Neuroethology of releasing mechanisms: Prey-catching in toads

  title={Neuroethology of releasing mechanisms: Prey-catching in toads},
  author={J. -P. Ewert},
  journal={Behavioral and Brain Sciences},
  pages={337 - 368}
  • J. Ewert
  • Published 1 September 1987
  • Biology
  • Behavioral and Brain Sciences
Abstract “Sign stimuli” elicit specific patterns of behavior when an organism's motivation is appropriate. In the toad, visually released prey-catching involves orienting toward the prey, approaching, fixating, and snapping. For these action patterns to be selected and released, the prey must be recognized and localized in space. Toads discriminate prey from nonprey by certain spatiotemporal stimulus features. The stimulus-response relations are mediated by innate releasing mechanisms (RMs… 

Behavior-Correlated Properties of Tectal Neurons in Freely Moving Toads

The present data obtained from T5.2 neurons in freely moving toads during prey-catching behavior support the concept that these neurons are best activated by prey objects and display at least four behavior-correlated properties: recognition, pre-motor activity, motor-feedback, and state-dependent modulation.

The Release of Visual Behavior in Toads: Stages of Parallel/Hierarchical Information Processing

The present neuroethological investigation suggests the neuro-physiological equivalent of a schema as a combination of neurons specified to encode significant coincidences of stimulus cues in space and time as a result of parallel/hierarchical processing in a neural macro-network.

Learning-related modulation of toad's responses to prey by neural loops involving the forebrain

Brain activity is mapped in a paradigm in which visual (prey) and olfactory (odor) cues are associated, whereby the visual prey-schema is extended (“generalized”) in response to any moving object only in the presence of the prey-associated odor.

Apomorphine Alters Prey-Catching Patterns in the Common Toad: Behavioral Experiments and 14C-2-Deoxyglucose Brain Mapping Studies

The 14C-2-deoxyglucose method is employed to compare the rate of local glucose utilization in 41 brain structures and reveals APO-induced increases in glucose utilization, which suggests that APO facilitates the ingestive component and inhibits the orientational and locomotory components of prey capture.

Characterization of lobula giant neurons responsive to visual stimuli that elicit escape behaviors in the crab Chasmagnathus.

Recording in vivo the responses of individual LG neurons to a wide range of visual stimuli presented in different segments of the animal's visual field will permit analysis of the role of each neuronal type for visually guided behaviors and will allow us to address specific questions on the neuronal plasticity of LGs that underlie the well-recognized memory model of the crab.

Visual Associative Learning: Searching for Behaviorally Relevant Brain Structures in Toads

Results of lesions in the medial pallium (MP) and the lateral amygdala (AL) further support the idea of the importance of these “limbic” structures in memory representation: Toads with bilateral ablation of the ventral MP prior to or post conditioning proved to be unable to show the CR.

Responses of medullary neurons to moving visual stimuli in the common toad

The observation of multiple properties in most medullary neurons suggests integration of various inputs by these cells, and this is in principle consistent with the concept of command releasing systems.

Neuronal correlates of the visually elicited escape response of the crab Chasmagnathus upon seasonal variations, stimuli changes and perceptual alterations

The relationship between behavioral and neuronal activities within a variety of experimental conditions that affected the level of escape supported the idea that the LG neurons from the lobula of crabs are deeply involved in the decision for escaping from VDS.

Motor pattern generators in anuran prey capture

The snapping stage of prey capture is a swift, stereotyped, and ballistic motor pattern with very little variability, it is the component with the smallest degree of variability in its duration and execution, and has several subcomponents.

Responses of Movement-Sensitive Visual Interneurons to Prey-Like Stimuli in the Praying Mantis Sphodromantis lineola (Burmeister)

Overall, the movement-elicited activity in both cords was dominated by very large spikes suggesting the existence of several large, descending movement-sensitive interneurons projecting both ipsilaterally and contralaterally from the optic lobes, but only the largest contralateral spikes occurred preferentially to prey-like stimuli.



Snapping in Toads: Some Aspects of Sensorimotor Interfacing and Motor Pattern Generation

It was reasoned that, if the neuronal traffic associated with this motor component was followed “upstream” it should eventually reach neuronal substrates that already had been explored from the sensory side and implicated to play a role in visually guided prey-capture.

Concepts in vertebrate neuroethology

  • J. Ewert
  • Biology, Psychology
    Animal Behaviour
  • 1985

Is the Mauthner Cell a Vertebrate Command Neuron? A Neuroethological Perspective on an Evolving Concept

The command neuron concept has been particularly influential in neurobiology because it provides a mechanism to explain how behavior patterns might be triggered by particular combinations of stimuli.

Focal attention in the frog: behavioral and physiological correlates.

Results of the present study suggest that self-exciting neural loops within the tectum mediate this type of selective attention in frogs.

Neural correlate of behavioral plasticity in command neurons of Pleurobranchaea.

The results suggest that the command neurons of Pleurobranchaea serve as a neural locus at which an animal's behavior is modulated by past experiences and establish a neural correlate of behavioral plasticity, in the form of synaptic inhibition of thecommand neurons.

The Jamming Avoidance Response in an Electric Fish: Algorithms in Sensory Information Processing and their Neuronal Realization

The electrosensory system of South American (gymnotiform) and African (mormyriform) electric fish has become a favorite model system to study the integration of sensory information and the resulting