Journal of Comparative Physiology A

, Volume 202, Issue 6, pp 389–398 | Cite as

Responses of infrared-sensitive tectal units of the pit viper Crotalus atrox to moving objects

  • Felix Kaldenbach
  • Horst Bleckmann
  • Tobias KohlEmail author
Original Paper


Rattlesnakes perceive IR radiation with their pit organs. This enables them to detect and strike towards warm-blooded prey even in the dark. In addition, the IR sense allows rattlesnakes to find places for thermoregulation. Animate objects (e.g., prey) tend to move and thus cause moving IR images across the pit membrane. Even when an object is stationary, scanning head movements of rattlesnakes will result in moving IR images across the pit membrane. We recorded the neuronal activity of IR-sensitive tectal neurons of the rattlesnake Crotalus atrox while stimulating the snakes with an IR source that moved horizontally at various velocities. As long as object velocity was low (angular velocity of ~5°/s) IR-sensitive tectal neurons hardly showed any responses. With increasing object velocity though, neuronal activity reached a maximum at ~50°/s. A further increase in object velocity up to ~120°/s resulted in a slight decrease of neuronal activity. Our results demonstrate the importance of moving stimuli for the snake’s IR detection abilities: in contrast to fast moving objects, stationary or slowly moving objects will not be detected when the snake is motionless, but might be detected by scanning head movements.


Infrared reception Rattlesnake Velocity Motion Tectum opticum 





Nucleus descendens lateralis nervi trigemini


Nucleus reticularis caloris


Receptive field



We thank Slawa Braun for animal care and Joachim Mogdans and Vera Schlüssel for critical reading of the manuscript. We also thank two anonymous reviewers for carefully reading and commenting on the manuscript. The authors acknowledge the financial support provided by the DFG (KO4835/1-1). Care and maintenance of experimental animals followed the guidelines for reptiles and venomous snakes. Animal housing and experiments were approved by the LANUVNRW (50.203.2-BN 7, 5/03).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interests.


