Dynamic mapping of network-level LTP in the hippocampus via high-resolution bioelectrical sensing

Area of Science:

• Neuroscience
• Bioengineering
• Systems Biology

Background:

• Traditional methods like patch-clamp recordings lack the scale and precision to study complex neural network dynamics, especially synaptic plasticity.
• Understanding long-term potentiation (LTP) across hippocampal subfields is crucial for memory research but limited by current technologies.

Purpose of the Study:

• To introduce EvoNES, a novel CMOS-based biosensing platform with 4096 microelectrodes for high-resolution neural recordings.
• To enable real-time, mesoscopic-scale quantification of hippocampal circuit activity and LTP dynamics.
• To investigate distributed mechanisms of memory encoding and age-dependent neural plasticity.

Main Methods:

• Utilized a CMOS-based 4096 microelectrode array (EvoNES) with bidirectional stimulus-responsive biosensing.
• Applied targeted stimulation to Schaffer collateral and medial perforant pathways.
• Performed simultaneous on-chip bioelectrical recordings and advanced computational analyses.

Main Results:

• EvoNES provided real-time quantification of evoked responses and LTP across the entire hippocampal circuit.
• Identified distinct waveform classes in CA1-CA3 networks and unique firing patterns in the dentate gyrus.
• Observed accelerated LTP induction, expanded activation zones, and network restructuring, with age-dependent alterations in aged mice.

Conclusions:

• EvoNES offers unprecedented insights into hippocampal memory formation and neural plasticity.
• The platform facilitates investigation of network interactions in health and disease states.
• Revealed distinct patterns of neural activity and plasticity across hippocampal subregions.