Molecules that Could Erase or Restore Memory

A picture of the past, a memory of a nice afternoon, sitting on the grass doing homework with someone you love. An image or a movie takes up space on a computer's hard drive, so what causes the reactions to store these memories in our mind? Let's take a look at a couple of recently discovered molecules that might be able to impact human memory in the coming decades. 

Our Understanding of Memory is still in its Infancy

Memories form because of interactions between several parts of the brain, with learning arising from the changes in neuron synapses. 

We are still in the infancy of knowing exactly how a memory is formed and subsequently altered, with most conclusions coming from trial and error observations involving hormones.

For example, injections of cortisol, a steroid hormone released by the adrenal gland in response to stress, and adrenaline into subjects have been shown to increase the retention of short term memory.

Long-term stress situations, however, which would allow for streams of cortisol to be present, have be shown to hamper short term memory (with this showing that there is a delicate chemical balance in place to separate remembering and forgetting). 

Additional work has looked at cell signaling and neurotransmitters, like dopamine, and what regions of the brain are populated by specific neurotransmitters.

Protecting our Memories

 

Using the small molecule P7C3, first mentioned in the journal article Discovery of a Pro-neurogenic, Neuroprotective Chemical, is a possibly way in which to aid in restoring memories. P7C3, due to its neuroprotective properties, could be used to ward off the later stages of Alzheimer's by aiding in the branching of neurons and protecting neurons from being degraded.

Exactly how P7C3 works, however, is not known. P7C3 and a more potent analogue, were discovered through a screen of over 1,000 individual molecules through in vivo assays. This is quite the "shotgun" approach, throwing a lot of previously synthesized molecules at a problem and seeing if any work. This is a common method used in drug discovery, and also shows that there is no "one" good way to design a memory enhancing molecule. Yet.

Can we Erase Bad Memories?

 

When the amount of the large molecule CaMKII (to give an idea of scale of CaMKII, it is about one thousand times larger than cortisol or P7C3) is spiked within in the brain of a mouse, the recall of a short term memory associated with fear decreases. 

That's according to research reported in the journal article Inducible and Selective Erasure of Memories in the Mouse Brain via Chemical-Genetic Manipulation

However, as with stress induced cortisol release, too much CaMKII can lead to the impaired ability to recall memories, and extending past cortisol, the erasure of new and fear-induced memories specifically without harming other memories.

 These experiments were only performed in mice, so implementation in humans might be years away or not possible at all, but it gives hope for research looking to radically change the memories on an individual for positive reasons.

CaMKII is also for sale as a reagent, increasing the accessibility and thus ease of research. It's not cheap, however, and if you do try to use it, it's not likely to be administered properly, so don't run out and buy it to black out your memories of the monsters that did live under your bed.

CaMKII release has recently been shown to be extremely specific and activated in the formation of dendritic spines, lending insight into how the molecule behaves and putting a bit of theory behind the molecule's ability to significantly alter neurochemistry enough to block memories.

If you play with your memories, are you changing who you are?

 

Would you want to erase a bad memory? In situations of physical abuse or harm, yeah, more than likely. But what about that test you failed or your first break-up? That time you drove home with the lights on in your car after watching a scary movie? These are the moments that help make us who we are, and in sum, condition us to change our decision-making in the future.

 So before we go around erasing memories, we probably want to make sure we are erasing the right types. For example, if all memories of a certain type (like those pertaining to fear) were erased, we would probably have to spend time acclimating ourselves to our environment and possibly remembering why we don't put our hand on a hot stove. Further research to help us learn the mechanism for how the molecules work couldn't hurt either.

by "environment clean generations"

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Posted in: biology,brain,dendritic spines,humans,mechanism,molecule,Molecules that Could Erase or Restore Memory,neuron synapses,neurons,neurotransmitters,reaction

Can Plants Think?

In a new study, scientists have found a cabbage relative capable of remembering and responding to information. The Persistence Of Memory A Polish study showed plants send electrochemical signals in a way that can be likened to an animal nervous system. This image shows chemical reactions in leaves that were not exposed to light; they are reacting to a chemical signal from a leaf that was exposed.

Plants are able to remember information and react to it, thanks to an internal communications system that can be likened to a central nervous system in animals, according to a new study by a Polish plant biologist.

Plants "remember" information about light, and a certain type of cell transmits that information, much like nerves do in animals. 

In the study, which was published in the early online version of the journal Plant Cell July 16, the researchers found that light shone on one leaf of an Arabidopsis thaliana plant caused the whole plant to respond.

The response lasted even after the light source was taken away, suggesting the plant remembered the light input.

"The signaling continiues after the light is off; it is building short-term memory," said the lead author, Stanislaw Karpinski, in an e-mail message. "The leaves are able to physiologically 'memorize' different excess light episodes and use this stored information, for example, for improving their acclimation and immune defenses."

