Corticotropin-Releasing Factor Signaling in Stress and Anxiety Disorders

The corticotropin-releasing factor (CRF) family of neuropeptides is the primary mediator of the physiological and behavioural response to stress and constitutes the apex of the hypothalamic–pituitary–adrenal (HPA) axis. Synthesised predominantly in the paraventricular nucleus of the hypothalamus, CRF triggers the release of adrenocorticotropic hormone from the anterior pituitary, culminating in glucocorticoid secretion by the adrenal cortex. Beyond this classical endocrine circuit, CRF and its paralogues urocortin 1, 2 and 3 modulate central circuits of fear and anxiety through two G protein-coupled receptors, CRF receptor 1 (CRFR1) and CRF receptor 2 (CRFR2). Activation of these receptors engages diverse intracellular cascades, including cAMP–protein kinase A, mitogen-activated protein kinase and β-arrestin pathways, which together regulate synaptic plasticity and dendritic spine dynamics. Acute CRF signalling may enhance memory processes and adaptive coping by transiently augmenting excitatory neurotransmission, whereas prolonged or excessive activation often precipitates dendritic remodelling, synaptic loss and heightened anxiety-like behaviours. Each receptor subtype displays distinct anatomical distributions—CRFR1 predominates in limbic forebrain structures implicated in anxiety, while CRFR2 is enriched in subcortical and brainstem regions—thereby orchestrating region-specific stress responses. Dysregulation of CRF signalling is a hallmark of anxiety disorders and post-traumatic stress disorder, making receptor antagonists and modulators of downstream effectors promising therapeutic avenues. Advancements in our understanding of CRF receptor desensitisation, peptidergic interactions and network-level effects continue to refine strategies for normalising stress resilience and alleviating anxiety pathology.

Research from Nature Portfolio

Recent studies have elucidated how chronic ligand exposure modulates CRF receptor 2 responsiveness and downstream signalling. Prolonged administration of the selective CRFR2 agonist urocortin 2 in rodent models leads to adaptive desensitisation of the receptor, shifting G protein coupling from stimulatory to inhibitory pathways. This receptor internalisation attenuates cAMP production upon subsequent ligand challenges and illustrates a dynamic mechanism that may underlie receptor tolerance in persistent stress exposure. Such insights into CRFR2 regulation offer a framework for designing therapies that balance acute anxiolytic effects against the risk of long-term receptor downregulation.

Corticotropin-Releasing Factor Signaling in Stress and Anxiety Disorders publication trend

The graph below shows the total number of articles in corticotropin-releasing factor signaling in stress and anxiety disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Corticotropin-Releasing Factor (CRF): A neuropeptide that initiates the stress hormone cascade and modulates central stress circuits.

Corticotropin-Releasing Factor Receptor 1 (CRFR1): A G protein-coupled receptor widely expressed in forebrain regions, mediating anxiety-related responses.

Corticotropin-Releasing Factor Receptor 2 (CRFR2): A G protein-coupled receptor enriched in subcortical areas, implicated in stress recovery and homeostasis.

Urocortins: Paralogue peptides of CRF that act on CRFR1 and CRFR2 with varying affinities to fine-tune stress responses.

Hypothalamic–Pituitary–Adrenal (HPA) Axis: The neuroendocrine system governing the release of glucocorticoids under stress.

Dendritic Spine: A specialised membranous protrusion on neurons that serves as the principal site of excitatory synaptic transmission.

References

1. Chronic UCN2 treatment desensitizes CRHR2 and improves insulin sensitivity. Nature Communications (2023).
2. Cdk5-dependent rapid formation and stabilization of dendritic spines by corticotropin-releasing factor. Translational Psychiatry (2024).
3. Recruitment of Corticotropin-Releasing Hormone (CRH) Neurons in Categorically Distinct Stress Reactions in the Mouse Brain. International Journal of Molecular Sciences (2023).