Voltage imaging and optogenetics reveal behaviour-dependent changes in hippocampal dynamics.

Area of Science:

• Neuroscience
• Biotechnology
• Molecular Imaging

Background:

• Simultaneous multi-neuron recordings in behaving animals are crucial for understanding brain function.
• Existing genetically encoded voltage indicators have limitations in signal-to-noise ratio and in vivo applicability.

Purpose of the Study:

• To develop advanced near-infrared voltage indicators and high-speed microscopy for simultaneous in vivo recordings of neuronal membrane potential.
• To enable detailed exploration of neuronal network dynamics and subcellular voltage changes in behaving animals.

Main Methods:

• Development of improved near-infrared voltage indicators (e.g., PAQUASAR3).
• Implementation of high-speed microscopy and targeted gene expression schemes.
• Simultaneous in vivo fluorescence and patch-clamp recordings in behaving mice.

Main Results:

• Achieved simultaneous in vivo recordings of supra- and subthreshold voltage dynamics in multiple hippocampal neurons.
• Revealed subcellular details of back-propagating action potentials and inter-neuronal voltage correlations.
• Demonstrated state-dependent changes in neuronal excitability linked to synaptic inputs and behavior.

Conclusions:

• The developed technology significantly advances the capability for multi-neuron recordings in vivo.
• Provides unprecedented insights into neuronal network dynamics and electrical signaling during behavior.
• Opens new avenues for exploring brain function at the cellular and network levels.