ISSN:
1432-0878
Schlagwort(e):
Neurones
;
Lumbricus
;
Monoamines
;
Neurosecretion
;
Electron microscopy
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Medizin
Notizen:
Summary The cerebral ganglion and the ventral nerve cord of Lumbricus terrestris have been studied with the electron microscope. The results are as follows: In the neuropile small granular vesicles (300 to 500 Å) occur in some varicose nerve fibres after fixation with potassium permanganate. This indicates the presence of noradrenaline. Sometimes only a few of the vesicles produce a positive reaction. After incubation with α-methyl-noradrenaline the numbers of nerve terminals with small granular vesicles greatly increase, indicating the presence of dopamine and/or 5-hydroxytryptamine. In this case the reaction is now complete. The number of small granular vesicles is largest in the terminal swellings. These findings are consistent with histofluorescence, chemical, and microspectrofluorometric analyses, which have demonstrated noradrenaline, dopamine, and 5-hydroxytryptamine in neurones in the central nervous system. Large granular vesicles (600 to 900 Å) are to be found in some perikarya, not identical with neurosecretory cell bodies. In this case the granular vesicles in the axon are smaller and fewer. This indicates a simultaneous proximo-distal transport and gradual decrease in size of the granular vesicles. The intraneuronal distribution of the vesicles is in agreement with the distribution of the fluorophores in the fluorescent neurones. Neurosecretory neurones are found most likely not to contain monoamines.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00306849
Permalink
