Cellular and Molecular Neurobiology

, Volume 6, Issue 1, pp 55–70 | Cite as

Divergent Regulation of Muscarinic Binding Sites and Acetylcholinesterase in Discrete Regions of the Developing Human Fetal Brain

  • Y. Egozi
  • M. Sokolovsky
  • E. Schejter
  • I. Blatt
  • H. Zakut
  • A. Matzkel
  • H. Soreq


The expression of muscarinic acetylcholine binding sites and of cholinesterases was studied in extracts prepared from discrete regions of the human fetal brain, between the gestational ages of 14 and 24 weeks. The specific binding of [3H]N-methyl-4-piperidyl benzilate ([4H]-4NMPB) to muscarinic binding sites ranged between 0.05 and 1.30 pmol/mg protein in the different brain regions, withK d values of 1.2 ± 0.2 nM. Binding of the cholinergic agonist oxotremorine fitted, in most of the brain regions examined, with a two-site model for the muscarinic binding sites. The density of muscarinic binding sites increased with development in most regions, with different rates and onset times. It was higher by about sixfold in some areas destined to become cholinergic, such as the cortex and midbrain, than in noncholinergic areas such as the cerebellum. In other areas destined to become cholinergic, such as the hippocampus and the caudate putamen, the receptor density remained low. Average density values increased from 0.1 ± 0.1 at 14 weeks up to 0.7 ± 0.4 pmol/mg protein at 24 weeks.

The variability in the specific activities of cholinesterase was relatively low, and extracts from different brain regions hydrolyzed from 5 to 30 nmol of [3H]acetylcholine/min/mg protein. These were mostly “true” acetylcholinesterase (EC activities, inhibited by 10−5 M BW284C51, with minor pseudocholinesterase (EC activities, inhibited by 10−5 M iso-OMPA. The enzyme from different brain regions and developmental stages displayed similarK m values toward [3H]acetylcholine (ca. 4 × 10−4 M −1). The ontogenetic changes in cholinesterase specific activities had no unifying pattern and/or relationship to the cholinergic nature of the various brain areas. In most of the brain regions, the arbitrary ratio between the specific activity of cholinesterase and the density of muscarinic binding sites decreased with development, with average values and variability ranges of 83 ± 50 and 19 ± 19 at 14 and 24 weeks, respectively. Our findings suggest divergent regulation for cholinergic binding sites and cholinesterase in the fetal human brain and imply that the expression of muscarinic receptors is related to the development of cholinergic transmission, while acetylcholinesterase is also involved in other functions in the fetal human brain.

