Activation of Neuronal Circuits by Circulating Hormones in Insects

  • James W. Truman
  • Janis C. Weeks


A central question in neuroethology is why do animals behave in the way they do? When confronted with a particular set of environmental stimuli, why does an animal act in one way at one time and then in a completely different fashion the next? Two factors that play a major role in this behavioral plasticity are the prior experience of the animal and the animal’s “behavioral state.” The latter feature is set by a number of internal conditions, perhaps the most important of which is the hormonal composition of the fluids bathing the nervous system. It has been clear for well over a hundred years since the first studies by Berthold (1849) that chemicals (that later turned out to be hormones) can unlock specific behaviors that are not accessible to the animal under other conditions. These earliest studies involved the expression of sexual behaviors, but it has since been shown that other coordinated behaviors such as those involved in hunger, thirst, aggression, and so forth are all called forth to a greater or lesser extent by their own specific circulating chemicals.


Motor Pattern Central Pattern Generator Abdominal Ganglion Dorsal Nerve Adult Eclosion 


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Copyright information

© Springer Science+Business Media New York 1985

Authors and Affiliations

  • James W. Truman
    • 1
  • Janis C. Weeks
    • 2
  1. 1.Department of ZoologyUniversity of WashingtonSeattleUSA
  2. 2.Department of EntomologyUniversity of California, BerkeleyBerkeleyUSA

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