The role of dendritic spines in neuronal information processing is still not completely clear. However, it is known that spines can change shape rapidly during development and during learning and these morphological changes might be relevant for information storage (memory formation). We demonstrate the impact of shape variations on electrical signal propagation via dendritic spines using a biologically realistic electrical simulation procedure. Basic properties of electrical signal transduction of single spines are estimated and approximated in relation to their individual shape features. Learning processes to adjust specific electrical properties are discussed and a possible mechanism is introduced.