Tuesday, August 6, 2019
How brain cells pick which connections to keep
Brain cells, or neurons, constantly tinker with their circuit connections, a crucial feature that allows the brain to store and process information. While neurons frequently test out new potential partners through transient contacts, only a fraction of fledging junctions, called synapses, are selected to become permanent.
The major criterion for excitatory synapse selection is based on how well they engage in response to experience-driven neural activity, but how such selection is implemented at the molecular level has been unclear. In a new study, MIT neuroscientists have identified the gene and protein, CPG15, that allows experience to tap a synapse as a keeper.
In a series of novel experiments described in Cell Reports, the team at MIT’s Picower Institute for Learning and Memory used multi-spectral, high-resolution two-photon microscopy to literally watch potential synapses come and go in the visual cortex of mice — both in the light, or normal visual experience, and in the darkness, where there is no visual input. By comparing observations made in normal mice and ones engineered to lack CPG15, they were able to show that the protein is required in order for visual experience to facilitate the transition of nascent excitatory synapses to permanence.
Mice engineered to lack CPG15 only exhibit one behavioral deficiency: They learn much more slowly than normal mice, says senior author Elly Nedivi, the William R. (1964) and Linda R. Young Professor of Neuroscience in the Picower Institute and a professor of brain and cognitive sciences at MIT. They need more trials and repetitions to learn associations that other mice can learn quickly. The new study suggests that’s because without CPG15, they must rely on circuits where synapses simply happened to take hold, rather than on a circuit architecture that has been refined by experience for optimal efficiency.
“Learning and memory are really specific manifestations of our brain’s ability in general to constantly adapt and change in response to our environment,” Nedivi says. “It’s not that the circuits aren’t there in mice lacking CPG15, they just don’t have that feature — which is really important — of being optimized through use.”
Watching in light and darkness
The first experiment reported in the paper, led by former MIT postdoc Jaichandar Subramanian, who is now an assistant professor at the University of Kansas, is a contribution to neuroscience in and of itself, Nedivi says. The novel labeling and imaging technologies implemented in the study, she says, allowed tracking key events in synapse formation with unprecedented spatial and temporal resolution. The study resolved the emergence of “dendritic spines,” which are the structural protrusions on which excitatory synapses are formed, and the recruitment of the synaptic scaffold, PSD95, that signals that a synapse is there to stay.
The team tracked specially labeled neurons in the visual cortex of mice after normal visual experience, and after two weeks in darkness. To their surprise, they saw that spines would routinely arise and then typically disappear again at the same rate regardless of whether the mice were in light or darkness. This careful scrutiny of spines confirmed that experience doesn’t matter for spine formation, Nedivi said. That upends a common assumption in the field, which held that experience was necessary for spines to even emerge.
By keeping track of the presence of PSD95 they could confirm that the synapses that became stabilized during normal visual experience were the ones that had accumulated that protein. But the question remained: How does experience drive PSD95 to the synapse? The team hypothesized that CPG15, which is activity dependent and associated with synapse stabilization, does that job.
CPG15 represents experience
To investigate that, they repeated the same light-versus-dark experiences, but this time in mice engineered to lack CPG15. In the normal mice, there was much more PSD95 recruitment during the light phase than during the dark, but in the mice without CPG15, the experience of seeing in the light never made a difference. It was as if CPG15-less mice in the light were like normal mice in the dark.
Later they tried another experiment testing whether the low PSD95 recruitment seen when normal mice were in the dark could be rescued by exogenous expression of CPG15. Indeed, PSD95 recruitment shot up, as if the animals were exposed to visual experience. This showed that CPG15 not only carries the message of experience in the light, it can actually substitute for it in the dark, essentially “tricking” PSD95 into acting as if experience had called upon it.
“This is a very exciting result, because it shows that CPG15 is not just required for experience-dependent synapse selection, but it’s also sufficient,” says Nedivi, “That’s unique in relation to all other molecules that are involved in synaptic plasticity.”
