Adapted from the “Action Potential Game” Designed by Jessica Koch, Neuroscience for Kids (Goo.Gl/P1nmke)

Adapted from the “Action Potential Game” designed by Jessica Koch, Neuroscience for Kids (goo.gl/P1NmKE)

Objective: Race to raise the resting potential above threshold to fire an action potential.

Background: When neurotransmitters cross a synapse, they can bind to receptors on dendrites. This binding can result in a flow of ions across the membrane and a change in the electrical potential of the neuron. At baseline, the electrical potential of a neuron is about -70 mV.

If the electrical potential is raised so that it reaches a certain threshold, an action potential will fire down the axon of a neuron. An EXCITATORY postsynaptic potential (EPSP) occurs when the inside of the neuron becomes more positive, bringing it closer to threshold, and making it more likely that an action potential will be generated. An INHIBITORY postsynaptic potential (IPSP) occurs when the inside of the neuron becomes more negative, making it less likely an action potential will be generated.

Examples of excitatory and inhibitory neurotransmitters

Materials needed: 3 large containers 2 large spoons Timer 26 ping pong balls, labeled with black marker: • “-2 mV” – 6 balls • “-8 mV” – 6 balls • “+10 mV” – 6 balls • “+5 mV” – 8 balls

© The Franklin Institute, in collaboration with the University of Pennsylvania, 2017. This project was supported by funding from the National Institutes of Health Blueprint for Neuroscience Research under grant #R25DA033023. How to Play: Players should be divided into two teams: the Excitatory Postsynaptic Potential (EPSP) Team and the Inhibitory Postsynaptic Potential (IPSP) Team. The teams will race to see who can get the greatest signal to their team’s cell body in 2 minutes. Each team lines up to act like a dendrite. At one end of the line, each team has a container with their starting set of ping pong balls (negative charges for the IPSP Team, positive charges for the EPSP team). At the other end is a shared container that represents the cell body.

Setup of the game

The first person in the line acts as the receptor, and picks up a signal (a ping pong ball) from the starting container. The ball is passed from person to person much like how an electrical signal travels down a dendrite toward the cell body. Students should pass the ball using a spoon. The signals are passed down the dendrites until they reach the end and are tossed into the cell body container. Then the spoon is handed back to the first person in the line and the process starts over with a new ball. Only one ball can be passed at a time. Each EPSP team signal successfully transferred to the cell body is worth the labeled number of millivolts. These values have been designed so that 2 comparably-paced teams would reach a voltage close to threshold at the end of the game.

To Win: The typical resting potential of a neuron is -70 mV. To cause an action potential, the membrane potential must reach a threshold value of -55 mV. At the end of 2 minutes, students add up the values of the signals collected in the cell body container. The total amount of millivolts is added to -70 mV to see if an action potential is fired. If greater than or equal to -55 mV, an action potential is fired and the EPSP team wins. If not, then the IPSP team wins.