journal neuron

Intuitively, we tend to think of forgetting as failure, as something gone wrong in our ability to remember.

Now, Canadian neuroscientists with the University of Toronto are challenging that notion. In a paper published Wednesday in the journal Neuron, they review the current research into the neurobiology of forgetting and hypothesize that our brains purposefully work to forget information in order to help us live our lives.

I spoke with Blake Richards, one of the co-authors of the paper, who applies artificial intelligence theories to his study of how the brain learns. He says that in the AI world, there’s something called over-fitting — a phenomenon in which a machine stores too much information, hindering its ability to behave intelligently. He hopes that greater understanding of how our brains decide what to keep and what to forget will lead to better AI systems that are able to interact with the world and make decisions in the way that we do.

Could The Best Memory System Be One That Forgets?

Photo: Jedrzej Kaminski/EyeEm/Getty Images

Science Terms for Non-scientists

There is a huge amount of misunderstanding around common science terms. So here I am to blow away the fog! Hopefully some of you can find this useful for both everyday life and your writing.

Hypothesis: A statement made by a researcher regarding what they think is going on. Also called an “educated guess,” as in the person has the background knowledge to attempt an explanation prior to any testing. A hypothesis must be testable.

Observation: Literally what it sounds like. It is a fact of something a person sees. For example, a researcher may make an observation that the sky appeared orange at sunset or that their rat ate 24 food pellets in month. There is no thinking about it, no extrapolation, just the facts.

Law: This is a statement made following repeated experimental observation. A law is always true under a given set of conditions. They are not theories, as they do not try to explain what is going on.

Theory: This is the explanation for the repeated observations. It is supported by experimentation. Note: theories can never be proven true, only false (you can never test every single instance of the situation). You can just build evidence to support it.

The scientific method (though not always followed):

  1. A person makes an observation.
  2. The person forms a hypothesis attempting to explain the observation.
  3. The person comes up with ways to test the hypothesis.
  4. The person implements these tests.
  5. The person evaluates results and revises the hypothesis if needed.

Field: This is the sub-specialization of a scientist. For example, a biologist may be a general biologist, marine biologist, molecular biologist, cancer biologist, neuroscientist, immunobiologist, epidemiologist, ecologist, behavioral researcher, neuropsychologist, etc.

Field work: This is the type of experiment that is performed outside of the lab. For example, an ecologist may be performing evaluations of stream conditions. While they are physically at the stream, they are doing field work.

Bench work: This is work inside the lab. For example, a scientist who is actively working on something like cell culture or running a gel is doing bench work.

Science writing: This is writing with a focus on science! It may be writing scientific articles, writing protocols, evaluating and editing proposals, or writing for popular press and audiences. Yes, this is its own separate career, typically requiring a background in at least science and possibly scientific writing or journalism.

Journal: This is where scientific papers are published. Some common journals in my field are Nature and The American Journal of Medicine and Neuron. There are a lot. And some are very obscure. They are rated by this thing called “impact factor” that is supposed to relate to journal quality (better impact factor gives your research better exposure), but in my opinion is nonsense. Also, you should trust peer reviewed journals more than journals that are not peer reviewed…that means that other professionals in their field have evaluated the paper.

Principle Investigator (PI): This is the person in charge of a particular study. Often that is the person who runs the lab out of which the study comes. Their name will be last on the paper. Note: name order on papers is very important. First and last author are the important ones. If your name is in the middle, you’re not as big of a contributor unless it is noted otherwise in the journal.

EDIT: It has been pointed out in the notes that author order sometimes varies by field. So these comments on order are not always true.

I hope you found this interesting and informative! Hopefully I will be able to post a biology-specific post like this soon. :)

Happy writing!

Improving memory with magnets

The ability to remember sounds, and manipulate them in our minds, is incredibly important to our daily lives – without it we would not be able to understand a sentence, or do simple arithmetic. New research is shedding light on how sound memory works in the brain, and is even demonstrating a means to improve it.

Scientists previously knew that a neural network of the brain called the dorsal stream was responsible for aspects of auditory memory. Inside the dorsal stream were rhythmic electrical pulses called theta waves, yet the role of these waves in auditory memory were until recently a complete mystery.

Keep reading

Seeing Less Helps The Brain Hear More

A few days in the dark can improve an animal’s hearing, scientists report this week in the journal Neuron. This temporary loss of visual input seems to trigger favorable changes in areas of the brain that process auditory information, they say.

