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.