Avoidance conditioning in bamboo sharks (Chiloscyllium griseum and C. punctatum): behavioral and neuroanatomical aspects
Animals face different threats; to survive, they have to anticipate how to react or how to avoid these. It has already been shown in teleosts that selected regions in the telencephalon, i.e., the medial pallium, are involved in avoidance learning strategies. No such study exists for any chondrichthyan. In nature, an avoidance reaction may vary, ranging from a ‘freeze’ reaction to a startling response and quick escape. This study investigated whether elasmobranchs (Chiloscyllium griseum and C. punctatum) can be conditioned in an aversive classical conditioning paradigm. Upon successful conditioning, the dorsal, medial and lateral pallium were removed (group 1) and performance tested again. In a second group, the same operation was performed prior to training. While conditioning was successful in individuals of both groups, no escape responses were observed. Post-operative performance was assessed and compared between individual and groups to reveal if the neural substrates governing avoidance behavior or tasks learned in a classical conditioning paradigm are located within the telencephalon, as has been shown for teleosts such as goldfish.
KeywordsElasmobranch Fish Cognition Learning Fear conditioning
We would like to thank M. Hofmann for technical support and helpful comments on the experimental setup. The research reported herein was performed under the guidelines established by the current German animal protection law (Landesamt für Natur, Umwelt und Verbraucherschutz NRW, 8.87-50.10.37.09.198).
- Aronson LR, Herberman R (1960) Persistence of a conditioned response in the cichlid fish, Tilapia macrocephala, after forebrain and cerebellar ablations. Anat Rec 138:332Google Scholar
- Compagno LJV, Dando M, Fowler S (2005) A field guide to the sharks of the world. Collins, London, pp 65–326Google Scholar
- Hofmann MH (2001) The role of the fish telencephalon in sensory information processing. In: Kapoor BG, Hara TJ (eds) Sensory biology of jawed fishes: new insights. Oxford & IBH Publishing Co. Pvt. Ltd., New Delhi, pp 255–274Google Scholar
- Hunt HF, Brady JV (1951) Some effects of electro-convulsive shock on a conditioned emotional response (“anxiety”). J Comp Physiol 44:88–98Google Scholar
- Nelson DR (1967) Hearing thresholds, frequency discrimination, and acoustic orientation in the lemon shark, Negaprion brevirostris (POEY). Bull Mar Sci 17:714–768Google Scholar
- Owen EH, Logue SF, Rasmussen DL, Wehner JM (1997) Assessment of learning by the Morris water task and fear conditioning in inbred mouse strains and F1 hybrids: implications of genetic background for single gene mutations and quantitative trait loci analyses. Neuroscience 80:1087–1099PubMedCrossRefGoogle Scholar
- Pavlov IP (1928) Lectures on conditioned reflexes: twenty five years of objective study of the higher nervous activity (behaviour) of animals, pp 103–204Google Scholar
- Thorndike EL (1898) Animal intelligence: an experimental study of the associative processes in animals. Psychol Rev Monogr Suppl 2:1–109Google Scholar
- Wilensky AE, Schafe GE, LeDoux JE (1999) Functional inactivation of the amygdala before but not after auditory fear conditioning prevents memory formation. J Neurosci 19:1–5Google Scholar