In 1979, Nobel-prize-winning scientist, Francis Crick, concluded that the anatomical complexity of the human exceeded the understanding of scientific thought, describing the task of recording cellular activity “impossible.”
Nearly 50 years later, over 150 researchers have achieved the impossible, mapping the structure in the cubic millimeter of a mouse’s brain that is responsible for sight. This landmark milestone advances the possibility for researchers to map the wiring of the entire brain of a mouse.
University of Washington graduate student in the neuroscience program, Leila Elabbady, is the lead author on one of the groundbreaking publications in Nature and a contributor on several others, which make up the special edition.
This massive undertaking is due to deep collaboration between researchers across 23 institutions. The partnerships began in 2016, when the U.S. government launched a $100 million effort to scan a cubic millimeter of a mouse brain. The project — called Machine Intelligence from Cortical Networks, or MICrONS — is led by scientists at the Allen Institute for Brain Science, Princeton University and Baylor College of Medicine.
Disentangling the brain
To make the brain map, researchers digitally disentangled tens of thousands of neurons – the treelike structures that are responsible for transmitting information through electrical or chemical signals – and traced their distinct branches, called dendrites, reconstructing them into a circuitry network or “connectome.”
This resulted in more than 500 million connections and more than 2 ½ miles of neuronal wiring – all in a tiny block of tissue in the brain’s region that involves vision.
The research is a testament to the complexity of the human brain. Simple human actions, such as moving, thinking and feeling could not happen without the over 86 billion neurons in a human brain – and over 100 trillion connections between them. Understanding how they work and are organized can lead to improved treatments and therapies for brain diseases and disorders.
Although progressing from partial mouse connectome to full human connectome will take time, this groundbreaking study, along with new techniques and technologies make the impossible within reach.
Video credit: Tyler Sloan/ Quorumetrix Studio