The suggests there may be a new way to help people with cochlear implants, , and disorders that make it difficult to understand speech, says , a researcher at the University of Maryland and one of the study’s authors.

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Txch This Week: Smarter Smartboards And Wireless Brain Sensors

by Jared Kershner

This week on Txchnologist, researchers looking to reveal the details of how dinosaurs move have created an advanced simulation using a chicken-like bird as their model. Moving virtual bones were then dropped in to recreate how the animal’s stride disturbs the surface it travels across. The work is providing new insights into dinosaur locomotion.

Researchers in South Korea and the U.S. may have built the smartest artificial skin yet – its texture is stretchy like human skin, and it also senses pressure, temperature and humidity. It even contains a built-in heater to mimic living tissue. The researchers have tested this new artificial skin on a prosthetic hand, and their next goal is to integrate the system with a patient’s nerves so amputees can sense what it feels.

NASA reports that its Curiosity rover has uncovered details of a large lake that existed on Mars more than 3 billion years ago. This body of water partially filled a crater called Gale near the planet’s equator, which was fed by melting snow that flowed in from its northern rim. Additionally the rover has found evidence of streams, river deltas and a history of filled and dried lakes around the crater, indicating that the area went through multiple hydrologic cycles over millions of years.

Now we’re bringing you the news and trends we’ve been following this week in the world of science, technology and innovation.

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Tau, not amyloid-beta, triggers neuronal death process in Alzheimer's

New research points to tau, not amyloid-beta (Abeta) plaque, as the seminal event that spurs neuron death in disorders such as Alzheimer’s disease. The finding, which dramatically alters the prevailing theory of Alzheimer’s development, also explains why some people with plaque build-up in their brains don’t have dementia.

The study is published online today in the journal Molecular Neurodegeneration.

Neuronal death happens when tau, found inside neurons, fails to function. Tau’s role is to provide a structure — like a train track —inside brain neurons that allows the cells to clear accumulation of unwanted and toxic proteins.

“When tau is abnormal, these proteins, which include Abeta, accumulate inside the neurons,” explains the study’s senior investigator, Charbel E-H Moussa, MB, PhD, assistant professor of neuroscience at Georgetown University Medical Center. “The cells start to spit the proteins out, as best they can, into the extracellular space so that they cannot exert their toxic effects inside the cell. Because Abeta is ‘sticky,’ it clumps together into plaque,” Moussa says.

He says his study suggests the remaining Abeta inside the neuron (that isn’t pushed out) destroys the cells, not the plaques that build up outside. “When tau does not function, the cell cannot remove the garbage, which at that point includes Abeta as well as tangles of nonfunctioning tau, and the cell dies. The Abeta released from the dead neuron then sticks to the plaque that had been forming.”

Moussa’s experiments in animal models also show less plaques accumulate outside the cell when tau is functioning; when tau was reintroduced into neurons that did not have it, plaques did not grow.

Malfunctioning tau can occur due to errant genes or through aging. As individuals grow older, some tau can malfunction while enough normal tau remains to help clear the garbage. In these cases, the neurons don’t die, he says. “That explains the confusing clinical observations of older people who have plaque build-up, but no dementia,” Moussa says.

Moussa has long sought a way to force neurons to clean up their garbage. In this study, he shows that nilotinib, a drug approved to treat cancer, can aid in that process. Nilotinib helps the neuron clear garbage, but requires some functional tau, he says.

“This drug can work if there is a higher percentage of good to bad tau in the cell,” Moussa says. “There are many diseases of dementia that have malfunctioning tau and no plaque accumulation, such as frontal temporal dementia linked to Parkinsonism,” Moussa says. “The common culprit is tau, so a drug that helps tau do its job may help protect against progression of these diseases.”

Insulin-like Growth Factor Linked to Hippocampal Hyperactivity in Alzheimer's Disease

The mechanisms underlying the stability and plasticity of neural circuits in the hippocampus, the part of the brain responsible for spatial memory and the memory of everyday facts and events, has been a major focus of study in the field of neuroscience. Understanding precisely how a “healthy” brain stores and processes information is crucial to preventing and reversing the memory failures associated with Alzheimer’s disease (AD), the most common form of late-life dementia.

