Corrí hacia ti porque sentí que te perdía y el hielo que se acumulaba a la velocidad de la luz en mi interior se estaba derritiendo. Grité tu nombre casi ahogándome por dentro. Te volteaste. Y que mierda hiciste? Me viste sin mirarme. Me oiste sin escucharme y te fuiste.

Mysterious desert fairy circles share pattern with skin cells

Patterns appearing on both the very large and very small scale are extremely rare, but researchers at Okinawa Institute of Science and Technology Graduate University (OIST) in Japan have found a similar pattern in two apparently unrelated systems – skin cells and fairy circles in the Namibian desert.

“It’s a completely amazing, strange match,” said Prof. Robert Sinclair, who heads the Mathematical Biology Unit at OIST.

Desert fairy circles are considered one of nature’s greatest mysteries because no one knows how they form. Different from mushroom rings, these fairy circles are large barren patches of earth ringed by short grass dotting the desert like craters on the moon or big freckles. Several groups are racing to figure out this bizarre phenomenon. Sinclair and his collaborator, Haozhe Zhang, believe they have identified a small, but vital piece of the puzzle.

The distribution of fairy circles throughout the desert may look random, but turns out to have a pattern that very closely matches the distribution pattern of skin cells. A pattern spanning such drastically different size scales – microscopic skin cells and the desert landscape – is almost unheard of in nature.

“It is still difficult to say why exactly they are similar, but the fact that they are similar is already very important,” Sinclair said. “This is suggesting there may be such types of patterns that cover really different size scales.”

The research was recently published in Ecological Complexity.

Haozhe Zhang, Robert Sinclair. Namibian fairy circles and epithelial cells share emergent geometric order. Ecological Complexity, 2015; 22: 32 DOI: 10.1016/j.ecocom.2015.02.001

Two apparently unrelated systems on vastly different scales – fairy circles in the Namibian desert (left) and microscopic skin cells (right) – appear to share a similar pattern, which is very, very unusual.Credit: Image courtesy of Okinawa Institute of Science and Technology - OIST

(Image caption: The striatum is part of the inner core of the brain that processes decisions and movements. OIST researchers investigated how the striatum’s three regions – the ventral, dorsomedial and dorsolateral – work together. Credit: Laura Petersen)

Calling the Shots: The Brain’s Decision-making Structure

A key part of the brain involved with decision making, the striatum, appears to operate hierarchically – much like a traditional corporation with executives, middle managers and employees, according to researchers at the Okinawa Institute of Science and Technology (OIST) Graduate University in Japan.

The striatum is part of the basal ganglia, the inner core of the brain that processes decisions and movements. Neuroscientists have thought the three regions of the striatum – ventral, dorsomedial and dorsolateral – have very distinct roles in motivation, adaptive decisions and routine actions, respectively.

However, OIST researchers found these parts do not operate in isolation, but work together in a coordinated hierarchy – like a traditional company with executives making decisions, delegating to middle managers and employees carrying out specific tasks.

“The three parts have not been investigated simultaneously in the same task before,” said Dr. Mokoto Ito, a researcher in OIST’s Neural Computation Unit and lead paper author. “We found the different parts work for the same behaviors, but in different roles.”

Their findings were published online on February 24 in The Journal of Neuroscience.

To observe what each part does, the researchers hooked up tiny electrodes to rats’ brains. The electrodes measured how frequently neurons in each section fired during a task, in which rats picked between two holes based on the probability of getting a sugar pellet reward. During fixed trials, the reward probability was held at different rates for the two holes, so the rats’ responses would become habitual over several weeks. During free-choice trials, the probability of reward jumped around, requiring the rats to adapt and evaluate their options more carefully.

The researchers found that while the three striatum regions have distinct roles, they work together in different phases in a trial.

“They do not work for separate behaviors,” said Prof. Kenji Doya, who heads OIST’s Neural Computation Unit and paper co-author. “It’s probably better to understand these different parts from a hierarchical control viewpoint.”

The ventral striatum (VS) was most active early on, when the rat decided whether it would participate in the activity or not. The dorsomedial striatum (DMS) changed firing levels as the rat evaluated the expected reward for each option while making a decision to turn left or right. The dorsolateral striatum (DLS) fired short bursts at a variety of times throughout the task, suggesting the involvement with the control of fine motor movements.

This is akin to a company’s president deciding to make a new product, middle managers evaluating different design and sales options, and employees building specific parts.

