Neural Modulation – Discover How Neurotransmitters Shape Sensory Responses

Understanding neurotransmitter modulation is crucial for grasping how substances influence brain and sensory function. Using a cricket's sensitive sensory system, this experiment demonstrates how substances like nicotine and MSG can dramatically alter neural responses, providing insight into the complexity of neurotransmitter action across different species.

Devices and Accessories2

About the Experiment

What Will You Learn?

How sensory neurons respond to air vibrations.
How inhibitory and excitatory substances modulate neural activity.
The contrasting effects of MSG and nicotine, which act on neurotransmitter receptors, on the cricket’s wind-sensing circuit.

Background

Crickets detect wind vibrations using cerci—specialized sensory organs sensitive to air movements. These cerci trigger neural activity that can be influenced by chemicals that act on neurotransmitter receptors. Interestingly, MSG typically inhibits neuronal activity in crickets, while nicotine usually enhances it, illustrating how neurotransmitters can have diverse effects in different organisms.

Procedure

Preparation:
1. Briefly anesthetize a cricket in ice water and secure it onto a stable platform without covering the cerci.
Electrode Placement:
1. Insert the recording pin into the abdomen along the cricket’s midline, just in front of the cerci.
2. Insert the ground pin along the midline farther forward (no gel is needed).
Baseline Recording:
1. Record baseline neural activity using your Neuron SpikerBox.
2. Stimulate cerci gently with air puffs to establish a baseline neural response.
Neurotransmitter Testing:
1. MSG Application:
2. Dissolve MSG in water. Using a small syringe, inject a tiny drop into the cricket’s abdomen near the recording electrode.
3. Record neural activity and compare with baseline.
4. Nicotine Application:
5. Prepare a nicotine solution from soaked tobacco leaves.
6. Inject a tiny drop into the abdomen near the recording electrode and compare with baseline.