Tris buffer attenuates acetylcholine responses in Aplysia neurons

Area of Science:

• Neuroscience
• Neurophysiology
• Marine Biology

Background:

• Acetylcholine is a key neurotransmitter in both central and peripheral nervous systems.
• Tris(hydroxymethyl)methylamine (Tris) is a widely used buffering agent in biological research.
• Understanding potential interactions between buffers and neurotransmitter systems is crucial for experimental design.

Purpose of the Study:

• To investigate the effect of Tris buffer on acetylcholine-mediated neuronal signaling.
• To determine if Tris antagonizes the action of iontophoretically applied acetylcholine.
• To quantify the impact of Tris on neuronal excitatory and inhibitory responses.

Main Methods:

• Experiments were conducted on neurons of Aplysia californica.
• Acetylcholine was applied iontophoretically.
• The effects of varying concentrations of Tris buffer (5-10 mM) on neuronal responses were measured.

Main Results:

• Tris(hydroxymethyl)methylamine (Tris) was found to antagonize the action of acetylcholine.
• Concentrations of 5 to 10 millimolar Tris markedly reduced neuronal responses to acetylcholine.
• Both excitatory and inhibitory responses mediated by acetylcholine were diminished by Tris.

Conclusions:

• The common buffering agent Tris can interfere with cholinergic neurotransmission.
• Researchers using iontophoresis techniques should be aware of Tris's potential to alter neuronal responses.
• Careful consideration of buffer choice is necessary in experiments involving neurotransmitter signaling.