Effects of early life stress on network and behavioral states

Background

Adverse childhood experiences (ACEs) are associated with numerous detriments in health, including increased vulnerability to psychiatric illnesses. Early life stress (ELS) in rodents has been shown to effectively model several of the behavioral and endocrine impacts of ACEs and has been utilized to investigate the underlying mechanisms contributing to disease. However, the precise neural mechanisms responsible for mediating the impact of ELS on vulnerability to psychiatric illnesses remain largely unknown.

Methods

We use behavior, immunoassay, in vivo local field potential (LFP) recording, histology, and patch clamp to describe the effects of ELS on stress-related behaviors, endocrine changes, network states, protein expression, and cellular physiology in male and female mice.

Results

We demonstrate that a murine maternal separation (MS) ELS model causes male-specific alterations in behavioral and hormonal responses following an acute stressor. LFP recordings in the basolateral amygdala (BLA) and frontal cortex (FC) reveal similar sex-specific alterations at baseline and in response to acute ethological stress. Furthermore, altered physiology of BLA principal neurons in males and BLA parvalbumin (PV) interneurons in females suggests a likely mechanism through which these effects may be mediated. These findings support a large body of literature demonstrating that these network states contribute to stress reactivity and vulnerability to psychiatric illnesses.

Conclusions

Collectively, these results implicate distinct, novel male- and female-specific mechanisms through which ACEs may impact psychiatric health, including altered cellular physiology and network states involved in emotional processing.