Ramping cells in the rodent medial prefrontal cortex encode time to past and future events via real Laplace transform

• 成果类型: Article
• 署名作者: Cao, Rui; Bright, Ian M.; Howard, Marc W.
• 署名单位: Boston University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14393
• DOI: 10.1073/pnas.2404169121
• 发表日期: 2024-09-17
• 关键词: neural basis; population; SEQUENCES; memory; REPRESENTATION; INFORMATION; mechanism; patterns; MODEL

摘要

In interval reproduction tasks, animals must remember the event starting the interval and anticipate the time of the planned response to terminate the interval. The interval reproduction task thus allows for studying both memory for the past and anticipation of the future. We analyzed previously published recordings from the rodent medial prefrontal cortex [J. Henke et al., eLife 10, e71612 (2021)] during an interval reproduction task and identified two cell groups by modeling their temporal receptive fields using hierarchical Bayesian models. The firing in the past cells group peaked at the start of the interval and relaxed exponentially back to baseline. The firing in the future cells group increased exponentially and peaked right before the planned action at the end of the interval. Contrary to the previous assumption that timing information in the brain has one or two time scales for a given interval, we found strong evidence for a continuous distribution of the exponential rate constants for both past and future cell populations. The real Laplace transformation of time predicts exponential firing with a continuous distribution of rate constants across the population. Therefore, the firing pattern of the past cells can be identified with the Laplace transform of time since the past event while the firing pattern of the future cells can be identified with the Laplace transform of time until the planned future event.