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Inactivation of Cerebellar Cortical Crus II Disrupts Temporal Processing of Absolute Timing but not Relative Timing in Voluntary Movements.

Yamaguchi K, Sakurai Y - Front Syst Neurosci (2016)

Bottom Line: We then tested the accuracy of their absolute or relative timing prediction using two timing tasks requiring almost identical reaching movements.Inactivation of the cerebellar cortex disrupted accurate temporal prediction in the absolute timing task.We concluded that a part of the cerebellar cortex, Crus II, contributes to the accurate temporal prediction of absolute timing and that the entire cerebellar cortex may be unnecessary in cases in which accurately knowing the absolute duration of an interval is not required for temporal prediction.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Graduate School of Letters, Kyoto UniversityKyoto, Japan; Japan Society for the Promotion of ScienceTokyo, Japan.

ABSTRACT
Several recent studies have demonstrated that the cerebellum plays an important role in temporal processing at the scale of milliseconds. However, it is not clear whether intrinsic cerebellar function involves the temporal processing of discrete or continuous events. Temporal processing during discrete events functions by counting absolute time like a stopwatch, while during continuous events it measures events at intervals. During the temporal processing of continuous events, animals might respond to rhythmic timing of sequential responses rather than to the absolute durations of intervals. Here, we tested the contribution of the cerebellar cortex to temporal processing of absolute and relative timings in voluntary movements. We injected muscimol and baclofen to a part of the cerebellar cortex of rats. We then tested the accuracy of their absolute or relative timing prediction using two timing tasks requiring almost identical reaching movements. Inactivation of the cerebellar cortex disrupted accurate temporal prediction in the absolute timing task. The rats formed two groups based on the changes to their timing accuracy following one of two distinct patterns which can be described as longer or shorter declines in the accuracy of learned intervals. However, a part of the cerebellar cortical inactivation did not affect the rats' performance of relative timing tasks. We concluded that a part of the cerebellar cortex, Crus II, contributes to the accurate temporal prediction of absolute timing and that the entire cerebellar cortex may be unnecessary in cases in which accurately knowing the absolute duration of an interval is not required for temporal prediction.

No MeSH data available.


Related in: MedlinePlus

Behavioral performance of the longer decline rats in the FR 2 DRL 500 ms tests. (A) IRT distributions for Rat 1 in the sham and inactivation conditions. “Correct responses” and “error” as for Figure 2. (B) IRT distributions for Rat 1, 5, and 7 combined. (C) Parameters of the longer decline rats considered as a group. Data presented are mean ± SD. Orange p-values highlight significant differences. ∗p < 0.05, ∗∗p < 0.01.
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Figure 3: Behavioral performance of the longer decline rats in the FR 2 DRL 500 ms tests. (A) IRT distributions for Rat 1 in the sham and inactivation conditions. “Correct responses” and “error” as for Figure 2. (B) IRT distributions for Rat 1, 5, and 7 combined. (C) Parameters of the longer decline rats considered as a group. Data presented are mean ± SD. Orange p-values highlight significant differences. ∗p < 0.05, ∗∗p < 0.01.

Mentions: Histogram plots of the IRT distributions of each rat revealed two types of frequency declines in IRT from the sham to the inactivation condition. We called the first type the “longer decline,” in which the frequency of the shortest correct IRT decreased and that of longer IRTs increased in the inactivation condition (Figures 3A,B). For example, for Rat 1 (Figure 3A), in the sham condition the IRT distribution increased sharply for IRTs of 500–600 ms and decreased sharply as they reached 700 ms. However, under the inactivation condition, the frequencies of IRTs of 500–900 ms were similar, and only decreased for IRTs > 900 ms. Rat 5 and 7 showed the same tendency. Statistical test results of the combined performance data for these three subjects treated as a group and comparison of parameters between the sham and inactivation conditions were similar to those of Rat 1 (Table 1), except for the Mood test result (Figures 3B,C). We designated these subjects as the “longer decline rats,” and concluded that for these individuals temporal prediction of absolute duration became longer than learned intervals, with little effect on motor ability, following inactivation of the cerebellar cortex.


