Featured Research

from universities, journals, and other organizations

Infant Pain, Adult Repercussions: How Infant Pain Changes Sensitivity In Adults

Date:
September 28, 2009
Source:
Georgia State University
Summary:
Scientists have uncovered the mechanisms of how pain in infancy alters how the brain processes pain in adulthood. Research is now indicating that infants who spent time in the neonatal intensive care unit show altered pain sensitivity in adolescence. These results have profound implications and highlight the need for pre-emptive and post-operative pain medicine for newborn infants.

A premature infant in a neonatal intensive care unit.
Credit: iStockphoto/Alison Hausmann

Scientists at Georgia State University have uncovered the mechanisms of how pain in infancy alters how the brain processes pain in adulthood.

Related Articles


Research is now indicating that infants who spent time in the neonatal intensive care unit (NICU) show altered pain sensitivity in adolescence. These results have profound implications and highlight the need for pre-emptive and post-operative pain medicine for newborn infants.

The study, published online in the journal Frontiers in Behavioral Neuroscience, sheds light on how the mechanisms of pain are altered after infant injury in a region of the brain called the periaqueductal gray, which is involved in the perception of pain.

Using Sprague-Dawley rats, Jamie LaPrairie, a graduate student in associate professor Anne Murphy's laboratory, examined why the brief experience of pain at the time of birth permanently decreased pain sensitivity in adulthood.

Endogenous opioid peptides, such as beta-endorphin and enkephalin, function to inhibit pain. They're also the 'feel good' substances that are released following high levels of exercise or love. Since these peptides are released following injury and act like morphine to dampen the experience of pain, LaPrairie and Murphy tested to see if the rats, who were injured at birth, had unusually high levels of endogenous opioids in adulthood.

To test this hypothesis, LaPrairie and Murphy gave adult animals that were injured at the time of birth a drug called naloxone. This drug blocks the actions of endogenous opioids. After animals received an injection of naloxone, they behaved just like an uninjured animal.

The scientists then focused on the periaqueductal gray region to see if inflammation at birth altered the natural opioid protein expression in this brain region. Using a variety of anatomical techniques, the investigators showed that animals that were injured at birth had endogenous opioid levels that were two times higher than normal.

While it's beneficial to decrease pain sensitivity in some cases, it's not good to be completely resilient to pain.

"Pain is a warning sign that something is wrong," Murphy explained. "For example, if your hand is in water that's too hot, pain warns you to remove it before tissue damage occurs."

Interestingly, while there is an increase in endorphin and enkephalin proteins in adults, there is also a big decrease in the availability of mu and delta opioid receptors. These receptors are necessary in order for pain medications, such as morphine, to work. This means that it takes more pain-relieving medications in order to provide relief as there are fewer available receptors in the brain. Studies in humans are reporting the same phenomenon.

The number of invasive procedures an infant experienced in the NICU is negatively correlated with how responsive the child is to morphine later in life; the more painful procedures an infant experienced, the less effective morphine is in alleviating pain.

The study by LaPrairie and Murphy has major implications for the treatment of infants in neonatal intensive care. On average, a prematurely born infant in a neonatal intensive care unit will experience 14 to 21 invasive procedures a day, including heel lance, insertion of intravenous lines, and intubation. All of these procedures are quite painful and are routinely conducted without prior analgesics or anesthetics.

"It's imperative that pain be treated," Murphy said. "We once assumed that a newborn infant is insensitive to pain, and this is clearly not the case. Even at that period of time, the central nervous system is able to respond to pain, and our studies show that the experience of pain completely changes the wiring of the brain in adulthood."

The next steps in Murphy's research include the study of how neonatal injury at birth alters stress responses, as well as the affects of infant injury on long-term learning and memory.

LaPrairie's and Murphy's work was supported by the National Institutes of Health, the Center for Behavioral neuroscience, a consortium of seven universities at Georgia State, and the Georgia State Brains and Behavior Program.

The article, titled "Neonatal injury alters adult pain sensitivity by increasing opioid tone in the periaqueductal gray," appears in the September 2009 edition of journal Frontiers in Behavioral Neuroscience, Vol. 3, p. 1-11.


Story Source:

The above story is based on materials provided by Georgia State University. Note: Materials may be edited for content and length.


Cite This Page:

Georgia State University. "Infant Pain, Adult Repercussions: How Infant Pain Changes Sensitivity In Adults." ScienceDaily. ScienceDaily, 28 September 2009. <www.sciencedaily.com/releases/2009/09/090927130048.htm>.
Georgia State University. (2009, September 28). Infant Pain, Adult Repercussions: How Infant Pain Changes Sensitivity In Adults. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2009/09/090927130048.htm
Georgia State University. "Infant Pain, Adult Repercussions: How Infant Pain Changes Sensitivity In Adults." ScienceDaily. www.sciencedaily.com/releases/2009/09/090927130048.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC: Get Vaccinated for Measles

CDC: Get Vaccinated for Measles

Reuters - US Online Video (Jan. 30, 2015) The CDC is urging people to get vaccinated for measles amid an outbreak that began at Disneyland and has now infected more than 90 people. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Obama To Outline New Plan For Personalized Medicine

Obama To Outline New Plan For Personalized Medicine

Newsy (Jan. 30, 2015) President Obama is expected to speak with drugmakers Friday about his Precision Medicine Initiative first introduced last week. Video provided by Newsy
Powered by NewsLook.com
NFL Concussions Down; Still on Parents' Minds

NFL Concussions Down; Still on Parents' Minds

AP (Jan. 30, 2015) The NFL announced this week that the number of game concussions dropped by a quarter over last season. Still, the dangers of the sport still weigh on players, and parents&apos; minds. (Jan. 30) Video provided by AP
Powered by NewsLook.com
U.S. Wants to Analyze DNA from 1 Million People

U.S. Wants to Analyze DNA from 1 Million People

Reuters - US Online Video (Jan. 30, 2015) The U.S. has proposed analyzing genetic information from more than 1 million American volunteers to learn how genetic variants affect health and disease. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins