title: High order neural correlates of social behavior in the honeybee brain.
abstract: BACKGROUND
  Honeybees are well established models of neural correlates of sensory function, learning and memory formation. Here we report a novel approach allowing to record high-order mushroom body-extrinsic interneurons in the brain of worker bees within a functional colony. New method The use of two 100 cm long twisted copper electrodes allowed recording of up to four units of mushroom body-extrinsic neurons simultaneously for up to 24h in animals moving freely between members of the colony. Every worker, including the recorded bee, hatched in the experimental environment. The group consisted of 200 animals in average.
  
  
  RESULTS
  Animals explored different regions of the comb and interacted with other colony members. The activities of the units were not selective for locations on the comb, body directions with respect to gravity and olfactory signals on the comb, or different social interactions. However, combinations of these parameters defined neural activity in a unit-specific way. In addition, units recorded from the same animal co-varied according to unknown factors. Comparison with existing method(s): All electrophysiological studies with honey bees were performed so far on constrained animals outside their natural behavioral contexts. Yet no neuronal correlates were measured in a social context. Free mobility of recoded insects over a range of a quarter square meter allows addressing questions concerning neural correlates of social communication, planning of tasks within the colony and attention-like processes.
  
  
  CONCLUSIONS
  The method makes it possible to study neural correlates of social behavior in a near-natural setting within the honeybee colony.
authors.affiliation: Institute of Biology, Neurobiology of the Freie Universität Berlin, Germany.
authors.forename: Aron
authors.initials: A
authors.lastname: Duer
authors.affiliation: Institute of Biology, Neurobiology of the Freie Universität Berlin, Germany.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Paffhausen
authors.affiliation: Institute of Biology, Neurobiology of the Freie Universität Berlin, Germany. Electronic address: menzel@neurobiologie.fu-berlin.de.
authors.forename: Randolf
authors.initials: R
authors.lastname: Menzel
mesh_terms: D000200:Action Potentials; D000818:Animals; D001516:Bees / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000502:physiology; D004566:Electrodes; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology; D007395:Interneurons / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D012919:Social Behavior
keywords: Combinatorial coding; Insect; Multi-unit extracellular recording; Mushroom body extrinsic neurons; Social behavior