions

channels can have high flux rates