Neuroscientists have long thought there are separate circuits for routine actions and actions in continuously changing environments. If true, the DLS would be more active if the probability is fixed, while the DMS would be more active in free-choice tasks that require the rat to learn and adapt. To the researchers’ surprise, there was little difference in DMS and DLS firing during fixed and free-choice tasks in this study.

That was not the only unexpected result. OIST’s Neural Computation Unit works on adaptive robots learning how to autonomously behave based on reward feedback. The core component of the robots’ algorithm is the “action value,” which keeps track of the probability for a positive outcome.

“The same variable we use for robot learning was also found in the rat’s brain,” Doya said. “This is quite a striking observation.”

This strongly suggests rats analyzed the potential benefit of choosing the left or right hole, and that analysis was constantly updated after each trial – the same way the robot algorithm works.

Sounds of Silence

New research published by the Neuronal Mechanism for Critical Period Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) has shown the effectiveness of chemogenetic inhibition used to suppress neuronal activity as well as interesting results on how vocalization is controlled through this techniques application in zebra finches. The research conducted by Professor Yoko Yazaki-Sugiyama and Dr. Shin Yanagihara of OIST was done in collaboration with scientists from the International Institute for Integrative Sleep Medicine at Tsukuba University and the Division of Sleep Medicine at Harvard University and shows that different areas of the brain govern unique aspects of vocalization.

The research showed that by silencing of neurons in the arcopallium, a region in the brain known to be responsible for song generation, that zebra finch songs would become erratic and incomplete. Previous studies which used micro lesions on this area of the brain showed a diminished ability to sing almost all components of a song. The chemogenetic inhibition method revealed however that the song was only diminished at specific parts, with only some syllables being affected or absent. The syllables affected differed from bird to bird, however the order of syllables did not change. This suggests that the portion of the brain studied, the arcopallium, is in control of the composition of acoustic structure of songs and not their order or timing. It also demonstrated how precise this neuronal suppression method can be in determining the function of very small groups of neurons.

As it is with human speech, vocalization can be identified as a series of motor patterns, or a coordinated set of movements involving both reflex and voluntary actions. The creation of specific acoustic patterns requires well-coordinated neuronal circuitry. The identification of which group of neurons is responsible for a specific action or response is complex as brain scans such as functional magnetic resonance imaging, fMRI, can give only so much detail. Prof. Yazaki-Sugiyama explains, “Even though we know which general areas are functioning during certain tasks or behaviors, we have no idea how many of the neurons in that area are actually working. In some cases even a 5% change in neuron activity can have an effect.” New methods for examining the brains function in more detail, such as chemogenetic inhibition, have been refined and gaining popularity in the scientific community over the past ten years.

This technique had been previously applied to mice as a model animal and was demonstrated to be just as effective in zebra finches. The chemogenetic technique uses genetic manipulation to make neurons sensitive to selected chemicals or drugs. Once the neurons are modified, a predetermined drug can then be administered to temporarily deactivate these newly sensitive neurons. Previously one of the only other methods of blocking neuronal activity was by creating micro-lesions in parts of the brain where almost all of neurons there are permanently damaged or killed. The technique implemented by Prof. Yazaki-Sugiyama is at the neuronal level and a temporary process, affecting only subsets of neurons. The finch’s ability to sing recovers within hours after the effect of the drug has worn off.

Zebra finches were used as a model because scientists understand their behavior, song patterns and brain anatomy well. Prof. Yazaki-Sugiyama wanted to determine what role a specific set of neurons plays in the brain area known to play a part in the finch’s song composition using chemogenetic methods. The finches were carefully observed and the patterns of their songs were recorded and analyzed with and without silencing neurons. With the effect of the drugs being only temporary as well as much more precise, the data Prof. Yazaki-Sugiyama was able to gather gives a much more detailed look at how unique neurons coordinate to produce vocalization.

The results themselves are not only interesting, but proof that the marriage between this highly refined technique and a well understood model animal in science has more to offer for future studies. Prof. Yazaki-Sugiyama adds “the technique itself is a causal one. So if you want to know the detail of how a general area in the brain functions, you could use this to silence the activity there and then see the behavioral change caused by the silencing. On top of that, one of the best merits of this is that its reversible as well, meaning we can be more thorough with follow ups in future research.”