A new model and method
In all, the paper’s data allowed Nedivi to propose a new model of experience-dependent synapse stabilization: Regardless of neural activity or experience, spines emerge with fledgling excitatory synapses and the receptors needed for further development. If activity and experience send CPG15 their way, that draws in PSD95 and the synapse stabilizes. If experience doesn’t involve the synapse, it gets no CPG15, very likely no PSD95, and the spine withers away.
The paper potentially has significance beyond the findings about experience-dependent synapse stabilization, Nedivi says. The method it describes of closely monitoring the growth or withering of spines and synapses amid a manipulation (like knocking out or modifying a gene) allows for a whole raft of studies in which examining how a gene, or a drug, or other factors affect synapses.
“You can apply this to any disease model and use this very sensitive tool for seeing what might be wrong at the synapse,” she says.
In addition to Nedivi and Subramanian, the paper’s other authors are Katrin Michel and Marc Benoit.
The National Institutes of Health and the JPB Foundation provided support for the research.
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Wendy Williams reportedly joins forces with her alleged cheating ex to continue joint business ventures
Is Wendy Williams softening her stance on her cheating ex-husband a bit?
—Wendy Williams sheds tears over divorce drama, but then gets real about it—
Could be since reported surface that the talk show host has hired Kevin Hunter, 47, back on her team to handle some of her business affairs, after he allegedly had an affair.
The two had been joined at the hip for more than 20 years as a married couple and together built an empire and had several business ventures together like the Hunter Foundation.
But when Williams, 55 reportedly found out her man had fathered a baby outside the marriage, she ousted him with the quickness, filed for divorce and dissolved her joint businesses.
But it appears poppa has rolled his way back into Wendy’s good graces and they released a joint press release saying that they will not dissolve their production company, publishing house or charitable foundation that they’ve built together.
“Wendy and Kevin’s marriage might be over but they still have love for one another and she realizes that when it comes to business they had a great partnership, there was definitely magic there,” a source close to the couple told DailyMail.com.
“Wendy has come around to the idea that it makes more sense for Kevin to stick around, it’s best for her business and career and for their family.
“Since he left the business there’s been a lot of infighting and back-biting behind the scenes, that’s the kind of stuff Kevin kept a handle on.”
—SHOCKING: Black man in Texas led by white police officers on horses with leash tied around his neck—
“Of course Wendy was furious with Kevin over his affair, she felt he had publicly humiliated her and she wanted to come out fighting, but she’s since softened her view of him and wants an amicable divorce.”
“He has been very supportive, particularly around her struggles with alcoholism.”
Williams has put on a brave face since her very public and she’s been celebrating her new lease on life since she filed for divorce. Still, talk show host still gets emotional when talking about the way her family has been torn apart over the last year.
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SHOCKING: Black man in Texas led by white police officers on horses with leash tied around his neck
In one of the most inhumane and emasculating moments a human could have, a photo has gone viral of a Black man in Texas being led on a leash by two white police officers.
Galveston Police was hit with a barrage of complaints over the weekend about the shocking photo of Donald Neely, 43, who was arrested on charges of criminal trespass at 22nd street and Mechanic, ABC 13 reports.
—Body of 4-year-old Baltimore boy reported missing found in dumpster, mother charged—
The photo hit a nerve among people of color at a time when racial tensions are high and white criminals are often treated in a more humane manner than Black suspects.
Chief Vernon L. Hale, III of the Galveston Police Department released a statement about the ordeal and apologized to Neely:
“First and foremost I must apologize to Mister Neely for this unnecessary embarrassment. Although this is a trained technique and best practice in some scenarios, I believe our officers showed poor judgement in this instance and could have waited for a transport unit at the location of arrest. My officers did not have any malicious intent at the time of the arrest, but we have immediately changed the policy to prevent the use of this technique and will review all mounted training and procedures for more appropriate methods.”
