A recent study published in the journal Nature has revealed key insights into the brain mechanisms that may contribute to infanticide in female mice. Researchers from NYU Grossman School of Medicine have identified a specific brain region, known as the principal nucleus of the bed nucleus of stria terminalis (BNSTpr), which is associated with emotional regulation and appears to drive female mice to kill their young. This behavior, often observed prior to their first birthing, is believed to be a strategy to preserve food resources.
The study conducted by NYU Grossman School of Medicine has provided significant findings regarding infanticide in female mice and the crucial role played by the BNSTpr. When the BNSTpr was activated, it triggered aggression towards the young, whereas blocking its activity almost entirely prevented infanticide. Interestingly, the BNSTpr operates in opposition to another brain region responsible for promoting maternal behaviors. Changes in the activities of these regions were found to correlate with shifts in infanticidal tendencies.
The study suggests that a middle-brain region involved in emotion control likely prompts female mice to kill their young. The presence of this region in humans raises the possibility of a similar role in understanding infanticide among women.
Notably, before giving birth for the first time, female mice are known to frequently engage in infanticide of other pups. This behavior may have evolved as a means to preserve scarce food resources for their own future offspring. However, most studies have primarily focused on infanticide by adult males, leaving the brain mechanisms underlying this behavior in females poorly understood.
The research team demonstrated that blocking the BNSTpr chemically prevented infanticide in nearly 100% of cases. Conversely, artificially stimulating the brain region led to both mothers and females without offspring killing pups in almost all trials, with attacks occurring within a second of the stimulation. It is worth noting that the mice rarely displayed aggression towards other adults, indicating that this brain structure specifically controls aggression towards young animals.
Furthermore, the investigation revealed that the BNSTpr and a brain region called the medial preoptic area (MPOA), known for promoting mothering behavior, operate in opposition to each other. The findings showed that mice that had not yet experienced motherhood exhibited high BNSTpr activity, which suppressed the MPOA. After giving birth, MPOA activity increased, potentially suppressing the infanticidal system. Consequently, new mothers tended to avoid infanticide regardless of whether the pup was their own.
Lead author of the study, Long Mei, PhD, a Leon Levy Foundation postdoctoral fellow in NYU Langone Health’s Neuroscience Institute, emphasized the significance of the investigation in pinpointing the brain mechanisms associated with infanticide in females. The study also revealed that pressure applied to the BNSTpr could reverse the switch to maternal behaviors.
Child abuse is the fourth leading cause of death among preschool children in the United States, according to the U.S. Centers for Disease Control and Prevention. While early studies primarily focused on potential problems in the parenting centers of the brain, recent efforts have sought to identify a separate system dedicated to infanticide and aggression against children.
To narrow down the brain regions responsible for infanticidal behavior, the researchers tracked connections to the MPOA. They then artificially stimulated each of the resulting seven regions in live mice to determine which ones led to attacks on pups. Subsequently, the team blocked the activity in the BNSTpr, the most promising candidate, to assess its impact on infanticide.
The study authors also conducted experiments on brain slices from female rodents, activating one region while recording cell activity in the other. They also observed changes in activity as the rodents reached motherhood, shedding light on the interplay between the BNSTpr and MPOA.
While these connecting regions in the middle of the brain exist in both rodents and humans, the authors caution that the roles they play may not be identical. Nevertheless, the findings suggest a potential target for understanding and potentially treating mothers who engage in child abuse, as these brain regions could become more active in response to triggers such as stress and postpartum depression.
The next steps for the research team involve examining the BNSTpr and MPOA in male mice and exploring non-invasive methods of inhibiting activity in the BNSTpr.
Reference: Mei, L., Yan, R., Yin, L., Sullivan, R., & Lin, D. (2023). Antagonistic circuits mediating infanticide and maternal care in female mice. Nature. DOI: 10.1038/s41586-023-06147-9.
The study received funding from various sources, including grants from the National Institutes of Health (NIH) and the Leon Levy Foundation.
Table of Contents
Frequently Asked Questions (FAQs) about Brain mechanisms influencing infanticide
What did the study reveal about infanticide in female mice?
The study revealed that a specific brain region called the principal nucleus of the bed nucleus of stria terminalis (BNSTpr) plays a crucial role in infanticide. When activated, it triggers aggression towards young, but when blocked, infanticide is almost entirely prevented.
Why do female mice engage in infanticide before giving birth?
Female mice engage in infanticide before giving birth as a strategy to preserve scarce food supplies for their own future offspring. This behavior may have evolved as a means of ensuring sufficient resources for their own offspring.
How does the BNSTpr interact with the medial preoptic area (MPOA)?
The BNSTpr and MPOA are brain regions that work in opposition to each other. Before giving birth, high BNSTpr activity suppresses the MPOA, but after giving birth, MPOA activity increases, likely suppressing the infanticidal system. These regions play a role in regulating maternal behaviors.
Could these findings be relevant to understanding infanticide by women?
Yes, since the middle-brain regions involved in the study can be found in both rodents and humans, the findings suggest that similar brain mechanisms may be at play in understanding infanticide by women. Further research is needed to establish the exact role of these regions in humans.
What are the implications of this research?
Understanding the brain mechanisms behind infanticide in females, both in mice and potentially in humans, has important implications. It could provide insights into preventing child abuse and supporting struggling mothers by identifying potential triggers and developing targeted interventions.
More about Brain mechanisms influencing infanticide
- Study: Antagonistic circuits mediating infanticide and maternal care in female mice
- NYU Grossman School of Medicine: Research Highlights
- U.S. Centers for Disease Control and Prevention (CDC): Child Abuse and Neglect
6 comments
Wow, this study shows the dark side of motherhood! It explores the brain regions that make female mice kill their own young. That’s some intense research.
NYU researchers found that a specific brain region, BNSTpr, triggers aggression in female mice towards their pups. Blocking it prevents infanticide. Amazing stuff!
It’s fascinating how the BNSTpr region opposes the brain region responsible for maternal behavior. These findings might help us understand why some mothers harm their children.
The study hints that similar brain mechanisms might be at play in humans too. Understanding these regions could be crucial in preventing child abuse and supporting struggling mothers.
Infanticide in female mice is a survival strategy to preserve resources for their own offspring. It’s intriguing how the brain regulates such behaviors. Can’t wait to see further research on this topic!
This study raises questions about the role of stress and postpartum depression in activating the BNSTpr region. More research is needed to uncover the complexities of maternal behavior in both mice and humans.