Jonathan Touboul is new Associate Professor in Mathematics

Jonathan Touboul is a new associate professor in the Department of Mathematics. He is also associated to the Neuroscience program, and member of the Volen National Center for Complex Systems. His research deals with mathematical equations modeling the behavior of neurons and networks of the brain. He is also interested in understanding how the brain is interconnected and if or how these interconnection patterns play a role information processing, learning and memory.

Prior to joining Brandeis, Jonathan Touboul led for a research team at Collège de France in Paris, within the Center for Interdisciplinary Research in Biology. He received his PhD in Mathematics from École Polytechnique (Paris) and spent some time as a postdoc at Pittsburgh University with Bard Ermentrout and at the Rockefeller University with Marcelo Magnasco.

At Brandeis, he intends to pursue his researches in models of large-scale neural networks, learning, memory and synchronized oscillations in Parkinson’s disease.

Grant funding for undergraduates doing Computational Neuroscience

The Division of Science is pleased once again to announce the availability of Traineeships for Undergraduates in Computational Neuroscience through a grant from the National Institute on Drug Abuse. Traineeships will commence in summer 2018 and run through the academic year 2018-19.

Please apply to the program by March 1, 2018 at 6 pm to be considered.

Computational Neuroscience undergraduate trainees were first authors on 2 papers in 2017; figure above from Christie et al., J. Neurophysiol., 2017

Traineeships in Computational Neuroscience are intended to provide intensive undergraduate training in computational neuroscience for students interested in eventually pursuing graduate research. The traineeships will provide approximately $5000 in stipend to support research in the summer, and $3000 each for fall and spring semesters during the academic year. Current Brandeis sophomores and juniors (classes of ’19, ’20) may apply. To be eligible to compete for this program, you must

  • have a GPA > 3.0 in Div. of Science courses
  • have a commitment from a professor to advise you on a research project related to computational neuroscience
  • have a course work plan to complete requirements for a major in the Division of Science
  • complete some additional requirements
  • intend to apply to grad school in a related field.

Interested students should apply online (Brandeis login required). Questions that are not answered in the online FAQ may be addressed to Steven Karel <divsci at brandeis.edu> or to Prof. Paul Miller.

Brandeis Alum, Tepring Piquado, Running for California State Assembly

Tepring Piquado CampaignThe career track for Brandeis alumni can lead them in interesting directions. Brandeis Alumna Tepring Piquado is running to represent California’s 54th Assembly District. The seat’s former occupant, Sebastian Ridley-Thomas, resigned in December. She is one of the candidates vying for the open seat in a special election, to be held April 3rd. Among the candidates are experienced political directors and activists. Dr. Piquado, a political newcomer, is the only neuroscientist.

While at Brandeis, Tepring was a part of Arthur Wingfield’s Memory and Cognition Lab, defending in 2010. Her research at Brandeis focused on the effects of aging and its impact upon the cognitive abilities of the elderly. While at Brandeis, Tepring was active in the Brandeis chapter of SACNAS. She currently serves as co-chair for the SACNAS Diversity and Inclusion Forum.

She now is a Research and Policy Scientist at the RAND Corporation. In speaking with us, Tepring said, “I love my job as a policy researcher at RAND Corporation where I provide policymakers with the best available information to help make decisions; but I’m ready to stand up and take part in state government.  My experience and expertise, coupled with my ability to think critically and act compassionately, make me the best person to address issues affecting our community.”

While speaking at the March for Science LA on April 22, 2017, Tepring said “Evidence matters! Research and analysis are only the means, not the End. Science gives us a process to find the best available data to help us get closer to the truth. The sooner we understand the facts; the sooner politicians can discuss policy solutions.”

You can join #TeamTepring or visit www.voteTepring.com to subscribe to her newsletter.

The Amygdala, Fraud and Older Adults

Figure from Zebrowitz-Gutchess paper

Figure 1. Peak amygdala activation as a function of face trustworthiness for older adult participants. Error bars represent standard errors. COPE is the contrast of parameter estimates [high or medium, or low trustworthy faces minus baseline fixation] from which peak values were extracted at the subject-level using FSL featquery. * p < .05.

There is a widespread belief that older adults are more vulnerable to consumer fraud than younger adults. Behavioral evidence supporting this belief is mixed, although there is a reliable tendency for older adults to view faces as more trustworthy than do younger adults.  One study provided supporting neural evidence by demonstrating that older adults failed to show greater amygdala activation to low than high trustworthy faces, in contrast to considerable evidence that younger adults do show this effect. This result is consistent with the argument for greater vulnerability to fraud in older adults, since the amygdala responds to threatening stimuli. More generally, however, the amygdala responds to biologically salient stimuli, and many previous studies of younger adults have shown that this includes not only threatening, low trustworthy faces, but also high trustworthy faces. The Zebrowitz Face Perception Lab therefore included medium trustworthy faces in order to detect separate effects of high trustworthiness and low trustworthiness on amygdala activation in older adults, something that the one previous study of older adults did not do. Consistent with that study we found that older adults did not show stronger amygdala activation to low than high trustworthy faces.  However, they did show stronger amygdala activation to high than to medium trustworthy faces, with a similar trend for low vs medium, although that difference was not strong enough to be confident that it would replicate (See Figure 1).

