Summary
We have studied the synaptic ultrastructure in human autopsy material from the locus ceruleus, an important noradrenergic center. Ten cases of Alzheimer's disease, ten cases of Parkinson's disease, and ten control brains were examined.
Only a few differences in synaptic morphology between the three groups were found. Multiple symmetrical and asymmetrical contacts on medium-sized dendrites were characteristically present. Axosomatic synapses were also common. In Alzheimer's disease axosomatic synapses on nerve cell perikarya containing neurofibrillary tangles, and in Parkinson's disease on perikarya containing Lewy bodies, could be demonstrated. Dendritic spines were rare, but the control group had structures interpreted as “minispines”. In agreement with studies in the rat, cat, and rabbit, no spine apparatus was present, but in contrast to those studies no somatic spines were identified. Rare axoaxonic synapses were found in the control group. Vesicle content was often pleomorphic with flattened vesicles.
Large dense core vesicles were present in variable numbers in nerve cell processes, and large accumulations of such vesicles were seen in two thirds of our cases, most abundant in the Alzheimer's and Parkinson's disease groups. Such terminals may be aminergic, perhaps serotonergic, and may be a normal component of the locus ceruleus. Their greater abundance in Alzheimer's and Parkinson's disease may be due to accumulation of the amines in afferent terminals, which have been deprived of their postsynaptic connections due to the degenerative disease process.
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References
Amaral DG, Sinnamon HM (1977) The locus coeruleus: Neurobiology of a central noradrenergic nucleus. Progr Neurobiol 9:147–196
Chan-Palay V (1976) 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
Choi BH, Antanitus DS, Lapham LW (1975) Fluorescence histochemical and ultrastructural studies of locus coeruleus of human fetal brain. J Neuropathol Exp Neurol 34:507–516
Forno LS (1978) The locus coeruleus in Alzheimer's disease. J Neuropathol Exp Neurol 37:614 (abstract)
Forno LS, Norville RL (1975) Ultrastructural studies of the human locus coeruleus (in middle-aged and older persons with and without parkinsonism). In: Kornyey S, Tariska S, Gosztonyi G (eds) VII International Congress of Neuropathology. Int Congress Series 362, vol II. Akademiai Kiado, Budapest, pp 459–462
Forno LS, Norville RL (1979) Ultrastructure of the neostriatum in Huntington's and Parkinson's disease. Adv Neurol 23:123–135
Greenfield JG, Bosanquet FD (1953) The brain stem lesions in parkinsonism. J Neurol Neurosurg Psychiatry 16:213–226
Hökfelt T, Fuxe K, Goldstein M, Johansson O (1974) Immunohistochemical evidence of the existence of adrenaline neurons in the rat brain. Brain Res 66:235–251
Leger L (1973) Etude ultrastructurale du locus coeruleus du chat. Thèse de Docteur de Spécialité (3ème cycle) Université Claude Bernard-Lyon-I, Lyon
Leger L, Descarries L (1978) Serotonin nerve terminals in the locus coeruleus of adult rat. A radioautographic study. Brain Res 145:1–13
Leger L, Hernandez-Nicaise M-L (1980) The cat locus coeruleus. Light- and electron-microscopic study of the neuronal somata. Anat Embryol (Berl) 159:181–198
Mizuno N, Nakamura Y (1972) An electron microscope study of the locus coeruleus in the rabbit, with special reference to direct hypothalamic and mesencephalic projections. Arch Histol Jpn 34:433–448
Moore RY, Bloom FE (1979) Central catecholamine neuron systems. Anatomy and physiology of the norepinephrine and epinephrine systems. In: Cowan WM, Hall ZW, Kandel ER (eds) Annual review of neuroscience, vol 2. Annual Review, Palo Alto, CA, pp 113–168
Norita M (1980) Neurons and synaptic patterns in the deep layers of the superior colliculus of the cat. A golgi and electron-microscopic study. J Comp Neurol 190:29–48
Pickel VM, Joh TH, Reis DJ (1977) A serotonergic innervation of noradrenergic neurons in nucleus locus coeruleus. Demonstration by immunocytochemical localization of the transmitter specific enzymes tyrosine and tryptophan hydroxylase. Brain Res 131:197–214
Pickel VM, Joh TH, Reis DJ, Leeman SE, Miller RJ (1979) Electron-microscopic localization of substance P and enkephalin in axon terminals related to dendrites of catecholaminergic neurons. Brain Res 160:387–400
Ramon-Moliner E (1974) The locus coeruleus of cat. III. Light- and electron-microscopic studies. Cell Tissue Res 149:205–221
Sakai K, Touret M, Salvert D, Jouvet M (1978) Afferents to the cat locus ceruleus and rostral raphe nuclei as visualized by the horseradish peroxidase technique. In: Garattini S, Pujol JF, Samanin R (eds) Interactions between putative neurotransmitters in the brain. Raven Press, New York, pp 319–342
Shimizu N, Imamoto K (1970) Fine structure of the locus ceruleus in the rat. Arch Histol Jpn 31:229–246
Tatemichi R, Ramon-Moliner E (1975) Structure of the somatic appendages of neurons of locus coeruleus in cat. Brain Res 96:317–322
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This study was supported by the Veterans Administration Medical Research Program
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Forno, L.S., Norville, R.L. Synaptic morphology in the human locus ceruleus. Acta Neuropathol 53, 7–14 (1981). https://doi.org/10.1007/BF00697178
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DOI: https://doi.org/10.1007/BF00697178