The effects of temperature on signalling in ocellar neurons of the desert locust, Schistocerca gregaria

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2011 Nov;197(11):1083-96. doi: 10.1007/s00359-011-0669-y. Epub 2011 Aug 10.

Abstract

In Schistocerca gregaria ocellar pathways, large second-order L-neurons use graded potentials to communicate signals from the ocellar retina to third-order neurons in the protocerebrum. A third-order neuron, DNI, converts graded potentials into axonal spikes that have been shown in experiments at room temperature to be sparse and precisely timed. I investigated effects of temperature changes that a locust normally experiences on these signals. With increased temperature, response latency decreases and frequency responses of the neurons increase. Both the graded potential responses in the two types of neuron and the spikes in DNI report greater detail about a fluctuating light stimulus. Over a rise from 22 to 35°C the power spectrum of the L-neuron response encompasses higher frequencies and its information capacity increases from about 600 to 1,700 bits/s. DNI generates spikes more often during a repeated stimulus but at all temperatures it reports rapid decreases in light rather than providing a continual measure of light intensity. Information rate carried by spike trains increases from about 50 to 185 bits/s. At warmer temperatures, increased performance by ocellar interneurons may contribute to improved aerobatic performance by delivering spikes earlier and in response to smaller, faster light stimuli.

Publication types

  • Comparative Study

MeSH terms

  • Action Potentials / physiology*
  • Action Potentials / radiation effects
  • Animals
  • Grasshoppers / anatomy & histology
  • Grasshoppers / physiology*
  • Hot Temperature
  • Light
  • Neurons / physiology*
  • Neurons / radiation effects
  • Photic Stimulation / methods
  • Photoreceptor Cells, Invertebrate / physiology*
  • Photoreceptor Cells, Invertebrate / radiation effects
  • Signal Transduction / physiology*
  • Signal Transduction / radiation effects
  • Thermosensing / physiology*
  • Thermosensing / radiation effects
  • Vision, Ocular / physiology*
  • Vision, Ocular / radiation effects