Key words

acetylcholinesterase muscarinic receptors human brain cholinergic transmission 


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  1. Austin, L., and Berry, W. K. (1953). Two selective inhibitors of cholinesterase.Biochem. J. 54695–700.PubMedGoogle Scholar
  2. Avissvar, S., Egozi, Y., and Sokolovsky, M. (1981). Biochemical characterization and sex dimorphism of muscarinic receptors in rat adenohypophysis.Neuroendocrinology 32303–310.CrossRefGoogle Scholar
  3. Balasubramanian, A. S. (1984). Have cholinesterases more than one function?Trends Neurosci. 7467–468.CrossRefGoogle Scholar
  4. Bartos, E. M., and Glinos, A. D. (1976).J. Cell Biol. 69638–646.PubMedCrossRefGoogle Scholar
  5. Bartus, R. T., Dean, R. L., Beer, B., and Lippa, A. S. (1982). The cholinergic hypothesis of geriatric memory dysfunction.Science 217408–417.PubMedCrossRefGoogle Scholar
  6. Burstein, S. A., Adamson, J. W., and Waker, L. A. (1980). Megakaryocytopoiesis in culture: Modulation by cholinergic mechanisms.J. Cell Physiol. 103201–208.PubMedCrossRefGoogle Scholar
  7. Chubb, I. (1984). Acetylcholinesterase-multiple functions. InCholinesterases—Fundamental and Applied Aspects (Brzin, M., Kiauta, T., and Barnard, E. A., Eds.), Walter de Gruyter, Berlin, pp. 345–349.Google Scholar
  8. Cortes, R., Probst, A., and Palacios, J. M. (1984). Quantitative light microscopic autoradiographic localization of cholinergic muscarinic receptors in the human brain stem.Neurosci. 121003–1026.CrossRefGoogle Scholar
  9. Davies, P., and Verth, A. H. (1978). Regional distribution of muscarinic acetylcholine receptor in normal and Alzheimer's type dementia brains.Brain Res. 138385–392.CrossRefGoogle Scholar
  10. Egozi, Y., Kloog, Y., and Sokolovsky, M. (1980). Studies of post-natal changes of muscarinic receptors in mouse brain. InNeurotransmitters and Their Receptors (Littauer, U. Z., Dudai, Y., Silman, I., Teichberg, V. I., and Vogel, Z., Eds.), John Wiley and Sons, New York, pp. 201–215.Google Scholar
  11. Enna, S. J., Bennet, J. P., Bylund, D. B., Creese, I., Charness, M. E., Yamamura, H. I., Simantov, R., and Snyder, S. H. (1977). Neurotransmitter receptor binding: Regional distribution in human brain.J. Neurochem. 28233–236.PubMedCrossRefGoogle Scholar
  12. Giacobini, E., Pilar, G., Suskiw, J., and Uchimura, H. (1979). Normal distribution and denervation changes of neurotransmitter related enzymes in cholinergic neurons.J. Physiol. Lond. 286233–253.PubMedGoogle Scholar
  13. Graybiel, A. M., and Ragsdale, C. W. (1982). Pseudocholinesterase staining in the primary visual pathways of the macque monkey.Nature 299439–442.PubMedCrossRefGoogle Scholar
  14. Greenfield, S. (1984). Acetylcholinesterase may have novel functions in the brain.Trends Neurosci. 7364–368.CrossRefGoogle Scholar
  15. Gurwitz, D., Razon, N., Sokolovsky, M., and Soreq, H. (1984). Expression of muscarinic receptors in primary brain tumors.Dev. Brain Res. 1461–70.CrossRefGoogle Scholar
  16. Johnson, D. C., and Russell, R. L. (1975). A rapid, simple radiometric assay for cholinesterase, suitable for multiple determinations.Anal. Biochem. 64229–238.PubMedCrossRefGoogle Scholar
  17. Karczmar, A. G. (1976). Central actions of acetylcholine, cholinomimetic and related drugs. InBiology of Cholinergic Function (Goldberg, A. M., and Hanin, I., Eds.), Raven Press, New York, pp. 395–449.Google Scholar
  18. Kloog,. Y., Egozi, Y., and Sokolovsky, M. (1979). Characterization of muscarinic acetylcholine receptors from mice brain: Evidence for regional heterogeneity and isomerization.Mol. Pharmacol. 15545–558.PubMedGoogle Scholar
  19. Kloog, K., Michaelson, D. M., and Sokolovsky, M. (1980). Characterization of the presynaptic muscarinic receptor in synaptosomes ofTorpedo electric organ by means of kinetic and equilibrium binding studies.Brain Res. 19497–115.PubMedCrossRefGoogle Scholar
  20. Kostovic, I., and Goldman-Rakic, P..S (1983). Transient cholinesterase straining in the mediodorsal nucleus of the thalamus and its connections in the developing human and monkey brain.J. Comp. Neurol. 219431–447.PubMedCrossRefGoogle Scholar
  21. Kostovic, I., and Rakic, P. (1984). Development of prestriate visual projections in the monkey and human fetal cerebrum revealed by transient cholinesterase staining.J. Neurosci. 425–42.PubMedGoogle Scholar
  22. Kristt, D. A., and Kasper, E. K. (1983). High density of cholinergic-muscarinic receptors accompanies high intensity of acetylcholinesterase staining in layer IV of infant rat somatosensory cortex.Dev. Brain. Res. 8373–376.CrossRefGoogle Scholar
  23. Kuhar, M. J. (1981). Autoradiographic localization of drug and neurotransmitter receptors in the brain.Trends Neurosci. 460–64.CrossRefGoogle Scholar
  24. Layer, P. G. (1983). Comparative localization of acetylcholinesterase and pseudocholinesterase during morphogenesis of the chicken brain.Proc. Natl. Acad. Sci. USA 806413–6417.PubMedCrossRefGoogle Scholar
