Abusive mothering aggravates the impact of stress hormones

Jun 21, 2010

In a new Biological Psychiatry article, Dr. Regina Sullivan and colleagues have dissected the behavior of mother rats and their infant pups, modeling nurturing by stroking and abuse with electric shock. In this animal model of infant abuse, they took into consideration the unique infant neurobehavioral learning attachment system that ensures infant rats' attachment to their caregiver regardless of the quality of care received.

Upon this background, the pups responded to a natural maternal odor or an artificial odor that was conditioned as a new maternal odor through pairings with either a positive stimulus (the stroking) or a negative stimulus (the shock). Exposure to both their mother's natural scent and the conditioned maternal scent evoked normal social responses, including those related to attachment.

The authors also evaluated the impact of raising the pups' levels of the stress hormone corticosterone, or being reared with an abusive mother. In these cases, pups with an abusive attachment showed disrupted social behavior with the mother and increased engagement of the amygdala, a region of the brain involved in regulating stress and emotion.

"Our work shows that, while the infant brain is wired to form attachments at all costs, abusive attachments have negative consequences in development," explained Dr. Raineki. "Most importantly, some effects of early life abuse may be hidden until the abused animal is challenged and the negative effects are uncovered."

Dr. John Krystal, Editor of , also commented, "It is interesting that the is primarily activated when abusive behavior of the mother is combined with a reaction within the infant, i.e., an increase in levels of the stress hormone corticosterone. Thus, the authors of this study elegantly highlight the dyadic nature of the mother-infant relationship."

Using this model of attachment may provide clues to understanding attachment in children with various conditions of care. The authors hope that this model will help us understand the neurobiological origins of psychopathology stemming from abuse, and possibly facilitate the development of treatments and/or interventions for victims of early-life trauma.

Explore further: Treatment of substance abuse can lessen risk of future violence in mentally ill, study finds

More information: The article is "Developing a Neurobehavioral Animal Model of Infant Attachment to an Abusive Caregiver" by Charlis Raineki, et al. The article appears in Biological Psychiatry, Volume 67, Issue 12 (June 15, 2010).

add to favorites email to friend print save as pdf

Related Stories

Changes in brain chemicals mark shifts in infant learning

Oct 26, 2009

When do you first leave the nest? Early in development infants of many species experience important transitions—such as learning when to leave the protective presence of their mother to start exploring the wider world. ...

Maternal love: How a mother's brain responds to her infant

Feb 28, 2008

The distinctive ability of mothers to identify the cries of their offspring is widely evident in nature, where it is critical to the survival of these offspring. In humans, we are aware that the distinctive ability of mothers ...

Genetic Risk for Anxiety Does Not Have to be Destiny

Apr 29, 2009

A growing body of basic animal research and studies of abused and neglected children provide a strong basis of support for the hypothesis that individuals with particular genotypes are at greater risk for depression, anxiety ...

Recommended for you

Omega-3 fatty acids may prevent some forms of depression

1 hour ago

Patients with increased inflammation, including those receiving cytokines for medical treatment, have a greatly increased risk of depression. For example, a 6-month treatment course of interferon-alpha therapy ...

Ethical behavior can be contagious, study says

1 hour ago

A new study from Penn State Smeal College of Business faculty members Steven Huddart and Hong Qu examines the power of social influence on managers' ethical behavior. The Department of Accounting researchers find that managers ...

Predicting the future course of psychotic illness

2 hours ago

University of Adelaide psychiatry researchers have developed a model that could help to predict a patient's likelihood of a good outcome from treatment – from their very first psychotic episode.

Boys will be boys? Yes, neuroscience now shows

13 hours ago

If you've ever tried to warn teenagers of the consequences of risky behavior - only to have them sigh and roll their eyes - don't blame them. Blame their brain anatomy.

Depression increasing across the country

17 hours ago

A study by San Diego State University psychology professor Jean M. Twenge shows Americans are more depressed now than they have been in decades.

User comments : 0