On Facebook, a woman, Christin Neely said Donald was her brother in law and explained that he is “mentally ill” and “homeless” but the family has contacted a lawyer to find out why he was treated in such an inhumane way.
“The MAN in the photos is my brother in law Donald Neely. He is mentally ill and homeless with family just over the causeway in Texas City. We have attempted many times to bring him home but he refuses. He gets arrested often for trespassing. After calling GPD and getting no where we have contacted our family lawyer who is working to get answers as to what occurred and why. We would like to thank everyone who has shared the original post and encourage you all to continue sharing! #wearenotourancestors #dontlookaway #share”
—Afton Williamson calls out ‘The Rookie” co-star she alleges sexually harassed her—
“You don’t even do a dog like that,” said Sherri Kelly about the troubling photo. “I don’t care. That’s inhumane.”
“Where were they walking him to and why did they rope him if he was handcuffed? I don’t think it’s right,” Cynthia Orise of Galveston said.
The officer under fire has been identified as P. Brosch and A. Smith. They were also wearing body cameras and police confirmed the cameras were activated.
Posted by Adrienne Bell for Congress TX-14 on Monday, August 5, 2019
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Daniel Freedman wins Special Breakthrough Prize in Fundamental Physics
Daniel Z. Freedman, professor emeritus in MIT’s departments of Mathematics and Physics, has been awarded the Special Breakthrough Prize in Fundamental Physics. He shares the $3 million prize with two colleagues, Sergio Ferrara of CERN and Peter van Nieuwenhuizen of Stony Brook University, with whom he developed the theory of supergravity.
The trio is honored for work that combines the principles of supersymmetry, which postulates that all fundamental particles have corresponding, unseen “partner” particles; and Einstein's theory of general relativity, which explains that gravity is the result of the curvature of space-time.
When the theory of supersymmetry was developed in 1973, it solved some key problems in particle physics, such as unifying three forces of nature (electromagnetism, the weak nuclear force, and the strong nuclear force), but it left out a fourth force: gravity. Freedman, Ferrara, and van Nieuwenhuizen addressed this in 1976 with their theory of supergravity, in which the gravitons of general relativity acquire superpartners called gravitinos.
Freedman’s collaboration with Ferrara and van Nieuwenhuizen began late in 1975 at École Normale Supérior in Paris, where he was visiting on a minisabbatical from Stony Brook, where he was a professor. Ferrara had also come to ENS, to work on a different project for a week. The challenge of constructing supergravity was in the air at that time, and Freedman told Ferrara that he was thinking about it. In their discussions, Ferrara suggested that progress could be made via an approach that Freedman had previously used in a related problem involving supersymmetric gauge theories.
“That turned me in the right direction,” Freedman recalls. In short order, he formulated the first step in the construction of supergravity and proved its mathematical consistency. “I returned to Stony Brook convinced that I could quickly find the rest of the theory,” he says. However, “I soon realized that it was harder than I had expected.”
At that point he asked van Nieuwenhuizen to join him on the project. “We worked very hard for several months until the theory came together. That was when our eureka moment occurred,” he says.
“Dan’s work on supergravity has changed how scientists think about physics beyond the standard model, combining principles of supersymmetry and Einstein’s theory of general relativity,” says Michael Sipser, dean of the MIT School of Science and the Donner Professor of Mathematics. “His exemplary research is central to mathematical physics and has given us new pathways to explore in quantum field theory and superstring theory. On behalf of the School of Science, I congratulate Dan and his collaborators for this prestigious award.”
Freedman joined the MIT faculty in 1980, first as professor of applied mathematics and later with a joint appointment in the Center for Theoretical Physics. He regularly taught an advanced graduate course on supersymmetry and supergravity. An unusual feature of the course was that each assigned problem set included suggestions of classical music to accompany students’ work.
“I treasure my 36 years at MIT,” he says, noting that he worked with “outstanding” graduate students with “great resourcefulness as problem solvers.” Freedman fully retired from MIT in 2016.
