Teen and Adult Brains Respond Differently to Stress Through Neuropeptide Y | Research

The takeaway

Adolescent mice showed elevated hippocampal NPY and resilience to anxiety after footshock stress, while adults showed reduced NPY and increased anxiety, revealing age-dependent neuropeptide stress responses.

Opposite NPY responses by age
Adolescents: elevated hippocampal NPY with no anxiety; Adults: reduced NPY with increased anxiety — after the same stressor

What the researchers found

After footshock stress, adolescent mice showed elevated hippocampal NPY and no anxiety increase, while adult mice showed reduced hippocampal NPY and increased anxiety — opposite neuropeptide responses to the same stressor.

Why it matters

Understanding why adolescent brains may be more resilient to acute stress could help develop age-appropriate treatments for anxiety and PTSD, particularly the role of NPY as a natural stress-protective factor.

The numbers in context

30-min footshock; adults: reduced EPM open arm time + reduced hippocampal NPY; adolescents: no anxiety change + elevated hippocampal NPY; both: hypolocomotion

How the study worked

Unpredictable footshock (30 min) in adolescent (6-week) and adult (3-month) male C57Bl6/J mice. Plasma corticosterone and NPY at baseline and post-shock. Elevated plus maze and open field 1 week later. Hippocampal NPY peptide expression by immunohistochemistry.

Who was studied

Male C57Bl6/J mice at 6 weeks (adolescent) and 3 months (adult)

What this study cannot tell us

Male mice only — sex differences in stress response are well-documented. Single stressor type (footshock). One-week post-stress timepoint may not capture long-term trajectories. Mouse adolescence may not perfectly model human adolescence.

How to read the evidence

Well-designed age-comparison study with behavioral and molecular measures. Provides important developmental neuroscience evidence.

When this study was published

Published in 2021, contributing to understanding age-dependent stress vulnerability and neuropeptide resilience factors.

The bigger picture

PTSD and anxiety disorders are characterized by reduced NPY levels. The finding that adolescents naturally upregulate NPY after stress while adults do the opposite suggests a developmental shift in stress resilience that may explain why some trauma exposures lead to lasting disorders while others don't.

Questions still open

What developmental changes cause the shift from NPY upregulation to downregulation after stress?
Would NPY supplementation in adults restore stress resilience?
Do female adolescent mice show the same protective NPY response?

Common questions

Are teenage brains more resilient to stress than adult brains?

This mouse study suggests they might be, at least for certain types of acute stress. Adolescent mice naturally increased their levels of the stress-protective molecule NPY after a stressful experience, while adult mice decreased it — and the adults developed anxiety-like behavior while the adolescents didn't.

What is NPY and why does it matter for stress?

Neuropeptide Y (NPY) is a brain chemical that helps regulate mood and stress responses. People with PTSD have reduced NPY levels. This study shows that the ability to increase NPY after stress may be a key factor in whether a traumatic experience leads to lasting anxiety or not.

Read the original research

Differences between adult and adolescent male mice in approach/avoidance and expression of hippocampal NPY in response to acute footshock.

Stress (Amsterdam, Netherlands), 24(6), 965-977

View on PubMed ↗Publisher’s paper ↗

Citation

Cortes, Mariana A; Corder, Katelynn M; Dobrunz, Lynn E. (2021). Differences between adult and adolescent male mice in approach/avoidance and expression of hippocampal NPY in response to acute footshock.. Stress (Amsterdam, Netherlands), 24(6), 965-977. https://doi.org/10.1080/10253890.2021.1976139