Summary
Five types of basket cell in the hippocampal denate gyrus of rats were analysed with a combined Golgi and electron microscopic method. Light microscopic observations show that the large somata of these different cell types are located either in the granule cell layer or within 30–50 μm of this layer. The somata of basket cells are pyramidal, horizontal, fusiform or multipolar. Dendrites of basket cells are aspinous or sparsely spinous and are found in all layers of the dentate gyrus. Their axons form an extensive plexus in the granule cell and lower molecular layers.
Electron microscopic preparations of Golgi-impregnated, gold-toned basket cells revealed gold-labelled neurons with distinct ultrastructural features. All somata of basket cells displayed an extensive perikaryal cytoplasm with large Nissl bodies and nuclei with infoldings, euchromatin, intranuclear rods and sheets, and large nucleoli. The aspinous dendrites as well as the somata had a mixture of asymmetric and symmetric synapses on their surfaces. Basket cell dendrites located in the hilus were contacted by numerous terminals with characteristics of mossy fibres derived from granule cells. Some of these terminals were identified positively in preparations that also contained impregnated granule cells. The axons of basket cells formed exclusively symmetric synapses. The most common postsynaptic structures to these terminals were the somata and dendrites of granule cells. Dendritic spines were rarely contacted by basket cell axons while the axon hillocks and initial segments of granule cells were never contacted. These findings are consistent with previous immunocytochemical, and physiological data that indicate feedback inhibitory mechanisms in the dentate gyrus are mediated via mossy fibre collaterals which synapse with GABAergic basket cells. In addition, the electron microscopic data for basket cells are similar to those for aspinous stellate cells in the neocortex, another type of cortical, GABAergic local circuit neuron. Thus, the basket cells in the dentate gyrus may have a function similar to other inhibitory, cortical local circuit neurons.
Similar content being viewed by others
References
Amaral, D. G. (1978) A Golgi study of cell types in the hilar region of the hippocampus in the rat.Journal of Comparative Neurology 182, 851–914.
Andersen, P. (1975) Organization of the hippocampal neurons and their interconnections. InThe Hippocampus (edited byIssacson, R. L. andPribram, K. H.), pp. 155–75. New York: Plenum.
Barber, R. &Saito, K. (1976) Light microscopic visualization of GAD and GABA-T in immunocytochemical preparations of rodent C.N.S. InGABA in Nervous System Function (edited byRoberts, E., Chase, T. N. andTower, D. B.), pp. 113–32. New York: Raven Press.
Blackstad, T. W. (1963) Ultrastructural studies on the hippocampal region.Progress in Brain Research 3, 122–48.
Cajal, S., Ramön, Y. (1911)Histologie du Système Nerveux de l'Homme et des Vertébrés Tome II. Paris: Maloine.
De Filipe, J. &Fairén, A. (1982) A type of basket cell in superficial layers of the cat visual cortex. A Golgi-electron microscope study.Brain Research 244, 9–16.
Fairén, A. &Valverde, F. (1980) A specialized type of neuron in the visual cortex of cat. A Golgi and electron microscope study of chandeliercells.Journal of Comparative Neurology 194, 761–79.
Fairén, A., Peters, A. &Saldanha, J. (1977) A new procedure for examining Golgi impregnated neurons by light and electron microscopy.Journal of Neurocytology 6, 311–37.
Gatter, K. C., Sloper, J. J. &Powell, T. P. S. (1978) An electron microscopic study of the termination of intracortical axons upon Betz cells in area 4 of the monkey.Brain 101, 543–53.
Gayoso, M. J., Diaz-Flores, L., Garrido, M., Sanchez, G. &Velasco, E. (1979) Hippocampal formation. IV. Interneurons.Morfologiá Normal y Patológica 3, 247–77.
Hazlett Jr, J. C. &Farkas, N. (1978) Short axon molecular layer neurons in the opossum fascia dentata: a Golgi study.Brain Research 143, 355–60.
Jones, E. G. (1975) Varieties and distribution of non-pyramidal cells in the somatic sensory cortex of the squirrel monkey.Journal of Comparative Neurology 160, 205–68.
Laatsch, R. H. &Cowan, W. M. (1966) Electron microscopic studies of the dentate gyrus of the rat. I. Normal structure with special reference to synaptic organization.Journal of Comparative Neurology 128, 359–96.
Lorente De Nó, R. (1934) Studies on the structure of the cerebral cortex. II. Continuation of the study of the Ammonic system.Journal für Psychologie und Neurologie 46, 113–77.
Marin-Padilla, M. (1969) Origin of the pericellular baskets of the human motor cortex: A Golgi study.Brain Research 14, 633–46.
Nunzi, M. G., Gorio, A., Smith, D. A. &Somogyi, P. (1982) A specific interneuron forming synapses exclusively with the axon initial segment of pyramidal cells in monkey hippocampus.Society for Neuroscience Abstracts 8, 216.
Palay, S. L. &Chan-Palay, V. (1974)Cerebellar Cortex. New York: Springer-Verlag.
Peters, A., Proskauer, C. C. &Ribak, C. E. (1982) Chandelier cells in rat visual cortex.Journal of Comparative Neurology 206, 397–416.
Ribak, C. E. (1978) Aspinous and sparsely spinous stellate neurons in the visual cortex of rats contain glutamic acid decarboxylase.Journal of Neurocytology 7, 461–78.
Ribak, C. E. (1982) A combined Golgi-electron microscopic analysis of pyramidal basket cells in the dentate gyrus of the hippocampus.Anatomical Record 202, 157A.
Ribak, C. E. &Anderson, L. (1980) Ultrastructure of the pyramidal basket cells in the dentate gyrus of the rat.Journal of Comparative Neurology 192, 903–16.
Ribak, C. E., Vaughn, J. E. &Saito, K. (1978) Immunocytochemical localization of glutamic acid decarboxylase in neuronal somata following colchicine inhibition of axonal transport.Brain Research 140, 315–32.
Seress, L. &Pokorny, J. (1981) Structure of the granular layer of the rat dentate gyrus. A light microscopic and Golgi study.Journal of Anatomy 133, 181–95.
Seress, L. &Ribak, C. E. (1983) GABAergic cells in the dentate gyrus appear to be local circuit projection neurons.Experimental Brain Research (in press).
Somogyi, P. (1977) A specific ‘axo-axonal’ interneuron in the visual cortex of the rat.Brain Research 136, 345–50.
Struble, R. G., Desmond, N. L. &Levy, W. B. (1978) Anatomical evidence for interlamellar inhibition in the fascia dentata.Brain Research 152, 580–5.
Author information
Authors and Affiliations
Additional information
On leave from the Department of Physiology, University Medical School, Pécs, Hungary.
Rights and permissions
About this article
Cite this article
Ribak, C.E., Seress, L. Five types of basket cell in the hippocampal dentate gyrus: a combined Golgi and electron microscopic study. J Neurocytol 12, 577–597 (1983). https://doi.org/10.1007/BF01181525
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01181525