Summary: Female rats that experienced severe early-life neglect developed altered connections between the amygdala and prefrontal cortex, revealing sex-specific brain changes linked to anxiety-like behavior.
Source: Northeastern University
Background: In the early 1990s more than 100,000 children in Romania lived in overcrowded, under-resourced orphanages where severe neglect and minimal caregiver contact were common. That profound lack of early nurturing changed the structure and function of many of those children’s brains and contributed to long-term emotional and behavioral difficulties.
Neuroscientists at Northeastern University modeled aspects of this early-life adversity in rats to examine the underlying brain changes that may explain increased vulnerability to anxiety and other mental health challenges. By combining anatomical tracing and functional imaging with behavioral measures, the researchers looked for sex-specific effects in corticolimbic circuits—the neural pathways that connect the amygdala, a center for emotion processing, with the prefrontal cortex, which is involved in regulation and decision-making.
Key findings: The study found that early-life adversity produced accelerated, or precocious, maturation of anatomical connections from the basolateral amygdala (BLA) to the prefrontal cortex (PFC). This shift in developmental timing was apparent earlier in female rats than in males. In addition to structural changes, females showed disrupted development of resting-state functional connectivity (rsFC) between these regions. Critically, in females the altered rsFC persisted and was associated with increased anxiety-like behavior during adolescence.
Methods in brief: The investigators used a maternal separation protocol to model early-life adversity (ELA). They applied anterograde tracing from the BLA to chart how axons innervate PFC targets at multiple developmental stages—juvenility (postnatal day 28) and adolescence (postnatal days 38 and 48). In a separate cohort, the team measured longitudinal resting-state functional connectivity at PD28 and PD48 and related those functional measures to behavioral assays that index anxiety-like responses. By combining anatomical tracing, functional imaging, and behavior, they assessed how ELA changes corticolimbic development differently in males and females.
Interpretation and significance: These results provide both anatomical and functional evidence that early neglect can alter the developmental trajectory of circuits that regulate emotion. The female-specific pattern—earlier anatomical maturation and persistent functional disruption linked to anxiety-like behavior—highlights sex as an important factor in vulnerability. The findings suggest that timing and sex should be considered when developing interventions or preventive strategies for children exposed to early adversity. Understanding how and when these circuits diverge from typical development could help target critical windows for therapy and support.
Research provenance: This work was conducted by researchers at Northeastern University and appears in an open-access paper in eLife. The study is titled “Altered corticolimbic connectivity reveals sex-specific adolescent outcomes in a rat model of early life adversity.” Authors include Jennifer A. Honeycutt, Camila Demaestri, Shayna Peterzell, Marisa M. Silveri, Xuezhu Cai, Praveen Kulkarni, Miles G. Cunningham, Craig F. Ferris, and Heather C. Brenhouse. DOI: 10.7554/eLife.52651.
Source:
Northeastern University
Media contact:
Laura Castañón – Northeastern University
Image source:
The image is in the public domain.
Abstract (summary):
Exposure to early-life adversity increases risk for psychiatric conditions that implicate amygdala–prefrontal cortex circuitry. While sex differences in vulnerability are recognized, the neurobiological bases that incorporate both development and sex are less well understood. In this rat model of maternal separation, anterograde tracing from the basolateral amygdala to the prefrontal cortex revealed sex-specific innervation patterns across juvenility (PD28) and adolescence (PD38; PD48). Resting-state functional connectivity was assessed longitudinally in a separate cohort (PD28; PD48). All measures were related to anxiety-like behavior. ELA-exposed rats displayed precocious BLA–PFC innervation, with females showing these changes earlier than males. ELA also disrupted maturation of female rsFC, producing lasting relationships between connectivity measures and anxiety-like behavior. The study offers combined anatomical and functional evidence for sex- and experience-dependent corticolimbic development.