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PART 3: MOTOR STRATEGIES #14: FLIGHT IN LOCUSTS II. CH6: flight in locusts locust flight flight system sensory integration during flight summary. PART 3: MOTOR STRATEGIES #14: FLIGHT IN LOCUSTS II. CH6: flight in locusts locust flight flight system - PowerPoint PPT Presentation
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CH6: flight in locusts locust flight flight system sensory integration during flight summary
PART 3: MOTOR STRATEGIES#14: FLIGHT IN LOCUSTS II
CH6: flight in locusts locust flight flight system sensory integration during flight summary
PART 3: MOTOR STRATEGIES#14: FLIGHT IN LOCUSTS II
IN301 & IN501... 2 of the known parts of the pattern generator
CELLULAR ORGANIZATION
how does proprioceptive feedback work ? ... so far... it can influence average pattern frequency it has no “essential” role in pattern generation
experiment... wingbeat imposed on 1 forewing how does sensory feedback from this wing influence flight rhythm of the other 3 wings ? observed that wings phase lock to imposed frequencies... proprioception does CPG
PROPRIOCEPTIVE FEEDBACK
what are the roles of the 3 types of receptors ? synaptic connections CPG interneurons stimulate wing hinge
receptor fires wingdepressor neuron
inhibits elevator
stimulate campaniform opposite effect
proprioceptors can initiate & maintain flight rhythm
PROPRIOCEPTIVE FEEDBACK
tegulae ?... neurons in phase
with elevatormotor neurons
neurons excite IN566
IN566 exciteselevator motorneuron
PROPRIOCEPTIVE FEEDBACK
tegulae ?... stimulation of afferent neurons resets flight rhythm
PROPRIOCEPTIVE FEEDBACK
wing proprioceptors are elements of the CPG:
1. phasically active ~ wingbeat cycle
2. activation initiate, entrain & maintain oscillation
3. deafferentation reduces operation of CPG
4. reset CPG when stimulated
PROPRIOCEPTIVE FEEDBACK
how do wing proprioceptors flight... 2 main inputs
1. wing depression excites tegulae
excites elevator motor neurons
2. wing elevation excites wing hinge stretch
excites depressor motor neurons
inhibits wing elevator motor neurons
PROPRIOCEPTIVE FEEDBACK
why is CPG control so complicated ?
1. stable core oscillating circuit, and
2. sensitive to sensory appropriate to situation
central rhythm generator integrated with sensory
normal flight pattern
PROPRIOCEPTIVE FEEDBACK
course control ?
must make rapid steering adjustment ~ wind
SENSORY INTEGRATION DURING FLIGHT
uses 3 different sensory systems... exteroceptors
1. compound eyes
2. ocelli (simple eyes)
3. wind-sensitive hairs
SENSORY INTEGRATION DURING FLIGHT
uses 3 different sensory systems... exteroceptors
1. compound eyes... 3D but
complex
~ slow (100 ms thorax ~ 2 wingbeat cycles)
2. ocelli (simple eyes)
3. wind-sensitive hairs simple
~ fast
SENSORY INTEGRATION DURING FLIGHT
uses 3 different sensory systems... exteroceptors
1. compound eyes... 3D but complex & slow
2. ocelli (simple eyes)... pitch & roll, fast
3. wind-sensitive hairs... yaw & pitch, fast
SENSORY INTEGRATION DURING FLIGHT
uses 3 different sensory systems... exteroceptors
1. compound eyes... 3D but complex & slow
2. ocelli (simple eyes)... pitch & roll, fast
3. wind-sensitive hairs... yaw & pitch, fast
2 sensorimotor pathways
1. slow head position,
steering by legs & abdomen
SENSORY INTEGRATION DURING FLIGHT
uses 3 different sensory systems... exteroceptors
1. compound eyes... 3D but complex & slow
2. ocelli (simple eyes)... pitch & roll, fast
3. wind-sensitive hairs... yaw & pitch, fast
2 sensorimotor pathways
1. slow head position, steering by legs & abdomen
2. fast thorax, course deviation information
SENSORY INTEGRATION DURING FLIGHT
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons (DDNs)
DNI – ipsilateral ocellus DNM – medial ocellus DNC – contralateral ocellus
DEVIATION-DETECTING INTERNEURONS
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons (DDNs)
DNI – ipsilateral ocellus DNM – medial ocellus DNC – contralateral ocellus
respond to different deviations~ movement detectors*
DEVIATION-DETECTING INTERNEURONS
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons (DDNs)
DNI – ipsilateral ocellus DNM – medial ocellus DNC – contralateral ocellus
respond to different deviations~ movement detectors*
relay to thoracic ganglia
DEVIATION-DETECTING INTERNEURONS
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons
DNC – contralateral ocellus* relay to thoracic ganglia integrated with
air current stimuli hairs visual stimuli eyes
DEVIATION-DETECTING INTERNEURONS
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons (DDNs) respond to different deviations ~ movement
detectors* integrated with air current
stimulus to hairs* and eyes hair signals ocelli signals
DEVIATION-DETECTING INTERNEURONS
ocelli (simple eyes)... detect horizon deviation 3 pairs of deviation-detecting neurons (DDNs) respond to different deviations ~ movement
detectors * integrated with air current
stimulus to hairs* and eyes hair signals ocelli signals ocelli signals hair signals
multimodal input critical... feature detector neurons
DEVIATION-DETECTING INTERNEURONS
DDNs integrated into thoracic circuitry via thoracic interneurons (TINs) only works during flight influenced by the CPG
phase-gated = signal atappropriate phase ofof cycle course control
... but not part of the CPG TINs integrate sensory
with phase-locked CPG
FLIGHT CONTROL CIRCUITRY
locusts have 2 pairs of wings @ thorax beat @ 20 Hz, 7 ms offset cycles 10 pairs of muscles / wing: 4 depressors, 6 elevators driven by 1-5 neurons / muscle isolated thoracic circuitry rhythmic motor output central pattern generator... influenced by
proprioceptive sensory feedback 3 types of sensilla: wing hinge, tegula, campaniform activation rhythmic motor output, part of CPG CPG = central oscillating core + sensory feedback
SUMMARY
CPG = central oscillating core + sensory feedback 3 primary exteroceptor types on head flight activate descending neurons, deviation-detecting
neurons (DDNs) are 1 type multimodal DDNs detect flight deviations DDNs thoracic interneurons (TINs) TIN motor neurons via interneurons tonic sensory signal phasic signal by CPG gating course control during flight CPG rhythms (1) wingbeat & (2) sensory
signal
SUMMARY