Multiphasic on/off pheromone signalling in moths as neural correlates of a search strategy

PLoS One. 2013 Apr 17;8(4):e61220. doi: 10.1371/journal.pone.0061220. Print 2013.

Abstract

Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK) channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Appetitive Behavior / drug effects*
  • Bicuculline / pharmacology
  • Male
  • Models, Neurological
  • Moths / drug effects*
  • Moths / physiology*
  • Neurons / drug effects*
  • Neurons / physiology*
  • Pheromones / pharmacology*
  • Picrotoxin / pharmacology
  • Potassium Channels, Calcium-Activated / metabolism
  • Reproducibility of Results

Substances

  • Pheromones
  • Potassium Channels, Calcium-Activated
  • Picrotoxin
  • Bicuculline