Researchers train sheep to complete MRI scans while awake

Magnetic resonance imaging (MRI) is a technique commonly used to examine the brains of sheep. Until now, it has only been performed under general anesthesia to ensure the immobility of the animal. However, anesthesia leads to stress and other negative side effects, in addition to compromising the study of brain activity.

A research team from INRAE ​​has developed a training protocol adapted to sheep to be able to perform MRI acquisitions in the animals while they are awake without the need for restraint. To do this, the researchers built on previous work with dogs, which until now were the only animal species capable of performing this type of protocol.

In the nursery of the Experimental Research Unit Animal Physiology Facility (UEPAO), located at the center of INRAE ​​​​Val de Loire in Nouzilly, the researchers started the familiarization phase as soon as the lambs were born. The aim was to find out which animals were most sensitive to being stroked or having foam objects placed near their heads.

The work is published in a journal Behavioral research methods.

After the selection of 10 lambs, the initial training phase took place at the Nouzilly sheep farm. The research team trained the animals to climb a ramp to reach a fake MRI scanner and then lie down. The lambs were also taught to place their heads in a mock MRI coil.

Once in the actual MRI room, the sheep were able to reproduce the same behavior very easily, but had some difficulty staying still. It took a few weeks for the animals to get used to the vibrations of the machine and stop moving for a few minutes. Finally, MRI images of their brains were comparable to those obtained from anesthetized sheep, a goal that was initially achieved in six of the ten sheep trained at the time of writing and has since been achieved in nine sheep. The protocol lasted nine months, from the birth of the lambs to the first MRI acquisition.

The success of this protocol is already opening new avenues for animal neuroimaging research (e.g., fMRI), as it allows studying brain functions in awake animals. He is currently studying the activation of certain areas of the brain in relation to hearing and is the subject of a Ph.D. work that relies on this training protocol.

This example of voluntary cooperation between trainer and sheep illustrates the animal’s ability to learn and highlights the importance of human-animal relationships in the development of innovative methods. The study also opens up new possibilities for training other animals to perform MRI scans while awake. Such training methods could have a number of other applications in areas such as shearing or medical training – when an animal learns to cooperate during veterinary care.