Department of Psychology, Tulane University; Tulane Brain Institute, Tulane University.
Department of Psychology, Tulane University; Tulane Brain Institute, Tulane University;
J Vis Exp. 2021 Jan 5(167). doi: 10.3791/61536.
Fear- and anxiety-related behaviors significantly contribute to an organism's survival. However, exaggerated defensive responses to perceived threat are characteristic of various anxiety disorders, which are the most prevalent form of mental illness in the United States. Discovering the neurobiological mechanisms responsible for defensive behaviors will aid in the development of novel therapeutic interventions. Pavlovian fear conditioning is a widely used laboratory paradigm to study fear-related learning and memory. A major limitation of traditional Pavlovian fear conditioning paradigms is that freezing is the only defensive behavior monitored. We recently developed a modified Pavlovian fear conditioning paradigm that allows us to study both conditioned freezing and flight (also known as escape) behavior within individual subjects. This model employs higher intensity footshocks and a greater number of pairings between the conditioned stimulus and unconditioned stimulus. Additionally, this conditioned flight paradigm utilizes serial presentation of pure tone and white noise auditory stimuli as the conditioned stimulus. Following conditioning in this paradigm, mice exhibit freezing behavior in response to the tone stimulus, and flight responses during the white noise. This conditioning model can be applied to the study of rapid and flexible transitions between behavioral responses necessary for survival.
恐惧和焦虑相关的行为对生物体的生存有重要贡献。然而，对感知到的威胁产生过度防御反应是各种焦虑障碍的特征，焦虑障碍是美国最常见的精神疾病形式。发现负责防御行为的神经生物学机制将有助于开发新的治疗干预措施。条件性恐惧反应是一种广泛用于研究与恐惧相关的学习和记忆的实验室范式。传统条件性恐惧反应范式的一个主要限制是只能监测到冻结这一种防御行为。我们最近开发了一种改良的条件性恐惧反应范式，允许我们在单个被试中同时研究条件性冻结和逃避（也称为逃跑）行为。该模型采用更高强度的足底电击和更多的条件刺激与非条件刺激配对。此外，该条件性逃避范式使用纯音和白噪声听觉刺激的连续呈现作为条件刺激。在该范式中进行训练后，老鼠会对音调刺激产生冻结行为，而在白噪声中则会产生逃避反应。这种训练模型可应用于研究生存所需的行为反应之间的快速和灵活转换。