Harnessing bacteria to move microscopic gears and ratchets

Computer simulations at OIST suggest new applications in industry by harnessing active microscopic particles in fluids. Previous research has already demonstrated that substantial quantities of self-motile or active agents such as bacteria in a fluid environment can be harnessed to do mechanical work like moving microscopic gears and ratchets. Bacteria as well as algae can also be used to transport or displace matter in fluidic environments.

The new research recently published by scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) in the journal Soft Matter carefully examines the relationships between self-motile and passive or inert agents to determine possibility of creating fully synthetic systems by looking into examples of biology interacting with mechanical mechanisms. Denis F. Hinz and Professor Eliot Fried of the OIST Mathematical Soft Matter Unit created the necessary models and investigated how such mixtures can work to achieve desired effects.

Denis F. Hinz, Alexander Panchenko, Tae-Yeon Kim, Eliot Fried. Motility versus fluctuations in mixtures of self-motile and passive agents. Soft Matter, 2014; 10 (45): 9082 DOI: 10.1039/C4SM01562B

The three distinct flow pattern phases found through computer simulations by Denis F. Hinz and Eliot Fried at OIST are shown. From left to right, mesoturbulant, polar flock and voritcal are visualized. Credit: OIST

Our closest wormy cousins: About 70% of our genes trace their ancestry back to the acorn worm

A team from the Okinawa Institute of Science and Technology Graduate University (OIST) and its collaborators has sequenced the genomes of two species of small water creatures called acorn worms and showed that we share more genes with them than we do with many other animals, establishing them as our distant cousins.

The study found that 8,600 families of genes are shared across deuterostomes, a large animal grouping that includes a variety of organisms, ranging from acorn worms to star fishes, from frogs to dogs, to humans. This means that approximately 70% of our genes trace their ancestry back to the original deuterostome. By comparing the genomes of acorn worms to other animals, OIST scientists inferred the presence of these genes in the common ancestor of all deuterostomes, an extinct animal that lived half a billion years ago. This research shows that the pharyngeal gene cluster is unique to the deuterostomes and it could be linked to the development of the pharynx, the region that links the mouth and nose to the esophagus in humans. These findings were published in Nature, summarizing an international collaboration between OIST researchers and teams from the US, UK, Japan, Taiwan and Canada.

Around 550 million years ago, a great variety of animals burst onto the world in an event known as the Cambrian explosion. This evolutionary radiation revealed several new animal body plans, and changed life on Earth forever, as complex animals with specialized guts and behavioural features emerged. Thanks to the genome sequencing of multiple contemporary animals of the deuterostome group, we can go back in time to unveil aspects of the long-lost ancestor of this diverse group of animals.

Acorn worms are marine creatures that live on the ocean floor and feed by filtering a steady flow of sea water through slits in the region of their gut between mouth and esophagus. These slits are distantly related to the gills of fish, and represent a critical innovation in evolution not shared with animals like flies or earthworms. Since acorn worms occupy such a critical evolutionary position relative to humans the researchers sequenced two distantly related acorn worm species, Ptychodera flava, collected in Hawaii, and Saccoglossus kowalevskii, from the Atlantic Ocean. “Their genomes are necessary to fill the gap in our understanding of the genes shared by the common ancestor of all deuterostomes,” explains Dr Oleg Simakov, lead author of this study.

Indeed, beyond sequencing these two organisms, the team was also interested in identifying ancient gene families that were already present in the deuterostome ancestor. The team compared the genomes of the two acorn worms with the genomes of 32 diverse animals and found that about 8,600 families of genes are homologous, that is, evolutionarily-related, across all deuterostomes and so are confidently inferred to have been present also in the genome of their deuterostome ancestor. Human arms, birds’ wings, cats’ paws and the whales’ flippers are classical examples of homology, because they all derive from the limbs of a common ancestor. As with anatomical structures, genes homology is defined in terms of shared ancestry. Because of later gene duplications and other processes, these 8,600 homologous genes correspond to at least 14,000 genes, or approximately 70%, of the current human genome.

