Study Provides New Insights into Honeybee ‘Waggle Dance’ Communication
According to a study published in the journal eNeuro (bioRxiv.org preprint), changes in vibration-sensitive neurons may equip forager honeybees for waggle dance communication.
Honeybees (Apis mellifera) are social insects. As they mature, adult honeybees engage in four primary social roles — cleaners, nursers, food storers and foragers — and perform different tasks in different roles.
Successful foragers inform their nestmates of the location of nectar or water sources by doing a waggle dance.
The dance encodes both the direction of and distance to the sources from the hive.
“Forager honeybees share information about the location and value of food sources by moving their body from side to side and beating their wings,” said lead author Dr. Ajayrama Kumaraswamy of the Ludwig-Maximilians-Universität München and colleagues.
“The observing bees interpret the waggle dance through sensory organs that send the information to vibration-sensitive neurons, including DL-INT-1.”
Vibration sensing, primary auditory center and DL-INT-1 interneuron in the honeybee: (a) airborne vibrations picked up by the flagellum are transduced by sensory neurons of the Johnston’s organ (JO) in the pedicel and transmitted to the primary auditory center of the honeybee brain, which consists of the medial posterior protocerebral lobe (mPPL), the dorsal lobe (DL) and the dorsal subesophageal ganglion (dSEG); (b) projection patterns of sensory afferents (green) and DL-INT-1 in the primary auditory center of the honeybee brain. DL-INT-1 has dendrites running close to sensory afferents in the dorsal lobe. Image credit: Kumaraswamy et al, doi: 10.1523/ENEURO.0454-18.2019.
In the study, Dr. Kumaraswamy and co-authors recorded the electrical activity of DL-INT-1 neurons in young, newly-emerged adult and mature forager honeybees.
Then they created computer simulations and 3D models of DL-INT-1 neurons.
In specific regions of the neurons, the older bees had less dense branching compared to the younger bees.
Additionally, the neurons in older bees demonstrated enhanced signaling and more precise connections to other brain regions.
“Our findings suggest that important adaptations occur in the honeybee during the transition into the forager role, which allow them to effectively communicate via the waggle dance,” the researchers said.
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Ajayrama Kumaraswamy et al. Adaptations during maturation in an identified honeybee interneuron responsive to waggle dance vibration signals. eNeuro, published online August 26, 2019; doi: 10.1523/ENEURO.0454-18.2019