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Succinic dehydrogenase histochemistry reveals the location of the putative primary visual and auditory areas within the dorsal ventricular ridge of Sphenodon punctatus.
- Source :
-
Brain, behavior and evolution [Brain Behav Evol] 2000 Jan; Vol. 55 (1), pp. 26-36. - Publication Year :
- 2000
-
Abstract
- In turtles, crocodilians, lizards and snakes, the dorsal ventricular ridge (DVR) is a nuclear cell mass that contains distinct visual and auditory thalamorecipient cell groups. In the tuatara (Sphenodon punctatus), the DVR is not organized into diverse cell groups but instead possesses a trilaminar cytoarchitecture resembling that characteristic of the telencephalic cortex in reptiles. To determine if visual and auditory fields might also be present in the DVR of Sphenodon punctatus, we used succinic dehydrogenase (SDH) histochemistry, which has been shown to delineate the visual and auditory fields of the DVR in turtles, crocodilians and lizards. We also used acetylcholinesterase (AChE) histochemistry to determine the boundary between the DVR and the basal ganglia in Sphenodon. We found an SDH-rich region in the neuropil ventral to the cell plate of the rostrolateral DVR and a slightly less intense SDH-rich zone in the neuropil deep to the cell plate of the ventromedial DVR. These SDH-rich zones appear to be located at the apical dendrites of the neurons of the adjacent cell plate. These SDH-rich zones were clearly located within the DVR and were distinct from the AChE-rich striatal part of the basal ganglia, which occupied the ventrolateral wall of the telencephalon. Based on findings in other reptiles, it seems likely that the SDH-rich zone in rostrolateral DVR represents the zone of termination of nucleus rotundus visual input to the DVR, whereas the zone in ventromedial DVR represents the zone of termination of nucleus reuniens auditory input. Because a trilaminar DVR such as that in Sphenodon might be the primitive DVR condition for reptiles, our results suggest that the cytoarchitecture of the DVR and the synaptic organization of its thalamic sensory input in the common ancestor of living reptiles might have been much like of the dorsal cortex.<br /> (Copyright (R) 2000 S. Karger AG, Basel)
- Subjects :
- Acetylcholinesterase metabolism
Animals
Basal Ganglia anatomy & histology
Cerebral Ventricles anatomy & histology
Histocytochemistry
Neuropil enzymology
Synapses enzymology
Telencephalon anatomy & histology
Thalamus enzymology
Basal Ganglia enzymology
Cerebral Ventricles enzymology
Hearing physiology
Lizards metabolism
Succinate Dehydrogenase metabolism
Telencephalon enzymology
Vision, Ocular physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-8977
- Volume :
- 55
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Brain, behavior and evolution
- Publication Type :
- Academic Journal
- Accession number :
- 10773623
- Full Text :
- https://doi.org/10.1159/000006639