Research Funding For Undergrads: Division of Science Fellowships

The Division of Science announces the opening of the Division of Science Summer Undergraduate Research Fellowship competition for Brandeis students doing undergraduate research in Summer 2017.  These fellowships are funded by generous alumni donations.

New this year are the Helaine B. Allen Summer Fellowships. These fellowships are for students working with Brandeis faculty members focusing in the sciences, specifically in the fields of Biochemistry, Biology, Biophysics, Chemistry, Neuroscience, and/or Physics.  There are five $5,000 awards available, each with $1,000 additional funding for laboratory supplies/support. See the Div Sci website for details of additional programs.

The due date for applications  is February 27, 2017,  at 6:00 PM EST.

Students who will be rising Brandeis sophomores, juniors, or seniors in Summer 2016 (classes of ’18, ’19, and ’20), who in addition are working in a lab in the Division of Science at the time of application, are eligible to apply. A commitment from a Brandeis faculty member to serve as your mentor in Summer 2017 is required.

The Division of Science Summer Program will run from May 30 – Aug 4, 2017. Recipients are expected to be available to do full time laboratory research during that period, and must commit to presenting a poster at the final poster session (SciFest VII) on Aug 3, 2017.

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>.

Research Funding for Undergrads: M. R. Bauer Fellows

The Division of Science is pleased to announce that a generous gift from the M. R. Bauer Foundation will again this year fund ten M. R. Bauer Foundation Summer Undergraduate Research Fellows. The due date for applications for Summer 2017 is February 27, 2017 at 6:00 PM EST. 

M. R. Bauer Fellows will receive $5000 as a stipend in support of their summer research (housing support is not included). Students who will be rising Brandeis sophomores, juniors, or seniors in Summer 2016 (classes of ’18, ’19, and ’20), are eligible to apply. A commitment from a Brandeis Division of Science faculty member to serve as mentor in Summer 2016 on a project leading to a senior thesis is required.

The Division of Science Summer Program will run from May 30 to Aug 4, 2017. M. R. Bauer Fellows are expected to be available to do full time laboratory research during that period, and must commit to presenting a poster at the final poster session (SciFest VII) on August 3, 2017. M.R. Bauer Fellows are also expected to give back to the University in ways that promote science and research.

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>.

Recycling is good for your brain

If you were able to remember where you put your keys on your way out the door this morning, it’s because – somehow – synapses in your brain changed their properties to encode this information and store it until you needed it. This process, known as “synaptic plasticity”, is essential for the continuity of our memory and sense of self, and yet we are only beginning to grasp the molecular mechanisms that enable this amazing feat of constant information storage and retrieval. Now a collaborative paper from the Turrigiano and Nelson labs just published in Cell Reports sheds important new light into how experience interacts with the genome to allow synapses to change their strength to store information.

Synapses are the connections between neurons, and it has long been appreciated that information is stored in large part through changes in the strength of these connections. Changes in strength at many synapses are in turn determined by the number of neurotransmitter receptors that are clustered at synaptic sites – the more receptors synapses have, the easier it is for neurons to excite each other to transmit information. Synapses are highly complicated molecular machines that utilize at least 300 different proteins that interact to traffic these receptors to synapses and sequester them there, and exactly how a change in experience alters the function of this nano-machine to enhance the number of synaptic receptors is still a matter of puzzlement.

In this study the Brandeis team devised a way to screen for candidate proteins that are critical for a particular form of synaptic plasticity: “synaptic scaling”, thought to be especially important for maintaining brain stability during learning and development. They were able to induce synaptic scaling within specific labelled neurons in the intact mouse brain (layer 4 star pyramidal neurons), and then sort out those labelled neurons from the rest of the brain and probe for changes in gene expression that were correlated with (and potentially causally involved in) the induction of plasticity.  This approach produced a small number of candidate genes that were up- or down-regulated during plasticity, to produce more or less of a given protein.  The team then went on to show that – when upregulated – one of these candidates (known as µ3A) acts to prevent neurotransmitter receptors from going into the cellular garbage bin (the lysosomes, where proteins are degraded) and instead recycles them to the synapse. Thus increased µ3A flips a switch within cells to enhance receptor recycling, and this in turn increases synaptic strength.

µ3A plays a critical role in the recycling of AMPA-type neurotransmitter receptors

A screen for genes with altered expression during synaptic plasiticity in specific neurons revealed that µ3A plays a critical role in the recycling of AMPA-type neurotransmitter receptors at the synapse. When this protein is upregulated, it prevents receptors from being trafficked into lysosomes, and instead allows them to be recycled back to synapses, increasing synapse number and enhancing synaptic strength.

It turns out that many other forms of synaptic plasticity use the same receptor recycling machinery as synaptic scaling, so it is likely that this mechanism represents  an important and general way for neurons to alter synaptic strength. This study also raises the possibility that defects in this pathway might contribute to the genesis of neurological disorders in which the stability of brain circuits is disrupted, such as epilepsy and autism. So next time you complain about having to sort your garbage, consider that your neurons do it all the time –  and what’s good for the planet turns out to be good for your brain as well.

Steinmetz CC, Tatavarty V, Sugino K, Shima Y, Joseph A, Lin H, Rutlin M, Lambo M, Hempel CM, Okaty BW, Paradis S, Nelson SB, Turrigiano G. Upregulation of μ3A Drives Homeostatic Plasticity by Rerouting AMPAR into the Recycling Endosomal Pathway. Cell reports. 2016.

