Journal of Comparative Physiology A

, Volume 167, Issue 4, pp 509–520 | Cite as

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

II. An intracellular recording and cobalt-lysine labeling study
  • W. W. Schwippert
  • T. W. Beneke
  • J. P. Ewert


Intracellular recording and labeling of cells from the toad's (Bufo bufo spinosus) medulla oblongata in response to moving visual (and tactual) stimuli yield the following results. (i) Various response types characterized by extracellular recording in medullary neurons were also identified intracellularly and thus assigned to properties of medullary cell somata. (ii) Focussing on monocular small-field and cyclic bursting properties, somata of such neurons were recorded most frequently in the medial reticular formation and in the branchiomotor column but less often in the lateral reticular formation. (iii) Visual object disrimination established in pretectal/tectal networks is increased in its acuity in 4 types of medullary small-field neurons. The excitatory and inhibitory inputs to these neurons evoked by moving visual objects suggest special convergence likely to increase the filter properties. (iv) Releasing conditions, temporal pattern, and refractoriness of cyclic bursting neurons resemble membrane characteristics of vertebrate and invertebrate neurons known to play a role in premotor/motor activity. (v) Integrating functions of medullary cells have an anatomical correlate in the extensive arborizations of their dendritic trees; 5 morphological types of medullary neurons have been distinguished.

Key words

Visuomotor integration Medulla oblongata Intracellular recording and labeling Toad 



stripe moving in antiworm configuration


moving in worm configuration




branchiomotor column


excitatory postsynaptic potential


inhibitory postsynaptic potential


medullary reticular formation


receptive field

M neurons

response properties of medullary neurons

T neurons

classes of tectal neurons

TH neurons

classes of thalamic/pretectal neurons


tractus tecto-bulbaris directus


tractus tecto-bulbaris et spinalis cruciatus


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Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • W. W. Schwippert
    • 1
  • T. W. Beneke
    • 1
  • J. P. Ewert
    • 1
  1. 1.Abteilung Neurobiologie, Fachbereich Biologie/ChemieUniversität KasselKasselFederal Republic of Germany

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