How does the brain learn, remember and adapt to stress?

We have recently shown that stress induces changes in how synapses onto stress command neurons, contained in the paraventricular nucleus of the hypothalamus (PVN) process information. This impacts how these cells respond to subsequent stressors. These new findings highlight the clever design of essential brain circuits that are capable of adapting and fine-tuning themselves when faced with an ever-changing environment. Effectively, the brain and specifically the stress-circuits in it, may be using stress experience during early life to prepare and optimize for subsequent challenges. This study was led by Wataru Inoue, a postdoctoral fellow in the lab and was published in Nature Neuroscience.

Key findings:

1)    A single, brief stress creates an ideal environment (in the brain) for learning in neural circuits responsible for coordinating the body’s response to stress (the ‘automatic’ stress command centre).

2)    The enhanced learning environment is made possible by noradrenaline acting at Beta adrenoceptors in the PVN.

3)    This enhanced learning capacity, which is only available for a short period of time manifests as activity-dependent plasticity at GABA synapses.


Why are these findings important?

1)    They reveal important insights about cellular and synaptic mechanisms that link early life stress to learning and information storage in the brain

2)    They demonstrate that systems thought to be ‘hardwired’ are in fact flexible during early life.