SciFest VI recap and stats

photo credit: Mike Lovett

photo credit: Mike Lovett

The Brandeis University Division of Science held its annual undergraduate research poster session SciFest VI on August 4, 2016, as a record number of student researchers presented posters with the results of their summer’s (or last year’s) worth of independent research. We had a great audience of grad students, postdocs, faculty, proud parents, and senior administrators.

More pictures and abstract books are available at the SciFest site.

SciFest VI by numbers

Neurons that make flies sleep

Sleep is known to be regulated by both intrinsic (what time is it?) and environmental factors (is it hot today?). How exactly these factors are integrated at the cellular level is a hot topic for investigation, given the prevalence of sleep disorders. Researchers in the Rosbash and Griffith labs are pursuing the question in the fruit fly Drosophila melanogaster, to take advantage of the genetic tools in the model system and the excellent understanding of circadian rhythms in the fly.

Like other animals, the fruit fly displays a robust activity/sleep pattern, which consists of a morning (M) activity peak, a middle-day siesta, an evening (E) activity peak and nighttime sleep. M and E peaks are controlled by different subgroups of circadian neurons such as wake-promoting M and E clock cells.

In a paper just published in Nature, Brandeis postdoctoral fellow Fang Guo and coworkers identify a small group of circadian neurons, a subset of the glutamatergic DN1 (gDN1s) cells, which have a critical role in both types of regulation. The authors manipulated the gDN1s activity by using recently developed optogenetics tools, and found activity of those neurons is both necessary and sufficient to promote sleep.

circadian-feedback

The cartoon model illustrates how the circadian neuron negative feedback set the timing of activity and siesta of Drosophila. The arousal-promoting M cells (sLNv) release pigment-dispersing factor (PDF) peptide to promote M activity at dawn. PDF peptide can activate gDN1s, which release glutamate to inhibit arousal-promoting M and E (LNds) cells and cause a middle-day siesta. At evening, the gDN1s activity is reduced to trough levels and release E cell activity from inhibition.

DN1s enhance baseline sleep by acting as feedback inhibitors of previously identified wake-promoting M and E clock cells, making them the first known sleep-promoting neurons in this circadian circuit. It is already known that M cell can activate gDN1s at dawn. Thus the daily activity-sleep pattern of Drosophila is timed by the circadian neuron negative feedback circuitry (see Figure).  More interestingly, by using in vivo calcium reporters, the authors reveal that the activity of the gDN1s is also shown to be sexually dimorphic, explaining the well-known difference in daytime sleep between males and females. DN1s also have a key role in mediating the effects of temperature on daytime sleep. The circadian and environmental responsiveness of gDN1s positions them to be key players in shaping sleep to the needs of the individual animal.

Authors on the paper include postdocs Guo, Junwei Yu and Weifei Luo, staff member Kate Abruzzi, and Brandeis graduate Hyung Jae Jung ’15 (Biology/HSSP).

Guo F, Yu J, Jung HJ, Abruzzi KC, Luo W, Griffith LC, Rosbash M. Circadian neuron feedback controls the Drosophila sleep-activity profile. Nature. 2016.

Celebrating Chris Miller at Christravaganza Millerpalooza

Since its founding at Brandeis in 1976, Chris Miller’s lab has been home to 25 graduate students and 35 postdocs. Many of them, together with friends and colleagues from around the world, came together on July 8 and 9 for a two day symposium celebrating Chris’ 70th birthday.

For four decades Miller has used electrophysiological methods to study single ion channels. Ion channels are proteins that open and close, selectively allowing specific ions to cross cell membranes, for example to drive muscle contraction or nerve cell signaling. The selective transport of ions across membranes is a fundamental feature of cells.

Miller began studying channels selective for potassium ions, and then in 1978 discovered a chloride selective channel, from Torpedo, the first member of the important CLC chloride channels whose malfunction is implicated in a variety of diseases. (Its name comes from the electric ray Torpedo californica from which the channel was first isolated.) Chris discovered the unusual “double barreled” architecture of the CLC family of ion channels. The lab continues to work on related proteins, including Cl/H+ exchange-transporters.

Miller’s lab has followed clues in recent years to find additional novel channels to study, including bacterial proteins involved in acid resistance and most recently channels that are selective for fluoride. Chris has been a Howard Hughes Medical Institute investigator since 1989 and in 2007 he was elected to the US National Academy of Sciences.

Rod MacKinnon ’78 was Chris’ very first student while he was an undergraduate at Brandeis. After medical school, Rod came back to Chris’ lab as a postdoc, and together they investigated the mechanism of calcium activated potassium ion channels. Later, at Rockefeller University, Rod used high resolution x-ray diffraction to determine the complete molecular structure of the proteins that form the channel. For this he was awarded the Nobel Prize for Chemistry in 2003. The structure confirmed a cartoon picture of how the potassium channel works that Chris, with postdoctoral fellows MacKinnon and Jaques Neyton, had developed ten years earlier.

Chris’ wife, Brandeis Professor of Russian and Comparative Literature Robin Feuer Miller, and their three daughters were in attendance. Lulu Miller (who is also co-host of the NPR program Invisibilia) introduced her father for the final talk of the symposium.

The editors thank Dan Oprian for help with this article. The photographs were taken by Heratch Ekmekjian.

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