h exam i h motor strategies h mate calling in crickets h song production by s h song recognition by...
TRANSCRIPT
exam I motor strategies mate calling in crickets
song production by s song recognition by s sender-receiver matching summary
PART 3: MOTOR STRATEGIES#12: MATE CALLING IN CRICKETS II
exam I motor strategies mate calling in crickets
song production by s song recognition by s sender-receiver matching summary
PART 3: MOTOR STRATEGIES#12: MATE CALLING IN CRICKETS II
recall… oscillogram cycles
carrier frequency (CF) = 5 kHz ~ 5 k file teeth / s
pulses = syllables 1 stridulation
chirps & trills sequences
SONG PRODUCTION BY s
recall… tracheal tubes = insect “lungs”
connect tympanum outside via spiracles
sound via 2 routes direct indirect
tracheal tube resonates @ 5 kHz = carrier frequency
CF
SONG RECOGNITION & LOCALIZATION
tracheal tubes amplify signal from inside ? ... somehow
mechanism called pressure-difference receiver sound locator how ?
distances... wave period ~ 7 cm legs ~ 1 cm apart (cannot resolve) indirect ~ 3.5 cm
SONG RECOGNITION & LOCALIZATION
@ left tympanum... sound from left peaks + troughs amplify (A) sound from right peaks – troughs cancel (B)
signal strength ~ tympanum movement
tuned to CF of call
sound zigzag walking behavior ?
SONG RECOGNITION & LOCALIZATION
sound zigzag walking behavior ?
SONG RECOGNITION & LOCALIZATION
60°MAX
120° ?
120° ?
60°MIN
sound zigzag walking behavior ?
SONG RECOGNITION & LOCALIZATION
60°MAX
120° ?
60°MIN
sound zigzag walking behavior ?
120° ZIGZAG
SONG RECOGNITION & LOCALIZATION
60°MAX
120° ?
60°MIN
sound zigzag walking behavior ?
behavior does not maximum sensory input*
120° ZIGZAG
... CNS
SONG RECOGNITION & LOCALIZATION
how does CNS sharpen the directional sensitivity ?
NEURAL PROCESSING OF SONG
how does CNS sharpen the directional sensitivity ?
s prefer 5 kHz song @ 30 pulses / s
tracking above & below 30 pulses / s
how is this sound feature recognized ?
NEURAL PROCESSING OF SONG
sensory neurons (aud. n. ) aud. neuropile (proth. g.) sharply tuned to signal ipsilateral connection
omega () neurons 2 (1 on each side) inhibit eachother ipsilateral excited contralateral inhibited = reciprocal inhibition
accentuate L / R signal
NEURAL PROCESSING OF SONG
neurons do not show 30 pulse / s preference
other candidates... large prothoracic neurons brain ascending neurons (ANs) excited by auditory receptor neurons
sensitive to 5 kHz sound directional sensitivity ~
inhibited by contralateral neurons what is their function ?
NEURAL PROCESSING OF SONG
crickets walking on spherical treadmill (A)
intracellular recording from L & R AN-1 neurons (B) (dye-filled)
NEURAL PROCESSING OF SONG
tracking (orientation ~ speaker) (C)
AN-1 firing rates... (D) call left, a > a' firing, track left
call right, b < b' firing, track right call left, c hyperpolarized (inhibited), track right
NEURAL PROCESSING OF SONG
tracking (orientation ~ speaker) (C)
AN-1 firing rates... (D) call left, a > a' firing, track left call right, b < b' firing, track right call left, c hyperpolarized (inhibited), track right
directional information transmitted by AN-1... play a role in positive phonotaxis
call song detectors ? no 30 pulse / s preferences
NEURAL PROCESSING OF SONG
AN-1 brain neurons brain neuron classes 1 & 2 (BNC-1, 2)
overlapping projections AN-1 & BNC-1 BNC-1 & 2
coordinated firing with
AN-1 song
NEURAL PROCESSING OF SONG
BNC-1 & 2 do not copy signals as do & AN-1
BNC-1 & 2 do show syllable preferences
BNC-1 low-pass filters (fire ~ rate < 30 / s) BNC-2 high-pass filters (fire ~ rate > 30 / s) BNC-2 band-pass filters (fire ~ 30 / s)
NEURAL PROCESSING OF SONG
organization of auditory system
logical AND gate (additive signals)
BNC-2
BNC-1
BNC-2
NEURAL PROCESSING OF SONG
genetic basis of song species specificity interbred 2 related & sympatric (co-existing) species
Teleogryllus commodus (T.c.) CF = 3.5 kHz Teleogryllus oceanicus (T.o.) CF = 5 kHz other qualitative differences as well
To x To
Tc x Tc
Tc x To
To x Tc
SENDER – RECEIVER MATCHING
hybrid s show intermediate song (A) dosage-dependent (next slide...)
hybrid s prefer songs of their brothers (B) F1 > reciprocal F1 & > either P
To x To
Tc x Tc
Tc x To
To x Tc
SENDER – RECEIVER MATCHING
dosage-dependent genetic basis song and preference GENOTYPE
C C C P O O O
C O 1 C : 1 O F1 O C 1 C : 1 O
C C O 3 C : 1 O C O C 3 C : 1 O O C O 1 C : 3 O O O C 1 C : 3 O C O C 3 C : 1 O O C C 3 C : 1 O C O O 1 C : 3 O
B
O C O 1 C : 3 O
s prefer
s s s s
SENDER – RECEIVER MATCHING
song 3 song types: call, courtship, aggressive structure: carrier frequency, syllables (pulses), chirps or trills, sequences song by stridulation: rubbing scraper & file
neural basis for song generator in thoracic ganglia triggered by descending neurons from brain
SUMMARY
reception attracted by 5 kHz CF & 30 syllables / s rate ears (in knees) filter sound directionally sensitive to CF
neural basis for song reception auditory neurons AN-1 BNC-1&2 2 & AN-1 sharpen signal BNC-1 (low pass) + BNC-2 (high pass) BNC-2 (band pass), sensitive to 30 syllables / s
genetic basis to sender-receiver matching
SUMMARY