Hydra Module

In this module, students will lean how to image and decipher brain activity using HydraHydra is a freshwater cnidarian (relative to jellyfishes) and is interesting because cnidarians represent the simplest nervous systems in evolution, so studying them could reveal basic principles of neural circuits and how they relate to behaviour. The Hydra nervous system is apparently simple, formed of two diffuse nerve nets (ectodermic and endodermic), which have sensory-motoneurons, ganglia neurons and mechanoreceptor cells named nematocytes. All of these cells differentiate from a common stem cell, which are continuously regenerating, making Hydra essentially immortal. In addition, Hydra is transparent and can be genetically engineered to express calcium indicators in every neuron of its nerve nets, so it is possible to image the activity of every neuron in the animal, while it is behaving. Because of these experimental advantages, it is not inconceivable that, soon, one maybe able to “break the code” of the nervous system in Hydra and decipher how its activity related to behavior in a systematic fashion. Finally, Hydra is a fun and cute preparation to work with and the Hydra research community, which will be well represented in the NS&B course, is a warm and welcoming one!

Fun fact! The idea for the Hydra Module occurred when Rafael Yuste visited the course in 2014 to give this Wednesday night lecture!

Hydra Module Faculty and Teaching Assistants

Rafael Yuste
Columbia University

Rafael Yuste is Professor of Biological Sciences and Neuroscience at Columbia University. He was born in Madrid, where he obtained his MD at the Universidad Autónoma. After a brief period in Sydney Brenner’s laboratory in Cambridge, UK, he performed Ph.D. studies with Larry Katz in Torsten Wiesel’s laboratory at Rockefeller University and was a postdoctoral student of David Tank at Bell Labs. In 1996 he joined the Department of Biological Sciences at Columbia University, where he is Full Professor. In 2005 he became HHMI Investigator and co-director of the Kavli Institute for Brain Circuits and in 2014 Director of the Neurotechnology Center at Columbia. Yuste is interested in the endogenous function of neural circuits, using both mouse visual cortex and Hydra vulgaris as experimental preparations. To study these questions, Yuste has pioneered the development of imaging techniques, such as calcium imaging of neuronal circuits, two-photon imaging of spines and circuits, photostimulation using inorganic caged compounds, two-photon optogenetics and holographic spatial light modulation microscopy. Yuste has obtained many awards for his work, including New York City Mayor’s, the Society for Neuroscience’s Young Investigator and the NIH Director Pioneer Awards. Finally, he led the group of researchers who proposed the Brain Activity Map Project, recently sponsored by the White House’s BRAIN initiative. Rafael was a Wednesday night lecture in 2014 when he was inspired to bring the Hydra module to NS&B in 2015.


robsteeleRob Steele
UC Irvine

My laboratory has been using Hydra as a model system to investigate questions in developmental and evolutionary biology since I joined the UC Irvine faculty in 1986. In 1989, my lab published the first paper describing the cloning of a Hydra protein-coding gene. I was the corresponding author on the Hydra genome paper that was published in Nature in 2010. Hydra is well known for its regenerative powers, its robust patterning system, its simple nervous system, and its lack of senescence. We are using a variety of approaches to manipulate genes in Hydra in an attempt to understand the molecular foundations of the remarkable biology of this seemingly simple animal. Hydra is a member of the animal phylum Cnidaria, which is the sister group to Bilateria, the animal group that includes humans; thus our studies with Hydra will inform us about human biology. Rob joined the Hydra faculty in 2015.




Shuting Han
Columbia University

Shuting Han is a fourth year graduate student in the Biological Sciences program in Columbia University. She received her B.S. from Peking University in 2013, and joined Yuste lab in 2014. She is interested in using Hydra as a model organism to study behaviors and the underlying neural networks. Her research currently focuses on developing an automatic behavior identification and classification algorithm for Hydra with machine learning approaches, but she also aims at constructing a full behavior map for Hydra and further modeling the neural networks for behaviors.

Shuting was a Hydra TA in 2015 and NS&B student in 2016.





John Szymanski
Columbia University

John Szymanski is a fifth year graduate student in the Integrated Program in Cellular, Molecular and Biomedical Studies at Columbia University.  He did his undergraduate studies at Brown University, working with Dr. Gilad Barnea on a molecular tool for trans-synaptic labeling of neural circuits.  His thesis work in the Yuste Lab is focused on mapping the structure of causal interactions in the Hydra nerve net using whole-animal calcium imaging and optogenetics.  He is also interested in charting the various patterns of muscle activity in Hydra and identifying the mechanisms of their coordination by the nerve net.

John has been a Hydra TA since 2016.


Jonathan Lovas
Columbia University

Jonathan joined as a Hydra TA in 2017.