A mother's touch may protect against drug cravings later
December 6, 2011 in Neuroscience
An attentive, nurturing mother may be able to help her children better resist the temptations of drug use later in life, according to a study in rats conducted by Duke University and the University of Adelaide in Australia.
A rat mother's attention in early childhood actually changes the immune response in the brains of her pups by permanently altering genetic activity, according to Staci Bilbo, an assistant professor of psychology and neuroscience at Duke, who led the research. High-touch mothering increased the brain's production of an immune system molecule called Interleukin-10, leaving these rats better able to resist the temptation of a dose of morphine much later in life.
This is the first study to show how morphine causes a molecular response in the glial cells of the brain's reward centers, which had only recently been identified as part of drug addiction's circuitry. "We set out to find out what that response looks like," Bilbo said.
To program some of the rat pups to produce more IL-10, the researchers used an established technique called the "handling paradigm," in which very young rat pups are removed from their mother's cage for 15 minutes and then returned. "As soon as they're returned, she checks them out vigorously," grooming the pups and cleaning them, Bilbo said. For a control group, another set of pups were never removed. Some of them had more attentive mothers than others, just by natural variation.
The animals then were put through a test called the "place preference chamber," a two-roomed cage in which they would be given a dose of morphine if they entered one side, or a dose of saline on the other. Over the next four weeks, the rats were returned to the two-sided chamber three times a week for five minutes, but were never given another dose of morphine. Initially, they all showed a preference for the morphine side, but over time, the handled rats showed little preference, which indicated their craving had been "extinguished," Bilbo said.
About 8 weeks after their first exposure to morphine, the animals were each given a very small dose of morphine to prime craving and then returned to the 2-sided chamber. The non-handled control rats preferred spending time in the morphine chamber; the handled rats still showed no clear preference.
Morphine activates the glial cells of the brain to produce inflammatory molecules which signal a reward center of the brain called the nucleus accumbens. But IL-10 works against that inflammation and reward. The more IL-10 the brain produces, the less likely morphine would cause an increase in craving or relapse weeks after the initial experience with the drug.
The brains of the rat pups who experienced high-touch mothering were found to have more active genes for producing IL-10 in the microglial cells of the brain, which apparently "completely knocked out this drug-seeking behavior," Bilbo said. They were producing about four times as much IL-10 as the control animals. "The nurturing moms can profoundly change outcomes," Bilbo said.
This is a change not of the genes themselves, but of the way they are controlled by something called methylation, which can keep a gene's activity suppressed. High-touch mothering removed methylation on the IL-10 gene, making these rats produce more of the anti-inflammatory molecule.
To further prove that IL-10 levels were key to the craving, the researchers used a drug called ibudilast to artificially increase IL-10 production in a group of control rats. These rats experience craving extinction much the same as the high-touch rats.
It's important to note that the genetic modification created by the mothering didn't change the initial rewarding effect of the morphine, it altered the craving for that reward much later, Bilbo said.
Bilbo said her team next wants to look at the long-term effects of maternal stress on the brain's immune response. They'll be working with the Children's Environmental Health Initiative at Duke, which examines real-world environmental health effects in Durham, NC in collaboration with the US Environmental Protection Agency.
More information: "Early-Life Experience Decreases Drug-Induced Reinstatement of Morphine CPP in Adulthood via Microglial-Specific Epigenetic Programming of Anti-Inflammatory IL-10 Expression," Jaclyn M. Schwarz, Mark R. Hutchinson and Staci D. Bilbo. The Journal of Neuroscience, Dec. 6, 2011. DOI -10.1523/JNEUROSCI.3297-11.2011
Provided by
Duke University
-
Source found for immune system effects on learning, memory
Oct 26, 2011 |
not rated yet |
0
-
The biggest loser: Maternal obesity puts a load on her offspring that lasts a lifetime
Feb 09, 2010 |
not rated yet |
0
-
New medication more potent, longer lasting than morphine
Jan 04, 2011 |
not rated yet |
0
-
Study first to confirm long-term benefits of morphine treatment in infants
Nov 03, 2008 |
not rated yet |
0
-
A safer, more effective morphine may be possible with IU discovery
Mar 24, 2011 |
not rated yet |
0
-
Motion perception revisited: High Phi effect challenges established motion perception assumptions
Apr 23, 2013 |
3 / 5 (2) |
2
-
Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update)
Apr 02, 2013 |
4.5 / 5 (11) |
5
-
The visual system as economist: Neural resource allocation in visual adaptation
Mar 30, 2013 |
5 / 5 (2) |
9
-
Separate lives: Neuronal and organismal lifespans decoupled
Mar 27, 2013 |
4.9 / 5 (8) |
0
-
Sizing things up: The evolutionary neurobiology of scale invariance
Feb 28, 2013 |
4.8 / 5 (10) |
14
-
Why is zone 1 in liver more prone to ischemic injury?
15 hours ago
-
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013
-
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013
-
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013
-
If you became brain-dead, would you want them to pull the plug?
May 17, 2013
-
MRI bill question
May 15, 2013
- More from Physics Forums - Medical Sciences
More news stories
Controlling mood through the motions of mitochondria
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
Neuroscience
1 hour ago |
4 / 5 (1) |
0
|
Brain uses internal 'average voice' prototype to identify who is talking
(Medical Xpress)—The human brain is able to identify individuals' voices by comparing them against an internal 'average voice' prototype, according to neuroscientists.
Neuroscience
5 hours ago |
1 / 5 (1) |
0
|
Depression common among children with temporal lobe epilepsy
A new study determined that children and adolescents with seizures involving the temporal lobe are likely to have clinically significant behavioral problems and psychiatric illness, especially depression. Findings published ...
Neuroscience
5 hours ago |
not rated yet |
0
The secret lives, and deaths, of neurons
As the human body fine-tunes its neurological wiring, nerve cells often must fix a faulty connection by amputating an axon—the "business end" of the neuron that sends electrical impulses to tissues or other ...
Neuroscience
7 hours ago |
5 / 5 (2) |
0
|
Regenerating spinal cord fibers may be treatment for stroke-related disabilities
A study by researchers at Henry Ford Hospital found "substantial evidence" that a regenerative process involving damaged nerve fibers in the spinal cord could hold the key to better functional recovery by most stroke victims.
Neuroscience
7 hours ago |
not rated yet |
0
|
Statin use is linked to increased risk of developing diabetes, warn researchers
Treatment with high potency statins (especially atorvastatin and simvastatin) may increase the risk of developing diabetes, suggests a paper published today in BMJ.
Consumers largely underestimating calorie content of fast food
People eating at fast food restaurants largely underestimate the calorie content of meals, especially large ones, according to a paper published today in BMJ.
Dual-source cardiac CT IDs CAD in hard-to-image patients
(HealthDay)—In patients who have previously been considered difficult to image, dual-source cardiac (DSC) computed tomography (CT) can identify clinically significant coronary artery disease, according ...
WHO: Scientific red tape mars efforts vs. virus
International efforts to combat a new pneumonia-like virus that has now killed 22 people are being slowed by unclear rules and competition for the potentially profitable rights to disease samples, the head ...
Future doctors unaware of their obesity bias
Two out of five medical students have an unconscious bias against obese people, according to a new study by researchers at Wake Forest Baptist Medical Center. The study is published online ahead of print in the Journal of ...
When oxygen is short, EGFR prevents maturation of cancer-fighting miRNAs
Even while being dragged to its destruction inside a cell, a cancer-promoting growth factor receptor fires away, sending signals that thwart the development of tumor-suppressing microRNAs (miRNAs) before it's dissolved, researchers ...