BIOL 320 Lecture Notes - Lecture 21: Stria Terminalis, Sex Steroid, Preoptic Area
Sakata is hosting a speaker (Matt Fuxjager). Don't be shy to attend these seminars! This Thursday, 3pm, Redpath. —
woah. this bird is snapping its wings
super
rapidly to make this snapping fire cracker sound.
—
Annoncements
communication is a social behaviour
•
social behaviours are traditionally thought as behaviour underlined by sex steroid hormones and […?]•
affected by sex steroid hormones
—
changes seasonally, along with other social behaviours—
mediated by activity within brain areas controlling other social behaviour (social behaviour network)
—
communication as social behaviour:
•
Communication
all these areas concentrate sex steroid hormones; contain receptors for these hormones
—
Sarah Newman (1999)
: proposed circuitry of hypothalamic and midbrain areas important for all sorts of social
behaviours.
•
pathway for hormones:
•
progesterone is the basic precursor for most hormones—
enzymes then transform progesterone into different hormones
—
so, what these hormones do is that they bind to receptors and this will lead to some change in the cell
—
and in this case,
will lead to change in social behaviour
•
classic hormone signalling: in a lot of these cells, you have intracellular receptor. hormones are lipophilic, can diffuse
through cell membrane and can bind to receptor in the cytoplasm. bound receptor can then migrate into nucleus and
modulate transcription of specific target genes
•
31. Social Behaviour Network I
April 4, 2018 11:35
BIOL 320 Page 1
BUT. there's still a disconnect between gene expression and neuron activity. so how do you go from sex steroid
hormones to display of social behaviours? it's useful to think about steroid hormones + social behaviour—but Sakata
argues it's far from a good mechanism to think about expression of social behaviour.
•
lots of cells in stria terminalis and preoptic area expressing androgen receptor •
migrate from deep ocean to intertidal zones from april
-
august
—
only type I males will display seasonal changes in communication, producing
long hums
used to attract females
—
E.G. painfin midshipman
•
it's only in april - august that shows changes in level of testosterone, which suggests it might be promoting display
of mating behaviour
—
brain areas:
•
across a lot of vertebrate species producing social vocalisation, neurons in the hindbrain often express androgen
receptors
—
so what brain circuits impinge on the vocal pattern network? —
red area = social behaviour network
—
BIOL 320 Page 2
Document Summary
This thursday, 3pm, redpath. woah. this bird is snapping its wings super rapidly to make this snapping fire cracker sound. Vst, apoa, etc. are social behaviour network that project back to hindbrain for vocalisation all express ar pathway: Biol 320 page 3 preoptic area is the main node projecting to the circuitry coronal sections: both dtam and xmn have androgen receptors (black circles) E. g. songbirds: there"s seasonal changes in testosterone levels that correlate with seasonal changes in mating behaviour in the fall/winter, there"s not really any detectable levels of t in the blood. but then there"s a huge surge around. March = breeding season around the same time as surge, there"s also high degree of singing, more territorial behaviour, courtship. Korsia & bottjer (1991): control males have ~4 syllables per song gave juveniles t one day after they were born. essentially tricks the brain into thinking they"re sexually mature.
