Samantha Butler

Samantha received her B.A from Cambridge University, working in Michael Akam’s laboratory, where she was instilled with a love of developing systems. She joined Yash Hiromi’s lab, then at Princeton University, for her Ph.D. studying the genetic mechanisms that establish cell fate in the Drosophila eye.  Since neurons had become increasingly important to her as she lost them during her years as a graduate student, she joined Jane Dodd’s laboratory at Columbia University to examine axon guidance mechanisms in the developing vertebrate spinal cord.

In her own laboratory as a Professor at UCLA, Samantha explores how the developmental mechanisms that first establish neural circuits can be reused to ameliorate damaged or diseased nervous systems.  She holds the Eleanor I. Leslie Chair in Pioneering Brain Research, and is funded by the NIH, CIRM, Department of Defense, March of Dimes and the Ablon, Rose Hills, Craig H. Neilsen and Jean Perkins foundations.  She is currently Vice Chair for Equity, Diversity and Inclusion in the Department of Neurobiology.

Sandy Alvarez

Sandy received her Bachelor of Science in Biology from the University of California Irvine. Soon after, she began her Masters studies at California State University, Los Angeles, where she studied effectors of the innate mucosal immune system. After completing her Masters, she made the long trek over to UCLA, where she is currently a graduate student in the Butler Laboratory. Sandy is interested on gaining a better understanding of the molecular mechanisms that regulate axon guidance. She hopes that this information can be applied to the prevention of neurodevelopmental defects and to the repair and regeneration of damaged nervous systems. Outside of the lab, she likes to run, hike, visit art museums and watch documentaries.

Salena Gallardo

Salena received her Bachelor of Science in Biochemistry from California State University, San Marcos. During her undergraduate studies, she was a California Institute for Regenerative Medicine (CIRM) Bridges to Stem Cell Research scholar, completing a one year internship in Larry Goldstein’s lab at the University of California San Diego. While at UCSD Salena utilized induced pluripotent stem cells to investigate the etiology of Late Onset Alzheimer’s Disease. As a graduate student in the Butler laboratory, Salena is interested in further defining the molecular mechanisms and signaling pathways that give rise to different classes of dorsal interneurons. Broadly, Salena hopes her research will aid in the development of novel therapeutics for damaged or diseased nervous systems. Apart from the lab, she enjoys running, camping, and spending time with her friends and family.

Yesica Mercado-Ayon

Yesica was born in Jalisco, Mexico and moved to California when she was 10.  She was a Cell Molecular and Developmental Biology undergraduate at the University of California, Riverside, where she studied the biogenesis of small RNAs in C. elegans.  She then joined the NIGMS Postbaccalaureate Research Education Program at UC Davis, to examine retinal ganglion cell differentiation.   Now in the Butler lab at UCLA, she is studying axon guidance mechanisms in early circuit formation.  She was awarded a Graduate Research Fellowship from the NSF.  Outside of lab, Yescia enjoys playing old school video games, watching psychological thrillers and trying new foods.

Keith Phan

Keith recieved his B.S. in Bioengineering from University of California at San Diego.  His research interests include understanding the mechanism by which commissural axons in the developing spinal cord make their rostral turn at the floorplate. For fun, he relives his youth through 80’s music and TV sitcoms.

Sandeep Gupta

Sandeep received his PhD in 2015 from the Indian Institute of Technology Kanpur, India.  In his graduate work, he studied the process of forebrain roof plate invagination and development of roof plate derived structures such as choroid plexus and hippocampus in chicken embryos.  Sandeep joined the Butler lab in 2015 and is interested in understanding how BMP signaling performs diverse functions such as patterning and regulating the neuronal growth in dorsal spinal cord.  His broad research interests are neural development and patterning, the molecular mechanisms of signaling pathways and regeneration. Apart from science, he enjoys exploring new places, spending time with friends, swimming, playing violin and Indian classical music.

