A new technique to unlock new understanding of neural circuitry

As you’re reading this sentence, cells in your brain known as neurons are rapidly transmitting information along specialised structures called axons that enable two-way communication with your muscles, organs and glands. Individual neurons are also rapidly communicating with their neighbouring neuron, and together these processes are responsible for controlling our movement, thinking and emotions

Unraveling how these individual nerve ‘circuits’ work together in the brain to do this is a major goal in neuroscience, with neuroscientists using techniques that selectively regulate individual neurons to do this. Common techniques include using light or designer drugs, yet neither of these approaches provide information about the neuronal connections that are responsible for controlling the neuron’s activity.

Enter Professor Ross Bathgate from the Florey and Professor Andrew Allen from the University of Melbourne. The duo led a team of researchers who developed and validated a new technique that is revealing new information about the brain.

Professor Ross Bathgate

“The technique takes the established method of using designer drugs, known as chemogenetics, one step further,” explains Professor Bathgate.

“We used a system that allows a specially designed virus to deliver a designer neuropeptide called allatostatin into a specific cell group while the receptor for the allatostatin receptor is delivered in a virus to another cell group. This allows us to understand which neural circuits are involved in turning on neurons as if the peptide and receptor are joined the neuron is switched off.”

“This approach may unlock questions that still puzzle neuroscientists, such as what causes a cell group to become active during a particular behaviour or disease state?”

This sounds deceptively simple, but has been proven to work for the first time and used to map a neural circuit that controls blood pressure. Most importantly, the researchers have developed a method that can be used to map all the neural circuitry that is connecting cell groups, and most importantly to understand how those circuits are working to control particular behaviours.

Director of The Florey, Professor Steven Petrou says the approach is what’s known in science as a ‘forever paper’ as it builds a foundation for others investigating the brain.

“New techniques in neuroscience allow researchers to unlock new information about health and disease states. The way the scientific community is picking up this technique and applying it to different areas means that I have no doubt that the work done by Ross, Andrew and their teams will be contributing to new discoveries for many years into the future.”

Red staining in a cross section of the brainstem shows the allatostatin neuropeptide binding its green-stained receptors, marking success of the technique’s special viral delivery system