The fact that older adults did not show greater amygdala activation to low than medium or high trustworthy faces is consistent with the suggestion that older adults may be more vulnerable to fraud. However, an important question is whether vigilant responding to untrustworthy-looking faces could actually protect one from fraud.  Arguing against this possibility is the finding that although younger adults have consistently shown greater amygdala activation to people who look untrustworthy, they do not show greater activation to those who actually cheat.  On the other hand, some evidence indicates that facial appearance does provide valid cues to threat. Face shape not only influenced younger adults’ trust of potential exploiters, but it also proved to be a valid indicator of economic exploitation.  Furthermore, this face shape cue influenced both younger and older adults’ accurate impressions of aggressiveness. To shed further light on neural mechanisms for any age differences in vulnerability to fraud that may exist requires investigating: 1) the sensitivity of neural responses to actual differences in trustworthiness in the domain of economic exploitation, and 2) whether any age differences in those neural responses are related to differential vulnerability to economic exploitation.

Zebrowitz, L.A., Ward, N., Boshyan, J., Gutchess, A., & Hadjikhani, N. (2017).  Older adults’ neural activation in the reward circuit is sensitive to face trustworthiness.  Cognitve, Affective, and Behavioral Neuroscience.

 

 

Communicating Memory Information Between the Hippocampus and Prefrontal Cortex

Jadhav paper full image

The brain has a remarkable capacity to record our daily experiences and recall this stored information to guide our behavior. For example, every time you decide to get a cup of coffee on campus, you immediately know where to go and then step toward your destination. The ability to successfully memorize paths and navigate in the environment is fundamental for animals searching for food (see Illustration), as well as for humans surviving in a complicated environment, especially when you don’t have your smartphone to rely on, but only your brain as the inner GPS! However, how does the brain learn and remember such plans that allow us to get from one place to another?

We know that a structure in brain called the hippocampus plays an important role in encoding and storing memories. The hippocampus is thought to replay remembered experiences during fast, ripple-like brain waves, termed sharp-wave ripples (SWRs), that occur during “down-time” for the brain, i.e., offline periods during sleep and during pauses in active behavior. It has been previously shown by Jadhav and colleagues that selectively disrupting these ripple oscillations using precisely-timed electrical impulses impairs the ability of animals to learn in spatial mazes, suggesting that this “mental replay” is important for navigation and memory (Jadhav et al., 2012, Science). Notably, mental replay is not isolated activity in the hippocampus, but works together with the prefrontal cortex (PFC), the executive center of brain involved in storing memories and making decisions (Jadhav et al., 2016, Neuron). However, exactly how such memory replay supports memory processing in waking and sleep states had remained elusive.

In a new article published in the Journal of Neuroscience (Tang et al., 2017), the Jadhav lab (the team included Neuroscience graduate students Wenbo Tang and Justin Shin) used high-density electrophysiology to record large numbers of neurons in both the hippocampus and prefrontal cortex in both sleep and awake states. They discovered that as rats learned a spatial memory task, the activity in the hippocampal-prefrontal network replayed recent experiences in a precise manner during SWRs that occurred when animals paused from actively exploring the maze. This structured mental replay related to ongoing spatial behavior is ideally suited for storing and retrieving memories to inform decisions. When animals were asleep after exploring the maze, the hippocampal-prefrontal replay, however, appeared “noisy” and mixed. This replay occurring during sleep periods can support the ability of the brain to consolidate memories, by selectively integrating related memories to build a coherent map for long-term storage (see Illustration). These findings show how memory information is communicated between the hippocampus and PFC during ripple oscillations, and indicate that mental replay during sleep and awake states serve distinct roles in memory. These studies collectively provide fundamental knowledge about the neural substrates of memories. They will thus provide important insights into memory deficits that are prevalent in many neurological disorders that involve the hippocampal-prefrontal network, such as Alzheimer’s disease and schizophrenia.

Hippocampal-Prefrontal Reactivation during Learning Is Stronger in Awake Compared with Sleep States. Wenbo Tang, Justin D. Shin, Loren M. Frank and Shantanu P. Jadhav. Journal of Neuroscience 6 December 2017, 37 (49) 11789-11805.

 

Clocks, fruit flies, and Sweden

We mentioned previously that Rosbash, Hall and Young are getting the Nobel Prize in Physiology or Medicine this year “for their discoveries of molecular mechanisms controlling the circadian rhythm”.

The Physiology/Medicine lectures were on Thursday Dec 7 at 1 pm CET (7 am Brandeis time) and are still available to view. The Biology Department enjoyed watching the lectures on “tape delay”:

From and about the winners, via Cell:

About the science and its implications:

If you need to flesh out your fantasy of going to Sweden to collect your prize, see What to expect when you’re expecting a Nobel Prize

Video:

Circadian Rhythms and When to Eat (Swedish Television)

 

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