Understanding excitatory neurotransmission provides critical insights into how the nervous system modulates sensory responses. In this experiment, you'll explore how nicotine—an agonist of excitatory nicotinic acetylcholine receptors—can significantly increase neural firing rates, highlighting key mechanisms underlying sensory processing.
Neurotransmitters modulate sensory inputs by increasing or decreasing neuron firing rates. In crickets, nicotine mimics the excitatory neurotransmitter acetylcholine, significantly amplifying neural responses in the sensory cercal system, which detects air movements. This experiment lets you observe how nicotine enhances neural signaling, illustrating fundamental excitatory mechanisms.
Notice an increase in firing rate after nicotine; if you also see bigger spikes, think about whether new (larger) neurons have started firing.
Analyze how nicotine binding to receptors enhances neural excitability and responses.
Draw the pathway from a wind-sensing hair on a cercus, along its sensory neuron, to the synapse in the cricket’s nerve cord where the message is passed on. Mark where your recording electrode sat and where you think nicotine acts.
Chemical synaptic signaling; drugs alter information processing.
MS-LS1-8 Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories.
HS-LS1-2 Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
2 Developing and Using Models
Draw the pathway from a cercal hair through its sensory neuron to the synapse in the nerve cord, and mark where you recorded and where you think nicotine acts.
3 Planning and Carrying Out Investigations
Record baseline responses to air puffs, inject nicotine and record again.
4 Analyzing and Interpreting Data
Compare firing rate before and after nicotine, and ask whether bigger spikes mean new neurons joining in.
6 Constructing Explanations and Designing Solutions
Explain the increase in firing through nicotine binding to nicotinic acetylcholine receptors.
Cause and Effect
Chemicals alter firing.
Structure and Function
Nicotine fits nicotinic acetylcholine receptors, so it excites these neurons.
LS1.D Information Processing
Chemical transmission.
LS1.A Structure and Function
Membrane receptors and channels.
Performance expectations, crosscutting concepts and core ideas from Hands-On Neuroscience Curriculum Overview, Unit 1, module 1.4, whose core lab this is. The practices are the ones this page asks students to do.
Why do we need more than one electrode to measure neural activity? In this experiment, you’ll explore the role of reference electrodes and how their placement affects recordings.
Ever wondered how substances like nicotine and MSG alter brain activity? Explore how chemicals that act on neurotransmitter receptors change a cricket's wind-sensing responses!
