Events

CiNet Seminar: David Lyon & James Bourne

 

CiNet Monthly Seminar

August 2, 2019
10:30-12:00
CiNet 1F Conference Room

10:30-11:15 “Cortical responses following retinal sheet transplantation in animal models of retinal degeneration”
David Lyon
Vice Chair & Graduate Director
Department of Anatomy and Neurobiology, University of California, Irvine

Abstract:
Age-related macular degeneration and retinitis pigmentosa lead to profound vision loss in millions of people worldwide. Many patients lose both retinal pigment epithelium and photoreceptors. Hence there is a great demand for the development of efficient techniques that allow for long term vision restoration. In our recent study, we transplanted dissected fetal retinal sheets which can differentiate into photoreceptors and integrate with the host retina of rats with severe retinal degeneration. For our model, we used the transgenic Rho-S334ter line-3 rat which loses photoreceptors at an early age and is effectively blind at post-natal day 30. Remarkably, we show that transplants generated visual responses in cortex similar in quality to normal rats. Furthermore, transplants preserved connectivity within visual cortex and the retinal relay from the lateral geniculate nucleus to visual cortex, supporting their potential application in curing vision loss associated with retinal degeneration.

11:15-12:00 “The role of thalamocortical circuits in neocortical development and associated dysfunction”
James Bourne
Professor
Australian Regenerative Medicine Institute, Monash University

Abstract:
The pulvinar is the largest collection of nuclei of the thalamus in primates, including humans, comprising 3 nuclei and further subdivisions. Even though it has been demonstrated to be embedded within sensory systems and connect with the majority of the neocortex, its function remains unclear. Over the past decade, my group have been instrumental in demonstrating in the marmoset monkey the role of the medial subdivision of the inferior pulvinar in the development of the dorsal stream visual cortex and the manifestations of a lesion to this region of the brain in early life. To this end, we now know that this area plays an implicit role in the development of the visual cortex and establishment of visuomotor behaviours, such as reaching and grasping. Furthermore, we have evidence that the pulvinar can route visual information to the visual cortex following a lesion of the geniculostriate pathway in early life in both monkeys and humans. Collectively, these data demonstrate an essential role for the inferior pulvinar thalamic nuclei in early life. Furthermore, up to this point, it was suggested that the thalamocortical circuits were ‘hardwired’ by birth yet we now have evidence and an example of their inherent plastic nature early in life and ability to reroute sensory information. Our attention is now focussed on the other pulvinar nuclei, establishing how they may be operating to ensure appropriate motor and cognitive behaviours, and investigating their links to developmental diseases such as schizophrenia, where this early life plasticity may be aberrant.

Host: Hiromasa Takemura (Kida Group)