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