Soizic Riche

Soizic received her PhD in 2015 from the Superior Normal School of Lyon, France.  In her graduate work, she studied the molecular mechanism of the spindle positioning during the first asymmetric division in one-cell Nematodes embryos.  Soizic is interested in understanding the molecular mechanisms underlying in the regeneration and repair of damaged or diseased nervous system. Outside of the lab, she enjoys travelling, trying new restaurants and reading or watching manga.

Pionik Shahgholian

Pionik Shahgholian is a Cell and Molecular biology major at California State University Northridge, who was first an CIRM Bridge research intern in the Butler lab and now has stayed on as a research assisstant. Pionik’s project aims to understand the molecular program of spinal cord development to improve methods of deriving spinal sensory interneurons from stem cells. Pionik likes to travel and train at the gym in her free time.

Cristian Rodriguez

Cristian Rodriguez is majoring in Cell and Molecular Biology at California State University Northridge, currently working in the Butler lab as a CIRM Bridges intern.  Cristian is interested in using stem cells as a model system to further understand the molecular mechanisms that pattern the dorsal spinal cord. He loves the outdoors, riding his motorcycle, and grilling.

Antonella del Toro

Antonella is a Molecular, Cell, and Developmental Biology major, and Biomedical Research Minor at UCLA. In the Butler Lab, she is researching the molecular processes that underlie axonal regeneration in the peripheral nervous system. In her free time, Antonella enjoys going to the beach, traveling, and spending time with her family.

Andyshea Afyouni

Andrew (Andyshea) is a Neuroscience major and Biomedical Research minor at UCLA. In high school, Andrew investigated the role of the dorsal medial hypothalamus in exaggerated cardiac reflex responses in the Longhurst laboratory at UCI.  Andrew is now working with the Butler Laboratory to designing ways to rebuild the sensory circuits of the spinal cord through stem cell-derived sensory neurons.  In his down time, Andrew loves singing, enjoys eating acai bowls, and cherishes any time he can spend with his two dogs and 2-year-old niece back in Irvine.

Andy is now medical student at UCI.

Madeline Andrews

Madeline received her Bachelor of Science in Psychology from Arizona State University in 2010 where she researched the effect of hormones on cognitive function during the aging process. She graduated from the Butler laboratory in May 2017, after researching the role of the Bone Morphogenetic Proteins in spinal cord development. Her research interests include neural development, stem cell biology and nervous system regeneration and repair. Outside of the laboratory, Madeline enjoys yoga, hiking, rock climbing, snowboarding and spending time at her favorite place, the beach.

After being a postdoc in Arnold Kreigstein’s lab at UCSF, Madeline is now an Assistant Professor at Arizona State.

Marcos Ayon

Marcos Ayon is a Psychobiology Major and Biomedical Research Minor at UCLA. Marcos is working on understanding the molecular mechanisms of axonal regeneration in the peripheral nervous system. In his free time, Marcos enjoys reading at sunset and having game nights with friends.

Jongseung Baek

Jongseung Baek is a Molecular, Cell, and Developmental Biology major and Biomedical Research minor at UCLA, working on axonal regeneration. His scientific interests include neuroregeneration, bioengineering, and bionics. During his free time, Jongseung enjoys playing strategy games, people watching, and hanging out with his friends.

David Bursalyan

David Bursalyan is a Biology major at California State University Northridge, who has joined the Butler lab as a CIRM Bridges trainee.  David is working on developing a stem cell model for neuromuscular junction disorders.  In his free time, David enjoys playing sports and spending time with his friends and family.

David is currently in the osteopathic medicine program at Touro University, Nevada.


Stephanie Castellanos

Stephanie is a Biology major at California State University, Northridge, who has joined the Butler lab as a CIRM Bridges CSUN-UCLA Stem Cell trainee. She is examining the the consequence of deleting Smad proteins on the development of  dorsal spinal sensory interneurons. In her free time, Stephanie enjoys watching Youtube and anime, playing with her dog, and hanging out with friends and loved ones.