The study also identified clusters of genes that are close together in acorn worm genomes and in the genomes of humans and other vertebrates. The ancient proximity of these gene clusters, preserved over half a billion years, suggests that the genes may function as a unit. One gene cluster connected with the development of the pharynx in vertebrates and acorn worms is particularly interesting. It is shared by all deuterostomes, but not present in non-deuterostome animals such as insects, octopuses, earthworms and flatworms. The pharynx of acorn worms and other animals functions to filter food and to guide it to the digestive system. In humans, this cluster is active in the formation of the thyroid glands and the pharynx. Scientists suggest there is a connection between the function of the modern thyroid and the filter feeding mechanism of acorn worms. This pharyngeal gene cluster contains six genes ordered in a common pattern in all deuterostomes and includes the genes for four proteins that are critical transcriptional regulators that control activation of numerous other genes. Genes ordered in the same way and located next to each other in the chromosomal DNA are linked and transferred together from one generation to the next. Interestingly, not only the DNA that codes for these transcription factor genes is shared among the deuterostomes, but also some of the DNA pieces that are used as binding sites for the transcription factors are conserved among these animals.

“Our analysis of the acorn worm genomes provides a glimpse into our Cambrian ancestors’ complexity and supplies support for the ancient link between the pharyngeal development and the filter feeding life style that ultimately contributed to our evolution,” explains Dr Simakov.

Recently, the OIST team also sequenced the genomes of the octopus and the coral Porites australiensis.

Image: This is a juvenile of Saccoglossus kowalevskii with one of the transcription factors expressed in the pharyngeal region (highlighted in blue).

Credit: Andrew Gillis

(Image caption: Fig 1. The image on the left shows all neurons (the black dots) in the rat striatum, a part of the brain that is involved in higher-level decision-making. The image on the right shows just the cholinergic interneurons. There are far fewer black dots because cholinergic interneurons make up only 1 to 2 percent of the neurons in the striatum. It is these neurons that influence mental flexibility. (The large white spots are bundles of nerves.))

Rare Neurons Enable Mental Flexibility

Behavioral flexibility – the ability to change strategy when the rules change – is controlled by specific neurons in the brain, Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have confirmed. Cholinergic interneurons are rare – they make up just one to two percent of the neurons in the striatum, a key part of the brain involved with higher-level decision-making. Scientists have suspected they play a role in changing strategies, and researchers at OIST recently confirmed this with experiments. Their findings were published in The Journal of Neuroscience.

“Not much is known about these neurons,” said Sho Aoki, a post-doctoral researcher at OIST and lead author of the paper. “But we now have clear evidence that they play a key role in remaining flexible in this ever-changing world.”

Previous studies tried to identify the role of cholinergic interneurons by recording brain wave activity during behavioral tasks. While that can strongly indicate specific neurons are correlated with a particular behavior, it is not definitive. In this study, Aoki killed cholinergic interneurons with a toxin that directly targets them, and then observed how rats reacted to rule changes compared with normal rats with intact neurons. “Our experiments show direct causation, not correlation,” Aoki said.

Rats with and without damaged neurons were given tasks for several weeks – they had to press either lever A or B to get a sugar pellet reward. During the first few days, Lever A always resulted in a reward. Both groups of rats had no problem learning the initial strategy to get the sugar pellet – press Lever A.

But then, the rules of the game changed. A novel stimulus was introduced – a light flashed above the correct lever, which oscillated between Lever A and B (Fig. 2A). To get their sugar fix, the rats had to shift strategy and pay attention to this new information. While normal rats quickly responded to the light, rats with damaged neurons could not. The latter group continued to repeat the strategy they had already learned, and were disinclined to explore what the light meant.

In another test, a light cue that had been flashing in a meaningless pattern during the initial learning phase switched to signaling the correct lever to push for reward (Fig. 2B). This meant to maximize rewards, and the animals should now pay attention to a stimulus they previously ignored. Again, the control rats had no problem adapting to this rule change, but the damaged rats stuck to their original strategy, even though it meant fewer rewards. They also decreased exploring what might increase their chance of success.

Interestingly, rats with neurons damaged in the dorsomedial part of the striatum had greater difficulty paying attention to previously irrelevant light cues (Fig. 2B). Rats with neurons damaged in the ventral part of the striatum had a harder time reacting to novel stimulants (Fig. 2A).

“This indicates that cholinergic interneurons throughout the striatum play a common role, namely inhibiting old rules and encouraging exploration, but different regions of the striatum are activated depending on the situation and type of stimulus,” Aoki said.

The research findings might help researchers and medical professionals who investigate aging. “Since cholinergic interneurons degenerate with age, this work may provide a clue for understanding the decline in mental flexibility that occurs with advancing age,” said Prof. Jeff Wickens, head of OIST’s Neurobiology Research Unit and senior paper author.

