Reliable optical detection of coherent neuronal activity in fast oscillating networks in vitro.

摘要: Abstract Cognitive and behavioral functions depend on the activation of stable neuronal assemblies, i.e. distributed groups co-active neurons within networks. It is therefore crucial to monitor patterns activity in real time with single-neuron resolution. Microelectrode recordings allow detection coincidence between discharges identified units at high temporal resolution, but are not able reveal full spatial pattern multi-cellular assemblies. Therefore, observation such sets a stronghold optical techniques, required sensitivity, speed still challenging current technology. Here, we report new approach for monitoring using memory-related network oscillations rodent hippocampal circuits as model. The cytosolic calcium-sensitive fluorescent protein GCaMP3.NES was expressed recombinant adeno-associated viral (rAAV)-mediated gene transfer CA3 pyramidal cultured mouse slices. After 14–21 days culture, field potential revealed spontaneous occurrence sharp wave-ripple events during which fraction local coherently activated. Using custom-built epi-fluorescence microscope could view 410 μm × 410 μm resolution (20 × objective, 0.4 NA). We developed highly sensitive specific wavelet-based method cell identification allowing simultaneous more than 150 frame rates up 60 Hz. Our recording configuration image analysis provide tool investigate cognition-related hippocampus other circuits.