Brian Chilin

Brian is a Biotechnology major at California State University Northridge, who has joined the Butler lab as a CIRM Bridges CSUN-UCLA Stem Cell trainee.   He is examining the mechanisms by which mESC can be directed to differentiate spinal sensory interneurons.  In his free time, Brian enjoys playing basketball, going on road trips, and spending time with friends and family.

Brian is now attending the Penn State College of Medicine.

Alexandra da Silva

Alexandra da Silva is a Microbiology, Immunology, and Molecular Genetics Major, Biomedical Research Minor at UCLA. Her undergraduate research in the Butler laboratory involves studying nerve regeneration and its relationship to immunosuppression. Her career goals include achieving an M.D./Ph.D., working in both a clinical and research setting. Outside of school, Alexandra enjoys going to concerts, relaxing at the beach, and spending time with her family.

Ali is now attending medical school at California Northstate University College of Medicine.

Lorenzo del Castillo

Lorenzo Del Castillo was a member of the 2014 CIRM Bridges to Stem Cell Research program as a Cell and Molecular Biology major at CSUN.   He defined a mESC directed differentiation protocol that permits the BMPsto be used to generate in vitro derived spinal senosory interneurons.  His scientific interests include developmental biology, genetics, and cell biology. Outside of the lab, Lorenzo enjoys going to see live music, hanging out at the beach, traveling, and playing his ukulele.

Lorenzo is currently a graduate student in the UCSF TETRAD program.

Gabriela Gajardo Del Real

Gabriela Gajardo Del Real is a Biology major at California State University Northridge, currently working in the Butler lab as a CIRM Bridges trainee.  Gabriela is interested in using novel stem cell model systems to study degenerative diseases that affect the peripheral and central nervous systems.  She is an international student from Chile, and in her free time, Gabriela enjoys going outdoors, trying new food, roller skating, and spending time with her puppy.

Armo Derbarsegian

Armo Derbarsegian received his B.S. in Molecular, Cell, and Developmental Biology from UCLA in 2019. While working in the Butler Laboratory, Armo researched the effects of R-SMADs on cell fate acquisition and axon guidance decisions during interneuron development. Armo’s research interests include neural development and neurodegenerative disease. During his free time, Armo enjoys skiing, hiking, and camping.

Michele Frendo

Michele Frendo received her B.S. degree in Biomedical Engineering at the University of California, Davis in 2008. She will be graduating from the University of Southern California with her PhD in Neuroscience in May 2014. Michele’s research interests include neural development, neuroregeneration and neurodegenerative diseases. In her free time, Michele enjoys snowboarding, baking, cooking, reading, hiking, bicycling, planning events, sewing, traveling and spending time with her family.

Michele is currently on the faculty of Nevin Platt Middle School, Boulder, CO.

Samantha Hain

Samantha Hain is a Cell and Molecular Biology major at CSUN.  She participated in the 2016 CSUN-UCLA Bridges to Stem Cell Research Program, and was the first to show that BMPs could be used to direct human iPS cells towards dorsal spinal interneural fates. Outside of the lab Samantha enjoys reading, art, going to the beach, and spending time with family and friends.

Sammie is currently back at CSUN, completing her masters in the de Bellard laboratory.

Ginger Hazen

Graduate student (2005-2011)

Ginger is currently a Professional Development Specialist in the Postdoctoral and Visiting Scholar Affairs office (UCSD).

Kaitlyn Honeychurch

Kaitlyn Honeychurch graduated UCLA with a major in Molecular, Cell, and Developmental Biology and minor in Biomedical Research. She is investigating the role of netrin in chick embryonic spinal cords and identifying the classes of axons that are affected by the loss of netrin. During her free time, Kaitlyn enjoys reading, hiking, traveling, and spending time with friends and family.

Kaitie is now a medical student at UC Davis.

Christian Makkar

Christian Makkar is a Biotechnology major at CSUN. He is participating in the CSUN-UCLA Bridges to Stem Cell Research Program where he will be investigating the role of Id proteins and their interactions with BMPs specifying cell fate in developing spinal cords.  During his free time, Christian enjoys surfing, hiking, traveling and enjoying times with friends and family.

