Hearing+Vestibular Flashcards
What type of sound field do antennal ears detect?
velocity
near/short range
low frequency
What type of sound field do tympanal ears detect?
pressure
long range
high frequency
What is the process of hearing in drosophila?
velocity component –> deflection of antennal receiver structure –> sound evoked receiver motion transmitted to primary neurons of Johnston organ –> coupled to receiver via support cells –> mechanically gated ion channels in JO neurons open in response to sound-induced receiver motion –> receptor potential across sensory membrane –> propagates to specialised neuronal site –> train of APs produced
What is the elementary unit of insect ears?
scolopidia
What are chordotonal organs?
miniature sensory organs present in insects and crustaceans but not found in any other class of animals
What are the roles of the arista and funiculus?
when acoustically activated they vibrate (rotate) about the longitudinal axis of funiculus activating JONs in pedicel
What are the stages of sound perception in the drosophila?
Reception (by antenna) Transmission to Johnstons Organ Coupling to scolopidium Transduction (directly) Processing Transformation
How does CO2 sedation affect flies?
active transducer frequency tuning not present
Which moquito ears respond to velocity?
(the vectorial component)
Flagellar ears
Which insect hearing system is under efferent control?
mosquito
not drosophila
By which forces do particles act on each other?
elastic force
inertial force
viscous force (friction)
In near field sound are pressure and particle velocity in phase?
not in phase
In far field sound are pressure and particle velocity in phase?
yes in phase
Does direct transduction mean that force and displacement are directly proportional?
no, not directly
What are the functions of the JO?
detect sound, gravity, wind
What is “slipping adaptation”?
ion channel position sliding down so tension in spring less, mechanically gated channels open less
motor dependent
stimulus is changed
What is the endolymph K concentration?
150 mM
What does Prestin do?
Wobbles in response to V change
is densely packed in membrane and causes expansion/contraction of cell
“broken” transporter with some residual activity
What is the human sound threshold of pain?
140 dB
In the semicircular canals stereocilia bending which way cause depolarisation?
toward kinocilia
Which otolith organ encodes up/down movements?
Saccule
Which otolith organ encodes left/right movements?
Utricle
In the utricle does bending towards the striola cause depolarisation or hyperpolarisation?
depolarisation
In the saccule does bending towards the striola cause depol or hyperpol?
hyperpolarisation
What are otoliths/otoconia?
calcium carbonate crystals on otolithic membrane over gelatinous membrane
What causes a sensation of dizziness?
post rotary activation
endolymph fluid still moves after rotation stops, perception of movement in opposite direction
Which cranial nerve carries efferent vestibular info?
VIII
vestibulocochlear
Where does the vestibulocochlear nerve project?
cortex, cerebellum
eye control - brainstem vestibular nuclei, ocular neurons
vestibulospinal tract
In which direction does GVS cause postural tilt?
towards the anode electrode