  25. Levey, A. I., Wainer, B. H., Mufson, E. J., and Mesulam, M.-M. (11983). Co-localization of acetylcholinesterase and choline acetyltransferase in the rat cerebrum.Neuroscience 99–22.CrossRefGoogle Scholar
  26. Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randall, R. J. (1951). Protein measurement with the Folin phenol reagent.J. Biol. Chem. 193265–275.PubMedGoogle Scholar
  27. Luabeya, M. K., Maloteaux, J.-M., and Laduron, P. M. (1984). Regional and cortical laminar distributions of serotonin receptors in human S2, benzodiazepine, muscarinic and dopamine D2 receptors in human brain.J. Neurochem. 431068–1071.PubMedCrossRefGoogle Scholar
  28. Massoulie, J., and Bon, S. (1982). The molecular forms of cholinesterase and acetylcholinesterase in vertebrates.Annu. Rev. Neurosci. 557–106.PubMedCrossRefGoogle Scholar
  29. Meflah, K., Bernard, S., and Massoulie, J. (1984). Interactions with lectins indicate differences in the carbohydrate composition of the membrane-bound enzymes acetylcholinesterase and 5′-nucleotidase in different cell types.Biochimie 6659–69.PubMedCrossRefGoogle Scholar
  30. Muller, F., Dumez, Y., and Massoulie, J. (1985). Molecular forms and solubility of acetylcholinesterase during the embryonic development of rat and human brain.Brain Res. (in press).Google Scholar
  31. Olivier, G., and Pineau, H. (1961). Horizons de Streeter et age embryonnaire.Bull. Assoc. Anat. (Nancy)47e573–576.Google Scholar
  32. Paulus, J. P., Maigen, J., and Keyhani, E. (1981). Mouse megakaryocytes secrete acetylcholinesterase.Blood 581100–1106.PubMedGoogle Scholar
  33. Rakic, P. (1981). Developmental events leading to laminar and areal organization of the neocortex. InThe Cerebral Cortex (Schmidt, F. D., Ed.), MIT Press, Cambridge, Mass., pp. 7–28.Google Scholar
  34. Razon, N., Soreq, H., Roth, E., Bartal, A., and Silman, I. (1984). Characterization of levels and forms of cholinesterases in human primary brain tumors.Exp. Neurol. 84681–695.PubMedCrossRefGoogle Scholar
  35. Sidman, R. L., and Rakic, P. (1973). Neuronal migration, with special reference to developing human brain: A review.Brain Res. 621–35.PubMedCrossRefGoogle Scholar
  36. Sitaram, N., Moore, A. M., and Gillin, J. C. (1978). Induction and resetting of Rem sleep rhythm in normal man by arecholine: Blockade by scopolamine.Sleep 183–90.PubMedGoogle Scholar
  37. Sokolovsky, M., Gurwitz, D., and Kloog, Y. (1983). Biochemical characterization of the muscarinic receptors.Adv. Enzymol. 55137–196.PubMedGoogle Scholar
  38. Soreq, H., Parvari, R., and Silman, I. (1982). Biosynthesis and secretion of active acetylcholinesterase inXenopus oocytes microinjected with mRNA from rat brain and fromTorpedo electric organ.Proc. Natl. Acad. Sci. USA 79830–834.PubMedCrossRefGoogle Scholar
  39. Soreq, H., Zevin-Sonkin, D., and Razon, N. (1984). Expression of cholinesterase gene(s) in human brain tissues: Translational evidence for multiple mRNA species.EMBO J. 31371–1375.PubMedGoogle Scholar
  40. Soreq, H., Gurwitz, D., Eliyahu, D., and Sokolovsky, D. (1985). Altered ontogenesis of muscarinic receptors in agranular cerebellar cortex.J. Neurochem. 39756–763.CrossRefGoogle Scholar
  41. Terry, R. D., and Davies, P. (1980). Dementia of the Alzheimer type.Annu. Rev. Neurosci. 377–95.PubMedCrossRefGoogle Scholar
  42. Vijayan, V. K., and Olschowska, J. A. (1977). Brain acetylcholinesterase activity and multiplicity in Bonnet monkey, Macaca radiata, and the rhesus monkey (Macaca mulatta).J. Neurochem. 281141–1143.PubMedCrossRefGoogle Scholar
  43. Wade, P. D., and Timiras, P. S. (1980). A regional study of the molecular forms of acetylcholinesterase in the brain of developing and adult rats.Dev. Neurosci. 3:101–108.PubMedCrossRefGoogle Scholar
  44. Wastek, G. J., and Yamamura, H. I. (1978). Biochemical characterization of the muscarinic cholienrgic receptor in human brain: Alterations in Huntington's disease.Mol. Pharmacol. 14768–780.PubMedGoogle Scholar
  45. White, P., Hiley, C. R., Goodhart, M. J., Carrasco, L. H., Keet, J. P., Williams, I. E. I., and Bowen, D. M. (1977). Neocortical cholinergic neurons in elderly people.Lancet 1668–671.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Publishing Corporation 1986

Authors and Affiliations

  • Y. Egozi
    • 1
  • M. Sokolovsky
    • 1
  • E. Schejter
    • 2
  • I. Blatt
    • 2
    • 4
  • H. Zakut
    • 2
    • 4
  • A. Matzkel
    • 3
  • H. Soreq
    • 3
  1. 1.Department of BiochemistryGeorge S. Wise Faculty for Life Sciences, Tel Aviv UniversityTel AvivIsrael
  2. 2.Department of Obstetrics and GynecologyThe Edith Wolfson HospitalHolonIsrael
  3. 3.Department of NeurobiologyThe Weizmann Institute of ScienceRehovotIsrael
  4. 4.Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael

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