To find out how anorexia nervosa changes the brain, scientists at New York University are studying a rat model of the disease called activity-based anorexia (ABA). Previously, they discovered that ABA rats develop unusually robust dendritic branching of neurons in part of the hippocampus. Their new study takes those findings a step further, illuminating more differences between the brains of healthy versus ABA rats, and offering evidence that ABA rats may be developing too early, closing a critical period of development too soon.
But before making any conclusions about ABA brains, the researchers made some interesting discoveries about normal brain development. Using Neurolucida to analyze CA1 pyramidal cells in the stratum radiatum layer of the ventral hippocampus, they found that after puberty, around postnatal day 51, dendrites go through a growth spurt, more than doubling the number of branches seen seven days earlier. This growth spurt is followed by a decrease, or a pruning, which the researchers say is part of the normal maturation process.