Adolescent conditioning affects rate of adult fear, safety and reward learning during discriminative conditioning

Abstract

Fear and reward memories formed in adulthood are influenced by prior experiences. Experiences that occur during sensitive periods, such as adolescence, can have an especially high impact on later learning. Fear and reward memories form when aversive or appetitive events co-occur with initially neutral stimuli, that then gain negative or positive emotional load. Fear and reward seeking behaviours are influenced by safety cues, signalling the non-occurrence of a threat. It is unclear how adolescent fear or reward pre-conditioning influences later dynamics of these conditioned emotions, and conditioned safety. In this study, we presented male rats with adolescent fear or reward pre-conditioning, followed by discriminative conditioning in adulthood. In this discriminative task, rats are simultaneously conditioned to reward, fear and safety cues. We show that adolescent reward pre-conditioning did not affect the rate of adult reward conditioning, but instead accelerated adult safety conditioning. Adolescent fear pre-conditioning accelerated adult fear and reward seeking behaviours but delayed adult safety expression. Together, our results suggest that the dynamics of safety conditioning can be influenced by adolescent priming of different valences. Taking adolescent experiences into consideration can have implications on how we approach therapy options for later learned fear disorders where safety learning is compromised.

The Effects of Dairy Heifer Age at Training on Rate of Learning and Retention of Learning in a Virtual Fencing Feed Attractant Trial

“…The adolescent and adult rats did not differ in rate of conditioning but stress during adolescence decreased context and cue memory later in life. Other evidence from laboratory rats shows that stress during adolescence increases fear or anxiety like behavior (e.g., Brydges et al, 2012;Yee et al, 2012;Müller et al, 2018) and risk-taking in the adult (Toledo and Sandi, 2011;Brydges et al, 2012;Traslaviña et al, 2014). We are unable to conclude whether the reduced performance of the 9month old heifers during re-training in this experiment is related to impaired cognitive function (e.g., behavioral suppression, attention, or decision making) or changes in emotional state (e.g., anxiety).…”

Know safety, no fear

“…A withinsubjects design, on the other hand, pits a discrete fear cue against a discrete safety cue, resulting in animals discriminating between the two cues to guide their fear and safety behaviors. Interestingly, fear to the background context can be low in this design indicating context fear is unnecessary to establish the CS− as a safety cue [24][25][26] . As the safety learning field moves forward, it will be important to keep in mind the nuanced differences between these procedures and how they may impact conclusions regarding safety cue discrimination.…”

Assaying Fear Memory Discrimination and Generalization: Methods and Concepts

“…Variations of the differential fear conditioning paradigm have been used to study "safety" learning and memory (Foilb, Flyer-Adams, Maier, & Christianson, 2016;Greiner, Müller, Norris, Ng, & Sangha, 2019;Müller, Brinkman, Sowinski, & Sangha, 2018;Sangha, Chadick, & Janak, 2013). While the various procedures for safety learning are outside of the scope of this methods article, there are several reviews on the topic (Christianson et al, 2012;Sangha et al, 2020).…”