TY - JOUR
T1 - Identifying tinnitus in mice by tracking the motion of body markers in response to an acoustic startle
AU - Wallace, Mark N.
AU - Berger, Joel I.
AU - Hockley, Adam
AU - Sumner, Christian J.
AU - Akeroyd, Michael A.
AU - Palmer, Alan R.
AU - McNaughton, Peter A.
N1 - Publisher Copyright:
Copyright © 2024 Wallace, Berger, Hockley, Sumner, Akeroyd, Palmer and McNaughton.
PY - 2024
Y1 - 2024
N2 - Rodent models of tinnitus are commonly used to study its mechanisms and potential treatments. Tinnitus can be identified by changes in the gap-induced prepulse inhibition of the acoustic startle (GPIAS), most commonly by using pressure detectors to measure the whole-body startle (WBS). Unfortunately, the WBS habituates quickly, the measuring system can introduce mechanical oscillations and the response shows considerable variability. We have instead used a motion tracking system to measure the localized motion of small reflective markers in response to an acoustic startle reflex in guinea pigs and mice. For guinea pigs, the pinna had the largest responses both in terms of displacement between pairs of markers and in terms of the speed of the reflex movement. Smaller, but still reliable responses were observed with markers on the thorax, abdomen and back. The peak speed of the pinna reflex was the most sensitive measure for calculating GPIAS in the guinea pig. Recording the pinna reflex in mice proved impractical due to removal of the markers during grooming. However, recordings from their back and tail allowed us to measure the peak speed and the twitch amplitude (area under curve) of reflex responses and both analysis methods showed robust GPIAS. When mice were administered high doses of sodium salicylate, which induces tinnitus in humans, there was a significant reduction in GPIAS, consistent with the presence of tinnitus. Thus, measurement of the peak speed or twitch amplitude of pinna, back and tail markers provides a reliable assessment of tinnitus in rodents.
AB - Rodent models of tinnitus are commonly used to study its mechanisms and potential treatments. Tinnitus can be identified by changes in the gap-induced prepulse inhibition of the acoustic startle (GPIAS), most commonly by using pressure detectors to measure the whole-body startle (WBS). Unfortunately, the WBS habituates quickly, the measuring system can introduce mechanical oscillations and the response shows considerable variability. We have instead used a motion tracking system to measure the localized motion of small reflective markers in response to an acoustic startle reflex in guinea pigs and mice. For guinea pigs, the pinna had the largest responses both in terms of displacement between pairs of markers and in terms of the speed of the reflex movement. Smaller, but still reliable responses were observed with markers on the thorax, abdomen and back. The peak speed of the pinna reflex was the most sensitive measure for calculating GPIAS in the guinea pig. Recording the pinna reflex in mice proved impractical due to removal of the markers during grooming. However, recordings from their back and tail allowed us to measure the peak speed and the twitch amplitude (area under curve) of reflex responses and both analysis methods showed robust GPIAS. When mice were administered high doses of sodium salicylate, which induces tinnitus in humans, there was a significant reduction in GPIAS, consistent with the presence of tinnitus. Thus, measurement of the peak speed or twitch amplitude of pinna, back and tail markers provides a reliable assessment of tinnitus in rodents.
KW - gap-induced prepulse inhibition
KW - guinea pig
KW - Preyer reflex
KW - rodent
KW - sodium salicylate
UR - http://www.scopus.com/inward/record.url?scp=85201637510&partnerID=8YFLogxK
U2 - 10.3389/fnins.2024.1452450
DO - 10.3389/fnins.2024.1452450
M3 - Article
AN - SCOPUS:85201637510
SN - 1662-4548
VL - 18
JO - Frontiers in Neuroscience
JF - Frontiers in Neuroscience
M1 - 1452450
ER -