Summary
A monoclonal antibody against choline acetyltransferase (ChAT), the acetylcholine synthesizing enzyme, was used to identify cholinergic neurons in the nucleus of the horizontal limb of the diagonal band of Broca at the light and electron microscopic levels. ChAT-labelled somata were fusiform, triangular or round in shape and varied considerably in size. Depending on the type of the cell, one to four dendrites emerged from the soma, but an axon could rarely be seen. The nuclei of most cells were round or oval, showed invaginations and displayed prominent nucleoli. The karyoplasm of the larger fusiform and triangular neurons contained abundant organelles including parallel arrays of granular endoplasmic reticulum. The synaptic input to labelled perikarya and proximal dendrites was sparse. It consisted chiefly of asymmetrical synaptic contacts, sometimes with postjunctional densities, but a few symmetrical synapses were also noted. ChAT-positive axon terminals were not identified which suggests that axon collaterals are rare within the nucleus of the horizontal limb of the diagonal band of Broca.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Armstrong, D. M., Kress, Y. &Terry, R. D. (1983) Electron microscopic immunocytochemical characterization of cholinergic neurons in the rat brain.Society for Neuroscience, Abstracts 9, 80.
Bigl, V., Woolf, N. J. &Butcher, L. L. (1982) Cholinergic projections from the basal forebrain to frontal, parietal, temporal, occipital, and cingulate cortices: a combined fluorescent tracer and acetylcholinesterase analysis.Brain Research Bulletin 8, 727–49.
Coyle, J. T., Price, D. L. &Delong, M. R. (1983) Alzheimer's disease: a disorder of cortical cholinergic innervation.Science 219, 1184–90.
Divac, I. (1975) Magnocellular nuclei of the basal forebrain project to neocortex, brain stem, and olfactory bulb. Review of some functional correlates.Brain Research 93, 385–98.
Eckenstein, F., Barde, Y. -A. &Thoenen, H. (1981) Production of specific antibodies to choline acetyltransferase purified from pig brain.Neuroscience 6, 993–1000.
Eckenstein, F. &Thoenen, H. (1982) Production of specific antisera and monoclonal antibodies to choline acetyltransferase: characterization and use for identification of cholinergic neurons.EMBO Journal 1, 363–8.
Henderson, Z. (1981) A projection from acetylcholinesterase-containing neurones in the diagonal band to the occipital cortex of the rat.Neuroscience 6, 1081–8.
Ingham, C. A., Bolam, J. P., Wainer, B. H. &Smith, A. D. (1985a) A correlated light and electron microscopic study of identified cholinergic basal forebrain neurons that project to the cortex in the rat.Journal of Comparative Neurology 239, 176–92.
Ingham, C. A., Bolam, J. P., Wainer, B. H. &Smith, A. D. (1985b) Cholinergic basal forebrain neurons with reference to their afferent and efferent connections: a correlated light and electron microscopic study.Neuroscience Letters Supplement 22, S55.
Johnston, M. V., McKinney, M. &Coyle, J. T. (1979) Evidence for a cholinergic projection to neocortex from neurons in the basal forebrain.Proceedings of the National Academy of Sciences USA 76, 5392–6.
Johnston, M. V., McKinney, M. &Coyle, J. T. (1981) Neocortical cholinergic innervation: a description of extrinsic and intrinsic components in the rat.Experimental Brain Research 43, 159–72.
Jones, E. G., Burton, H., Saper, C. B. &Swanson, L. W. (1976) Midbrain, diencephalic and cortical relationships of the basal nucleus of Meynert and associated structures in primates.Journal of Comparative Neurology 167, 385–420.
Kelly, P. H. &Moore, K. E. (1978) Decrease of neocortical choline acetyltransferase after lesion of the globus pallidus in the rat.Experimental Neurology 61, 479–84.
