Ilana B. Witten facts for kids

Ilana B. Witten is an American neuroscientist and a professor at Princeton University. She studies the brain, especially how we learn about rewards and make decisions. Her work focuses on a part of the brain called the mesolimbic pathway, which is important for feeling pleasure and motivation.

Early Life and Education

Ilana Witten grew up in Princeton, New Jersey. Her parents were both professors at Princeton University. Her father, Edward Witten, was a theoretical physicist, which means he studied the basic laws of nature. Her mother, Chiara Nappi, was a physics professor.

Ilana went to Princeton High School. Then she stayed in her hometown to study at Princeton University for her first college degree. Her sister, Daniela Witten, also became a scientist, studying math and biology.

At Princeton, Ilana first studied physics. But during her time there, she became very interested in biology, especially how the brain works. In her first year, she helped with research in a lab that studied how living things work at a tiny level, looking at molecules and genes.

Later, she joined another lab where she used computers to study the brain. Her project was about how the eye's retina processes information. She graduated in 2002 with a degree in physics.

After college, Ilana wanted to learn more about the brain. So, in 2003, she went to Stanford University for her advanced studies in neuroscience. There, she worked with a mentor named Eric Knudsen. She explored how owls pay attention and process information in their brains.

How Barn Owls Process Sounds

Our brains are always trying to predict what will happen next. This helps us react quickly to changes around us. In her early research, Ilana Witten studied how barn owls predict where sounds are coming from, especially if the sounds are moving.

Owls have a special part of their brain called the optical tectum. This area helps them turn their heads and eyes towards a sound. Neurons in this area create a "map" of where sounds are in space. Ilana wanted to know how this map changes when sounds move. She found that the owl's brain actually shifts its sound map to predict where a moving sound will go.

She also looked at how the brain finds a single object when it gets many different kinds of sensory information. She suggested that the brain changes its connections based on how different senses (like sight and sound) represent the same object. Stronger signals from one sense could guide these changes. This helps the brain combine information from different senses to understand the world.

Using Light to Study Brain Circuits

After finishing her PhD in 2008, Ilana Witten continued her research at Stanford University. She joined the lab of Karl Deisseroth. There, she learned about a cool new tool called optogenetics. This technology uses light to control specific types of brain cells.

Ilana was especially interested in certain brain cells called cholinergic neurons. These cells are found in the brain's reward system. In 2010, she published an important paper showing how these tiny cells, which make up only 1% of the neurons in a brain area called the nucleus accumbens, play a huge role in controlling behavior. Her work showed that even a small group of neurons can have a big impact on how we act.

Ilana and Deisseroth even filed a patent for using optogenetics to study these specific neurons in the brain's reward system. They wanted to use this tool to better understand how rewards affect behavior in animals.

To do this, Ilana created special types of rats that allowed her to use optogenetics. By shining light on specific neurons in these rats, she could see how they affected reward-seeking behaviors. She confirmed that activating certain dopamine neurons in the rats' brains made them seek out more stimulation. This showed how powerful her new tools were for studying specific brain circuits in rats.

Ilana continued to study these brain circuits and the role of dopamine neurons in driving reward behaviors during her four years in the Deisseroth Lab.

Career and Research

In 2012, Ilana Witten became a professor at Princeton University. She started her own lab there. Her main goal was to understand the brain circuits that help us learn about rewards and make decisions.

Her lab uses many different techniques. They use optogenetics (light to control brain cells), study animal behavior, record brain activity (electrophysiology), take pictures of the brain (imaging), and use computer models. With these tools, Ilana and her team are discovering new ways that brain areas, especially the striatum, control our behaviors. In 2018, she became a tenured professor at Princeton, which means she has a permanent position.

Besides her research, Ilana also helps her university community. She is part of committees that help choose students for programs and design courses. She also teaches classes at Princeton. She is part of a big project funded by the National Institutes of Health (NIH) that studies how working memory helps us make decisions.

Understanding Reward Circuits

In 2016, Ilana Witten and her team published a paper about different groups of dopamine neurons in the brain. They found that dopamine neurons that connect to one part of the striatum (the ventral striatum) respond strongly to rewards and clues that predict rewards. But dopamine neurons that connect to another part (the dorsomedial striatum) respond more to choices that animals make.

Even though both groups of neurons showed "reward-prediction error" (meaning they reacted when a reward was different than expected), Ilana's findings showed that different parts of the striatum have specialized jobs when it comes to rewards.

She also continued to study the cholinergic neurons in the striatum, which she had worked on during her postdoctoral studies. Her new work showed how these neurons can change and control how we learn about rewards.

Brain Circuits for Social and Spatial Information

Since social interactions can feel rewarding, Ilana became interested in how the brain processes social information. In 2017, her team studied a special group of neurons in the prefrontal cortex (PL) that are involved in social behavior. These neurons connect to other important brain areas like the nucleus accumbens (NAc) and amygdala.

