Glossary

Synaptic plasticity

What is synaptic plasticity?

Think of your brain as a big city with billions of roads, these roads are your synapses, the connections between brain cells (neurons). When you use a road a lot, say, you practice a skill or remember a name, it gets upgraded i.e. widened, paved and lit up. That’s long-term potentiation (LTP): a busy road becomes stronger and faster.

However, if you stop using a road, it falls into disrepair. Eventually, it might get shut down altogether. That’s long-term depression (LTD). Your brain is constantly remodelling itself like this, fixing, rerouting and upgrading its roads based on traffic. This constant roadwork is what we call synaptic plasticity.

When we’re young, the brain overbuilds, it’s like laying down every possible street in the city, but then like a good city planner, it tears down the ones that aren’t useful, optimizing for the routes we actually use. That’s why kids can learn languages or instruments so quickly, their brains are still choosing which roads to keep.

Now, these upgrades don’t happen randomly. Special crews like proteins, receptors and even the brain’s energy plants (mitochondria), handle all the construction. Mitochondria are like the power stations that fuel every repair and they also keep the system balanced, especially when calcium (a kind of electrical signal) flows through the roads.

When mitochondria break down, the whole system suffers. Imagine power outages across the city, roads crumble, traffic lights fail. This is what we see in diseases like Alzheimer’s and Parkinson’s: the city infrastructure starts to fail. Communication breaks down.

Researchers are working on ways to support the brain’s infrastructure. Think of giving the brain better materials to build with (like omega-3s, uridine, and choline), or using traffic engineers (certain drugs or natural compounds) that encourage road upgrades. Some scientists are even exploring high-tech tools, like deep brain stimulation, which acts like a GPS rerouting traffic, or optogenetics, which is like installing light switches on specific roads to turn them on and off.

Epigenetics is like a master control panel for the whole system, adjusting which blueprints are used depending on experience. Even the brain’s immune cells, once thought to be passive janitors, are actually active in shaping the roads, deciding which to keep or remove.

To understand this sprawling city in real time, scientists are building simulations, virtual brains that let us watch the traffic patterns, predict where jams will occur, and test new solutions. These models help us understand not just how the brain works when it’s healthy, but how to repair it when things go wrong.

So the next time you learn something new or remember where you left your keys, know this: your brain just rerouted traffic or built a new road. Learning is construction, and your brain is always under renovation.

Nonsense mutation

A nonsense mutation is a change in a gene’s DNA that causes the cell to stop making a protein too soon. This usually results in a protein that is too short and doesn’t work properly (source: genome.gov)
It’s like putting a period in the middle of a sentence, the rest of the message gets cut off, so the protein can’t be made the right way

Missense mutation

A missense mutation is a change in one DNA letter (base) that results in a different amino acid being added to a protein. This can change how the protein works, sometimes a little, sometimes a lot (source: genome.gov)

In other words, a missense mutation is like changing one word in a sentence. Depending on the word, the sentence (or protein) might still make sense, might be confusing, or might not work at all.

Neurodegenerative disorders

Neurodegenerative disorders are diseases that involve the progressive loss of structure or function of neurons, including their death. These disorders often get worse over time and can affect movement, memory and thinking (source: genome.gov)
In other words, neurodegenerative disorders are brain diseases where nerve cells slowly get damaged or die. This causes difficulties like memory loss, trouble moving, or thinking clearly and these problems usually get worse over time.

Neurodevelopmental disorders

Neurodevelopmental disorders are conditions that happen when the brain doesn’t grow or develop properly. These disorders usually appear early in life and can affect how a person thinks, learns, moves, or behaves (source: genome.gov)
In other words, neurodevelopmental disorders are conditions that affect how the brain grows and works. They often show up in childhood and can affect learning, behavior, speech and/or movement.

Haploinsufficiency

Haploinsufficiency happens when one copy of a gene is not enough to keep the body working properly. Normally, we have two copies of each gene and if one doesn’t work, the other can usually make up for it. But with haploinsufficiency, having only one working copy isn’t enough, which can lead to health problems (source: genome.gov)
In other words, Haploinsufficiency means one good copy of a gene isn’t strong enough to do the job alone. The body needs both copies to work properly and when one is missing or broken, it can cause disease(s).