What would it take to record every neuron in a human brain? · Grey Matter

The human brain has about 86 billion neurons.

What would it take to record every neuron in a human brain?

The human brain has about 86 billion neurons. Sampling each one's voltage at 1 kHz with 10 bits (a modest choice, since Neuropixels samples its spike band at 30 kHz with 10-bit converters) gives about 8.6×10148.6 \times 10^{14}8.6×1014 bits per second, close to 101510^{15}1015, against 384 channels for one Neuropixels shank. Electronics in the head also make heat, and implant designs keep tissue warming within about 1 °C, which caps how much amplification, digitisation and transmission can sit inside the skull. Sorting spikes on the device and sending only events helps, but reaching every cell would also take a way of placing sensors through the whole volume without damaging it, which no current technology has.