He is now a visiting professor at Stanford University and lives in Palo Alto, California, with his wife, Miriam, an attorney specializing in public education law.
The son of small-business people, Freedman was the first in his family to attend college. He became interested in physics during his first year at Wesleyan University, when he enrolled in a special class that taught physics in parallel with the calculus necessary to understand its mathematical laws. It was a pivotal experience. “Learning that the laws of physics can exactly describe phenomena in nature — that totally turned me on,” he says.
Freedman learned about winning the Breakthrough Prize upon returning from a morning boxing class, when his wife told him that a Stanford colleague, who was on the Selection Committee, had been trying to reach him. “When I returned the call, I was overwhelmed with the news,” he says.
Freedman, who holds a BA from Wesleyan and an MS and PhD in physics from the University of Wisconsin, is a former Sloan Fellow and a two-time Guggenheim Fellow. The three collaborators received the Dirac Medal and Prize in 1993, and the Dannie Heineman Prize in Mathematical Physics in 2006. He is a fellow of the American Academy of Arts and Sciences.
Founded by a group of Silicon Valley entrepreneurs, the Breakthrough Prizes recognize the world’s top scientists in life sciences, fundamental physics, and mathematics. The Special Breakthrough Prize in Fundamental Physics honors profound contributions to human knowledge in physics. Earlier honorees include Jocelyn Bell Burnell; the LIGO research team, including MIT Professor Emeritus Rainer Weiss; and Stephen Hawking.
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BREAKING NEWS: Nobel laureate Toni Morrison has died
A publisher at Knopf has just confirmed that the Nobel laureate and Pulitzer Prize-winning author, Toni Morrison has died Monday night in New York City.
Born Chloe Anthony Wofford in 1931 in Lorain (Ohio), Morrison was the second of four children from a black working-class family. She went on to study at both Howard and Cornell Universities and developed a career as a literary critic and editor for Random House.
Her first novel, “The Bluest Eye” was released in 1970, and went on to receive the Pulitzer Prize in 1988.
Most recently, a new documentary on her life was released. The film, Toni Morrison: The Pieces I Am focused on the legendary author’s career, highly acclaimed novels, and life, OprahMag reports.
The documentary also looks back on her childhood, her experience as an undergraduate student at Howard University, and much more.
The biopic, directed by Timothy Greenfield-Sanders, offers fans a better understanding of Morrison’s perspective on topics such as racial identity, prejudice, and the “plight of Black Women.” It also highlight her current achievements.
Morrison, who died last night was 88 years old.
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Real Housewives of Potomac’s Ashley Darby meets her dad for the first time in 30 years
Real Housewives of Potomac star Ashley Darby took a journey into her past on Sunday’s episode to confront her father, a man who she has never met in 30 years.
—John Legend and Rihanna call out Donald Trump over El Paso and Dayton mass shootings—
While you’ll have to wait until next week to see what Darby and her dad discussed, the episode was all about the journey of confronting the man who divorced her mom 30 years ago and left his family without much explanation.
Darby made the trek to Atlanta, Georgia to get answers of a past that has haunted her and to douse the burning desire to better understand why her father left when she was one year old, PEOPLE reports.
Darby admits that five years ago she tried to reach out to her dad on Facebook, but in pure Facebook fashion, he blocked her.
“It was really hurtful,” Darby recalled. “And yet even still, I have this nagging desire to find my dad.”
“When I sit with myself, I think about my life and who I am and all that. I think about my dad a lot,” she added. “I have never known my dad … I’m tired of thinking about it. I need it for myself. I need to close this chapter of my life to look to the future.”
She continued: “This is something I’ve been thinking about a long time, reconnecting with my other side of my family. So what’s stopping me? As I’m trying to embark on starting a family, I’m thinking about my kid and what my kid will ask. They will want to know about their grandparents and their aunts and uncles. I feel like it’s a responsibility of mine to foster those relationship.”
