Navigation Links
Neurobiologists find chronic stress in early life causes anxiety, aggression in adulthood
Date:3/27/2014

Cold Spring Harbor, NY -- In recent years, behavioral neuroscientists have debated the meaning and significance of a plethora of independently conducted experiments seeking to establish the impact of chronic, early-life stress upon behavior both at the time that stress is experienced, and upon the same individuals later in life, during adulthood.

These experiments, typically conducted in rodents, have on the one hand clearly indicated a link between certain kinds of early stress and dysfunction in the neuroendocrine system, particularly in the so-called HPA axis (hypothalamic-pituitary-adrenal), which regulates the endocrine glands and stress hormones including corticotropin and glucocorticoid.

Yet the evidence is by no means unequivocal. Stress studies in rodents have also clearly identified a native capacity, stronger in some individuals than others, and seemingly weak or absent in still others, to bounce back from chronic early-life stress. Some rodents subjected to early life stress have no apparent behavioral consequences in adulthood they are disposed neither to anxiety nor depression, the classic pathologies understood to be induced by stress in certain individuals.

Today, a research team led by Associate Professor Grigori Enikolopov of Cold Spring Harbor Laboratory (CSHL) reports online in the journal PlOS One the results of experiments designed to assess the impacts of social stress upon adolescent mice, both at the time they are experienced and during adulthood. Involving many different kinds of stress tests and means of measuring their impacts, the research indicates that a "hostile environment in adolescence disturbs psychoemotional state and social behaviors of animals in adult life," the team says.

The tests began with 1-month-old male mice the equivalent, in human terms of adolescents -- each placed for 2 weeks in a cage shared with an aggressive adult male. The animals were separated by a transparent perforated partition, but the young males were exposed daily to short attacks by the adult males. This kind of chronic activity produces what neurobiologists call social-defeat stress in the young mice. These mice were then studied in a range of behavioral tests.

"The tests assessed levels of anxiety, depression, and capacity to socialize and communicate with an unfamiliar partner," explains Enikolopov. These experiments showed that in young mice chronic social defeat induced high levels of anxiety helplessness, diminished social interaction, and diminished ability to communicate with other young animals. Stressed mice also had less new nerve-cell growth (neurogenesis) in a portion of the hippocampus known to be affected in depression: the subgranular zone of the dentate gyrus.

Another group of young mice was also exposed to social stress, but was then placed for several weeks in an unstressful environment. Following this "rest" period, these mice, now old enough to be considered adults, were tested in the same manner as the other cohort.

In this second, now-adult group, most of the behaviors impacted by social defeat returned to normal, as did neurogenesis, which retuned to a level seen in healthy controls. "This shows that young mice, exposed to adult aggressors, were largely resilient biologically and behaviorally," says Dr. Enikolopov.

However, in these resilient mice, the team measured two latent impacts on behavior. As adults they were abnormally anxious, and were observed to be more aggressive in their social interactions. "The exposure to a hostile environment during their adolescence had profound consequences in terms of emotional state and the ability to interact with peers," Dr. Enikolopov observes.


'/>"/>
Contact: Peter Tarr
tarr@cshl.edu
516-367-5055
Cold Spring Harbor Laboratory
Source:Eurekalert

Related biology news :

1. New book on stereology by Mark West is essential reading for neurobiologists
2. Genetic mutation found in familial chronic diarrhea syndrome
3. Effect of chronic exposure to chemicals used as weapons, pesticides under study
4. BYU engineers conceive disc replacement to treat chronic low back pain
5. Neuroprotective dietary supplements for chronic spinal cord injury
6. Why chronic pain is all in your head
7. Chronic inflammation in the brain leads the way to Alzheimers disease
8. miR loss may power maligant transformation in chronic leukemia
9. How chronic obstructive pulmonary disease increases risk of lung cancer
10. Basal cell carcinoma risk can be chronic
11. Chronic 2000-04 drought, worst in 800 years, may be the new normal
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/9/2016)... , June 9, 2016 ... Police deploy Teleste,s video security solution to ensure the safety ... France during the major tournament Teleste, ... communications systems and services, announced today that its video security ... to back up public safety across the country. ...
(Date:6/2/2016)... June 2, 2016 Perimeter Surveillance ... Unmanned Systems, Physical Infrastructure, Support & Other Service  ... visiongain offers comprehensive analysis of the global ... will generate revenues of $17.98 billion in 2016. ... Inc, a leader in software and hardware technologies for ...
(Date:5/12/2016)... WearablesResearch.com , a brand of Troubadour ... from the Q1 wave of its quarterly wearables survey. ... receptivity to a program where they would receive discounts ... company. "We were surprised to see that ... LaColla , CEO of Troubadour Research, "primarily because there ...
Breaking Biology News(10 mins):
(Date:6/27/2016)...  Sequenom, Inc. (NASDAQ: SQNM ), a ... the development of innovative products and services, announced today ... States denied its petition to review decisions ... U.S. Patent No. 6,258,540 (",540 Patent") are not patent ... Supreme Court,s Mayo Collaborative Services v. Prometheus Laboratories decision.  ...
(Date:6/27/2016)... 27, 2016  Liquid Biotech USA ... of a Sponsored Research Agreement with The University ... (CTCs) from cancer patients.  The funding will be ... correlate with clinical outcomes in cancer patients undergoing ... then be employed to support the design of ...
(Date:6/24/2016)... NC (PRWEB) , ... June 24, 2016 , ... Researchers ... the most commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are ... to read it now. , Diagnostic biomarkers are signposts in the blood, lung ...
(Date:6/23/2016)... SILVER SPRING, Md. , June 23, 2016 ... evidence collected from the crime scene to track the criminal ... sick, and the U.S. Food and Drug Administration (FDA) uses ... Sound far-fetched? It,s not. ... whole genome sequencing to support investigations of foodborne illnesses. Put ...
Breaking Biology Technology: