In their study, the Duke researchers explored the effects of choline on neurons in the hippocampus, a brain region that is critical for learning and memory. They fed pregnant rats extra amounts of choline during a brief but critical window of pregnancy and, then studied how their hippocampal neurons differed from those of control rats. They found that hippocampal neurons were larger, and they possessed more tentacle-like “dendrites” that reach out and receive signals from neighboring neurons.

“Having more dendrites means that a neuron has more surface area to receive incoming signals,” said neuropsychologist Scott Swartzwelder, Ph.D., senior author of the study. “This could make it easier to push the neuron to the threshold for firing its signal to another neuron.”

When a neuron fires a signal, it releases brain chemicals called “neurotransmitters” that trigger neighboring neurons to fire, thus creating a neural circuit that can process new information. The study showed that the neurons also “fired” electrical signals more rapidly, sustained their firing for longer periods of time, and rebounded more easily from their resting phase in between firing signals. These findings complement a previous study by this group showing that neurons from supplemented animals were less susceptible to toxic drugs that kill neurons.

Collectively, these behaviors should heighten the neurons’ capacity to accept, transmit and integrate incoming information, said Swartzwelder.