The leaves remember light quality as well as quantity, Karpinski added -- different wavelengths of light produce a different response, suggesting the plants use the information to generate protective chemical reactions like pathogen defense or food production.

 Scientists found that light shining on a leaf cell triggered a cascade of events that was immediately signaled to the rest of the plant via a type of cell called a bundle sheath cell. Those cells exist in every part of a plant. Karpinski, of the Warsaw University of Life Sciences in Poland, measured the electrical signals from those cells, and compared it to finding a central nervous system for plants.

Terence Murphy, a plant biology professor at the University of California-Davis who was not involved in the research, said shining light on that first leaf could have any number of effects. 

"The leaf would be loaded up with starch, maybe; that's going to have a real effect on how it communicates through the phloem (vascular system) to other leaves. It's not unreasonable that you could illuminate one leaf and affect the other leaves," he said. 

The trick is finding out how the other leaves are informed -- and that's what appears to have been done in the Polish study. Bundle sheath cells surround the veins in leaves, stems and roots, so it's reasonable to think they transmit the electrical impulse, Murphy said.

Biologists have long known that plants can remember -- they need to know whether they've gone through a cold season before they can germinate in the spring, for instance. It's not memory as we know it, but a prolonged change in plant internal systems that causes effects later.

What's more, scientists already know plants transmit electrical signals in response to a stimulus, just as nerves do. This is easily measured using a basic electrode setup, according to Murphy. 

Karpinski said the light memory represents a new way for plants to respond to pathogens or disease -- normally, they respond by direct contact with an invader. 

"This information would not be a revelation untill we find that plant leaves can remember it for several days and process this memorized information to (bolster) their defense mechanisms against seasonal diseases," he wrote.

 

Karpinski is well-known among plant biologists for earlier work on how plants respond to light stress. In a previous study, he also showed chemical signals can be passed throughout whole plants, allowing them to respond to and survive environmental changes. Understanding the mechanisms that cause those signals is a new step, however.

William John Lucas, distinguished professor of plant biology at UC-Davis and chair of the plant biology department, said an internal communication system would provide a wealth of information to different parts of the plant.

"A particular tissue within a plant needs to be able to signal to the rest of the plant in terms of what are its conditions, what should you expect," he said. "If a young leaf is emerging out of a plant, it would be nice for that leaf to know about the conditions in which it is going to emerge."

Lucas studies how plants pick up non-biological information, such as water and light, and how they transmit that information so the entire plant knows under which constraints it will grow. Plants can't move to a sunnier, wetter spot, so they need to make the most of their environment. 

Tapping into their "nervous system" would help scientists understand how they do that, Lucas said. That knowledge could lead to optimized food crops or hardier trees.

"There are no neurons in plants, but there is a communication network that we don't fully understand," he said. "There are important implications for these kinds of studies."

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Posted in: biology,leaves,memory,neurons,plants,think

Computerized brains

                       

                     In a scientific experiment, researchers led by University of Wisconsin-Madison, USA, samples of nerve cells in the process of training, harvested from mice, and were developed to explore the ramifications of semiconductor nano-tubes specifically designed to form a true cross network. 

                    The discovery of the expansive  cerebrospinal cells may stimulate new research methods to neurological disorders. Moreover, further studies could lead to the development of brain-computer interfaces, capable of integrating directly, for example, any kind of prosthesis in the body.

          
                   

           To determine the initial phase of nervo-electronic hybridization, scientists  Justin Williams and Minrui Yu, assisted by colleagues, have created layered tubes of silicon and germanium, materials able to isolate the electrical signals transmitted from one nerve cell. Nanotubes had different shapes and sizes, large enough neuronal so that extensions to make room in them, but too small to allow proper access of the body of any nerve cells. 

          

          When young neural samples were placed  at the entrance of such "tunnels", they began to explore by stretching the tentacles into the tubes, whether straight or winding. At this stage of research, scientists have found that nerve cells are capable and determined to explore biological environments that seem friendly, and their excrescences will follow the network route to physically interconnect .

           However, it became unclear yet if the nerves communicate with each other, sending signals as a functioning body. Future experiments will bring on stage photovoltaic sensors and other devices to allow researchers to better monitor nerve cells. 

           Limited space of small tunnels will be a good environment for measurement, allowing, perhaps, scientists studying the way nerve cells respond to some drugs, or to compare the behavior of healthy neurons to that of abnormal neurons, typical of patients suffering multiple sclerosis or Parkinson's. 

          And the supreme achievement, researchers believe, would be widely entwining of living cells with the technology, bio-engineering and neuroscientific methods that even scholars considered them difficult and hazardous. 

            

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Posted in: nano-tubes,nerve cells,neurons