Interestingly, activating these PL-NAc connections actually made animals less social. So, Ilana and her team wanted to understand what kind of information these connections were carrying. They found that these neurons carried both spatial information (where things are) and social information. This allowed the brain to form connections between social situations and locations, which helps guide social behavior.

Different Roles for Dopamine Neurons

Ilana Witten and her colleagues then looked more closely at dopamine neurons in the VTA (Ventral Tegmental Area). While these neurons are well-known for their role in reward, they are also involved in many other behaviors. Ilana wanted to see if they encoded information about rewards, clues that predict rewards, past rewards, spatial location, movement, and choices.

Using a technique that allowed them to see brain activity in living animals, Ilana and her team found that different groups of VTA dopamine neurons were linked to both reward-related and non-reward-related information. These groups of neurons were also clustered together in specific areas within the VTA. This showed that dopamine neurons are more diverse in their functions than previously thought.

Awards and Honors

• 2017 Daniel X Freedman Prize for Exceptional Basic Research
• 2017-2022 NYSCF-Robertson Neuroscience Investigator Award
• 2017-2022 Simons Collaboration on the Global Brain Investigator
• 2017-2022 Co-PI on BRAIN Initiative U19
• 2015-2019 NIH R01 (from NIMH) 2015 PNI Innovation Award
• 2014-2016 McKnight Scholars Award in Neuroscience
• 2014-2017 Co-PI on BRAIN Initiative U01
• 2014-2015 NARSAD Young Investigator Award
• 2014 Award from Essig and Enright ’82 Innovation Fund
• 2013-2017 Pew Scholarship in the Biomedical Sciences
• 2013-2015 Alfred P. Sloan Research Fellowship
• 2013 Winter Conference Brain Research Travel Award
• 2012-2017 NIH Director's New Innovator Award
• 2009-2012 Helen Hay Whitney Foundation Postdoctoral Fellowship
• 2008 Swartz Travel Fellowship for CoSyNe
• 2008 2003-2006 NSF Graduate Research Fellowship
• 2002 Allen G. Shenstone Prize in physics
• 2002 High honors awarded by the Princeton Department of Physics
• 2002 Sigma Xi Research Honor Society nomination
• 2000 Lucent Technology Prize of the Princeton Department of Physics
• 1998 Edward J. Bloustein Scholarship

Select Publications

• Combined social and spatial coding in a descending projection from prefrontal cortex. Murugan M, Park M, Jang HJ, Miller E, Taliaferro J, Cox J, Parker NF, Bhave V, Nectow A, Pillow J, Witten IB. Cell. Dec 2017.
• Dissociated sequential activity and stimulus encoding in striatal neurons during spatial working memory. Akhlaghpour H, Wiskerke J, Choi JY, Taliaferro J, Au J, Witten IB. eLife. 2016; 10.7554/eLife.19507.
• Reward and choice encoding in terminals of midbrain dopamine neurons depends on striatal target. Parker NF, Cameron C, Taliaferro J, Choi JY, Lee J, Davidson T, Daw ND, Witten IB. Nature Neuroscience. 2016 Apr 25. doi:10.1038/nn.4287.
• Mesolimbic dopamine dynamically tracks, and is causally linked to, discrete aspects of value-based decision making. Saddoris MP, Sugam JA, Stuber GD, Witten IB, Deisseroth K, Carelli RM. Biol Psychiatry. 2015 May 15;77(10):903-11. doi: 10.1016/j.biopsych.2014.10.024. Epub 2014 Nov 13.
• Recombinase-driver rat lines: tools, techniques, and optogenetic application to dopamine-mediated reinforcement. Witten IB*, Steinberg E*, Lee SY, DavidsoTJ, Zalocusky KA, Brodsky M, Yizhar O, Cho SL, Gong S, Ramakrishnan C, Stuber GD, Tye K, Janak P, Deisseroth K. Neuron. 2011 Dec 8;72(5):721-33.
• A dominance hierarchy of auditory spatial cues in barn owls. Witten IB, Knudsen PF, Knudsen EI. PLoS ONE. 2010; 5(4): e10396.
• A Hebbian learning rule mediates asymmetric plasticity in aligning sensory representations. Witten IB, Knudsen EI, Sompolinsky H. Journal of Neurophysiology. 2008; 100(2): 1067–79.
• Dynamic shifts in the owl's auditory space map predict moving sound location. Witten IB*, Bergan JF*, Knudsen EI. Nature Neuroscience. 2006; 9(11):1439- 45.
• Why seeing is believing: merging auditory and visual worlds. Witten IB, Knudsen EI. Neuron. 2005; 48(3):489-96.