FearConditioning, ClassicalFreezing Reaction, CatalepticConditioning (Psychology)AmygdalaExtinction, PsychologicalElectroshockGalvanic Skin ResponseStartle ReactionMemoryAvoidance LearningAssociation LearningPhobic DisordersBehavior, AnimalAnxietyAcoustic StimulationDental AnxietyCuesRats, Long-EvansCycloserineLearningAnalysis of VarianceHippocampusDesensitization, PsychologicFacial Expression