Mapping of brain activity in mesencephalic and diencephalic structures of toads during presentation of visual key stimuli: a computer assisted analysis of (14C)2DG autoradiographs

Finkenstädt, Th.; Adler, Norman T.; Allen, T. O.; Ebbesson, Sven O. E.; Ewert, Jörg-Peter

doi:10.1007/bf00613968

Cited by 48 publications

(5 citation statements)

References 26 publications

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“…11; see vOB y LS y vMP Y A Y R) [Hoffmann, 1973;Kicliter and Northcutt, 1975;Northcutt and Royce, 1975;Northcutt and Kicliter, 1980;Neary and Wilczynski, 1980]. Previous 14 C-2DG studies have shown that activity in the ventral medial pallium is associated with conditioning [see Finkenstädt, 1989;Finkenstädt et al, 1985;Merkel-Harff and Ewert, 1991;Papini et al, 1995;Ewert et al, 1994bEwert et al, , 1999. The increase in glucose utilization in the ventral medial pallium might also result from the action of APO as a positive reinforcer [e.g.…”

Section: Apo-induced Facilitation Of Snappingmentioning

confidence: 99%

“…Brain sections were stained with cresyl violet. For methodological details we refer to Finkenstädt et al [1985Finkenstädt et al [ , 1986.…”

Section: C-2dg Autoradiographymentioning

confidence: 99%

“…The comparisons are based on a statistical analysis of the group mean values X′ P* and X′ P (see Materials and Methods) [X′ P;C -and X′ N;C -values, i.e. the alteration in glucose utilization of APO-untreated toads, in response to different visual stimuli, was described in detail by Finkenstädt et al, 1985Finkenstädt et al, , 1986.…”

Section: Apo-treated Vs Untreated Prey-stimulated Groupsmentioning

confidence: 99%

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

Glagow

Ewert²

1999

Brain Behav Evol

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Previous studies on the dopaminergic modulation of visuomotor functions in amphibians showed that the dopamine agonist apomorphine (APO) alters prey-catching strategies. After systemic administration of APO in common toads Bufo bufo, prey-oriented turning and locomotion was attenuated whereas snapping toward prey was facilitated in a dose dependent manner. With systemic APO administration, toads which had previously been hunting, that is pursuing prey, behaved in a waiting position, that is sitting motionless and waiting for prey. This suggests that APO facilitates the ingestive component and inhibits the orientational and locomotory components of prey capture. To help unravel the cerebral sites of action of APO, the present study employs the ¹⁴C-2-deoxyglucose method to compare the rate of local glucose utilization in 41 brain structures. The retinal projection fields – e.g. superficial optic tectum, pretectal nuclei, and anterior dorsal thalamic nucleus – showed an elevation in glucose utilization due to APO-induced increases in retinal output. The medial tectal layers and the ventral striatum, both involved in visuomotor functions related to prey-oriented turning and locomotion, displayed APO-induced decreases in glucose utilization. APO-induced increases in glucose utilization were observed in the medial reticular formation and the hypoglossal nucleus which participate in the motor pattern generation of snapping. APO-induced increases in glucose utilization were also detected in the nucleus accumbens and the ventral tegmentum (mesolimbic system) as well as in the ventromedial pallium (‘primordium hippocampi’) and the septum, both of which belonging to the limbic system. These structures contribute to motivational level control and may be responsible for the APO-induced elevation of the snapping rate. Various other structures revealed APO-induced increases in glucose utilization. These structures include the olfactory bulb, lateral pallium, suprachiasmatic nucleus, nucleus of the periventricular organ, and the nucleus of the solitary tract. The lateral amygdala displayed APO-induced decreases in glucose utilization. The APO-induced alterations in local cerebral glucose utilization are evaluated with reference to the distribution of dopaminergic structures, and this is compared with similar data obtained in the rat by other authors. A neural network explaining the APO-induced behavioral syndrome in the common toad is discussed.

