Automatic Slide Preparation System for Neuropathology Epilepsy Research

Immunohistochemsitry is a standard technique to demonstrate proteins in tissue sections and has been widely used in epilepsy research, including surgical resections from patients with focal epilepsy as well as post-mortem studies. Quantitative analysis of the distribution of expressed neuronal and glial markers with immunohistochemistry has been used to explore cellular dysfunction of relevance to epileptogenic processes promoting seizures and importantly the consequence of epilepsy, including neuronal loss, glial and vascular dysfunction. The latter is of relevance to co-morbidities in patients with poorly controlled seizures, particularly memory decline. Furthermore regional brain dysfunction in central automomic centres, as the amygdala that regulates respiratory function, is implicated in sudden and unexpected death in epilepsy (SUDEP). Our current research addresses neuropathological alterations that could underpin the brain network changes observed in epilepsy on neuroimaging, neuropsychometrics, functional and automomic studies that cause memory and cognitive decline and can increase SUDEP risk. The primary advantages of quantitative immunohistochemistry is that it enables cellular localisation and regional distribution in human brain samples and can be correlated with parallel genetic and gene-expression studies in study groups compared to controls. Research at our centre is enabled by the Epilepsy society brain and tissue bank, a research tissue bank of donated surgical and post mortem cases collected over 30 years.

Quantitative immunohistochemistry is greatly aided by automated systems that improve efficiency, reliability and tracking of immunostained sections enabling seamless antigen detection, slides scanning and digitised automated image analysis. In modern epilepsy neuropathology research, large study groups are required and from many brain regions to correlate with neuroimaging, genetics, clinical outcome and psychometric data as we have demonstrated in our previous publications. Modern immunostaining machines also have additional capabilities including multichannel labelling which allows simultaneous analysis of up to eight antigens, enabling localisation of a disease biomarker with a specific cell type and its relationship to adjacent cells and vascular structures, thus providing insight into disease mechanisms and progression.

The current automated immunohistochemistry machine available for epilepsy research is over 12 years old with reduced capacity and functionality and is costly and inefficient to maintain. Our objective is to replace this system with a modern platform that would enhance immunostaining throughput, quality and capability, to improve delivery in our active funded research projects. Our objectives are to ensure this system is adequately maintained and managed and that is made available to epilepsy and neuropathology research staff as well as UCL students who will be trained and fully supported.

Automated immunohistochemistry machines are essential equipment for neuropathology research, for the delivery of rapid, high quality and capacity immunostaining. Standardised staining protocols with the enhanced flexibilities enable the introduction of new assays for target biomarkers in research. Importantly, uniform automated staining reduces batch differences from manual labelling, slides labelling errors and enables rigorous quantitative analysis to compare between study groups. We propose that an update to the Ventana Discover Ultra automated immunostainer, primarily dedicated for neuropathology epilepsy research at UCL, will greatly enhance our research throughput and importantly provide multiplexed capabilities. Increased multiplexing with up to eight channels will enable detailed cell-type localisation of biomarkers in our funded neurodegenerative research projects. This machine will be a replacement for an old, second hand Leica Bondmax machine which is inefficient to run and has reduced functionality. The Ventana system will interface seamlessly with existing slide scanning facilities for streamlined research pipelines and greatly improve our research output with barcode tracking, archiving of scanned images and next stage automated image analysis. Quantitative immunohistochemistry has formed a vital part of our epilepsy neuropathology research in recent decades, on brain tissues from large epilepsy surgical and post-mortem cohorts. Immunohistochemistry data is correlated with co-registered neuroimaging data, genetics and gene-expression data as well as clinical and functional data in deeply-phenotyped epilepsy surgical patients. Funding for service contracts for 3 years would ensure its maintenance and longevity and an electronic booking calendars for research personnel would ensure fair access and timetabled research experiments.