Influences of light on the subcommissural organ in European green frogs

Vullings, H. G. B.; Diederen, J. H. B.; Smeets, Aude

doi:10.1016/0300-9629(83)90630-8

Cited by 6 publications

(3 citation statements)

References 10 publications

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“…In this respect, the findings by Vullings et al (1983) and Jiménez et al (1993) become relevant. The former found that in the frog, the SCO is more active during the night period; the latter established that numerous fibers from the frog pineal tract establish synaptic contacts with the SCO secretory cells.…”

Section: Is the Sco A Component Of The Circadian Timing System?mentioning

confidence: 97%

“…The presence in the PVT of binding sites for RFglycoproteins poses the interesting possibility of a functional relationship between the SCO and the PVT. In this respect, the findings by Vullings et al (1983) andJime ´nez et al (1993) become relevant. The former found that in the frog, the SCO is more active during the night period; the latter established that numerous fibers from the frog pineal tract establish synaptic contacts with the SCO secretory cells.…”

Section: Is the Sco A Component Of The Circadian Timing System?mentioning

confidence: 98%

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Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

Miranda

Almonacid

Rodrı́guez

et al. 2001

Microsc. Res. Tech.

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The molecular organization of Reissner's fiber (RF), the structure of its proteins, and the permanent turnover of these proteins are all facts supporting the possibility that RF may perform multiple functions. There is evidence that CSF-soluble RF-glycoproteins may occur under physiological conditions. The present investigation was designed to investigate the probable existence within the CNS of specific binding sites for RF-glycoproteins. Three experimental protocols were used: (1) immunocytochemistry of the CNS of bovine fetuses using anti-idiotypic antibodies, raised against monoclonal antibodies developed against bovine RF-glycoproteins; (2) in vivo binding of the RF glycoproteins, perfusing into the rat CSF 125I-labeled RF-glycoproteins, or grafting SCO into a lateral ventricle of the rat; (3) in vitro binding of unlabeled RF-glycoproteins to rat and bovine choroid plexuses maintained in culture. One of the anti-idiotypic antibody generated by a Mab raised against RF-glycoproteins binds to choroidal cells. Furthermore, binding of RF-glycoproteins to the rat choroid plexus was obtained when: (1) the choroid plexus was cultured in the presence of unlabeled RF-glycoproteins; (2) the concentration of soluble RF-glycoproteins in the CSF was increased by isografting SCOs into a lateral ventricle; (3) radiolabeled glycoproteins were perfused into the ventricular CSF. This evidence suggests that the apical plasma membrane of the ependymal cells of the choroid plexus has specific binding sites for RF-glycoproteins, of unknown functional significance. The radiolabeled RF-glycoproteins perfused into the rat CSF also bound to the paraventricular thalamic nucleus, the floor of the Sylvian aqueduct and of the rostral half of the fourth ventricle, and the meninges of the brain and spinal cord. The labeling of the paraventricular thalamic nucleus points to a functional relationship between this nucleus and the SCO. The possibility that the SCO may be a component of the circadian timing system is discussed. Microsc.

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Section: Is the Sco A Component Of The Circadian Timing System?mentioning

confidence: 97%

Section: Is the Sco A Component Of The Circadian Timing System?mentioning

confidence: 98%

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

Miranda

Almonacid

Rodrı́guez

et al. 2001

Microsc. Res. Tech.

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“…To see the influence of light on the SCO, complex experimental studies have been carried out in Rana esculenta and Rana temporaria. These experiments consisted in the separate or combined elimination of the frontal organ, the pineal organ, and the lateral eyes (Diederen, 1975), and the use of different light wavelengths (Vullings et al, 1983). In these studies, evidence has been obtained indicating that light apparently exerted an inhibitory influence on the growth rate of Reissner's fiber.…”

Section: Neural Connections Of the Subcommissural Organ With The Pineal Complex And The Circadianmentioning

confidence: 99%

Neural input and neural control of the subcommissural organ

Jiménez

Fernández-Llébrez

Pérez-Fígares

2001

Microsc. Res. Tech.

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The neural control of the subcommissural organ (SCO) has been partially characterized. The best known input is an important serotonergic innervation in the SCO of several mammals. In the rat, this innervation comes from raphe nuclei and appears to exert an inhibitory effect on the SCO activity. A GABAergic innervation has also been shown in the SCO of the rat and frog Rana perezi. In the rat, GABA and the enzyme glutamate decarboxylase are involved in the SCO innervation. GABA is taken up by some secretory ependymocytes and nerve terminals, coexisting with serotonin in a population of synaptic terminals. Dopamine, noradrenaline, and different neuropeptides such as LH-RH, vasopressin, vasotocin, oxytocin, mesotocin, substance P, ␣-neoendorphin, and galanin are also involved in SCO innervation. In the bovine SCO, an important number of fibers containing tyrosine hydroxylase are present, indicating that in this species dopamine and/or noradrenaline-containing fibers are an important neural input. In Rana perezi, a GABAergic innervation of pineal origin could explain the influence of light on the SCO secretory activity in frogs. A general conclusion is that the SCO cells receive neural inputs from different neurotransmitter systems. In addition, the possibility that neurotransmitters and neuropeptides present in the cerebrospinal fluid may also affect the SCO activity, is discussed.

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Dynamic Aspects of the Secretory Process in the Amphibian Subcommissural Organ

Diederen¹,

Vullings²

1993

The Subcommissural Organ

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Influences of light on the subcommissural organ in European green frogs

Cited by 6 publications

References 10 publications

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

Neural input and neural control of the subcommissural organ

Dynamic Aspects of the Secretory Process in the Amphibian Subcommissural Organ

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