Learning under the microscope
The hippocampus plays a major part in memory formation and learning. Linking facts together is also crucial for learning, but the brain must distinguish between sets of stimuli and make the distinction between them. Previous research has indicated that distinct contexts are represented by separate neural assemblies. The IMAGING LEARNING project looked at immediate early genes as indications of neuronal activity. The researchers looked specifically at two genes' expression, Arc and Homer1a, both implicated in synaptic plasticity during two separate behavioural episodes. Project scientists successfully set up the Arc/Homer1a fluorescent in situ hybridisation (catFISH) system and generated data. To speed up the time-consuming data analysis, IMAGING LEARNING developed a new software tool for automatic analysis, and the researchers intend this to be the subject of a publication following validation. IMAGING LEARNING investigated N-methyl-D-aspartate receptor antagonists such as dizocilpine to model schizophrenia. Results showed that the ability of rats to avoid a hidden place on a constantly rotating carousel was impaired when faced with misleading information about this space. The results indicate that a key aspect of schizophrenia is the compromised discrimination of relevant and irrelevant information. Investigation of the dentate gyrus (DG) in the hippocampus supported the theory that this site facilitates separation of discordant information into coherent subsets. However, this was reversible using incremental training, indicating that inescapable stress exacerbates the effects of lesions on the DG. Following completion of data analysis of the investigations, the results will be prepared for publishing. Deliverables will form a substantial knowledge platform on the neural basis of diseases such as schizophrenia and how learning can be optimised.
Keywords
Learning, schizophrenia, neuronal activity, catFISH, dentate gyrus
