Stimulus-specific long-term habituation of visually guided orienting behavior toward prey in toads: a 14C-2DG study.
The regional distribution of cerebral glucose utilization, revealed by the 14C-2DG technique, was compared between (i) toads after stimulus-specific long-term habituation of the orienting response toward a repeatedly presented prey dummy ('habituation group') and (ii) non-habituated toads, readily orienting toward the repetitively presented prey stimulus ('naive group'). In the 'habituation group', the ventral medial pallium (vMP), a certain portion of the preoptic area (PO), and the dorsal hypothalamus (dHYP) showed a statistically significant increase in 14C-2DG-uptake; decrease was observed in the ventral layers of the optic tectum (vOT), a portion of the tegmental reticular formation (RET), the ventral cerebellum (vCB), and the striatum (STR). The results suggest that stimulus-specific long-term habituation of prey-catching affects both, components of the stimulus-response mediating circuit (e.g., involving OT), and structures extrinsic to it, (e.g., vMP, PO, dHYP), which may belong to a modulatory circuitry. Bilateral lesions to vMP strongly delay habituation. Our results are suggesting that damping of the adequate behavioral motor response during habituation involves active inhibitory processes of a modulatory system that develops in strength during stimulus repetition so as to suppress response output, which basically supports Sokolov's hypothesis (1975).
D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D001345:Autoradiography; D002023:Bufo bufo / Q000502:physiology*; D002250:Carbon Radioisotopes; D002531:Cerebellum / Q000033:anatomy & histology / Q000378:metabolism; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000378:metabolism; D004027:Diencephalon / Q000033:anatomy & histology / Q000378:metabolism; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D008636:Mesencephalon / Q000033:anatomy & histology / Q000378:metabolism; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D011235:Predatory Behavior / Q000502:physiology*; D013687:Telencephalon / Q000033:anatomy & histology / Q000378:metabolism
D002250:Carbon Radioisotopes