*Interval Timing in Aging Mice*
*Ezgi Gür1, Yalçın Akın Duyan1, Sertan Arkan2, Ayşe Karson2, Fuat Balcı1,*
***
1Koç University, Department of Psychology, Research Center for
Translational Medicine, Istanbul, Turkey
2Kocaeli University, Faculty of Medicine, Department of Physiology,
Kocaeli, Turkey
The aim of this study was to investigate how interval timing behavior of
mice as assessed in the dual peak procedure is altered by aging. To this
end, 38 male mice (C57BL/6) at different ages (4, 10 and 18 months old)
were tested in the dual peak procedure with 25s and 50s target intervals.
Start, stop, middle times, and spread derived from single-trial analysis
were compared between age groups for steady-state performance. Correlations
between start-stop, start-spread, and middle-spread were examined to
estimate the contribution of different sources of timing variability in
different age groups (Gibbon & Church, 1992). Preliminary analyses showed
that aged mice acquired temporally controlled response terminations later
than young and adult mice. Although no differences were observed between
the start times of different age groups, the stop times of old mice were
significantly later than the stop times of young and adult mice at steady
state. Middle times were longer than the short interval in all age groups,
while it was also longer than the long interval in aged mice. Positive
start-stop, negative start-spread, and positive middle-spread correlations
pointed at the contribution of both clock/memory and decision processes to
timing variability in all age groups. Although the obtained correlation
patterns did not point at altered contributions of different sources of
timing variability across age groups, the prominent differences in stop
times are suggestive of the failure of behavioral inhibition in old mice.
We are currently investigating the relationship between these behavioral
observations and the neurobiological markers that relate to the
dopaminergic and acetylcholinergic function.
Keywords: duration; behaviour; aging; animal (C57BL/6 mice); secs-mins.
*fbalci@ku.edu.tr
*References*
Gibbon, J., & Church, R. M. (1992). Comparison of variance and covariance
patterns in parallel and serial theories of timing. J Exp Anal Behav,
