2012-13 Summer Students

Posted by on 3 November 2013

The cornerstone funding from the Selwyn Foundation plus additional grants from Family Trusts have enabled us to grant a number of summer studentships.

Ankita Umapathy, PhD candidate - University of Auckland

Antiox-idant strategies to prevent eye disease – is the lens a reservoir of glutathione? Age-related cataracts are the leading cause of blindness in the world. Although cataract surgeries are the only treatment for the disease, they are one of the safest and most effective surgical procedures performed today. However, there is growing evidence that persistent damage can occur to other tissues in the eye, such as the cornea, several years following lens removal during cataract surgery.

Of all the tissues in the eye, the lens has the highest concentration of protective antioxidants, such as glutathione (GSH). Previous work in our lab has demonstrated that the lens has the capacity for GSH export. Therefore, it is our hypothesis and the overall aim of my PhD project, that the lens is a reservoir of GSH, capable of supplying the antioxidant to other tissues such as the cornea. When this reservoir is inadvertently eliminated during cataract surgery, the reduction in GSH availability causes other tissues to become increasingly susceptible to damage and consequent diseases.

Thus far, my preliminary data has confirmed that not only does the ocular lens export GSH, this export can be stimulated by addition of glutathione into the media. Currently I am investigating ways of modulating this efflux by introducing oxidative stress into culture conditions and confirming the transporters and channels involved in glutathione efflux by introducing inhibitors.

I am also currently in the process of identifying and localising glutathione uptake, efflux and breakdown pathways in the lens, cornea and ciliary body using immunohistochemical techniques. This work will provide evidence of the capacity for inter-tissue exchange of GSH in the front of the rat eye.

Rashika Karunsinghe, PhD candidate - University of Auckland

Are brain cells that degenerate in Parkinson’s disease also susceptible to stroke-induced damage? Parkinson’s disease is a debilitating motor disorder that affects mainly senior citizens. Its symptoms are attributed to the relatively selective vulnerability of a population of dopaminergic neurons, found within a region of the brain known as the Substantia Nigra pars compacta. The loss of these neurons has been associated with certain genetic or environmental (for example, exposure to toxic agricultural compounds) factors. Such injury leads to a depletion of dopamine, the neurotransmitter used by these neurons. My study investigates the effect of brain ischemia, a condition mimicking a stroke, on this neuron population.

By recording the electrical activity of these neurons as a measure of functional integrity, and assessing their morphology and chemical content as indicators of cell integrity, I hope to understand the potential for acute ischemic injury in these neurons. This will be compared with responses observed in the hippocampus, a brain region known to be highly vulnerable to ischemic damage. Using a rodent brain slice model, my results so far suggest that nigral dopaminergic neurons respond differently when challenged by an ischemic insult compared to the hippocampus. This study is of particular interest in the context of a relatively under-studied, sudden-onset form of parkinsonism called Vascular Parkinsonism.

Louise Cowpertwait, PhD candidate - Massey University

Depression is a debilitating mental disorder characterised by low mood or loss of pleasure along with an array of other symptoms which cause clinically significant distress. Research has found that, contrary to stereotypes of depressive old age, most older people are not depressed. However, the number of older people who are depressed and the costs associated with this is still significant. There is a need to understand depression among older adults to ensure prevention and treatment efforts are efficient and effective in this population, particularly in the context of ageing populations. Psychological theory recognises the impact that social factors can have on depression risk. My research aims to improve current understanding of the relationship between depression and social support, by quantitatively investigating a large, longitudinal dataset from community dwelling older adults living in New Zealand. I will investigate how various aspects of social support (such as the size of ones network, frequency of social interactions, and ones subjective evaluation of their social network) predict levels of depression over time. A literature review has been completed, which has highlighted the need for this research, and initial stages of data analysis will begin in June.

Michael Annear, PhD candidiate - University of Otago

Christchurch has the oldest population structure of New Zealand’s large cities. It is, therefore, necessary to understand and promote conditions that support activity and independence in later life to maximise the opportunities of population ageing. Our research explores the potential influence of social and physical environmental conditions on active ageing behaviours in diverse urban areas, including a consideration of the unanticipated impacts of the 2010 and 2011 Canterbury earthquakes.

The research is characterised by the use of a participatory and mixed method design undertaken with a volunteer sample of 355 older adult collaborators from 12 urban areas. Methods of investigation include environmental observations, a participant-designed questionnaire, a 14-day activity diary augmented with photographic procedures, and group discussions. We are now in the final year of this project and are beginning to synthesise and disseminate the results to community stakeholders. Emerging and notable findings include the identification of home and local environment as a nexus of activity participation and the central influence of accessibility, amenity, and social network characteristics as environmental influences on behaviour. Moreover, analysis of earthquake impacts suggests a dichotomy of vulnerability and resilience within the older adult cohort in Christchurch. It is hoped that the findings, recommendations, and theory emerging from this study will help to inform age-friendly urban development in Christchurch and earthquake recovery initiatives that are sensitive to the diverse needs of older adults.