Early life stress and development of the endocannabinoid system: A bidirectional process in programming future coping

Area of Science:

• Neuroscience
• Developmental Psychology
• Endocrinology

Background:

• The endocannabinoid system (ECS) is crucial for regulating stress and emotions during development.
• Early life stress can alter ECS gene expression in a sex- and region-specific manner, evident even in adolescence.
• The ECS influences neuroendocrine and behavioral stress responses and is itself affected by stress.

Purpose of the Study:

• To review the bidirectional relationship between the endocannabinoid system and emotionality in response to early life stress.
• To highlight how early life stress impacts ECS development and function.
• To examine the long-term consequences of these alterations on brain circuits and psychopathology vulnerability.

Main Methods:

• This review synthesizes existing research on the endocannabinoid system and early life stress.
• It analyzes studies investigating gene expression, receptor density, and neurochemical levels (anandamide, 2-AG).
• Focus is placed on developmental trajectories and sex-dependent effects in brain regions like the amygdala and hippocampus.

Main Results:

• Early life stress alters the ontogeny of the ECS, leading to functional deficits, especially in the hippocampus.
• Bidirectional changes in anandamide and 2-AG levels occur in the amygdala and hippocampus following early stress.
• CB1 receptor density is downregulated later in life after early life stress exposure.
• Stress exposure alters emotional responses and synaptic plasticity, modulated by the ECS and glucocorticoid systems.

Conclusions:

• Early life stress significantly impacts the endocannabinoid system's development and function.
• These disruptions contribute to altered emotionality and increased risk for adult psychopathology.
• Understanding these bidirectional interactions is key for developing targeted interventions.