Neuroactive nectar: compounds in nectar that interact with neurons

Abstract

As well as sugars to entice pollinators, nectar contains many other chemicals including amino acids and plant secondary compounds such as phenolics, alkaloids, and glycosides. Rather than simply the byproducts of plant metabolism or contamination by compounds meant to deter herbivory, it is clear that these chemicals may have important roles in nectar. Proposed functions of non-sugar components of nectar include pollinator nutrition, reducing nectar robbing, and defense against microbes. Additionally, some of these compounds are able to interact directly with the nervous system via binding to receptor proteins found on the surface of neurons. Thus, these neuroactive components of nectar may be able to manipulate pollinator behavior. To increase our ability to analyze the many functions of nectar, it is important to understand how specific components may interact with neurons. This review examines the neurotransmitter receptors that are targets of some of the chemicals present in nectar. Although these compounds also affect the nervous systems of vertebrates, the focus of this review is on the interactions between nectar and insect pollinators.