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Section: Apo-induced Facilitation Of Snappingmentioning

confidence: 99%

“…Brain sections were stained with cresyl violet. For methodological details we refer to Finkenstädt et al [1985Finkenstädt et al [ , 1986.…”

Section: C-2dg Autoradiographymentioning

confidence: 99%

Section: Apo-treated Vs Untreated Prey-stimulated Groupsmentioning

confidence: 99%

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

Glagow

Ewert²

1999

Brain Behav Evol

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“…B Computer-processed auto radiographic image of a 14C_2_ deoxyglucose (2DG)-labeled midbrain section (corresponding to Fig. l1c) from a common toad (sitting in a glass vessel) repetitively snapping toward a visual prey dummy moving (outside the vessel) to and fro; black indicates the strongest metabolic activity in the "snapping evoking area" of the tectum (Finkenstiidt et al 1985). C Sites in the midbrain which electrically stimulated elicited snapping in toads; grid width = 0.5 mm.…”

Section: Afferents Of the Medial Reticular Formationmentioning

confidence: 99%

Sensorimotor Processes That Underlie Feeding Behavior in Tetrapods

Ewert

Beneke

Schürg-Pfeiffer

et al. 1994

Biomechanics of Feeding in Vertebrates

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“…Among these the characteristic of the disynaptic striatopretecto-tectal pathway (cf. For example, studies mapping the local cerebral glucose utilization showed a positive correlation between the toad's visually elicited prey catching orienting activity and increases in 14 C-2DG uptake in the caudal ventral striatum and the optic tectum, whereas the pretectal Lpd nucleus revealed a decrease [96,105]. For example, studies mapping the local cerebral glucose utilization showed a positive correlation between the toad's visually elicited prey catching orienting activity and increases in 14 C-2DG uptake in the caudal ventral striatum and the optic tectum, whereas the pretectal Lpd nucleus revealed a decrease [96,105].…”

Section: How May Striatum Influence Tectum?mentioning

confidence: 99%

Modulation of visual perception and action by forebrain structures and their interactions in amphibians

Ewert

Schwippert

Neurotransmitter Interactions and Cognitive Function

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Nervous systems of lower animals appraised simple prove to be relatively complexDo amphibians "know" while humans "learn"?Towards the middle of the last century, many ethologists suggested that behaviors displayed among so-called "lower" invertebrates or vertebrates -such as some crustaceans or amphibians, respectively -are predominantly innate and rigid in their performance (e.g., [1]). Moreover, responses to behaviorally significant sign stimuli should proceed reflex-like, for example, the lobster's tailflip-reflex in response to a threatening stimulus (e.g., [2]) and the toad's snap-reflex in response to a prey stimulus (e.g., [3]). In detail it was assumed, that a sign [key] stimulus activates an innate releasing mechanism (IRM), that -much like a safe is unlocked by a keyreleases the corresponding action pattern (e.g., [4,5]). According to the IRM concept, (re-)cognition and motor skills are innate. Neurophysiologically, the concept of IRM suggests an inborn sensorimotor interface that translates perception into action: recognizing ("detecting") the sign stimulus at its afferent input-side and activating ("commanding") the corresponding motor system at the efferent output-side. Hence, the concepts of "feature detector" and "command neuron" were born (e.g., [6,7]). Theoretically, the simplest innate releasing mechanism would consist of a command neuron, CN, operating in a chain like: sign-stimulus → CN → motor pattern generator → behavior In this case, the commanding neuron should be a cell specifically tuned to the feature of the sign stimulus, and the axon of that neuron should have access to the motor pattern generating network.Meanwhile, the concepts of command neuron and innate releasing mechanism were revisited and revised from many points of view (e.g., [8][9][10][11][12][13]). First of all, appetitive and consummative behavioral responses both in so-called lower and higher animals depend on state-dependent modulatory influences (referring to motivation

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Mapping of brain activity in mesencephalic and diencephalic structures of toads during presentation of visual key stimuli: a computer assisted analysis of (14C)2DG autoradiographs

Cited by 48 publications

References 26 publications

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

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

Sensorimotor Processes That Underlie Feeding Behavior in Tetrapods

Modulation of visual perception and action by forebrain structures and their interactions in amphibians

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