Optical image of neurons sheds light on brain

Optical image of neurons sheds light on brain function

Generations of researchers have tried to explain the inner workings of the brain but exactly how brain cells process signals and turn them into appropriate actions remains unclear. An Auckland group of physiologist has developed a new technique which will take us a step closer to under-standing the complexity of grey matter.

Dr Gregory Funk, Professor Mark Cannell and Dr Christian Soeller, at the University of Auckland’s Physiology department, have been awarded a grant from the competitive Marsden Fund to map brain neurons in order to describe how the cells process information.

The group uses brain cells that drive respiratory muscles. Like most neurons, these cells have a tree-like structure which branches out into a complex network of dendrites intertwining with those of other neurons. Each cell is equipped with both specific receptors and synapses, the first to react to chemicals sent out by other cells and the latter to emit these neurotransmitters. Signals received from other cells are transmitted along the nerve cell in the form of currents.

Neurons are often compared to electrical cables, but the researchers are now able to demonstrate that signal transmission in a neuron is more complex than that. With the help of the group’s new optical technique, the two-photon molecular excitation microscopy, neurons can be shown in their three-dimensional structure with a detailed map of the distribution of receptors.
In combination with conventional electrophysiological techniques, the researchers will be able to examine the anatomical structure of nerve cells as well as their behaviour, correlating changes in morphology with the consequent functions.

The group will also develop a new technique which will allow them to excite or block out parts of the neuron selectively. These experiments will clarify the hypothesis that spatial distribution of receptors creates pockets of specialised responses along the dendrite membrane. The work will therefore provide new insight into neuronal integration and how the brain achieves such remarkable information processing.

The group’s grant is worth $180,000 for the first year, and $170,000 for each of the following two years.

© Scoop Media