They say that their research is more likely to lead to new treatments than studies based on mouse and rat models.
Dr Ed Lein, who leads the initiative at the Allen Institute has set up a scheme with local doctors to study left over tissue just hours after surgery.
He gave details at the American Association for the Advancement of Science meeting in Seattle.
“It is a little bit crazy that we have such a huge field where we are trying to solve brain diseases and there is very little understanding of the human brain itself,” said Dr Lein.
“The field as a whole is largely assuming that the human brain is similar to those of animal models without ever testing that view.
“But the mouse brain is a thousand times smaller, and any time people look, they find significant differences.”
Dr Lein and his colleagues at the Allen Institute in Seattle set up the scheme with local neurosurgeons to study brain tissue just hours after surgery – with the consent of the patient.
It functions as if it is still inside the brain for up to 48 hours after it has been removed.
So Dr Lein and his colleagues have to drop everything and often have to work through the night once they hear that brain tissue has become available.
“What we are finding is that there are many more types of cells in the human brain than in animal models. Their electrical properties and their anatomy can be significantly different between mouse and human,” he said.
And it is for this reason that efforts to come up with treatments for brain diseases, such as Alzheimer’s and Parkinson’s have been “relatively fruitless”, according to Dr Lein.
He says that patients, undergoing invasive brain surgery for disorders such as epilepsy, have been enthusiastic about signing up to the scheme.