Researchers from the Brookhaven National Laboratory and Stony Brook University have built the first positron emission tomography (PET) scanner that is suitable for rats and other small rodents.

A PET scan shows how the body’s tissues and organs are functioning, but requires the subject to stay still in order to generate clear images. This is a simple enough instruction for humans, but not so easy to convey to rats.
Until now, it’s been difficult to run a PET scan on the brain of a rodent that hasn’t been anesthetized.
The new device, which uses a microchip and photosensors called avalanche photodiodes, attaches to a rat’s head and weighs very little.
“We needed to make it as small as possible, and new technology has allowed us to miniaturize this,” said Paul Vaska, a physicist at Brookhaven and one of the study’s authors.
Dr. Vaska and his colleagues report the details of their device in the current issue of the journal Nature Methods.
The scanner also has a grounded spring system that keeps it from weighing the rat down while still allowing the rat to move freely within a confined space.
By using the new scanner, researchers can better understand functions in the rat brain, and eventually the human brain, said Daniela Schulz, a neuroscientist at Brookhaven and the study’s first author.
“We can study changes in dopamine connected to drug abuse,” Dr. Schulz said, “but also the effect of change in other psychiatric disorders where proteins in the brain are important, like schizophrenia, attention deficit hyperactivity disorder and depression.”
(Source: The NYT)