Work

Accelerated maturation of fear regulation systems in infant rats following early life inflammation

Year: 2025

Type: article

Abstract: Early life stress is a well-established risk factor for neuropsychiatric and neurodevelopmental disorders, yet the mechanisms underlying this lifelong vulnerability remain unclear. One possibility is that early stress exposure disrupts the developmental trajectory of neural systems involved in emotion regulation, creating long-term susceptibility to psychopathology. Therefore, here we explored the impact of two forms of early-life adversity on maturation of emotional regulation in infant rats. Two forms of adversity were examined: maternal separation (MS) and to early-life inflammation (ELI) via post-natal injections of the bacterial endotoxin lipopolysaccharide. In Experiment 1, we examined the effects of these two types of early life stress in infant male rats. Based on the results of the first experiment, in Experiment 2 we replicated the procedures from Experiment 1 in females but only examined ELI as an early stressor. In both experiments, ELI infants displayed a precocious emergence of context-mediated relapse of extinguished fear, whereas standard-rearing (SR) and MS male infants did not. These findings suggest that ELI accelerates the development of infant emotion regulation, consistent with studies using other stressors (e.g., psychosocial), and point to shared mechanisms underlying the long-term adverse effects of early-life stress.

Source: Neurobiology of Learning and Memory

DOI: 10.1016/j.nlm.2025.108109

Authors: Tayla B. McCutcheon, Sara M. Simenson-Braun, Rick Richardson

Institution: UNSW Sydney

Language: English

Topic: Stress Responses and Cortisol

Subfield: Behavioral Neuroscience

Field: Neuroscience

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,000