Inactivation of Cerebellar Cortical Crus II Disrupts Temporal Processing of Absolute Timing but not Relative Timing in Voluntary Movements.

Yamaguchi K, Sakurai Y - Front Syst Neurosci (2016)

Behavioral performance of the longer decline rats in the FR 2 DRL 500 ms tests. (A) IRT distributions for Rat 1 in the sham and inactivation conditions. “Correct responses” and “error” as for Figure 2. (B) IRT distributions for Rat 1, 5, and 7 combined. (C) Parameters of the longer decline rats considered as a group. Data presented are mean ± SD. Orange p-values highlight significant differences. ∗p < 0.05, ∗∗p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764692&req=5

Figure 3: Behavioral performance of the longer decline rats in the FR 2 DRL 500 ms tests. (A) IRT distributions for Rat 1 in the sham and inactivation conditions. “Correct responses” and “error” as for Figure 2. (B) IRT distributions for Rat 1, 5, and 7 combined. (C) Parameters of the longer decline rats considered as a group. Data presented are mean ± SD. Orange p-values highlight significant differences. ∗p < 0.05, ∗∗p < 0.01.
Mentions: Histogram plots of the IRT distributions of each rat revealed two types of frequency declines in IRT from the sham to the inactivation condition. We called the first type the “longer decline,” in which the frequency of the shortest correct IRT decreased and that of longer IRTs increased in the inactivation condition (Figures 3A,B). For example, for Rat 1 (Figure 3A), in the sham condition the IRT distribution increased sharply for IRTs of 500–600 ms and decreased sharply as they reached 700 ms. However, under the inactivation condition, the frequencies of IRTs of 500–900 ms were similar, and only decreased for IRTs > 900 ms. Rat 5 and 7 showed the same tendency. Statistical test results of the combined performance data for these three subjects treated as a group and comparison of parameters between the sham and inactivation conditions were similar to those of Rat 1 (Table 1), except for the Mood test result (Figures 3B,C). We designated these subjects as the “longer decline rats,” and concluded that for these individuals temporal prediction of absolute duration became longer than learned intervals, with little effect on motor ability, following inactivation of the cerebellar cortex.

Bottom Line: We then tested the accuracy of their absolute or relative timing prediction using two timing tasks requiring almost identical reaching movements.Inactivation of the cerebellar cortex disrupted accurate temporal prediction in the absolute timing task.We concluded that a part of the cerebellar cortex, Crus II, contributes to the accurate temporal prediction of absolute timing and that the entire cerebellar cortex may be unnecessary in cases in which accurately knowing the absolute duration of an interval is not required for temporal prediction.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Graduate School of Letters, Kyoto UniversityKyoto, Japan; Japan Society for the Promotion of ScienceTokyo, Japan.

ABSTRACT
Several recent studies have demonstrated that the cerebellum plays an important role in temporal processing at the scale of milliseconds. However, it is not clear whether intrinsic cerebellar function involves the temporal processing of discrete or continuous events. Temporal processing during discrete events functions by counting absolute time like a stopwatch, while during continuous events it measures events at intervals. During the temporal processing of continuous events, animals might respond to rhythmic timing of sequential responses rather than to the absolute durations of intervals. Here, we tested the contribution of the cerebellar cortex to temporal processing of absolute and relative timings in voluntary movements. We injected muscimol and baclofen to a part of the cerebellar cortex of rats. We then tested the accuracy of their absolute or relative timing prediction using two timing tasks requiring almost identical reaching movements. Inactivation of the cerebellar cortex disrupted accurate temporal prediction in the absolute timing task. The rats formed two groups based on the changes to their timing accuracy following one of two distinct patterns which can be described as longer or shorter declines in the accuracy of learned intervals. However, a part of the cerebellar cortical inactivation did not affect the rats' performance of relative timing tasks. We concluded that a part of the cerebellar cortex, Crus II, contributes to the accurate temporal prediction of absolute timing and that the entire cerebellar cortex may be unnecessary in cases in which accurately knowing the absolute duration of an interval is not required for temporal prediction.

No MeSH data available.


Related in: MedlinePlus