To help ease the tension of meeting her father for the first time as an adult, Darby brought along her dad’s brother-in-law Uncle Jim and his sister, Aunt Sheila, two relatives whom she has kept in phone contact with other years. Her mother Sheila Matthews, also came along.
“When I put myself in my dad’s shoes, I think the shame of having abandoned me is too much for him to bare,” Darby said. “He can’t confront it. But I’m hoping that my dad will feel a little more comfortable having Uncle Jim and Aunt Sheila there. Maybe he’ll be more receptive to having a conversation?”
“Even if I haven’t been able to have a close relationship with my dad, the fact that my aunt and uncle still make an effort to want to talk to me and show me that they care about me? That warms my heart,” Darby said.
—Is RHOA star Porsha Williams back with her ex Dennis McKinley?—
But there’s no promise that Aunt Sheila and Uncle Jim’s presence will ease the meeting especially since they said they haven’t talked to Darby’s dad in eight years.
“I’ve attempted to try, but nothing has happened,” Sheila said. “Dad has not spoken to me since 2011. I really don’t know.” “
“I have mixed feelings about you going to see your dad,” Jim told Darby. “I think your mom did absolutely the right thing, keeping you away from him. 20 years ago, he had a lot of demons running around inside of him. … I hope I’m 100 percent wrong.”
“My husband says the same thing. He does not think this is a good idea,” Darby said. “Honestly, what I’m just really looking for from this is just some sort of acknowledgement. Just to see his face.’ Cause everyone says we have the same face shape.”
“At this point in my life, I feel like I owe it to myself to make that effort and see what kind of response I get,” she added, admitting that while she was “scared,” she felt empowered. “Before, what would hold me back is this fear that he will reject me. But it’s not so scary that I couldn’t get on the plane.
Darby’s mom just wants closure for her daughter.
“All I know is I am looking for my daughter to finally having some form of closure in my life,” Matthews said.
“Oh my god,” Matthews said in the preview. “There’s your father.”
You’ll have to wait until The Real Housewives of Potomac airs next Sunday (8 p.m. ET) on Bravo to find out what happens or if they get the door closed in their faces.
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Is RHOA star Porsha Williams back with her ex Dennis McKinley?
Porsha Williams and Dennis McKinley are reportedly back together again.
The Real Housewives of Atlanta star and her former fiancé broke the internet when they broke up earlier this year shortly after Williams gave birth to their baby Pilar in March.
—RHOA’ star Porsha Williams accuses LAX restaurant of being “completely racist.”—
Last season on the show, rumors swirled that McKinley was a lady’s man and her castmates worried and predicted that the relationship wouldn’t last.
The gossip mill also overflowed with reports that McKinley had cheated on Williams with WAGS Atlanta star Sincerely Ward. Ward however denied the affair and said she “never met” McKinley.
McKinley previously fought back against the rumors saying they were false.
But eventually the two broke up. It was a sad turn of events given that Williams fought hard against claims on her reality show by Kandi Burruss that McKinley was a playboy in Atlanta.
McKinley previously sent a statement to E! News in an attempt to clear the air. “These false and slanderous allegations against me are made solely to damage my reputation, jeopardize my ongoing businesses, and negatively impact my family,” he said at the time. “My attempts to ignore this slander have only empowered Latasha Kebe (aka Tasha K.) to create more false accusations. I am currently taking legal action—and am currently being represented by Michael T. Sterling of Dreyer Sterling, LLC.”
—RHOA’ star Porsha Williams accuses LAX restaurant of being “completely racist.”—
Now it’s a new day and a new season and filming has started all around Atlanta. A source confirmed to Us Weekly that Williams, 38 and McKinley, 39 have been spotted together and during a recent interview with the outlet she was sporting her engagement ring. They were also reportedly seen together on a RHOA cast trip too.
So, will bells be ringing sometime soon?
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