Biogenic amines for individual and social learning

Individuals learn about their environment through personal observation or by observing their social conspecifics. The speed-accuracy trade-off associated with these two strategies results in two possible learning phenotypes – slow but more accurate individual learners and fast but more inaccurate social learners. While the costs and benefits of these different learning strategies are well known, we know much less about the possible neurophysiological mechanisms that underlie such cognitive variation. Neurotransmitters, based on their important role in driving cognitive differences in all taxa, are the most likely candidates that underlie the neurophysiological differences between these learning phenotypes. We measured individual honeybees for their performance on an individual and a social learning task followed by quantifying the concentrations of various neurotransmitters in their brains. Our results show that the two learning phenotypes and their accompanying differences in the speed-accuracy trade-off are consistently characterized by the opposite effects of an interaction between octopamine and serotonin and another between octopamine and glutamate. These findings challenge the general notion that social learning is simply an extension of individual learning and provide an important insight into the mechanistic underpinnings of the two different learning phenotypes and the neurophysiological mechanism that underlies slow-fast differences across taxa.