Identification of Neurons Containing Calcium-Permeable AMPA and Kainate Receptors Using Ca²⁺ Imaging

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Calcium-permeable AMPA receptors (CP-AMPARs) and kainate receptors (CP-KARs) are vital for synaptic plasticity and neurological functions.
• Existing methods for identifying these receptors have limitations in throughput and functional assessment.
• Distinguishing functional CP-AMPARs and CP-KARs in living neurons is crucial for understanding neurological processes.

Purpose of the Study:

• To develop and validate a novel calcium imaging protocol for the vital identification of neurons expressing CP-AMPARs and CP-KARs.
• To provide a high-throughput, functional assay for receptor expression in large neuronal populations.
• To offer a versatile tool for studying synaptic plasticity and neurological disorders.

Main Methods:

• Neurons were loaded with Fura-2 AM, a calcium-sensitive fluorescent probe.
• KCl was used to identify all neurons, followed by specific agonist applications (5-fluorowillardiine for CP-AMPARs, domoic acid for CP-KARs) in the presence of channel blockers and antagonists.
• NASPM, a CP-AMPAR antagonist, was used to differentiate CP-KARs.

Main Results:

• The protocol successfully identified neurons expressing CP-AMPARs and CP-KARs in living neuronal populations.
• The method demonstrated high throughput, allowing simultaneous assessment of numerous neurons.
• Functional receptor expression was distinguished, overcoming limitations of traditional methods.

Conclusions:

• This novel calcium imaging technique provides a fast, reproducible, and non-invasive method for vital identification of CP-AMPARs and CP-KARs.
• The protocol can be combined with other techniques and is valuable for pharmacological screening and disease-related research.
• This approach enhances the study of synaptic plasticity and neurological disorders by offering functional insights into receptor expression.