Various types of non-pyramidal hippocampal neurons project to the septum and contralateral hippocampus
- 29 October 1986
- journal article
- Published by Elsevier BV in Brain Research
- Vol. 386 (1-2), 146-154
- https://doi.org/10.1016/0006-8993(86)90151-4
Abstract
The morphology was studied of hippocampal neurons which had their somata in the hilus of the area dentata, and in stratum radiatum or stratum oriens of Ammon's horn, and which sent projections to the septum and contralateral hippocampus, respectively. The fluorescent marker Fast Blue was injected into the septum or contralateral hippocampus. Somata were then identified by their fluorescent label in slices of perfused brains. After intracellular injection of these somata with Lucifer Yellow, it was found that contralaterally projecting neurons were pyramidal cells, inverted fusiform and multipolar cells in CA3c, and stellate, fusiform and multipolar cells in the hilus. After septal injections, we identified two groups of aspiny stellate cells in the hilus; pyramidal basket cells, polygonal basket cells, horizontal basket cells in stratum oriens; and stellate cells in stratum radiatum of CA1 and CA3, as well as pyramid-like aspiny cells in stratum radiatum of CA1. These cells also had short locally arborizing axons, thus probably contributing to local circuits. Such cells may constitute a third class of hippocampal neurons combining the properties of principal cells and interneurons. These results support the opinion that the simple concept of separating hippocampal cells into projection neurons and local-circuit neurons needs reconsideration.Keywords
This publication has 40 references indexed in Scilit:
- Cholinergic amacrine cells in the rat retinaJournal of Comparative Neurology, 1986
- Feed-forward inhibition in the hippocampal formationProgress in Neurobiology, 1984
- Direct commissural connections to the basket cells of the hippocampal dentate gyrus: anatomical evidence for feed-forward inhibitionJournal of Neurocytology, 1984
- Ultrastructure of commissural neurons of the hilar region in the hippocampal dentate gyrusExperimental Neurology, 1983
- Five types of basket cell in the hippocampal dentate gyrus: a combined Golgi and electron microscopic studyJournal of Neurocytology, 1983
- Evidence for separate projections of hippocampal pyramidal and non-pyramidal neurons to different parts of the septum in the rat brainNeuroscience Letters, 1982
- CCK-containing terminals in the hippocampus are derived from intrinsic neurons: an immunohistochemical and radioimmunological studyBrain Research, 1981
- Organization of projection neurons of the hippocampusExperimental Neurology, 1979
- Physiological and morphological identification of a nonpyramidal hippocampal cell typeBrain Research, 1978
- Aspinous and sparsely-spinous stellate neurons in the visual cortex of rats contain glutamic acid decarboxylaseJournal of Neurocytology, 1978