Experts have long suspected that part of the process of turning fleeting short-term memories into lasting long-term memories occurs during sleep. Now, researchers at the RIKEN-MIT Center for Neural Circuit Genetics of MIT’s Picower Institute for Learning and Memory have shown that mice prevented from “replaying” their waking experiences while asleep do not remember them as well as mice who are able to perform this function.

The work, which has a profound implication in the century-old search for the purpose of sleep, will be reported in the June 25 issue of Neuron.

It is widely believed that memories of events and spaces are stored briefly in the hippocampus before they are consolidated in the neocortex for permanent storage. The seahorse-shaped hippocampus is thought to play a key role in learning and memory, but the precise circuits and mechanisms involved are not well understood.

“Our work demonstrates the molecular link between post-experience sleep and the establishment of long-term memory of that experience,” said Susumu Tonegawa, the Picower Professor of Biology and Neuroscience at MIT and lead author of the study. “Ours is the first study to demonstrate this link between memory replay and memory consolidation. The sleeping brain must replay experiences like video clips before they are transformed from short-term into long-term memories.”

The researchers looked at a circuit within the hippocampus known as the trisynaptic pathway, in which neuronal information passes through the hippocampus’ three main substructures before moving on. “We demonstrated that this pathway is crucial for the transformation of a recent memory, formed within a day, to a remote memory that still exists at least six weeks later,” Tonegawa said.

Creating a strain of engineered mice in which a change of diet shuts down trisynaptic circuits, the researchers implanted electrodes that monitored the activities of the animals’ hippocampal cells as the animals ran a maze and then slept.

Not-so-instant replay

While they were still awake and running, the mice formed within their brains a pattern of place cells, or neurons that were firing in recognition of the maze the mice had learned to negotiate. During their post-run sleep, particularly during a deep sleep phase called slow-wave, the specific sequence of place cells that fired during the run was “replayed” in a similar sequence.

In human studies testing the role of slow-wave sleep in memory consolidation, the group that napped after memorizing word pairs such as “fruit-banana” and “tool-pliers,” was able to recall a greater number of word pairs than those who did not nap.

This replay during sleep had been speculated, but has never been demonstrated, to be important for converting the recent memory stored in the hippocampus to a more permanent memory stored in the neocortex. “We have demonstrated that in the mutant mice in which the trisynaptic pathway is blocked, this replay process during the slow-wave sleep is impaired,” Tonegawa said. The animals were able to form long-term memories of the maze only when their trisynaptic pathways were functioning after the formation of the short-term memory.

“Our conclusion is that the trisynaptic pathway-mediated replay of the hippocampal memory sequence during sleep plays a crucial role in the formation of a long-term memory,” he said.

In addition to Tonegawa, authors are Picower Institute research scientist Toshiaki Nakashiba, Picower Institute postdoctoral associate Derek L. Buhl and Picower Institute research scientist Thomas J. McHugh.

This work was supported by the National Institutes of Health and Otsuka Pharmaceutical Development & Commercialization Inc. based in Tokyo.

Written by Deborah Halber, Picower Institute

Source
MIT

Snoring is not an isolated problem but affects the whole family with the constant interruptions throughout the night. Research has shown that in today’s world, snoring has become a reason for relationships to break, divorce and is known to be a reason for accidents on the road and at work. It also contributes to various health problems both to the snorer and the bed partner due to interrupted sleep through out the night on a regular basis. With years of constant snoring, you are more at risk of heart diseases, strokes, hypertension and complications with diabetes. While secondary diseases like depression, low concentration and other mental challenges crop up slowly with constant snoring.

The person who sleeps next to the snorer is also not spared as they suffer from sleep interruptions also. The snorer may be snoring due to throat infections, asthma and even enlarged tonsils can sometimes lead to snoring. In most cases, snoring is caused by obstructed breathing due to weak muscles of the throat and jaws.

If you have think snoring an issue of jokes, think again as it can lead to sleep apnea, a leading cause of deaths all over the world. Sleep apnea is a fatal disease that heavy snorers develop with time that is marked with pauses in breathing for about 10 seconds. The sad part is that the person sleeping with the snorer ends up with numerous issues related to sleep deprivation. Low concentration, alertness, drowsiness leads to poor efficiency and accidents at work. Apart from that chronic snoring leads to deterioration of a normal life and adversely affects marriages. One of the main reasons in most breakups in relationships is the irritating snoring noises and lack of intimacy therewith.

Most couples start with ear plugs or go to bed earlier that the snoring partner but this usually does not work for long especially with heavy snorers. For husbands and wives who suffer with a snoring spouse start looking for some respite over time. Shifting to another bedroom is a common occurrence to avoid sleep deprivation which takes away spontaneous intimacy and physical touch. Generally problems start with small fights that are based on irritability from not sleeping properly, but start affecting the relationship with time.

