Striatal dynamics explain duration judgments
| Autor: | Thiago S Gouvêa, Tiago Monteiro, Asma Motiwala, Sofia Soares, Christian Machens, Joseph J Paton |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
neural dynamics
QH301-705.5 Science striatum Population Striatum Biology Bioinformatics General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Time estimation Basal ganglia Animals Biology (General) education interval timing Neurons education.field_of_study General Immunology and Microbiology General Neuroscience General Medicine Time perception humanities Rats Brain region Interval (music) Muscimol chemistry Categorization nervous system population code Dynamics (music) Duration (music) Time Perception Ventral Striatum Medicine Rat Neuroscience Research Article |
| Zdroj: | eLife eLife, Vol 4 (2015) |
| DOI: | 10.1101/020883 |
| Popis: | The striatum is an input structure of the basal ganglia implicated in several time-dependent functions including reinforcement learning, decision making, and interval timing. To determine whether striatal ensembles drive subjects' judgments of duration, we manipulated and recorded from striatal neurons in rats performing a duration categorization psychophysical task. We found that the dynamics of striatal neurons predicted duration judgments, and that simultaneously recorded ensembles could judge duration as well as the animal. Furthermore, striatal neurons were necessary for duration judgments, as muscimol infusions produced a specific impairment in animals' duration sensitivity. Lastly, we show that time as encoded by striatal populations ran faster or slower when rats judged a duration as longer or shorter, respectively. These results demonstrate that the speed with which striatal population state changes supports the fundamental ability of animals to judge the passage of time. DOI: http://dx.doi.org/10.7554/eLife.11386.001 eLife digest You know someone is a good cook from their rice - grains must be well cooked, but not to the point of being mushy. Despite consistently using the same pot and stove, we, however, will sometimes overcook it. It is as if our inner sense of time itself is variable. What is it about the brain that explains this variability in time estimation and indeed our ability to estimate time in the first place? One issue the brain must confront in order to estimate time is that individual brain cells typically fire in bursts that last for tens of milliseconds. So how does the brain use this short-lived activity to track minutes and hours? One possibility is that individual neurons in a given brain region are programmed to fire at different points in time. The overall firing pattern of a group of neurons will therefore change in a predictable way as time passes. Gouvêa, Monteiro et al. found such predictably changing patterns of activity in the striatum of rats trained to estimate and categorize the duration of time intervals as longer or shorter than 1.5 seconds. Interestingly, when rats mistakenly categorized a short interval as a long one, population activity had travelled farther down its path than it would normally (and vice-versa for long intervals incorrectly categorized as short), suggesting that variability in subjective estimates of the passage of time might arise from variability in the speed of a changing pattern of activity across groups of neurons. As further evidence for the involvement of the striatum, inactivating the structure impaired the rats’ ability to correctly classify even the longest and shortest interval durations. The next challenge is to determine exactly how the striatum generates these time-keeping signals, at which stage variability originates, and how the brain regions that the striatum signals to use them to control an animal’s behavior. DOI: http://dx.doi.org/10.7554/eLife.11386.002 |
| Databáze: | OpenAIRE |
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