Visual Neuroscience

Group leaders

Visual Neuroscience Group Photo

L:R - Felix Weltzien, Kumiko Percival, Will Dobbie, Natalie Zeater, Ulrike Grünert, Sander Pietersen, Cindy Guy, Paul R Martin, Soon Keen (Kenny) Cheong. Photo: Clive Jeffery

Group Members

Paul R MartinBSc, PhD, Group Leader
Ulrike GrünertDipl Biol, PhD, Group Leader
Sander PietersenBsc, PhD, Research Officer
Felix WeltzienDipl Biol, PhD, Research Officer
Kumiko PercivalBASc (Hons), PhD, Research Officer
Will DobbieBSc(Hons), Research Assistant
Cindy GuyResearch Assistant
Kenny CheongBBioMedSc (Hons), Postgraduate Student
Natalie ZeaterBSc (Hons), Postgraduate Student

Research Activity

Our research aims to better understand the way visual information is transferred from the eye to the brain in segregated pathways for colour, motion and shape. We know that the image captured by the eye is sent to the brain as a series of parallel “movies” but the way that nerve cells (neurones) in the eye are wired together to create these movies is poorly understood. By analyzing the wiring diagram of the normal eye, we gain knowledge that can be used in clinical practice and treatment of eye disease.

Projects

Structure of normal and myopic retina

Abbott, McBrien (Uni Melbourne), Grünert, Pianta (Uni Melbourne)

The long-term aim of this project is to understand how the eye is changed by severe myopia (shortsightedness). We investigated the retinal origin of the optical coherence tomography (OCT) signal by aligning images taken from a live retina with corresponding vertical histologic sections. These results provide a basis for relating the OCT signal to underlying retinal anatomy. This interpretation can be used in the clinical setting to identify layers of the retina affected by disease such as myopia.

Synaptic inputs onto small bistratified (blue-ON / yellow-OFF) ganglion cells in the retina

Percival, Jusuf, Martin, Grünert

The retina is composed of ten different layers, and the inner plexiform layer, a dense layer of connections between different types of cells, contains subdivisions that segregate ON and OFF type light responses. We studied the ON and OFF connections to a class of retinal ganglion cells (small bistratified – blue-ON/yellow-OFF) ganglion cells in marmosets (Callithrix jacchus). The results show that direct input from bipolar neurons can account for both ON and OFF responses in this cell type.

Segregation of short-wavelength sensitive (S) cone signals in the brain

Roy (Uni Melbourne), Jayakumar (Uni Melbourne), Martin, Dreher (Uni Sydney), Saalmann (Uni Melbourne), Hu (Uni Melbourne), Vidyasagar (Uni Melbourne)

An important problem in the study of the mammalian visual system is whether retinal ganglion cells of different types are segregated anatomically in the brain. We recorded signals from individual cells in the LGN followed by histological reconstruction to investigate the distribution of colour-selective cells in the LGN of the macaque (Old World monkeys). We found that cells carrying signals from blue-cones were located in the koniocellular layers, while the red/green cells were found in the parvocellular layers. We conclude that there is anatomical segregation of blue/yellow and red/green colour signals for colour vision at early levels of visual processing in the brain.

History