New York University study: Infantile memory study points to critical periods in early-life learning for brain development

19 Jul

Prolonged stress can have adverse effects on humans. Moi wrote about the Adverse Childhood Experiences Study in Study: Some of the effects of adverse stress do not go away:

Sarah D. Sparks writes in the Education Week article, Research Traces Impacts of Childhood Adversity:

Research from Dr. Shonkoff’s center and from other experts finds that positive stress—the kind that comes from telling a toddler he can’t have a cookie or a teenager that she’s about to take a pop quiz—causes a brief rise in heart rate and stress hormones. A jolt can focus a student’s attention and is generally considered healthy.

Similarly, a child can tolerate stress that is severe but may be relatively short-term—from the death of a loved one, for example—as long as he or she has support….

‘Toxic’ Recipe

By contrast, so-called “toxic stress” is severe, sustained, and not buffered by supportive relationships.

The same brain flexibility, called plasticity, that makes children open to learning in their early years also makes them particularly vulnerable to damage from the toxic stressors that often accompany poverty: high mobility and homelessness; hunger and food instability; parents who are in jail or absent; domestic violence; drug abuse; and other problems, according to Pat Levitt, a developmental neuroscientist at the University of Southern California and the director of the Keck School of Medicine Center on the Developing Child in Los Angeles…. http://www.edweek.org/ew/articles/2012/11/07/11poverty_ep.h32.html?tkn=QLYF5qldyT3U0BI0xqtD5885mihZIxwbX4qZ&cmp=clp-edweek

Here is information about the Adverse Child Experiences Study. The Centers for Disease Control and Prevention provides access to the peer-reviewed publications resulting from The ACE Study. http://acestudy.org/

https://drwilda.com/2012/11/09/study-some-of-the-effects-of-adverse-stress-do-not-go-away/

Science Daily reported in Infantile memory study points to critical periods in early-life learning for brain development:

A new study on infantile memory formation in rats points to the importance of critical periods in early-life learning on functional development of the brain. The research, conducted by scientists at New York University’s Center for Neural Science, reveals the significance of learning experiences over the first two to four years of human life; this is when memories are believed to be quickly forgotten — a phenomenon known as infantile amnesia.

“What our findings tell us is that children’s brains need to get enough and healthy activation even before they enter pre-school,” explains Cristina Alberini, a professor in NYU’s Center for Neural Science, who led the study. “Without this, the neurological system runs the risk of not properly developing learning and memory functions…”

In their study, which appears in the journal Nature Neuroscience, the researchers examined the mechanisms of infantile memory in rats — i.e., memories created 17 days after birth. This is the equivalent of humans under the age of three and when memories of who, what, when, and where — known as episodic memories — are rapidly forgotten. The phenomenon, referred as to “infantile or childhood amnesia,” is in fact the inability of adults to retrieve episodic memories that took place during the first two to four years of life.

In addressing this matter, Alberini and her colleagues compared rats’ infantile memory with that when they reached 24 days old — that is, when they are capable of forming and retaining long-term memories and at an age that roughly corresponds to humans at six to nine years old.

The episodic memory tested in the rodents was the memory of an aversive experience: a mild foot shock received upon entering in a new place. Adult rats, like humans, remember unpleasant or painful experiences that they had in specific places, and then avoid returning to them.

To do so, rodents were placed in a box divided into two compartments: a “safe” compartment and a “shock” compartment. During the experiment, each rat was placed in the safe compartment with its head facing away from the door. After 10 seconds, the door separating the compartments was automatically opened, allowing the rat access to the shock compartment. If the rat entered the shock compartment, it received a mild foot shock.

The first set of results was not surprising. The authors found infantile amnesia for the 17 day-old rats, which showed avoidance of the “shock” compartment right after the experience, but lost this memory very rapidly: a day later these rats quickly returned to this compartment. In contrast, the rats exposed to the shock compartment at 24 days of life learned and retained the memory for a long time and avoided this place — revealing a memory similar to that of adult rats.

However, remarkably, the younger rats, which had apparently forgotten the initial experience, subsequently showed they actually had kept a trace of the memory. When, later in life, these rats were prompted with reminders — i.e., they were presented with recollections of the context and the foot shock — they indicated having a specific memory, which was revealed by their avoidance of the specific context in which they received a shock at day 17 of life. These findings show how early life experience, although not expressed or remembered, can influence adult life behavior.

The findings raised the following question: what is occurring — neurologically — that explains why memories are retained by the younger rats only in a latent form but are stored and expressed long-term by older ones? Or, more specifically, what occurs during development that enhances the ability to form lasting memories?

A critical period is a developmental stage during which the nervous system is especially sensitive to environmental stimuli. If, during this period, the organism does not receive the appropriate stimuli required to develop a given function, it may be difficult or even impossible to develop that function later in life. Well-known examples of critical period-based functions are sensory functions, like vision, and language acquisition.

The study shows that there is a critical period for episodic learning and that during this period the hippocampus learns to become able to efficiently process and store memories long-term…                               https://www.sciencedaily.com/releases/2016/07/160718111939.htm

Citation:

Infantile memory study points to critical periods in early-life learning for brain development

Date:         July 18, 2016

Source:      New York University

Summary:

A new study on infantile memory formation in rats points to the importance of critical periods in early-life learning on functional development of the brain. The research reveals the significance of learning experiences over the first two to four years of human life.

