Objective: to prepare a targeting drug for brain-derived neurotrophic factor (BDNF) and study its therapeutic effect in Alzheimer's disease (AD) transgenic mice.

The genetically engineered rat, Hobbie-J, over-expresses a gene that regulates neuron communication, greatly enhancing the rat's ability to navigate mazes and remember toys.

The same was found for scent-marking. Like normal males, the mutant mice urinated in various spots around their cage (unlike females, who create a single latrine).