Kievit, J. &Kuypers, H. G. J. M. (1975) Basal forebrain and hypothalamic connections to frontal and parietal cortex in the rhesus monkey.Science 187, 660–2.
Lamour, Y., Dutar, P. &Jobert, A. (1982) Topographic organization of basal forebrain neurons projecting to the rat cerebral cortex.Neuroscience Letters 34, 117–22.
Lemann, W. &Saper, C. B. (1985) Evidence for a cortical projection to the magnocellular basal nucleus in the rat: an electron microscopic axonal transport study.Brain Research 334, 339–43.
McKinney, M., Coyle, J. T. &Hedreen, J. C. (1983) Topographic analysis of the innervation of the rat neocortex and hippocampus by the basal forebrain cholinergic system.Journal of Comparative Neurology 217, 103–21.
Mesulam, M.-M., Mufson, E. J., Levey, A. I. &Wainer, B. H. (1983a) Cholinergic innervation of cortex by the basal forebrain: cytochemistry and cortical connections of the septal area, diagonal band nuclei, nucleus basalis (substantia innominata) and hypothalamus in the rhesus monkey.Journal of Comparative Neurology 214, 170–97.
Mesulam, M.-M., Mufson, E. J., Wainer, B. H. &Levey, A. I. (1983b) Central cholinergic pathways in the rat: an overview based on an alternative nomenclature (Chl-Ch6).Neuroscience 10, 1185–201.
Mesulam, M.-M., &Van Hoesen, G. W. (1976) Acetylcholinesterase-rich projections from the basal forebrain of the rhesus monkey to neocortex.Brain Research 109, 152–7.
Mizuno, N., Uemura-Sumi, M., Yasui, Y., Konishi, A. &Matsushima, R. (1982) Direct projections from the extrathalamic forebrain structures to the neocortex in the macaque monkey.Neuroscience Letters 29, 13–17.
Palay, S. L. &Chan-Palay, V. (1974)Cerebellar Cortex. Cytology and Organization. Berlin: Springer-Verlag.
Parnavelas, J. G., Kelly, W., Franke, E. &Ckenstein, F. (1986) Cholinergic neurons and fibres in the rat visual cortex.Journal of Neurocytology 15, 329–36.
Peters, A. (1970) The fixation of central nervous tissue and the analysis of electron micrographs of the neuropil, with special reference to the cerebral cortex. InContemporary Research Methods in Neuroanatomy (edited byNauta, W. J. H. &Ebbesson, S. O. E.), pp. 56–76. Berlin: Springer-Verlag.
Price, J. L. &Stern, R. (1983) Individual cells in the nucleus basalis-diagonal band complex have restricted axonal projections to the cerebral cortex in the rat.Brain Research 269, 352–6.
Ribak, C. E. &Kramer, W. G. (1982) Cholinergic neurons in the basal forebrain of the cat have direct projections to the sensorimotor cortex.Experimental Neurology 75, 453–65.
Wahle, P. C., Sanides-Buchholtz, C., Eckenstein, F. &Albus, K. (1984) Concurrent visualization of choline acetyltransferase-like immunoreactivity and retrograde transport of neocortically injected markers in basal forebrain neurons in cat and rat.Neuroscience Letters 44, 223–8.
Wainer, B. H. &Rye, D. B. (1984) Retrograde horseradish peroxidase tracing combined with localization of choline acetyltransferase immunoreactivity.Journal of Histochemistry and Cytochemistry 32, 439–43.
Wenk, H., Bigl, V. &Meyer, U. (1980) Cholinergic projections from magnocellular nuclei of the basal forebrain to cortical areas in rats.Brain Research Reviews 2, 295–316.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dinopoulos, A., Parnavelas, J.G. & Eckenstein, F. Morphological characterization of cholinergic neurons in the horizontal limb of the diagonal band of Broca in the basal forebrain of the rat. J Neurocytol 15, 619–628 (1986). https://doi.org/10.1007/BF01611861
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01611861