Disinhibition of Tectal Neurons by Pretectal Lesions in the Frog

Ingle, Dwight J.

doi:10.1126/science.180.4084.422

Cited by 131 publications

(33 citation statements)

References 17 publications

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“…Among these non-optic afferents to the tectum, the thalamic pretectal nucleus is assumed to be the source of tectal inhibition which influences the control of retinotectal excitatory processes [12] . Earlier brain lesion studies [13][14][15] provide evidence for such pretectotectal inhibitory influence. Lesions to the caudal dorsal thalamic pretectal region (Lpd/P) in toads lead to hyperactive prey-catching in response to any moving visual stimulus including very large objects that are normally avoided.…”

Section: Introductionmentioning

confidence: 99%

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

Kang

2007

Neurosci. Bull.

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Objective A few investigations have been reported about pretectal suppressive influences on the optic tectum of frog, but characteristics of tectal activity to pretectal input are left unknown. We made intracellular recordings to demonstrate the unexpected complexity in synaptic mechanisms involved in the suppressive influences of pretecal stimulation on the tectal cells. Methods In the present study, we investigated the neuronal activity evoked by pretectal (Lpd/ P) nuclei stimulation using intracellular recording technique. Results The pretectal stimulation mainly elicited two types of responses in the ipsilateral tectum: an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP) and a pure IPSP. The latter predominated in the tectal cells responding to pretectal stimulation. In a few cells, biphasic hyperpolarization appeared under stronger stimulus intensities. The spikes of tecto-pretectal projecting cells elicited by antidromical stimulation were recorded in the ipsilateral tectum, which revealed reciprocal connections between the tectum and particular pretectal nuclei. The synaptic natures underlying pretecto-tectal information transformation have also been demonstrated. EPSPs with short latencies were concluded to be monosynaptic. Most IPSPs were generated through polysynaptic paths, but monosynaptic IPSPs were also recorded in the tectum. Nearly 98% of impaled tectal cells (except for antidromically projecting cells) showed inhibitory responses to pretectal stimulation. Conclusion The results provide strong evidence that pretectal cells broadly inhibit tectal neurons as that has suggested by behavioral and extracellular recording studies.

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Section: Introductionmentioning

confidence: 99%

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

Kang

2007

Neurosci. Bull.

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“…11; see Lpd/P y OT) in which increased retinal inputs to the contralateral pretectum and tectum could lead to an attenuation of tectal output. For evidence of inhibitory pretecto-tectal influences see Ewert [1968], Ingle [1973], Ewert et al [1974, Kozicz and Lázár [1994], Chapman and Debski [1995], Schwippert and Ewert [1995], and Schwippert et al [1998]. Pretecto-tectal connections were traced anatomically by Wilczynski and Northcutt [1977] and assigned physiologically to pretectal thalamic neurons of the classes TH3 and TH4 by BuxbaumConradi and Ewert [1995].…”

Section: Apo-induced Suppression Of Orientingmentioning

confidence: 99%

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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“…Ingle [1973] reports that specific lesions in the pretectum, which has reciprocal connections with the tectum, have eliminated attenuation of prey-catching in toads. Lettvin et al [1961] noted 44 Brain Behav Evol 199852:37-45 Stull/Gruberg Fig.…”

Section: Discussionmentioning

confidence: 99%

Prey Selection in the Leopard Frog: Choosing in Biased and Unbiased Situations

Stull¹,

Gruberg²

1998

Brain Behav Evol

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When given the option between a ground-level prey presented in front and another prey presented 90° to the side, leopard frogs have a front preference. When given a choice between prey objects presented at the left and right sides, some individual leopard frogs have a side preference. Repeated prey object presentations at one side predispose leopard frogs to respond to the opposite side when presented with prey objects at both sides. The phenomenon is preserved through a half minute delay between single prey presentations (biasing) and two prey presentations (testing) but not through a three-minute delay between biasing and testing. Ten biasing presentations on a side are sufficient to induce opposite side preference, while three biasing presentations are insufficient. Attempts to permanently modify preferences by completely exhausting responsiveness to a single side were unsuccessful. A neural model for the effect of biasing on behavior is shown.

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Disinhibition of Tectal Neurons by Pretectal Lesions in the Frog

Cited by 131 publications

References 17 publications

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

An intracellular study of pretectal influence on the optic tectum of the frog, Rana catesbeiana

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

Prey Selection in the Leopard Frog: Choosing in Biased and Unbiased Situations

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