Researchers at the Universities of Washington and Texas say previous studies had determined parts of the brains of the wasp species (Polybia aequatorialis) enlarged as the animal engaged in more complex tasks.
The new research describes how that occurs as dendrites, or extensions from individual neurons, reach out to receive information from other brain cells and form a dense network of connections. The networks help the wasps integrate information from visual, olfactory and touch sensory systems, the scientists said.
"I was astounded when we found that some of the individual neurons had dendrites that were seven to eight millimeters long in a brain that is roughly the size of two grains of sand," said study co-author Sean O'Donnell, a University of Washington associate professor of psychology.
The researchers said they found the biggest changes in brain neuron architecture occurred when the wasps shifted from working on the nest exterior to foraging.
The study that included Associate Professor Theresa Jones and research associate Nicole Donlan, both at the University of Texas, appears in the early online edition of the journal Neurobiology of Learning and Memory.