Deciphering Ca²⁺-controlled biochemical computation governing neural circuit dynamics via multiplex imaging.

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Neuronal circuits process information through complex patterns of synaptic transmission and electrical activity.
• Calcium ions (Ca²⁺) act as crucial second messengers, triggering downstream effectors like Ca²⁺/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN).
• CaMKII and CaN competitively regulate synaptic plasticity, gene expression, learning, and memory.

Purpose of the Study:

• To investigate the spatiotemporal activation of CaMKII and CaN in living neurons.
• To develop novel genetically-encoded fluorescent probes for visualizing CaMKII and CaN activity.
• To explore how these enzymes decode neuronal input to control dendritic spine structural plasticity.

Main Methods:

• Development of genetically-encoded fluorescent probes for CaMKII and CaN.
• Multiplex Förster Resonance Energy Transfer (FRET) imaging.
• Creation of orthogonal color variants of Ca²⁺ indicators (XCaMPs).

Main Results:

• Distinct spatiotemporal patterns of CaMKII and CaN co-activation were observed in dendrites and synapses.
• These patterns are likely involved in the biochemical decoding of neuronal input.
• New fluorescent probes and Ca²⁺ indicators were successfully created and validated.

Conclusions:

• The developed tools enable detailed investigation of CaMKII and CaN dynamics in neurons.
• Understanding these spatiotemporal dynamics is key to deciphering brain information processing.
• This research advances our knowledge of neurochemistry, pathophysiology, and neuro-inspired engineering.