If you think your relationship or marriage is breaking down due to the factors such as irritability, squabbles, or lack of intimacy due to separate bedrooms, it is time to look for anti snoring methods. You don’t need to go in for expensive surgeries or long term methods to stop snoring but over the counter stop snoring treatments are known to work effectively. Out of the innumerable anti snoring methods available, you can check which one suits your condition the most. The best part is chin straps, nasal strips, throat and nose sprays work well in most cases. To save a relationship, costs does not matter but still a little less helps to keep your pocket filled. Start today and find a way to get your relationship on track again.

Fighting Insomnia with Sleeping Aids

Due to many people around the world suffering from insomnia, there has been a great deal of research and studies. There are different forms of sleeping problems that affect people but there are now numerous aids that can help them. A certain amount of people suffer from short term insomnia whereas a number of individuals suffer from what is known as chronic insomnia.

Consider how you feel if you wake up early or without having a full nights sleep. It is very common to feel cranky or uncomfortable and the feeling can last all day. For most people, this is not a lasting occurrence and is usually rectified by a sound sleep at night. Some people are not so lucky though. Many people are experiencing this situation each and every day of their life.

Knowing that you are never able to get enough sleep that your body craves or desires can start to have an extremely negative affect on a person. They will always be feeling lethargic or not up to their best. They will dread trying to get to sleep every night and this anxiety will only make matters worse. A problem for many people with insomnia is that a cyclical effect can occur where worrying about a lack of sleep can further cause a person to be awake all night. Suffering from insomnia is an extremely uncomfortable ailment to experience.

Both types of insomnia can have a massive impact on how a person is able to function throughout their normal life. Research on Insomnia and Sleeping Aide has shown that people need seven or eight hours of sleep each day on a regular basis to be at their optimum level. This is why there is an increasing market for sleeping aids and there are a great number of commercial products looking to take advantage of this situation.

When a person is unable to get to sleep, quite often it is to due to an imbalance in the chemicals that are active within their body. If a person has more awake chemicals than sleep chemicals active, they can find difficulty in sleeping but there are numerous aids available to make life more bearable. Using any one of the sleeping products available can ensure a person gets proper nights sleep and that they are fully charged and ready for whatever life may throw at them in the following day.

Although possibly not seen as one of the more dangerous ailments a person can suffer from, insomnia is able to change a person’s mood or happiness in a very short span of time. Having problems with sleeping can cause great difficulty for a person and this is why so many people are looking for cures or aids to alleviate the difficulties they face. A lack of proper sleep can reduce a person’s ability to concentrate or focus, making problem solving and decision making a far harder task than what it should be. Sleeping is considered to be the body’s natural way of recharging; therefore it is advisable to seek aids or assistance to ensure a proper night’s sleep. Many doctors or pharmacists would be happy to offer advice to people having difficulty with this matter.

Another problem in recognizing insomnia as a major hazard to people’s health is that a great majority of people do not consider it to be a serious ailment. Quite commonly, people may pass it off as a symptom of some other health issue they are experiencing as opposed to being a serious issue within its own right. There is a growing need for people to accept that lack of sleeping is a major issue and they require medical advice and aids to ensure they are able to overcome difficulties caused by this situation.

Many products to aid sleeping can be purchased freely over the counter and this has led to a boon in this burgeoning industry. With a lack of sleep being a major concern for a great number of individuals having a quick solution at hand has been a boon for many sufferers. With this form of medication being available over a counter, many users may consider it to be risk free. Whilst there may not be a risk level that is associated with many other more serious forms of medication, it should be noted that this medication can still cause problems.

Given that insomnia sufferers are likely to be desperate to get some sleep, they may consider an increase in dosage to be a good idea. Increasing the recommended dose levels is never a sensible idea as it can quickly lead to addiction. Addiction to over the counter forms of medication is rising sharply and catches many people unaware. There needs to be a greater level of awareness of dangers that all medicine can cause if used improperly.

Medication to cure or reduce insomnia can have an extremely positive impact on users but caution needs to be applied to its use. No matter whether it is taken in a tablet, liquid or capsule form, all forms of medication can cause addiction and if a user has any doubt they should always seek the opinion of their doctor or pharmacist.

As more and more people become aware of disadvantages in lack of sleeping and the negative impact it has on quality of life, expect this market for aids to cure insomnia to thrive. As with all ailments, if you are suffering from insomnia the same should be informed to your doctor or local medical facility. It should be their decision whether you need medication to increase your chances of falling asleep.

Research on Insomnia and Sleeping Aide