Heterozygous neuron-specific LPL deficient mice (NEXLPL+/-) also develop obesity on a delayed time course, and herein we use aged NEXLPL+/- mice to show for the first time that mice with neuron-specific deficiency of LPL display learning and memory deficits in addition to other behavioral abnormalities, clearly demonstrating the importance of neuronal LPL in cognitive function. This evidence concerns the gene LPL and obesity disorder.