science

For decades, glia were dismissed as neural glue. We now know astrocytes modulate synaptic strength, microglia sculpt circuits, and oligodendrocytes set the speed of thought. The other half of your brain has been ignored.

Before optogenetics, neuroscientists could record neurons or stimulate brain regions bluntly with electricity. Deisseroth's method uses channelrhodopsins to turn specific cell types on or off with a flash of light — giving researchers causal control over circuits for the first time.

A complete wiring diagram of the human brain would contain roughly 100 trillion synapses. Connectomics is the field attempting to map them — starting with the roundworm, scaling toward us.

Neuroscience produces spectacular images and spectacular overreach. The replication crisis hit brain imaging hard — many published findings don't hold up. Here's a sober tour of what the field has actually proven, what remains genuinely uncertain, and how to read the next breathless headline.

You don't see the world — you see your brain's best guess about it. Predictive processing flips neuroscience upside down: the cortex is a prediction engine, and sensory signals are just correction signals.

Neuroscientists once dismissed brain activity during rest as noise. Then they found the default mode network — a highly organized system that activates precisely when you stop focusing on the world.