Protein scaffold

Right before a cell starts to divide to give birth to a daughter cell, its biochemical machinery unwinds the chromosomes and copies the millions of protein sequences comprising the cell’s DNA, which is packaged along the length of the each chromosomal strand. These copied sequences also need to be put back together before the two cells are pulled apart. Mistakes can lead to genetic defects or cancerous mutations in future cell generations.

Just like raising a building requires scaffolding be erected first, cells use biochemical scaffolding machinery to reassemble copied genomic fragments back into chromosomes. Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have mapped the points along the genome where a scaffolding protein crucial to maintaining the genome’s structure binds. The paper was published in Genes to Cells.

Caption:The cells on the left are normal yeast cells, in the process of dividing successfully. As can be seen, the replicated chromosomes have completely separated from the original. The cells on the right produced mutant condensin and their chromosomes were unable to segregate properly. Credit:OIST

borelightarty  asked:

Eso nos enseña...que no se deben donar partes (? Oiste Baby? no vuelvas a donar partes :V (creo recordar que uste dijo que eso fue lo que paso jajaja)

una lecion muy importante XXD

Seeking the Causes of Hyperactivity

The 60 trillion cells that comprise our bodies communicate constantly.  Information travels when chemical compounds released by some cells are received by receptors in the membrane of another cell. In a paper published in the Journal of Neuroscience, the OIST Cell Signal Unit, led by Professor Tadashi Yamamoto, reported that mice lacking an intracellular trafficking protein called LMTK3, are hyperactive.  Hyperactivity is a behavioral disorder that shows symptoms including restlessness, lack of coordination, and aggressive behavior. Identifying the genetic factors that contribute to such behaviors may help to explain the pathological mechanisms underlying autism and Attention Deficit Hyperactivity Disorder, ADHD, in humans.

LMTK3 is abundant in two brain regions: the cerebral cortex, which coordinates perception, movement, and thought, and the hippocampus, which governs memory and learning. In the brain, neurons communicate via connections called synapses. To send a message, a nerve terminus in the pre-synapse releases neurotransmitters to be received by the post-synaptic receptors. Yamamoto’s team discovered that LMTK3 regulates trafficking of neurotransmitter receptors at synapses. In neurons of mice deficient in LMTK3, internalization of receptors are augmented in the post-synapse, suggesting that synaptic communication is impaired. The LMTK3-deficient mice exhibited various hyperactive behaviors such as restlessness and hypersensitivity to sound. Interestingly, their dopamine levels were elevated. Dopamine is a neurotransmitter known to be involved in regulation of movement and hormone levels, motivation, learning, and expression of emotion. Excessive dopamine secretion results in schizophrenia, causing a loss of integrity of neuronal activity, and abnormal thoughts and emotions. The relationships between regulation of neurotransmitter receptor expression by LMTK3, dopamine turnover, and the biochemical pathways that induce hyperactivity, remain unknown.

Functions of many human proteins are still not understood. The Cell Signal Unit continues genetic studies of intracellular proteins that maintain and regulate complex functions such as behaviors, through their activities inside cells. “We hope to advance our research in order to elucidate genetic defects that result in behavioral abnormalities,” Yamamoto said.

Mental Flexibility Enabled With Help of Rare Neuron

Behavioral flexibility, the ability to change strategy when the rules change, is controlled by specific neurons in the brain, Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have confirmed. Cholinergic interneurons are rare – they make up just one to two percent of the neurons in the striatum, a key part of the brain involved with higher-level decision-making.

The research is in Journal of Neuroscience. (full access paywall)

Research: “Role of Striatal Cholinergic Interneurons in Set-Shifting in the Rat” by Sho Aoki, Andrew W. Liu, Aya Zucca, Stefano Zucca, and Jeffery R. Wickens in Journal of Neuroscience doi:10.1523/JNEUROSCI.0490-15.2015

Image: Figure 1. The image on the left shows all neurons (the black dots) in the rat striatum, a part of the brain that is involved in higher-level decision-making. The image on the right shows just the cholinergic interneurons. There are far fewer black dots because cholinergic interneurons make up only 1 to 2 percent of the neurons in the striatum. It is these neurons that influence mental flexibility. (The large white spots are bundles of nerves.) Image credit: Laura Petersen/OIST.

