Functional assessment of an animal model of glaucoma by two-photon imaging
PhD Research
Start Date: 1st October 2012
Funding:
The studentship is funded for 3 years by the Medical Research Council and includes payment of tuition fees and a tax free maintenance stipend for UK applicants. EU students are only eligible to have their tuition fees paid unless they have been resident in the UK for three years prior to the start date of the programme and then they are also entitled to receive the maintenance stipend. Unfortunately overseas applicants are not eligible to apply.
Primary Supervisor: Professor Frank Sengpiel (SengpielF@cf.ac.uk)
Secondary Supervisor: Professor James Morgan (School of Optometry) (MorganJE3@cf.ac.uk)
Project details:
Glaucoma is the second most common cause of blindness in the UK, resulting from loss of retinal ganglion cells (RGCs). While current therapies focus on the prevention of progressive damage this project addresses the possibility of recovery of lost vision. Prior to the onset of cell death, RGCs undergo a prolonged period of degeneration in which their dendritic processes shrink. An important factor restricting adult neuronal plasticity and repair following injury is the perineuronal net (PNN), a proteoglycan matrix that surrounds neurons and their processes. Evidence that the disruption of this net can allow neurons to recover raises the prospect of its use as a therapeutic intervention.
We have developed a rat model of experimental glaucoma in which intraocular pressure (IOP) is elevated by injecting paramagnetic microspheres into the eye’s anterior chamber. This model produces gradual changes in RGCs; RGC dendritic fields will be quantified by biolistic labelling of cells with pYFP and dendritic atrophy will be quantified by Scholl analysis. We will analyse recovery of RGCs following IOP normalisation and the intravitreal injection of chondroitinase which induces partial digestion of the PNN. In pilot studies we have established that this treatment can increase RGC dendritic field area and number of branch points, but whether it can promote visual recovery in glaucoma will depend on improved RGC function. Retinas will be explanted and cultured, remaining viable for 2-3 weeks. We will employ two-photon imaging to map structural and functional RGC changes. For functional imaging, RGCs will be transduced with a calcium indicator and will be activated by temporal modulation of a stimulus of a wavelength shorter than that of the optical signal; visual response will be calculated as percentage of fluorescence change. Patch recordings from RGCs will establish whether recovering dendrites make synaptic connections with cells in the inner plexiform layer.
Eligibility criteria:
The applicant must be eligible for UK/EU fee status and should hold a First or Upper Second Class Honours BSc degree and/or a Masters degree, or equivalent degree. If English is not the applicant's native language an English Language qualification, such as IELTS is required. For IELTS an average score of 6.5 is required with a minimum score of 6 in each element.
How to apply:
To apply, complete the online application form at: http://www.cf.ac.uk/regis/general/applyonline/index.html