Numerous studies of learning ability have suggested that some genetic factor or factors are involved in the regulation of cognitive development, but the biological nature of such factors remains largely unknown. Dr. Wehner is searching for these factors using a clever animal model which encompasses both genetics and learning. Highly inbred strains of mice are trained to perform in a complex learning task, and their learning performances are then compared to the brain chemistry of several identifiable regions in the brain. Each individual within an inbred population is equivalent to every other (like identical twins). This provides an excellent population of subjects in which to examine how genetically determined components of brain chemistry might govern the processes of learning and memory. Dr. Wehner's studies are correlating the activity of the neurotransmitter acetylcholine with learning ability using both a spatial and a non-spatial learning task. It is well known, for example, that the hippocampus (a major structure within the forebrain) plays an important role in spatial learning, but that it is not involved in many forms of non-spatial learning. Thus, these investigations are providing information about the nature of the learning process itself, as well as the role of genetic determinants of brain chemistry in different forms of learning. She has already observed, for example, that specific enzymes within the hippocampus vary with the learning abilities of different mouse strains.
