Lesson Plans

Sowing the Seeds of Neuroscience – If Worms Drank Coffee: Investigating the Effects of Plant Extracts on Planaria Movement

Created by : 
University of Washington

Students will observe and count planaria (flatworms) movements with and without the addition of a plant extract. Plants and herbs have been used around the world for millennia to alter brain function; in most places, plants are used daily to alter mental function. For example, coffee and black tea help people to wake up in the morning and chamomile tea helps people to relax in the evening. Some people regularly use alcohol, nicotine, and illegal drugs such as cocaine; these drugs are derived from plants and have large effects on the human nervous system. Students will explore how plant extracts act as stimulants or depressants and affect planaria movement. Planaria are a widely used model organism. This lesson is part of the Sowing the Seeds of Neuroscience Series

What’s In the Lesson Plan: 

  • Teacher instruction guide
  • Student handouts
  • Laboratory instructions
  • Extensions and additional resources

Grade Level(s): 


Student Skills Targeted: 

  • Understanding that naturally produced chemicals can affect animal movement
  • Understanding that electrical signals in muscles causes contraction and movement
  • Understanding that humans have a complex nervous system that evolved from a simpler one
  • Understanding that testing chemicals or plant extracts on animals is a way to determine their likely effect on humans

Time / Duration: 

  • 3 class periods


  • Copies of student handouts
  • Planaria
  • Plant extracts
  • Graph paper, pen, permanent marker, lab tape for labeling, timer, clicker for counting planaria movement, paintbrush, square hinged-lid plates, 100 ml beakers; conditioned water, pipette, medicine cup for plant extracts, 10 ml graduated cylinder
  • Safety goggles and gloves

Alignment with National Standards: 

  • Next Generation Science Standards
  • Common Core Standards: Mathematics Practice
  • Common Core Standards: English Language Arts


  • English