Journal of Comparative Physiology A

, Volume 161, Issue 2, pp 175–185 | Cite as

Dynamics and stimulus-dependence of pacemaker control during behavioral modulations in the weakly electric fish,Apteronotus

  • John Dye


  1. 1.

    Weakly electric fish generate around their bodies low-amplitude, AC electric fields which are used both for the detection of objects and intraspecific communication. The types of modulation in this signal of which the high-frequency wave-type gymnotiform,Apteronotus, is capable are relatively few and stereotyped. Chief among these is the chirp, a signal used in courtship and agonistic displays. Chirps are brief and rapid accelerations in the normally highly regular electric organ discharge (EOD) frequency.

  2. 2.

    Chirping can be elicited artificially in these animals by the use of a stimulus regime identical to that typically used to elicit another behavior, the jamming avoidance response (JAR). The neuronal basis for the JAR, a much slower and lesser alteration in EOD frequency, is well understood. Examination of the stimulus features which induce chirping show that, like the JAR, there is a region of frequency differences between the fish's EOD and the interfering signal that maximally elicits the response. Moreover, the response is sex-specific with regard to the sign of the frequency difference, with females chirping preferentially on the positive and most males on the negative Df. These features imply that the sensory mechanisms involved in the triggering of these communicatory behaviors are fundamentally similar to those explicated for the JAR.

  3. 3.

    Additionally, two other modulatory behaviors of unknown significance are described. The first is a non-selective rise in EOD frequency associated with a JAR stimulus, occurring regardless of the sign of the Df. This modulation shares many characteristics with the JAR. The second behavior, which we have termed a ‘yodel’, is distinct from and kinetically intermediate to chirping and the JAR. Moreover, unlike the other studied electromotor behaviors it is generally produced only after the termination of the eliciting stimulus.



Frequency Difference Modulative Behavior Stimulus Feature Communicatory Behavior Electric Organ 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



difference frequency between two periodic signals


electric organ discharge


jamming avoidance response


non-selective response


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  1. Bastian J, Yuthas J (1984) The jamming avoidance response ofEigenmannia: Properties of a diencephalic link between sensory processing and motor output. J Comp Physiol A 154:895–908Google Scholar
  2. Bullock TH (1969) Species differences in effect of electroreceptor input on electric organ pacemakers and other aspects of behavior in electric fish. Brain Behav Evol 2:85–118Google Scholar
  3. Bullock TH (1970) Reliability of neurons. J Gen Physiol 55:565–584Google Scholar
  4. Bullock TH, Hamstra RH Jr, Scheich H (1972a) The jamming avoidance response of high frequency electric fish. I. General features. J Comp Physiol 77:1–22Google Scholar
  5. Bullock TH, Hamstra RH Jr, Scheich H (1972b) The jamming avoidance response of high frequency electric fish. II. Quantitative aspects. J Comp Physiol 77:23–48Google Scholar
  6. Dye J, Heiligenberg W (1987) Intracellular recording in the medullary pacemaker nucleus of the weakly electric fish,Apteronotus, during modulatory behaviors. J Comp Physiol A 161:187–200Google Scholar
  7. Elekes K, Szabo T (1985) Synaptology of the medullary command (pacemaker) nucleus of the weakly electric fish (Apteronotus leptorhynchus) with particular reference to comparative aspects. Exp Brain Res 60:500–520Google Scholar
  8. Hagedorn M (1986) The ecology, courtship, and mating of gymnotiform electric fish. In: Bullock TH, Heiligenberg W (eds) Electroreception. Wiley, New York, pp 497–525Google Scholar
  9. Hagedorn MM, Heiligenberg W (1985) Court and spark: Electric signals in the courtship and mating of gymnotoid fish. Anim Behav 33:254–265Google Scholar
  10. Heiligenberg W (1977) Principles of electrolocation and jamming avoidance in electric fish. A neuroethological approach. Studies of brain function, vol 1. Springer, Berlin Heidelberg New YorkGoogle Scholar
  11. Heiligenberg W (1986) Jamming avoidance responses. Model systems for neuroethology. In: Bullock TH, Heiligenberg W (eds) Electroreception. Wiley, New York, pp 613–649Google Scholar
  12. Heiligenberg W, Baker C, Matsubara J (1978) The jamming avoidance response inEigenmannia revisited: The structure of a neuronal democracy. J Comp Physiol 127:267–286Google Scholar
  13. Heiligenberg W, Finger T, Matsubara J, Carr C (1981) Input to the medullary pacemaker nucleus in the weakly electric fish,Eigenmannia (Sternopygidae, Gymnotiformes). Brain Res 211:418–423Google Scholar
  14. Hopkins CD (1972) Sex differences in electric signaling in an electric fish. Science 176:1035–1037Google Scholar
  15. Hopkins CD (1974) Electric communication: Functions in the social behavior ofEigenmannia virescens. Behaviour 50:270–305Google Scholar
  16. Landaw EM, DiStefano JJ III (1984) Multiexponential, multicompartmental, and noncompartmental modeling. I. Data analysis and statistical considerations. Am J Physiol 246:R651-R664Google Scholar
  17. Larimer JL, MacDonald JA (1968) Sensory feedback from electroreceptors to electromotor pacemaker centers in gymnotids. Am J Physiol 214:1253–1261Google Scholar
  18. Lorenz K (1979) Das Jahr der Graugans. R. Piper, München ZürichGoogle Scholar
  19. Maler E, Ellis WG (1987) Inter-male aggressive signals in weakly electric fish are modulated by monoamines. Behav Brain Res (in press)Google Scholar
  20. Powell MJD (1968) A fortran routine for solving systems of non-linear algebraic equations. Atomic Energy Research Establishment R 5947, Harwell Berkshire, EnglandGoogle Scholar
  21. Rose G, Heiligenberg W (1986) Neural coding of difference frequencies in the midbrain of the electric fishEigenmannia: Reading the sense of rotation in an amplitude-phase plane. J Comp Physiol A 158:613–624Google Scholar
  22. Scheich H, Bullock TH (1974) The detection of electric fields from electric organs. In: Fessard A (ed) Handbook of sensory physiology, vol III/3. Springer, Berlin Heidelberg New York, pp 201–256Google Scholar
  23. Szabo T, Enger PS (1964) Pacemaker activity of the medullary nucleus controlling electric organs in high frequency gymnotid fish. Z Vergl Physiol 49:285–300Google Scholar
  24. Watanabe A, Takeda K (1963) The change of discharge frequency by A.C. stimulus in a weak electric fish. J Exp Biol 40:57–66Google Scholar

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • John Dye
    • 1
  1. 1.Department of Neurosciences and Neurobiology UnitScripps Institution of Oceanography, UCSD A-002La JollaUSA

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