Related Experiment Video
Updated: Jul 6, 2026
Fear Incubation Using an Extended Fear-Conditioning Protocol for Rats
Published on: August 22, 2020
Contextual fear conditioning differs for infant, adolescent, and adult rats
Francisco J Esmorís-Arranz1, Cástor Méndez, Norman E Spear
1Universidad de Santiago de Compostela, Spain. fesmoris@usc.es
Insights
Infant and adolescent rats show strong contextual fear conditioning, unlike adults. Adolescent fear conditioning is influenced by context extinction, not stimulus extinction, revealing developmental changes in learning and memory.
Area of Science:
- Neuroscience
- Developmental Psychology
- Behavioral Science
Background:
- Contextual fear conditioning is a key learning paradigm.
- Understanding developmental differences in fear conditioning is crucial for cognitive development research.
Purpose of the Study:
- To investigate age-related changes in contextual fear conditioning in rats.
- To explore the impact of stimulus and context extinction on fear memory across development.
Main Methods:
- Pavlovian fear conditioning using auditory conditioned stimulus (CS) and footshock (US) in varied contexts.
- Assessing fear suppression and extinction effects in infant, adolescent, and adult rats.
- Analyzing sex differences in extinction paradigms.
Main Results:
- Infants and adolescents exhibited robust contextual fear conditioning, while adults did not.
- Adolescents showed reduced fear conditioning with unpaired stimuli, unlike infants and adults.
- Context extinction, but not CS extinction, affected adolescent fear conditioning, indicating developmental specificity.
Conclusions:
- Fear conditioning and extinction processes mature across adolescence.
- Developmental shifts in perceptual-cognitive processing and hippocampus function influence fear memory.
- Sex differences emerge in extinction learning during adolescence.
Abstract:
Contextual fear conditioning was tested in infant, adolescent, and adult rats in terms of Pavlovian-conditioned suppression. When a discrete auditory-conditioned stimulus (CS) was paired with footshock (unconditioned stimulus, US) within the largely olfactory context, infants and adolescents conditioned to the context with substantial effectiveness, but adult rats did not. When unpaired presentations of the CS and US occurred within the context, contextual fear conditioning was strong for adults, weak for infants, but about as strong for adolescents as when pairings of CS and US occurred in the context. Nonreinforced presentations of either the CS or context markedly reduced contextual fear conditioning in infants, but, in adolescents, CS extinction had no effect on contextual fear conditioning, although context extinction significantly reduced it. Neither CS extinction nor context extinction affected responding to the CS-context compound in infants, suggesting striking discrimination between the compound and its components. Female adolescents showed the same lack of effect of component extinction on response to the compound as infants, but CS extinction reduced responding to the compound in adolescent males, a sex difference seen also in adults. Theoretical implications are discussed for the development of perceptual-cognitive processing and hippocampus role.
