Differential cannabinergic effects on temporal perception and production

TL;DR

This study shows that cannabinoids affect how rats perceive time but not how they produce timed actions, indicating separate mechanisms for these processes.

Contribution

The study reveals that cannabinoids impair temporal perception but not interval production, suggesting distinct neural mechanisms.

Findings

CP55940 caused temporal overestimation in a fixed-interval task, indicating impaired time perception.

The same treatment increased movement duration but was due to slower movement, not altered time processing.

Cannabinoids slowed locomotion but did not disrupt timed motor sequences, preserving interval production.

Abstract

Cannabinoids have traditionally been associated with motor and cognitive impairments, including slowness of movement and altered temporal perception. However, it remains unclear whether cannabinoids specifically affect the perception and/or production of temporal intervals. To explore these possibilities, we evaluated the effects of systemic administrations of the synthetic cannabinoid CP55940 on behavioral performance in male rats trained in three distinct paradigms designed to assess time interval perception and production. Systemic administration of CP55940 caused temporal overestimation in a fixed-interval task, which was primarily linked to impaired perception of elapsed time in the range of tens of seconds. In contrast, while the same treatment increased forelimb reach duration in a two-interval production task (in the hundreds of milliseconds range), these effects were more accurately attributed to a general reduction in movement speed rather than altered temporal processing. These findings were further confirmed in a third motor task, where animals executed a complex timed motor sequence with spatiotemporal constraints while running on a treadmill. Here, CP55940 administration slowed locomotion but did not disrupt motor timing. Our results demonstrate that, in addition to inducing motor slowness, systemic cannabinoid administration impairs temporal perception but preserves interval production, suggesting distinct underlying mechanisms for these two processes.

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