Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil.
Department of Entomology and Plant Pathology, State University of North Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
J Neurosci Methods. 2022 Jan 15;366:109429. doi: 10.1016/j.jneumeth.2021.109429. Epub 2021 Nov 28.
Reduced locomotion with repeated exposure to a novel environment is often used as a measure of the basic adaptive learning process of habituation. While this is a well-established and reliable measure of habituation, it is not useful for the investigation of neurobiological changes before and after habituation because of the uncontrolled differential activity levels in a novel versus habituated environment. In this study we report a behavioral method that uses spontaneous locomotion to measure habituation, in which the total spontaneous locomotion in an initially novel environment does not change with repeated testing but, the ratio of central to peripheral activity does change and is indicative of habituation. The test sessions are brief (5 min) and the locomotion is measured in 2 separate zones. The peripheral zone comprises 8/9 of the test arena and the central zone 1/9 of the arena.
RESULTS/COMPARISON WITH EXISTING METHODS: In contrast to methods that use between-session reductions in locomotion to assess habituation, this method employs brief test sessions in which overall activity between sessions does not change, but the distribution of locomotion in the periphery versus the central zone of the arena does change. The brevity of the test session also enables us to utilize post-trial drug treatment protocols to impact memory consolidation.
The progressive change in the central/peripheral activity ratio with repeated testing can be determined independently of total activity and provides a habituation acquisition function that permits the measurement of neurobiological changes without the complication of effects related to changes in locomotor activity per se. The present report also presents evidence that this method can be used with post-trial drug treatment protocols to study the learning and memory effects of the post-trial treatments without the use of explicit rewards and punishments.
在重复暴露于新环境时，运动减少通常被用作习惯化基本适应学习过程的测量。虽然这是一种经过充分验证和可靠的习惯化测量方法，但由于新环境与习惯化环境中活动水平的差异不受控制，因此它对于习惯化前后神经生物学变化的研究并不有用。在这项研究中，我们报告了一种使用自发运动来测量习惯化的行为方法，其中在最初的新环境中，总自发运动不会随重复测试而改变，但中央到外周活动的比例会改变，这表明习惯化了。测试时间很短（5 分钟），并且在两个独立区域测量运动。外周区占测试场地的 8/9，中央区占 1/9。
结果/与现有方法的比较：与使用运动减少来评估习惯化的方法相反，这种方法采用简短的测试会议，在这些会议中，会议之间的整体活动没有变化，但运动在场地的外围与中央区的分布发生了变化。测试会议的短暂性还使我们能够利用试验后药物治疗方案来影响记忆巩固。
随着重复测试，中央/外周活动比例的逐渐变化可以独立于总活动来确定，并提供了习惯化获得功能，允许在不考虑运动活动本身变化的影响的情况下测量神经生物学变化。本报告还提供了证据，表明该方法可以与试验后药物治疗方案一起使用，以研究试验后治疗的学习和记忆效应，而无需使用明确的奖励和惩罚。
