The spinal cord contains stem cells whose number decreases with developmental age, as it gets progressively restricted to in the central canal. Signalling in the spinal cord is plastic and can change in response to different stimuli such as pain, suggesting that the stem cells maybe involved in remodelling, changing spinal response. In order to assess whether spinal stem cells are affected by sustained pain states, the project will compare the number, distribution and marker expression of stem cells in the spinal cord of animals from control or chronic pain models. Advanced tissue analysis techniques will be used to map, monitor and characterise spinal cord stem cells in a model mouse model benefiting from a fluorescent marker specific to stem cells. This project will provide original information on the nature and regulation of stem cells present in the spinal cord, a key signalling centre in pain. The spinal cord plays many roles in sensation, and transfers the signal of pain from the body to the brain. Recently, it was shown that the spinal cord contains a small proportion of stem cells, which are still poorly identified. Stem cells found in other parts of the nervous system are able to produce new brain cells throughout life, however it is not clear whether the stem cells found in the spinal cord are also able to generate new spinal cells. It is also not clear whether the experience of prolonged pain can cause changes the spinal cord and affect the stem cells. During this project, I will learn advanced microscopy techniques that will be used for the observation and mapping of the stem cells in the mouse spinal cord. By comparing samples before and after the experience of chronic pain, this project will address the important question of whether prolonged pain can alter the stem cells present in the spinal cord.

Peptidoglycan-targeting antimicrobial peptides are presently under-utilized in bacterial management and resistance remains uncommon, yet these compounds hold much promise and may offer routes to novel strategies for bacterial control. The management of Gram-negative bacteria is particularly problematic as they are encapsulated in a protective lipopolysaccharide (LPS) layer. The LPS molecule contains a lipid moiety, lipid A, a core polysaccharide region, which is extensively phosphorylated and pyrophosphorylated and an outer polysaccharide O-antigen region. LPS presents a major barrier to pharmacological control of Gram-negatives. A commercially developed and well-characterised lantibiotic, nisin, is produced by the Gram-positive bacterium Lactococcus lactis and is effective against Staphylococci, Clostridia and Lysteria. Currently having numerous applications in food protection worldwide, nisin is a non-toxic and highly effective antimicrobial, which targets pyrophosphate-derivatised peptidoglycan intermediates. We hypothesise that pyrophosphorylated saccharides in the LPS core region present viable targets for recognition by chemotherapeutic agents and can serve as templates for antimicrobial design. We propose a computational study of the interactions between an established antimicrobial compound and LPS and to verify experimentally the interaction using solid state NMR. At a functional level, we will assess the stability of lipid membranes without or with LPS when incubated with membrane-disrupting antimicrobial peptide nisin. Resistance to antibiotics and the spread of infectious diseases in a globalised society present significant challenges to infection management and disease control. The development of new antibacterial compounds, which exploit previously undeveloped specific bacterial targets remains of prime interest in antimicrobial drug design. We hypothesise that a lipopolysaccharide (LPS) protective layer, present in some particularly challenging organisms, presents viable molecular targets for antibacterial drug design. We will use high performance computing tools to investigate molecular complexes between LPS and a well-known antimicrobial, nisin (E234). The computational analysis will provide templates for antimicrobial design. We seek experimental verification of the existence of such complexes by following changes in LPS molecular motions by nuclear magnetic resonance (NMR). We also propose that LPS facilitates the disruption of lipid membranes by nisin and will test this hypothesis using fluorescence spectroscopy.