Leech Module

In Cycle 1, all of the students work on the leech as an experimental system. Students learn neurophysiology and neuroanatomical techniques. Techniques include intracellular electrophysiological recordings in current clamp and voltage clamp configuration, extracellular recordings, and intracellular dye injection, and MATLAB instruction. The goal is to identify neurons by their electrophysiological properties and learn about their electrical and chemical interactions. Towards the end of the cycle students work in pairs on individual research projects that they design.

For a detailed list of lectures and activities, visit the google calendar. As a general rule of thumb, most weekdays will begin with two lectures in the morning followed by an afternoon and evening in the lab.

Since 2014, all the leech module lectures have been recorded and archived.  Please watch and tell your friends about excellent resource.

Leech Module Faculty

headshotMichael Wright
California State University, Sacramento

Research Interests: 
My lab is interested in how the nervous system produces rhythmic behaviors like walking and swimming. In particular, I am interested in the role that motor neurons, the output pathway of the nervous system, play in the production of these behaviors. My lab uses electrophysiology, modeling and a hybrid systems approach using the dynamic-clamp to address these questions.




James Angstadt
Siena College

James’ lab studies the serotonergic modulation of ionic conductances underlying postinhibitory rebound in swim motor neurons. James has been an NS&B faculty member since 2008.


William Kristan
UC San Diego

Bill has studied the neuronal basis of leech behaviors—swimming, crawling, bending, shortening, feeding—for over 40 years. His lab has used electrophysiological, voltage-sensitive dye imaging, anatomical, and computational techniques to identify and characterize the neuronal circuits responsible for these behaviors, as well as how the circuits are established developmentally, and how leeches decide which behavior to produce in response to tactile stimulation. Bill is now officially retired, which gives him time to do experiments himself. Bill has been an NS&B faculty member since the beginning of the course, in 1978.


Brian Norris
California State University San Marcos

Research Interests: 
Generating boatloads of Data for Angela Wenning, much of which she discards.
Brian was an NS&B student in 1982 and a TA in 1992. He has been a faculty member in the leech module since 2006.
IMG_7306-resizeJosh Puhl
Univ. of Minnesota

My research interests revolve around understanding the neural bases of natural behaviors. My work focuses on studying the organization of neural networks at the cellular and network levels of detail. I am, specifically, interested in the organization of pattern and rhythm generating neural circuits [i.e., central pattern generators (CPGs)], how CPGs are modulated by neuromodulatory compounds like dopamine, and understanding the interface of descending command systems with CPGs. I conduct my research using the European medicinal leech, Hirudo verbena, because of its simpler nervous system (relative to vertebrate animals), experimental accessibility, and robust, yet tractable, behavioral repertoire. My work focuses on locomotor behaviors with an emphasis on crawling. I also participate in neuroengineering projects where I employ the leech as a test-bed for neural recording devices. I have been teaching in the Neural Systems and Behavior course in a teaching capacity since 2010, with 2017 being my eighth consecutive year.



Lidia Szczupak
University of Buenos Aires, Argentina

Lidia’s lab studies the network architecture of sensorimotor circuit.
Lidia has been a NS&B faculty member since 2000.

Krista Todd
Westminster College

Research Interests: 
I study the neurohormonal basis of reproductive behavior. This includes the initiation, progression, and termination of reproductive behavioral modules as well as the pattern generator(s) responsible for such complex behaviors.
Krista was a TA in 2009 and has been a faculty member since 2010.
DavidWeisblatDavid Weisblat
UC Berkeley

My lab studies cell lineage and cell fate decisions in the leech embryo at the cellular and molecular levels. We’re interested in how leeches develop and how their development differs from those of other animals (Evo-Devo). In addition, a collaboration with Diana Bautista (UCB) and Francisco Fernandez de Miguel (UNAM, Mexico City) aims for a molecular analysis of neuronal differentiation and function, starting with transcriptional profiling of the famous T, P, N and Rz neurons from Hirudo. David joined the Leech faculty in 2015. He had previously assisted in short courses on leech neurobiology and development that were started by John Nicholls.


2015 Leech Module Lectures

  1. Jim Angstadt: Membrane Potential and Passive Properties of Neurons (Part 1) – 06/08/15
  2. Jim Angstadt: Membrane Potential and Passive Properties of Neurons (Part 2) – 06/08/15
  3. Jim Angstadt: Voltage-Gated Ionic Currents Underlying Neuronal Electrical Activity (Part 1) – 06/09/15
  4. Jim Angstadt: Voltage-Gated Ionic Currents Underlying Neuronal Electrical Activity (Part 2) – 06/09/15
  5. Brian Norris: Synaptic Transmission (Part 1) – 06/11/2015
  6. Brian Norris: Synaptic Transmission (Part 2) – 06/11/2015
  7. Lidia Szczupak: Low Threshold Calcium Conductance As a Signal Amplifier – 06/12/2015
  8. Josh Puhl: Studying The Neural Circuits That Generate Locomotion: One Crawl Step At A Time –  06/12/2015
  9. Bill Kristan – Three ways to decide: Behavioral choices by the leech nervous system (Part 2) – 06/15/2015
  10. David Weisblat: Development of the Leech Part 1 -06/16/2015
  11. David Weisblat: Development of the Leech Part 2 – 06/18/2015
  12. Bill Kristan: Systems Neurophysiology vs. Neuroethology: Two approaches (Part 1) –  06/19/2015
  13. Bill Kristan: Systems Neurophysiology vs. Neuroethology: Two approaches (Part 2) – 06/19/2015

2014 Leech Module Lectures

  1. 06/09/14 – Part 1: Membrane potential of neurons (Ron Calabrese)
  2. 06/09/14 – Part 2: Membrane potential of neurons (Ron Calabrese)
  3. 06/10/14 – Part 1: Voltage-gated Ionic Currents (James Angstadt)
  4. 06/10/14 – Part 2: Voltage-gated Ionic Currents (James Angstadt)
  5. 06/12/14 – Part 1: Synaptic Transmission (Brian Norris)
  6. 06/12/14 – Part 2: Synaptic Transmission (Brian Norris)
  7. 06/13/14 – Part 1: Central Pattern Generators (Ron Calabrese)
  8. 06/13/14 – Part 2: Central Pattern Generators (Ron Calabrese)
  9. 06/16/14 – Part 1: Neural Systems and Behavioral Choice (Bill Kristan)
  10. 06/16/14 – Part 2: Neural Systems and Behavioral Choice (Bill Kristan) [BAD AUDIO at the beginning and LECTURE CUT OFF]
  11. 06/17/14 – Studying the Neural Circuits that generate locomotion: one crawl step at a time (Josh Puhl)
  12. 06/17/14 – The importance of neural modulation and context for behavioral selection (Karen Mesce)
  13. 06/20/14 – Systems Neurophysiology vs Neuroethology (Bill Kristan)
  14. 06/20/14 – Intro to Principle and Independent Component Analysis of High Dimensional Data (Paxon Frady)