Journal Reference:

  1. Alessio Travaglia, Reto Bisaz, Eric S Sweet, Robert D Blitzer, Cristina M Alberini. Infantile amnesia reflects a developmental critical period for hippocampal learning. Nature Neuroscience, 2016; DOI: 10.1038/nn.4348

Here is the press release from New York University:

Infantile Memory Study Points to Critical Periods in Early-Life Learning for Brain Development

July 18, 2016

A new study on infantile memory formation in rats points to the importance of critical periods in early-life learning on functional development of the brain. The research, conducted by scientists at New York University’s Center for Neural Science, reveals the significance of learning experiences over the first two to four years of human life; this is when memories are believed to be quickly forgotten—a phenomenon known as infantile amnesia.

“What our findings tell us is that children’s brains need to get enough and healthy activation even before they enter pre-school,” explains Cristina Alberini, a professor in NYU’s Center for Neural Science, who led the study. “Without this, the neurological system runs the risk of not properly developing learning and memory functions.”

The other authors of the study, conducted in collaboration with the Icahn School of Medicine at Mt. Sinai, included: Alessio Travaglia, a post-doctoral researcher at NYU; Reto Bisaz, an NYU research scientist at the time of the study; Eric Sweet, a post-doctoral fellow at the Icahn School of Medicine at Mt. Sinai; and Robert Blitzer, a professor at the Icahn School of Medicine at Mt. Sinai.

In their study, which appears in the journal Nature Neuroscience, the researchers examined the mechanisms of infantile memory in rats—i.e., memories created 17 days after birth. This is the equivalent of humans under the age of three and when memories of who, what, when, and where–known as episodic memories–are rapidly forgotten. The phenomenon, referred as to “infantile or childhood amnesia,” is in fact the inability of adults to retrieve episodic memories that took place during the first two to four years of life.

In addressing this matter, Alberini and her colleagues compared rats’ infantile memory with that when they reached 24 days old—that is, when they are capable of forming and retaining long-term memories and at an age that roughly corresponds to humans at six to nine years old.

The episodic memory tested in the rodents was the memory of an aversive experience: a mild foot shock received upon entering in a new place. Adult rats, like humans, remember unpleasant or painful experiences that they had in specific places, and then avoid returning to them.

To do so, rodents were placed in a box divided into two compartments: a “safe” compartment and a “shock” compartment. During the experiment, each rat was placed in the safe compartment with its head facing away from the door. After 10 seconds, the door separating the compartments was automatically opened, allowing the rat access to the shock compartment. If the rat entered the shock compartment, it received a mild foot shock.

The first set of results was not surprising. The authors found infantile amnesia for the 17 day-old rats, which showed avoidance of the “shock” compartment right after the experience, but lost this memory very rapidly: a day later these rats quickly returned to this compartment. In contrast, the rats exposed to the shock compartment at 24 days of life learned and retained the memory for a long time and avoided this place—revealing a memory similar to that of adult rats.

However, remarkably, the younger rats, which had apparently forgotten the initial experience, subsequently showed they actually had kept a trace of the memory. When, later in life, these rats were prompted with reminders—i.e., they were presented with recollections of the context and the foot shock—they indicated having a specific memory, which was revealed by their avoidance of the specific context in which they received a shock at day 17 of life. These findings show how early life experience, although not expressed or remembered, can influence adult life behavior.

The findings raised the following question: what is occurring—neurologically—that explains why memories are retained by the younger rats only in a latent form but are stored and expressed long-term by older ones? Or, more specifically, what occurs during development that enhances the ability to form lasting memories?

To address this, the scientists focused on the brain’s hippocampus, which previous scholarship has shown is necessary for encoding new episodic memories. Here, in a series of experiments similar to the box tests, they found that if the hippocampus was inactive, the ability of younger rats to form latent memories and recall them later by reminders as they got older was diminished. They then found that mechanisms of “critical periods” are fundamental for establishing these infantile memories.

A critical period is a developmental stage during which the nervous system is especially sensitive to environmental stimuli. If, during this period, the organism does not receive the appropriate stimuli required to develop a given function, it may be difficult or even impossible to develop that function later in life. Well-known examples of critical period-based functions are sensory functions, like vision, and language acquisition.

The study shows that there is a critical period for episodic learning and that during this period the hippocampus learns to become able to efficiently process and store memories long-term.

“Early in life, while the brain cannot efficiently form long-term memories, it is ‘learning’ how to do so, making it possible to establish the abilities to memorize long-term,” explains Alberini. “However, the brain needs stimulation through learning so that it can get in the practice of memory formation—without these experiences, the ability of the neurological system to learn will be impaired.”

These studies, the researchers observe, suggest that using learning and environmental interventions during a critical period may significantly help to address learning disabilities.

The research was supported, in part, by grants from the National Institute of Mental Health (R01-MH074736, R01-NS072359), part of the National Institutes of Health, and the Geneva-based Agalma Foundation.

This Press Release is in the following Topics:
Research, Arts and Science, Faculty

Type: Press Release

Press Contact: James Devitt | (212) 998-6808

Our goal as a society should be:

A healthy child in a healthy family who attends a healthy school in a healthy neighborhood ©

Resources:

The Effects of Stress on Your Body                                                                       http://www.webmd.com/mental-health/effects-of-stress-on-your-body

The Physical Effects of Long-Term Stress                                                              http://psychcentral.com/lib/2007/the-physical-effects-of-long-term-stress/all/1/

Chronic Stress: The Body Connection                                                      http://www.medicinenet.com/script/main/art.asp?articlekey=53737

Understanding Stress Symptoms, Signs, Causes, and Effects                     http://www.helpguide.org/mental/stress_signs.htm

Dr. Wilda says this about that ©

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COMMENTS FROM AN OLD FART ©                                                http://drwildaoldfart.wordpress.com/

Dr. Wilda Reviews ©                                                                         http://drwildareviews.wordpress.com/

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