Summary
The recently discovered indoleamine-accumulating retinal neurons were studied electron microscopically after destruction of the dopaminergic retinal neurons and subsequent labeling with 5,6-dihydroxytryptamine. These observations confirm earlier fluorescence microscopical studies on the distribution of the indoleamine-accumulating neurons in the rabbit retina. Their perikarya are known to be located in the inner nuclear layer (INL) among the amacrine cell bodies. Their processes are found only in the inner plexiform layer (IPL), most of them in the innermost third part of that layer. The indoleamine-accumulating terminals are pre- and postsynaptic to bipolar neurons in the innermost sublayer of the IPL. Reciprocal synapses are probably the rule. The synaptic vesicles of indoleamine-accumulating synapses onto bipolar cells are arranged in “globular” clusters around a central electron dense, round body. A number of synapses formed by unlabeled amacrine neurons with postsynaptic indoleamine-accumulating elements were also detected. These synapses were mainly found in the outermost third of the IPL. Synaptic contacts between presynaptic indoleamine-accumulating neurons and postsynaptic unlabeled processes of amacrine cells are very rare.
Similar content being viewed by others
References
Andén, N.-E., Grabowska, M.: Synthesis and disappearance of central noradrenaline and dopamine: regulation via nerve impulses and receptor activity. In: Chemical tools in catecholamine research. II. Regulation of catecholamine turnover (O. Almgren, A. Carlsson, J. Engel, eds.), pp. 143–149. Amsterdam-London: North-Holland Publ. Comp. 1975
Andersen, P., Eccles, J.C.: Locating and identifying postsynaptic inhibitory synapses by the correlation of physiological and histological data. Symp. Biol. Hung. 5, 219–242 (1965)
Baumgarten, H.G., Björklund, A.: Neurotoxic indoleamines and monoamine neurons. Ann. Rev. Pharmacol. Toxicol. 16, 101–111 (1976)
Björklund, A., Falck, B., Owman, C.H.: Fluorescence microscopic and microspectrofluorometric techniques for cellular localization and characterization of biogenic amines. In: Methods of investigative and diagnostic endrocrinology (J.E. Rall, I. Kopin, eds.), pp. 318–368. Amsterdam-London: North-Holland Publ. Comp. 1972
Burnstock, G.: Do some nerve cells release more than one transmitter? Neuroscience 1, 239–248 (1976)
Chan-Palay, V.: Serotonin axons in the supra- and subependymal plexuses and in the leptomeninges; their roles in local alterations of cerebrospinal fluid and vasomotor activity. Brain Res. 102 103–130 (1976)
Costa, E., Gessa, G.L., Sandler, M.: Serotonin — new vistas. Adv. Biochem. Psychopharmacol. 10 and 11 (1974)
Cottrell, G.A.: Identified amine-containing neurones and their synaptic connexions. Neuroscience 2, 1–18 (1977)
Dowling, J.E., Ehinger, B.: Synaptic organization of the amine-containing interplexiform cells of the goldfish and Cebus monkey retinas. Science 188, 270–273 (1975)
Dowling, J.E., Ehinger, B.: Synaptic organization of the dopaminergic neurons in the rabbit retina. J. Comp. Neurol. 180, 203–220 (1978a)
Dowling, J.E., Ehinger, B.: The interplexiform cell system. I. Synapses of the dopaminergic neurons of the goldfish retina. Proc. Roy. Soc. 201, 7–26 (1978b)
Dowling, J.E., Ehinger, B., Florén, L: Fluorescence and electron microscopical observations on the amine accumulating neurons of the Cebus monkey retina. (In preparation, 1979)
Ehinger, B., Florén, I.: Indoleamine-accumulating neurons in the retina of rabbit, cat and goldfish. Cell Tissue Res. 175, 37–48 (1976)
Ehinger, B., Florén, I: Quantitation of the uptake of indoleamines and dopamine in the rabbit retina. Exp. Eye Res. 26, 1–11 (1978a)
Ehinger, B., Florén, I.: Absence of indoleamine-accumulating neurons in the retina of humans and Cynomolgus monkeys. Albrecht von Graefes Arch. Ophthalmol. 209, 145–153 (1979)
Ehinger, B., Florén, I.: Chemical removal of indoleamine-accumulating terminals in rabbit and goldfish retina. Exp. Eye Res. 26, 321–328 (1978b)
Ehinger, B., Nordenfeit, L.: Destruction of retinal dopamine-containing neurons in rabbit and goldfish. Exp. Eye Res. 24, 179–187 (1977)
Florén, I.: Indoleamine-accumulating neurons in the retina of chicken and pigeon. A comparison with dopaminergic neurons. Acta Ophthalmol. (Kbh.), in press (1979a)
Florén, L: Arguments against 5-hydroxytryptamine as neurotransmitter in rabbit retina. J. Neurol. Transm., in press (1979b)
Florén, I., Hansson, H.C.: Aspects on 5-hydroxytryptamine as neurotransmitter in the retina of rabbit and chicken. Invest. Ophthalmol., in press (1979)
Palay, S.L., Chan-Palay, V.: A guide to the synaptic analysis of the neuropil. In: The synapse. Cold Spring Harbor Symposium on quantitative biology, Vol. XL, 1–16 (1976)
Pletscher, A.: Neuronal activity and catecholamine turnover in spreading depression and feedback control. In: Chemical tools in catecholamine research. II. Regulation of catecholamine turnover (O. Almgren, A. Carlsson, J. Engel, eds.), pp. 99–106. Amsterdam-London: North-Holland Publ. Comp. 1975
West, R.W., Dowling, J.E.: Synapses onto different morphological types of retinal ganglion cells. Science 178, 510–512 (1972)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ehinger, B., Holmgren, I. Electron microscopy of the indoleamine-accumulating neurons in the retina of the rabbit. Cell Tissue Res. 197, 175–194 (1979). https://doi.org/10.1007/BF00233913
Issue Date:
DOI: https://doi.org/10.1007/BF00233913