WOOT WOOT!! I hit 1300 followers!  I”m so amazed by all the people I have met on here and how great you all are so thanks and stuff like that


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Gabi ( @emisongray )- you’re such a cute and pleasant person and you make me laugh and do the happy when you talk so thanks for that and thanks for being awesome ily and kabi is real

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(Figure 1 (left): This is a freeze fracture replica image showing the voltage-gated calcium channels clusters on presynaptic membrane in rats. The green circles represent channel clusters, and inside each green circle are small black dots, which are the individual channels. This is easier to see in the inset, labeled A3, where the channels are blue dots. Credit: OIST. Figure 2 (right): This diagram shows the new model that Professor Takahashi and his collaborators have proposed. Circles are vesicles filled with blue neurotransmitters, and the smaller grey circles are voltage-gated channels. Instead of measuring from the vesicle to the center of the channel cluster (green line), Takahashi suggests measuring to the perimeter of the channel cluster (red line). The difference is that measuring to the center varies with the size of the cluster, whereas measuring to the perimeter will always describe the closest channel to the vesicle. Credit: OIST)

Tackling Neurotransmission Precision

Behind all motor, sensory and memory functions, calcium ions are in the brain, making those functions possible. Yet neuroscientists do not entirely understand how fast calcium ions reach their targets inside neurons, and how that timing changes neural signaling. Researchers at the Okinawa Institute of Science and Technology Graduate University have determined how the distance from calcium channels to calcium sensors on vesicles affects a neuron’s signaling precision and efficacy. In international collaboration with research institutes such as the Pasteur Institute and the Institute of Science and Technology Austria, Professor Tomoyuki Takahashi and the Cellular and Molecular Synaptic Function Unit described the locations of voltage-gated calcium channels, which allow calcium ions to enter into the neuron, triggering vesicles to release neurotransmitters, signaling to the next neuron. This research, to be published the January 7, 2015 issue of Neuron, illuminates decades of mystery behind the precision and efficacy of neurotransmitter release, suggesting how signaling changes as an animal matures.

After an electrical spike, or an instantaneous change in voltage, travels through the neuron, it reaches the presynaptic terminal. The presynaptic terminal is an area facing the synaptic cleft, or the gap between one neuron and the next. The electrical spike triggers voltage-gated calcium channels to open, allowing calcium ions to enter the presynaptic terminal. The calcium ions then diffuse locally around the channels and encounter synaptic vesicles, small packages of neurotransmitters, which are signaling molecules. The calcium ions interact with sensor proteins on the vesicle, triggering the vesicles to fuse with the presynaptic terminal membrane, and releasing neurotransmitters into the synaptic cleft toward the next neuron.

Yet researchers have never fully grasped how calcium travels from gated channel to vesicle. Some researchers argued that the channels were spread across the active zone of the presynaptic terminal, while others argued that a ring of gated channels surrounded each vesicle. Therefore, Takahashi’s project began with an electron microscope technique, where the researchers froze the presynaptic membrane and broke it open to expose the calcium channels (Figure 1). They found that the channels existed in clusters, with a variable number of channels in each cluster.

Next, the researchers ran various tests and simulations to determine how the channel clusters impact signaling. They found that clusters with more calcium channels more effectively trigger a nearby vesicle to release neurotransmitters. Importantly, channel clusters closer to vesicles trigger neurotransmitter release more quickly and more efficiently than clusters located farther from vesicles, increasing signal precision. “The calcium sensor on vesicles need a high concentration of calcium to trigger vesicle release,” Takahashi said. “If the calcium entered from farther away, then it would diffuse into a lower concentration or bind to other proteins before reaching the calcium sensor on the vesicle.”

Takahashi and his collaborators also studied how the distance changes as their rat subjects developed, and how the distance changes affect neural signaling. As the rat aged from seven days to fourteen days, the distance between the gated channels and the vesicle shrank from 30 nanometers to 20 nanometers. “This maturation is fairly significant,” Takahashi said, explaining that the vesicles release much more quickly after calcium enters the synapse. “The signal becomes 30% faster,” he said.

Moving forward, Takahashi and his collaborators propose the perimeter release model for use in neuroscience research (Figure 2). This model establishes that calcium channels exist in clusters and that the distance from these clusters to a vesicle is significant. “If you measure the distance from the center of the cluster, then this distance depends on the size of the cluster,” Takahashi said. Therefore, the researchers propose the distance from vesicle to gated channel clusters be measured from the perimeter of the cluster, rather than the center. Distances calculated using this new model can explain how signaling precision increases during development.

“If there is anything which widens this distance,” Takahashi said, “it actually interferes with neural precision and it can interfere with memory formation.”