Cellular Aspects of Catecholaminergic Neurons

Geffen, L. B.; Jarrott, Bevyn

doi:10.1002/cphy.cp010115

Cited by 8 publications

(5 citation statements)

References 405 publications

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“…But the majority of the neuronal vesicles belong to the synaptic vesicles, which contain neurotransmitter substance for the presynaptic terminals. We did not observe any chemical synaptic contacts in the retina and the neuropil, but axons in the plexiform layer and in the neuropil contained both dense‐core and clear vesicles, a feature, according to Geffen and Jarrott (1977), that usually characterizes catecholaminergic neurones. Moreover, it was shown for Aplysia that the ratio of dense‐core/clear vesicles changes with the release of hormones (Haskins et al .…”

Section: Discussionmentioning

confidence: 60%

Eyes and vision in Arion rufus and Deroceras agreste (Mollusca; Gastropoda; Pulmonata): What role does photoreception play in the orientation of these terrestrial slugs?

et al. 2009

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Zieger, M.V., Vakoliuk, I.A., Tuchina, O.P., Zhukov, V.V. and Meyer-Rochow, V.B. 2009. Eyes and vision in Arion rufus and Deroceras agreste (Mollusca; Gastropoda; Pulmonata): What role does photoreception play in the orientation of these terrestrial slugs? -Acta Zoologica (Stockholm) 90 : 189-204This paper deals with the orientational behaviour in the two terrestrial slugs Arion rufus and Deroceras agreste . It presents anatomical details of their eyes and provides an appraisal of the eyes' optical system. In both species the retinae contain two principal types of cell: photoreceptive and pigmented supportive cells. While only the eye of A. rufus apparently contains neurosecretory neurones, that of D. agreste is the only one equipped with a small additional retina with its own separate lens. Lens shapes vary between ovoid ( A. rufus ) and spherical ( D. agreste ). Our results demonstrate that the camera-type eyes in A. rufus and D. agreste have optical systems that do not allow the production of a sharp image on the retina. The slugs demonstrate negative visually mediated phototactic behaviour, but no polarization sensitivity. Only one aspect of the visual environment, namely the overall distribution of light and dark, seems to be important for these slugs. As the main role of the slugs' photoreceptors is to monitor environmental brightness and to assist the animal in orientating towards dark places, we conclude that these slugs do not need to perceive sharp images.

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Section: Discussionmentioning

confidence: 60%

Eyes and vision in Arion rufus and Deroceras agreste (Mollusca; Gastropoda; Pulmonata): What role does photoreception play in the orientation of these terrestrial slugs?

et al. 2009

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“…4, and the synaptic vesicles are spherical and transparent. An important characteristic found in these axon terminals is the presence of very few dense-cored vesicles in contrast with the other studied species (Geffen andJarrot 1977, Palacios-Prü et al 1998).…”

Section: Discussionmentioning

confidence: 74%

“…2); the second, localized at the posterolateral region of the ganglion, showed a predominance of neuronal cell bodies with a high production of vesicles, both dense-cored neurosecretory and electron transparent synaptic vesicles ( Fig. 2) (Geffen and Jarrot 1977, Peters et al 1991, Palacios-Prü et al 1998. Most of the neurons showed reduced cytoplasm and large, elongated nuclei with peripheral and central accumulations of dense heterochromatin (Fig.…”

Section: Resultsmentioning

confidence: 95%

Synaptic dimorphism in Onychophoran cephalic ganglia

Peña-Contreras¹,

Mendoza-Briceño²,

Miranda-Contreras³

et al. 2003

RBT

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The taxonomic location of the Onychophora has been controversial because of their phenotypic and genotypic characteristics, related to both annelids and arthropods. We analyzed the ultrastructure of the neurons and their synapses in the cephalic ganglion of a poorly known invertebrate, the velvet worm Peripatus sedgwicki, from the mountainous region of El Valle, Mérida, Venezuela. Cephalic ganglia were dissected, fixed and processed for transmission electron microscopy. The animal has a high degree of neurobiological development, as evidenced by the presence of asymmetric (excitatory) and symmetric (inhibitory) synapses, as well as the existence of glial cell processes in a wide neuropile zone. The postsynaptic terminals were seen to contain subsynaptic cisterns formed by membranes of smooth endoplasmic reticulum beneath the postsynaptic density, whereas the presynaptic terminal showed numerous electron transparent synaptic vesicles. From the neurophylogenetic perspectives, the ultrastructural characteristics of the central nervous tissue of the Onychophora show important evolutionary acquirements, such as the presence of both excitatory and inhibitory synapses, indicating functional synaptic transmission, and the appearance of mature glial cells.

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“…It seems likely, therefore, that the isolated varicosities were mainly derived from the axons of postganglionic neurons rather than the preganglionic axons which display conventional synaptic membrane modifications. Postganglionic axon terminals characteristically lack these specializations and instead consist of lengths of branching processes with many transmitter-rich varicosities interconnected by narrow transmitter-poor intervaricose segments (GEFFEN & JARROTT, 1978). The varicosites isolated in these experiments are probably mainly derived from these terminal axons.…”

Section: Discussionmentioning

confidence: 89%

Isolation of Axonal Varicosities (Autonomic Synaptosomes) From the Enteric Nervous System

Jonakait

Gintzler

Gershon

1979

Journal of Neurochemistry

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Abstract— A subcellular fraction enriched with varicosities of autonomic axons was obtained from homogenates of strips of guinea‐pig longitudinal muscle and adherent myenteric plexus using differential and sucrose‐or Ficoll‐density gradient ultracentrifugation. This fraction contained the marker, [G‐3H]5‐hydroxytryptamine (5‐HT), taken up by serotonergic axon terminals present in the preparation during a period of incubation prior to homogenization. Electron microscopic examination showed that the isolated varicosities resembled CNS synaptosomes in containing vesicles and mitochondria but, as is characteristic of autonomic postganglionic terminals, they lacked synaptic membrane specializations. Quantitative electron microscopic radioautography revealed that [G‐3H]5‐HT was confined to isolated varicosities. Isolated varicosities were capable of taking up and sequestering 5‐HT from the surrounding medium; this uptake was temperature‐sensitive and blocked by fluoxetine. The subcellular distribution of [G‐3H]l‐tryptophan was also studied by subfractionation of strips in an attempt to determine which structures were responsible for the high‐affinity uptake of that amino acid. Although most of the [G‐3H]l‐tryptophan was found in the high‐speed supernatant, particulate [G‐3H]l‐tryptophan was most concentrated in the subcellular fraction containing isolated axonal varicosities. These studies indicate that a fraction containing functional serotonergic varicosities can be isolated from the gut. These varicosities are probably one of the elements responsible for the high‐affinity uptake of l‐tryptophan by the myenteric layer of the gut.

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Cellular Aspects of Catecholaminergic Neurons

Cited by 8 publications

References 405 publications

Eyes and vision in Arion rufus and Deroceras agreste (Mollusca; Gastropoda; Pulmonata): What role does photoreception play in the orientation of these terrestrial slugs?

Eyes and vision in Arion rufus and Deroceras agreste (Mollusca; Gastropoda; Pulmonata): What role does photoreception play in the orientation of these terrestrial slugs?

Synaptic dimorphism in Onychophoran cephalic ganglia

Isolation of Axonal Varicosities (Autonomic Synaptosomes) From the Enteric Nervous System

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