BIOL 320 Lecture Notes - Lecture 18: Java Sparrow, Hindbrain, Motor Program
schedule for the rest of the course should not change.•
recall that tmrw is another microscopy lab, and also assignment 3 is due•
Logistics
it's likely that burst activity in nerves produces burst vocalisation in ancestral species. and
through speciation you get diversification, e.g. click
•
take home message: there's different mechanisms in which click vocalisation has emerged •
ploidy: number of pulses per second = pulse rate
→
diploid has higher PR than tetraploid. and in
diploid there's a stronger relationship between PR and temperature, vs. more flat curve in
tetraploid. 2 phenotypic differences.
•
cryoprobes will specifically cool particular brain areas and then you can selectively test the
contributions of that particular brain area
—
why cooling? cooling = changing temporal dynamics of the brain area. you're slowing down
the biochemical processes.
—
so you're cooling in DTAM and recording in larynx. —
both fast and slow trill are equally affected—so some neural dynamics in DTAM is
regulating CAP rates. but we don't know what's going on.
—
selective manipulation of particular brain areas, e.g. cryoprobes in DTAM•
Recap
so in birds, they have pretty similar hindbrain organisation, e.g. nuclei in rhombomere XIII, RAm
and PAm are important for respiration
•
there's lots of species of birds. but they all share this common caudal hindbrain circuitry:•
BIRDS
birds do have a larynx, but it's small and they don't really use it for vocalisation. same with
Amb—not really used for vocalisation
—
in addition to caudal hindbrain nuclei, there's also areas in rostral hindbrain (PB) and
midbrain (DM) that innervate these areas. because they innervate these structures, they're
likely also involved in vocalisation
—
stimulated DM with electrode. at each stimulation, you would get a vocalisation. their
control experiment was squeezed the sparrow instead of electrically stimulating (forced
expiration) to produce a sound instead
—
Sellers (1980)
: looked at Java sparrow•
18. Vocal Communication III
March 21, 2018 11:34
BIOL 320 Page 1
Fukushima & Aoki (2002)
: Bengalese finch have call & call back (i.e. response to vocalisation). so
they induced this by playing back a recording. there's a consistent increase in activity during
calling in the DM. if you stimulate neurons in the DM, you can evoke calling
•
looked at spontaneously produced chirping calls. could be induced by midbrain stimulation—
in different locations in DM, you could get different types of chirping—
Potash (1970)
: non-songbird, Japanese quail
•
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songbirds aren't
born
with their vocalisations, but they have to learn it! unlike non-songbirds. so
how do you know that songbirds need to learn their vocalisations?
•
zebra finch song:•
you have a father & a pupil (in this case, son). father sings this typical motif, repeated
syllables over and over. that's their
only song
(song sparrows have repertoires, but zebra
finch only have one)
—
the pupil will have high correspondence with the father's song. pupil has same syllables
and produces them in the same order. so both acoustic structure and sequencing are
highly similar. so this is an example of a father housed with his offspring
—
but if you take an offspring away from its nest and let it develop
in isolation
: as an adult, the
song it produces is not at all similar to its father's song. and
females hate these songs
! in
order for a male to be reproductively successful, it needs to learn the song of its own
species
—
song learning in white-crowned sparrows:•
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Document Summary
March (cid:1006)(cid:1005), (cid:1006)(cid:1004)(cid:1005)8 (cid:1005)(cid:1005):(cid:1007)(cid:1008) schedule for the rest of the course should not change. recall that tmrw is another microscopy lab, and also assignment 3 is due. Amb not really used for vocalisation in addition to caudal hindbrain nuclei, there"s also areas in rostral hindbrain (pb) and midbrain (dm) that innervate these areas. because they innervate these structures, they"re likely also involved in vocalisation. Sellers (1980): looked at java sparrow stimulated dm with electrode. at each stimulation, you would get a vocalisation. their control experiment was squeezed the sparrow instead of electrically stimulating (forced expiration) to produce a sound instead. Potash (1970): non-songbird, japanese quail looked at spontaneously produced chirping calls. could be induced by midbrain stimulation in different locations in dm, you could get different types of chirping. Biol 320 page 3 you have these 3 different populations. and these are the spectrograms of their songs.