  1. Bakken GS, Colayori SE, Duong T (2012) Analytical methods for the geometric optics of thermal vision illustrated with four species of pitvipers. J Exp Biol 215:2621–2629CrossRefPubMedGoogle Scholar
  2. Beavers RA (1976) Food habits of the western diamondback rattlesnake, Crotalus atrox, in Texas (Viperidae). Southwest Nat 20:503–515CrossRefGoogle Scholar
  3. Blum B, Auker CR, Carpenter DO (1978) A head holder and stereotaxic device for the rattlesnake. Brain Res Bull 3:271–274CrossRefPubMedGoogle Scholar
  4. Borst A, Euler T (2011) Seeing things in motion: models, circuits, and mechanisms. Neuron 71:974–994CrossRefPubMedGoogle Scholar
  5. Bullock TH, Diecke F (1956) Properties of an infra-red receptor. J Physiol 134:47–87CrossRefPubMedPubMedCentralGoogle Scholar
  6. Bullock TH, Fox W (1957) The anatomy of the infra-red sense organ in the facial pit of pit vipers. J Cell Sci 3:219–234Google Scholar
  7. Chen Q, Deng H, Brauth SE et al (2012) Reduced performance of prey targeting in pit vipers with contralaterally occluded infrared and visual senses. PLoS ONE 7:e34989CrossRefPubMedPubMedCentralGoogle Scholar
  8. De Cock Buning T (1983) Thresholds of infrared sensitive tectal neurons in Python reticulatus, Boa constrictor and Agkistrodon rhodostoma. J Comp Physiol A 151:461–467CrossRefGoogle Scholar
  9. De Cock Buning T, Terashima S, Goris RC (1981a) Crotaline pit organs analyzed as warm receptors. Cell Mol Neurobiol 1:69–85CrossRefPubMedGoogle Scholar
  10. De Cock Buning T, Terashima S, Goris RC (1981b) Python pit organs analyzed as warm receptors. Cell Mol Neurobiol 1:271–278CrossRefPubMedGoogle Scholar
  11. Djawdan M (1988) Maximal running speeds of bipedal and quadrupedal rodents. J Mammal 69:765–772CrossRefGoogle Scholar
  12. Ebert J, Westhoff G (2006) Behavioural examination of the infrared sensitivity of rattlesnakes (Crotalus atrox). J Comp Physiol A 192:941–947CrossRefGoogle Scholar
  13. Eskew EA, Willson JD, Winne CT (2009) Ambush site selection and ontogenetic shifts in foraging strategy in a semi-aquatic pit viper, the Eastern cottonmouth. J Zool 277:179–186CrossRefGoogle Scholar
  14. Goris RC, Nomoto M (1967) Infrared reception in oriental crotaline snakes. Comp Biochem Physiol 23:879–892CrossRefPubMedGoogle Scholar
  15. Goris RC, Terashima S (1973) Central response to infra-red stimulation of the pit receptors in a crotaline snake, Trimeresurus flavoviridis. J Exp Biol 58:59–76PubMedGoogle Scholar
  16. Gracheva EO, Ingolia NT, Kelly YM et al (2010) Molecular basis of infrared detection by snakes. Nature 464:1006–1011CrossRefPubMedPubMedCentralGoogle Scholar
  17. Gruberg ER, Kicliter E, Newman EA et al (1979) Connections of the tectum of the rattlesnake Crotalus viridis: an HRP study. J Comp Neurol 188:31–41CrossRefPubMedGoogle Scholar
  18. Harris JF, Gamow RI (1971) Snake infrared receptors: thermal or photochemical mechanism? Science 172:1252–1253CrossRefPubMedGoogle Scholar
  19. Hartline PH, Kass L, Loop MS (1978) Merging of modalities in the optic tectum: infrared and visual integration in rattlesnakes. Science 199:1225–1229CrossRefPubMedGoogle Scholar
  20. Heiligenberg W, Rose GJ (1987) The optic tectum of the gymnotiform electric fish, Eigenmannia: labeling of physiologically identified cells. Neuroscience 22:331–340CrossRefPubMedGoogle Scholar
  21. Kardong, Bels (1998) Rattlesnake strike behavior: kinematics. J Exp Biol 201:837–850PubMedGoogle Scholar
  22. Kardong KV, Mackessy SP (1991) The strike behavior of a congenitally blind rattlesnake. J Herpetol 25:208–211CrossRefGoogle Scholar
  23. Kishida R, Amemiya F, Kusunoki T, Terashima S (1980) A new tectal afferent nucleus of the infrared sensory system in the medulla oblongata of Crotaline snakes. Brain Res 195:271–279CrossRefPubMedGoogle Scholar
  24. Kohl T, Colayori SE, Westhoff G, Bakken GS, Young BA (2012) Directional sensitivity in the thermal response of the facial pit in western diamondback rattlesnakes (Crotalus atrox). J Exp Biol 215:2630–2636CrossRefPubMedGoogle Scholar
  25. Kohl T, Bothe MS, Luksch H, Straka H, Westhoff G (2014) Organotopic organization of the primary infrared sensitive nucleus (LTTD) in the western diamondback rattlesnake (Crotalus atrox). J Comp Neurol 522(18):3943–3959CrossRefPubMedGoogle Scholar
  26. Krochmal AR, Bakken GS (2003) Thermoregulation in the pits: use of thermal radiation for retreat site selection by rattlesnakes. J Exp Biol 206:2539–2545CrossRefPubMedGoogle Scholar
  27. Lynn WG (1931) The structure and function of the facial pit of the pit vipers. Am J Anat 49:97–139CrossRefGoogle Scholar
  28. Marasco PD, Catania KC (2007) Response properties of primary afferents supplying Eimer’s organ. J Exp Biol 210:765–780CrossRefPubMedGoogle Scholar
  29. Moiseenkova V, Bell B, Motamedi M, Wozniak E, Christensen B (2003) Wide-band spectral tuning of heat receptors in the pit organ of the copperhead snake (Crotalinae). Am J Physiol Integr Comp Physiol 284:598–606CrossRefGoogle Scholar
  30. Molenaar GJ (1974) An additional trigeminal system in certain snakes possessing infrared receptors. Brain Res 78:340–344CrossRefPubMedGoogle Scholar
  31. Newman EA, Hartline PH (1981) Integration of visual and infrared information in bimodal neurons in the rattlesnake optic tectum. Science 213:789–791CrossRefPubMedPubMedCentralGoogle Scholar
  32. Newman EA, Gruberg ER, Hartline PH (1980) The infrared trigemino-tectal pathway in the rattlesnake and in the python. J Comp Neurol 191:465–477CrossRefPubMedGoogle Scholar
  33. Noble GK, Schmidt A (1937) The structure and function of the facial and labial pits of snakes. Proc Am Phil Soc 77:263–288Google Scholar
  34. Schroeder DM, Loop MS (1976) Trigeminal projections in snakes possessing infrared sensitivity. J Comp Neurol 169:1–11CrossRefPubMedGoogle Scholar
  35. Shine R, Li-Xin S (2002) Arboreal ambush site selection by pit-vipers Gloydius shedaoensis. Anim Behav 63:565–576CrossRefGoogle Scholar
  36. Shine R, Sun L, Kearney M, Fitzgerald M (2002) Why do Juvenile Chinese pit-vipers (Gloydius shedaoensis) select arboreal ambush sites? Ethology 108:897–910CrossRefGoogle Scholar
  37. Shine R, Sun L, Kearney M, Fitzgerald M (2006) Thermal correlates of foraging-site selection by Chinese pit-vipers (Gloydius shedaoensis, Viperidae). J Therm Biol 27:405–412CrossRefGoogle Scholar
  38. Terashima S, Goris RC (1976) Receptive area of an infrared tectal unit. Brain Res 101:155–159CrossRefPubMedGoogle Scholar
  39. Terashima S, Goris RC (1979) Receptive areas of primary infrared afferent neurons in crotaline snakes. Neuroscience 4:1137–1144CrossRefPubMedGoogle Scholar
  40. Terashima S, Goris RC, Katsuki Y (1968) Generator potential of crotaline snake infrared receptor. J Neurophysiol 31:682–688PubMedGoogle Scholar
  41. Van Dyke JU, Grace MS (2010) The role of thermal contrast in infrared-based defensive targeting by the copperhead, Agkistrodon contortrix. Anim Behav 79:993–999CrossRefGoogle Scholar
  42. Wagner H, Takahashi T (1990) Neurons in the midbrain of the barn owl are sensitive to the direction of apparent acoustic motion. Naturwissenschaften 77:439–442CrossRefPubMedGoogle Scholar
  43. Zittlau KE, Class B, Münz H (1986) Directional sensitivity of lateral line units in the clawed toad Xenopus laevis Daudin. J Comp Physiol A 158:469–477CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Felix Kaldenbach
    • 1
  • Horst Bleckmann
    • 1
  • Tobias Kohl
    • 2
    Email author
  1. 1.Institute of ZoologyRheinische Friedrich-Wilhelms-University BonnBonnGermany
  2. 2.Chair of ZoologyTechnical University of MunichFreising-WeihenstephanGermany

Personalised recommendations