Hyperactivity of the hippocampus is known to be associated with conditions that confer risk for AD, including amnestic mild cognitive impairment. A new Tel Aviv University study finds that the insulin-like growth factor 1 receptor (IGF-1R), the “master” lifespan regulator, plays a vital role in directly regulating the transfer and processing of information in hippocampal neural circuits. The research reveals IGF-1R as a differential regulator of two different modes of transmission — spontaneous and evoked — in hippocampal circuits of the brain. The researchers hope their findings can be used to indicate a new direction for therapy used to treat patients in the early stages of Alzheimer’s disease.

The study was led by Dr. Inna Slutsky of TAU’s Sagol School of Neuroscience and Sackler School of Medicine and conducted by doctoral student Neta Gazit. It was recently published in the journal Neuron. “People who are at risk for AD show hyperactivity of the hippocampus, and our results suggest that IGF-1R activity may be an important contributor to this abnormality,” Dr. Slutsky concluded.

Resolving a controversy

“We know that IGF-1R signaling controls growth, development and lifespan, but its role in AD has remained controversial,” said Dr. Slutsky. “To resolve this controversy, we had to understand how IGF-1R functions physiologically in synaptic transfer and plasticity.”

Using brain cultures and slices, the researchers developed an integrated approach characterizing the brain system on different scales — from the level of protein interactions to the level of single synapses, neuronal connections and the entire hippocampal network. The team sought to address two important questions: whether IGF-1Rs are active in synapses and transduce signalling at rest, and how they affect synaptic function.

“We used fluorescence resonance energy transfer (FRET) to estimate the receptor activation at the single-synapse level,” said Dr. Slutsky. “We found IGF-1Rs to be fully activated under resting conditions, modulating release of neurotransmitters from synapses.”

While acute application of IGF-1 hormone was found to be ineffective, the introduction of various IGF-1R blockers produced robust dual effects — namely, the inhibition of a neurotransmitter release evoked by spikes, electrical pulses in the brain, while enhancement of spontaneous neurotransmitter release.

A test for Alzheimer’s?

“When we modified the level of IGF-1R expression, synaptic transmission and plasticity were altered at hippocampal synapses, and an increase in the IGF-1R expression caused an augmented release of glutamate, enhancing the activity of hippocampal neurons,” said Gazit.

“We suggest that IGF-1R small inhibitors, which are currently under development for cancer, be tested for reduction aberrant brain activity at early stages of Alzheimer’s disease,” said Dr. Slutsky.

The researchers are currently planning to study how IGF-1R signaling controls the stability of neural circuits over an extended timescale.

We know we should put the cigarettes away or make use of that gym membership but in the moment, we just don’t do it. There is a cluster of neurons in our brain critical for motivation, though. What if you could hack them to motivate yourself?

These neurons are located in the middle of the brain, in a region called the ventral tegmental area. A paper published Thursday in the journal Neuron suggests that we can activate the region with a little bit of training.

Could You Hack Your Brain To Get More Motivated?

Illustration: Gary Waters/Getty Images/Ikon Images

theguardian.com
Whoa there! Brain area found to help spot bad decisions | Science | The Guardian

A new brain region that appears to help humans identify whether they have made bad decisions has been discovered by researchers. The size and shape of a large Brussels sprout, the ball of neural tissue seems to be crucial for the kind of flexible thought that allows us to consider switching to a more promising course of action. While other brain parts keep track of how well, or not, our decisions are working for us, the new structure is more outward-looking, and mulls over what we might have done instead. Scientists spotted the region, named the lateral frontal pole, after scanning the brains of healthy humans in two different ways. Further scans failed to find any comparable region in monkeys, suggesting the area is exclusive to humans. “We know there are differences between humans and monkeys. But it is surprising how many similarities there can be, and how a couple of differences can mean our behaviour is so far removed from them,” said Matthew Rushworth, a professor of cognitive neuroscience, who led the study at Oxford University. “There are a few brain areas that monitor how good our choices are, and that is a very sensible thing to have. But this region monitors how good the choices are that we didn’t take. It tells us how green the grass is on the other side of the fence.” The remarkable finding highlights how much scientists have to learn about the human brain and how cutting-edge lab techniques are redrawing the map of the most complex organ in the known universe. One expert who spoke to the Guardian said the work was “stunning” and could pave the way for fresh advances in understanding psychiatric diseases. Details of the work are published in the Neuron journal.