How do different areas of our brain have specific functions if they’re all made up of the same cells?

257 views

Title.

In: Biology

Your brain is (mostly) a network of neurons. It’s the pattern & weighting of the connections that matters, not the individual cells.

It’s very similar to asking how different parts of a microchip work when it’s all just wires and transistors…it’s all about how they’re hooked up.

A wire can carry HDTV or a telephone signal or AC power or DC power…the wire doesn’t know or care. What matters is what it’s hooked to.

Amazing question. Different areas of the brain often do have different kinds of cells. Here is a small sample of some of the many different kinds of neurons from different parts of the brain:

* [spindle neurons](https://en.wikipedia.org/wiki/Von_Economo_neuron) in the frontal lobe
* [giant pyramidal cells](https://en.wikipedia.org/wiki/Betz_cell) in the motor cortex (also frontal lobe)
* [place cells](https://en.wikipedia.org/wiki/Place_cell) and [grid cells](https://en.wikipedia.org/wiki/Grid_cell) in the hippocampus
* [Purkinje cells](https://en.wikipedia.org/wiki/Purkinje_cell) in the cerebellum
* [magnocellular cells](https://en.wikipedia.org/wiki/Magnocellular_neurosecretory_cell) and [parvocellular cells](https://en.wikipedia.org/wiki/Parvocellular_neurosecretory_cell) in the hypothalamus
* [dopamine neurons](https://en.wikipedia.org/wiki/Pars_compacta) in the substantia nigra
* [serotonin neurons](https://en.wikipedia.org/wiki/Dorsal_raphe_nucleus) in the dorsal raphe nucleus
* [acetylcholine neurons](https://en.wikipedia.org/wiki/Nucleus_basalis) in the basal forebrain
* [norepinephrine neurons](https://en.wikipedia.org/wiki/Locus_coeruleus) in the locus coeruleus

But I think I know what you mean. The way I would ask this question would be, “How do different parts of the cerebral cortex have different functions if they’re all made up of the same cells ([pyramidal cells](https://en.wikipedia.org/wiki/Pyramidal_cell))?”

The simple answer is that the function of an individual cell in the cortex depends on its inputs and its outputs. To see the function of a single neuron, you would notice what cells it receives input from, and also notice what cells it connects to. If you took some neuron out of a circuit and then re-connected it somewhere else, you would change its function. Imagine two identical neurons. One receives input from the eye and sends output to the brain stem. The other receives input from the ear and sends output to the cerebral cortex. These two neurons will have very different functions, even though they’re basically the same.

Have you ever watched a colony of ants work? Some of them explore, looking for new food. Some of them march along, fetching the food already found. Some guard the nest. Some feed the babies. Some care for the queen.

You could imagine brain working in a similar way. Every part has its assigned role, although many of those parts could easily have taken up a different role. They all fell into line as you developed, like soldiers, and they work together to exchange information and make sure that the whole machine ticks over together.