An Introduction to Connectomics
Connectomics is an emerging field of technology which has the potential to disrupt the way we understand cognitive characteristics from studying personality to identifying neurodegenerative diseases. And while this is great, what actually is connectomics?
What is Connectomics?
Neurons are the basic building blocks of the nervous system. They have a role in basically everything your body does from keeping your heart beating to fighting with your siblings, running a 10 km or acing (or failing) a math test.
These neurons form connections with each other which in turn comprise a vast and intricate network in your brain and through your spinal chord. In recent years, it has been theorized that the nature of these networks heavily influence who we are as individuals: how we develop and store memories, how we respond to visual and auditory cues and how we make decisions.
Connectomes are comprehensive maps of these networks. And comprehensive means completely, totally, unimaginably COMPREHENSIVE. These maps are capable of capturing nerves with as much detail as we are able to view our thumb. They can depict their relative sizes, shape in 3D space and connections to surrounding nerves.
Connectomics is the study of connectomes - these incredibly high resolution images of our nerves.
How does imaging work?
- Scientists slice a sample of neural tissue into pieces less than 300 atoms thick.
- Each slice is viewed under an electron microscope which enables it to be analyzed at an atomic level.
- The magnified sample is then photographed.
- These photographs are played in rapid succession on a video clip. This allows scientists to see how the nerve structures change from one side of the tissue to the other — when new connections emerge, where they grow and shrink in size and what shape they assume in space. It’s kind of like stop motion animation, but instead of moving through time, you’re moving through space.
- These photographs can also be layered to form a digital representation of a 3D section of the tissue. Some software even allows the user to highlight one specific nerve and see it’s shape and position in relationship to other nerves
The first connectome to be created was that of a roundworm. The project started in Sydney Brenner’s Lab in 1970 with the goal of mapping the 7,000 connections in the species’ brain. In 1986, the team published a preliminary version of the connectome, but it was only until over 20 years later when scientists actually achieved a complete image.
The Human Connectome Project was a research initiative that aimed to create a connectome of the human brain. In 2012, they successfully imaged an entire brain, and released their data as open source for the use of researchers around the globe.
What are some potential challenges for connectomics?
1. Imaging the brain is time intensive.
The process of cutting neural tissue into microscopic slices and imaging each one of them is nothing short of time consuming. Because the field is still in its early stages, this imaging process is mostly done by humans, and so is arguably, well, pretty boring.
2. A LOT of data is generated.
Taking a high quality image of every nano slice from a whole tissue generates A LOT of data. The sheer amount of data requires an immense amount of storage and high computational efficiency to organize.
Amongst researchers in this field, these two challenges constitute what is termed the “Big Data” challenge.
What is the future of connectomics?
In the future, connectomics will largely be applied to the medical field, specificically understanding how our neural structure relates to mental health disorders including Parkinson’s disease, schizophrenia and autism.
Artificial Intelligence also has great potential for this field. Google AI, for instance, is already starting to examine how they can leverage this technology in order to automate the imaging process and make it more efficient.
