Child silhouette with divided brain representing trauma impact.

Early Trauma: How It Impacts Boys and Girls Differently

Soraya Malik in Mind & Education September 2025 • 4 min read.

"New research reveals sex-specific differences in how early life stress affects brain development and cognitive functions. Discover why boys may be more vulnerable and what it means for mental health."

Adverse childhood experiences (ACEs) are increasingly recognized as significant contributors to neurodevelopmental disorders. These early stressors can disrupt brain development, cognitive abilities, and overall mental health, leading to long-term consequences.

One such ACE is maternal deprivation (MD), where infants are separated from their mothers for extended periods. Studies have shown that MD can alter the levels of calcium-binding proteins like calretinin (CALR) and calbindin-D28k (CALB) in the hippocampus, a brain region crucial for learning and memory. However, the effects of MD may not be the same for everyone.

New research investigates how MD affects hippocampal CALR and CALB protein levels and cognitive behaviors in rats, while exploring whether these effects differ between males and females. By understanding these sex-specific responses, we can gain valuable insights into the mechanisms underlying the impact of early trauma and develop more targeted interventions.

Boys vs. Girls: Unpacking the Brain Differences in Response to Trauma

Child silhouette with divided brain representing trauma impact.

The study involved separating rat pups from their mothers for three hours daily between postnatal days 2 and 14, mimicking the effects of maternal deprivation. Researchers then assessed the levels of CALR and CALB in the hippocampus at various time points. They also conducted behavioral tests, including open field tests to measure exploration and Morris water maze tests to assess spatial learning and memory.

The results revealed that MD affected hippocampal CALR and CALB levels in both male and female rats. However, males showed reduced exploration in the open field test after MD, while females did not. The Morris water maze tests indicated that MD impaired spatial memory in both sexes, but sex-specific differences emerged in CALR and CALB levels.

Vulnerability: Male rats are more susceptible to the stress of MD than female rats.
Cognitive Impairment: Both male and female rats experienced spatial learning impairment after MD.
CALR and CALB Levels: Sex differences in CALR and CALB levels may point to varying underlying mechanisms behind behavioral observations.

These findings suggest that males are more vulnerable to the effects of MD, exhibiting reduced exploration and spatial learning impairment. While both sexes experience cognitive deficits, the underlying mechanisms, as indicated by CALR and CALB levels, appear to differ. These insights highlight the importance of considering sex as a critical factor in understanding and addressing the impact of early trauma.

Why This Matters: Implications for Mental Health

The study underscores the importance of early interventions and support for children who have experienced ACEs. Understanding the sex-specific vulnerabilities and mechanisms can help tailor interventions to maximize their effectiveness.

Further research is needed to fully elucidate the complex interplay between early trauma, brain development, and cognitive function. Longitudinal studies tracking individuals exposed to ACEs are crucial for understanding the long-term consequences and identifying potential targets for intervention.

By recognizing the unique ways in which trauma affects boys and girls, we can work towards creating more supportive and nurturing environments that promote resilience and mitigate the lasting impact of adverse childhood experiences.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1186/s12993-018-0142-y, Alternate LINK

Title: Sex Differences In Associations Between Maternal Deprivation And Alterations In Hippocampal Calcium-Binding Proteins And Cognitive Functions In Rats

Subject: Behavioral Neuroscience

Journal: Behavioral and Brain Functions

Publisher: Springer Science and Business Media LLC

Authors: Hongyu Xu, Yuqin Ye, Yelu Hao, Fei Shi, Zhiqiang Yan, Guohao Yuan, Yuefan Yang, Zhou Fei, Xiaosheng He

Published: 2018-05-15

Everything You Need To Know

What are some examples of early trauma?

Early trauma can stem from Adverse Childhood Experiences (ACEs), such as maternal deprivation (MD). MD is a type of ACE where infants are separated from their mothers for extended periods. These experiences can disrupt brain development and cognitive abilities, leading to long-term consequences. The study focused on MD and its impact on rat pups, finding differences in how males and females respond.

How does early trauma impact the brain?

Maternal Deprivation (MD) affects the brain by potentially altering levels of calcium-binding proteins like calretinin (CALR) and calbindin-D28k (CALB) in the hippocampus. The hippocampus is crucial for learning and memory. The research indicates that MD can lead to cognitive impairment, specifically affecting spatial learning and memory in both male and female rats. However, the study reveals that the underlying mechanisms and the severity of impact can vary between sexes, highlighting the significance of considering sex-specific approaches.

What differences were observed in the study between male and female rats?

The study found that male rats exhibited reduced exploration in the open field test after experiencing Maternal Deprivation (MD), while females did not show this behavioral change. The Morris water maze tests indicated that both sexes experienced impaired spatial memory. The key finding indicates that males are more vulnerable to MD. Sex-specific differences in CALR and CALB levels also emerged, which suggests varying underlying mechanisms contributing to the observed behavioral differences.

What are CALR and CALB?

CALR (calretinin) and CALB (calbindin-D28k) are calcium-binding proteins located in the hippocampus. The levels of these proteins were measured to understand how early trauma, such as Maternal Deprivation (MD), affects brain development. The study revealed that the levels of CALR and CALB were altered by MD in both male and female rats, but with sex-specific differences. These differences in protein levels point to varied mechanisms influencing behavioral outcomes, such as exploration and spatial memory.

Why is it important to consider sex when addressing early trauma?

Understanding sex-specific responses to early trauma is crucial for developing effective interventions. The study's findings emphasize that interventions for children who have experienced Adverse Childhood Experiences (ACEs) may need to be tailored to account for the different ways boys and girls are affected. The recognition of sex-specific vulnerabilities and mechanisms can help maximize the effectiveness of support programs, ultimately improving mental health outcomes. This understanding can lead to more targeted support for those who have experienced Maternal Deprivation (MD) or other ACEs.