Interval timing in mice does not rely upon the circadian pacemaker.

P A Lewis; R C Miall; S Daan; A Kacelnik

doi:10.1016/s0304-3940(03)00521-4

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Interval timing in mice does not rely upon the circadian pacemaker.

P A Lewis·R C Miall·S Daan·A Kacelnik

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Abstract

The suprachiasmatic nucleus (SCN) of the hypothalamus is a precise timekeeper that controls and synchronizes the circadian period of countless physiological and behavioural functions and entrains them to the 24 h light/dark cycle. We examined the possibility that it is also indirectly involved in measurement of a briefer interval by observing the effects of lesions targeted at the SCN, and abolishing circadian rhythmicity, upon interval timing behaviour. Fourteen house mice (Mus musculus) were trained to estimate a 10 s interval using a modified peak procedure, and then underwent electrolytic lesions. Six individuals became behaviourally arrhythmic. Peak interval performance was then assessed in 12:12 light/dark conditions and in constant darkness. No significant change in peak characteristics was observed as a consequence of the lesion for either rhythmic or arrhythmic groups. These results show that the accurate measurement of 10 s requires neither a functioning circadian pacemaker nor entrained behavioural rhythmicity.

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Animals Biological Clocks Circadian Rhythm Conditioning, Operant Darkness Lighting Male Mice Mice, Inbred C57BL Time Factors Journal Article Research Support, Non-U.S. Gov't

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P A Lewis, R C Miall, S Daan, A Kacelnik. 2003-09-18. Interval timing in mice does not rely upon the circadian pacemaker.. https://doi.org/10.1016/s0304-3940(03)00521-4

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