Loading neurons with dextran-conjugated calcium indicators in intact nervous tissue

Area of Science:

• Neuroscience
• Cellular Biology
• Biochemistry

Background:

• Accurate visualization of neuronal structure and function is crucial for understanding neural circuits.
• Calcium indicators are vital tools for monitoring neuronal activity.
• Existing methods for loading indicators may have limitations in scope or application.

Purpose of the Study:

• To describe robust methods for filling neurons with dextran-conjugated calcium indicators.
• To enable visualization of neuronal populations and their processes, including presynaptic terminals.
• To provide versatile techniques applicable to various experimental setups.

Main Methods:

• Utilizing dextran-conjugated calcium indicators for neuronal loading.
• Applying techniques for in vivo neuronal filling in central nervous tissue.
• Adapting methods for subsequent analysis in vivo, brain slices, or en bloc preparations.
• Demonstrating suitability for staining neurons in acute and organotypic brain slices.

Main Results:

• Successful loading of neuronal populations and their processes with calcium indicators.
• Demonstrated efficacy of in vivo filling for subsequent analysis.
• Versatility of the methods across different preparations (in vivo, slices, en bloc).

Conclusions:

• The described methods provide reliable means for calcium indicator loading in neurons.
• These techniques enhance the study of neuronal populations and their synaptic connections.
• The described protocols are broadly applicable in neuroscience research across different vertebrate models.