Ari Migdale

Ari Migdale is a Neuroscience major, Spanish minor at UCLA.  As an undergraduate researcher in the Butler laboratory, he is interested in the potential use of stem cells to regenerate damaged spinal cord circuits.  His other interests span physiology, neuroregeneration, neuroplasticity, and molecular biology. An outdoor enthusiast, Ari enjoys backpacking, hiking, surfing and rock climbing. He is also an avid musician and drummer.

Eliana Ochoa-Bolton

Eliana Ochoa-Bolton is a Cellular and Molecular Biology major at CSUN. She is a participant of the 2015 CIRM Bridges to Stem Cell Research cohort. She is investigating the mechanistic basis by which BMPs direct cell fate in the dorsal spinal cord throughout embryogenesis. During her free time, Eliana enjoys going to plays, concerts, beach days with her dogs, traveling, and spending time with her loved ones.

Eliana is now part of the Clinical Lab Scientist Trainee program at Los Robles Thousand Oaks Hospital.

Carmen Panaitof

Postdoctoral fellow (2010-2011)

Carmen is currently an Assistant Professor at the University of Nebraska, Kearney.

Ashok Reddy

Ashok Reddy is a Molecular, Cellular, and Developmental Biology major at UCLA. Ashok is interested in studying and altering the expression patterns of proteins involved in axon guidance during embryogenesis. He likes to spend his free time running, playing guitar, and learning photography.

Sanamjit Singh

Sanamjit is a Physiological Sciences Major at UCLA and was a laboratory assistant in the Butler lab.  In his free time he enjoys hiking, running and playing basketball.

Daniel Sivalingam

Dan received his B.S. in Cell and Molecular Biology from California State University Northridge. He started working at UCLA in his final year as an undergrad in the CIRM Bridges program. He was an an SRA in the Butler and Novitch laboratories, interested in the development of interneurons in the dorsal neural tube and  using stem cell technology to study neural disease. When he is not in lab, Dan enjoys backpacking, rock climbing, scuba diving, brewing beer, trap shooting, riding his motorcycles and reading.

Dan currently has a position at Kite Pharma.

Jenna Tijerina

Jenna is a Neuroscience Major and Biomedical Research Minor at UCLA.  In the Butler Lab, she investigates the molecular mechanisms of axon guidance. In her free time she enjoys powerlifting and exploring LA as an amateur foodie.

Stephen Tymanskyj

Postdoctoral fellow (2010-2012)

Stephen is currently a postdoctoral fellow in the Ma laboratory, USC.

Supraja G Varadarajan

Supraja received her Bachelor of Engineering in Biotechnology from Visvesvaraya Technological University in Bangalore, India, following which she completed her Masters in Biomedical Engineering from New Jersey Inst. of Technology. She spent two years as staff at UCI working with the Christopher and Dana Reeve Foundation Core, studying regenerative approaches to spinal cord injury using biomaterial scaffolds. Sup graduated from the Butler lab in May 2018 after redefining the role of netrin1 in spinal circuit formation.  In her spare time she likes to bake and read.

Sup is now a postdoctoral fellow in Andy Huberman’s lab at Stanford.

Ken Yamauchi

Graduate student (2005-2011)

Ken is currently a postdoctoral fellow in the Novitch laboratory at UCLA.

Diane Zhao

Diane Zhao is a physiological sciences major at UCLA. She is investigating the mechanisms of sciatic nerve regeneration.  In her free time, she enjoys eating ice cream, watching horror movies, and looking at cute corgi photos.


Coco is the lab dog.  She likes meeting new people and greeting them over enthusiastically, but she mostly spends her time snoozing.  Her favorite things to do are playing fetch and eating chicken.

Coco passed away in June 2022.  She is much missed.


Matilda is our second lab dog.  She loves shredding paper, sleeping in her den and greeting visitors.