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Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Other authors, however, include structures in addition to the hippocampus proper, the dentate gyrus, and the subiculum. The entire parahippocampal gyrus, for example, is included by Snell (1980, p. 275); and major parts of it are also included by Brodal (“entorhinai area”—(1981, p. 674) and by Martinez Martinez (“the presubiculum,” “the parasubiculum,” and “the entorhinai area”—1982, p. 2581). A few authors also include structures which (as a group) are contiguous with the dentate gyrus in the adult, extending first posteriorly, then superiorly and anteriorly, and finally inferiorly as they course over the curving superior surface of the corpus callosum: Brodal mentions the “subcallosal gyrus” and “induseum griseum” (p. 673—footnote), Martinez Martinez mentions the “indusium griseum” and the “gyrus fasciolaris” (p. 68–69), and Mitchell and Mayor mention “the indusium griseum” and “the longitudinal striae” (1983, p. 672). Finally, Martinez Martinez uniquely includes a portion of the efferent fibers from the hippocampus—the “fimbria hippocampi”—within the hippocampal formation (p. 69).
Phylogeny, Gene Structure, Expression, and Signaling
Published in Divya Vohora, The Third Histamine Receptor, 2008
Pertti Panula, CongYu Jin, Kaj Karlstedt, Remko A. Bakker
H3R radioligand [3H]Nα-methylhistamine binding is detected through all parts of the hippocampal formation and entorhinal cortex (Jin and Panula, unpublished; Figure 4.4G). The binding is most prominent in the dentate gyrus, high in the subicular complex and entorhinal cortex, and moderate to low in the hippocampal CA1–4 regions. In the hippocampus, H3R binding is prominent in CA1 and distributes in a decreasing order in CA3, CA4, and CA2. Similar to the other cortical areas, a layer preference is observed also in the subicular complex and entorhinal cortex. In the subicular complex, the binding density is high in the deep layer of subiculum and the superficial layers of presubiculum and parasubiculum. In the entorhinal cortex, the binding density is higher in the superficial and deep layers than the middle layers.
Protective role of zinc against the neurotoxicity induced by exposure to cadmium during gestation and lactation periods on hippocampal volume of pups tested in early adulthood
Published in Drug and Chemical Toxicology, 2018
Safa Ben Mimouna, Marouane Chemek, Sana Boughammoura, Zohra Haouas, Imed Messaoudi
Different subregions of the hippocampus, the CA1, CA2, and CA3 fields, derive their names from an even older name for the structure, the cornu ammonis (horn of Amun, an ancient Greek god). Together with the dentate gyrus (DG) and parahippocampal regions, including the subiculum, presubiculum, parasubiculum, and the entorhinal cortex, the hippocampus is thought to play a key role in memory and navigation (Deshmukh et al.2012). In fact, the hippocampus is used for rapid, unstructured storage of information involving activity potentially arriving from many areas of the cortex, while the neocortex would gradually build and adjust on the basis of much accumulating information the semantic representation (McClelland et al. 1995). Within the hippocampus, recent studies have suggested important differences in the function of areas. Indeed, the CA3a,b subregion of the hippocampus plays an important role in the encoding of new spatial information, within short-term memory with a duration of seconds and minutes, novelty detection, and one-trial cued recall (all forms of episodic memory). Also, CA3a,b mediates encoding of information requiring multiple trials to construct relational representations. It should be noted that CA3a,b can also be involved in short-term memory retrieval as evidenced by support for a pattern completion process. Finally, the CA3c function is in part based on modulation of the DG in supporting pattern separation processes and may contribute to pattern separation of the geometry of the environment (Deshmukh and Knierim 2012, Kesner 2007, 2013). The CA1 recodes information from CA3 and sets up associatively learned back projections to neocortex to allow subsequent retrieval of information to neocortex. Behaviorally, the CA1 is implicated in processing temporal information as shown by investigations requiring temporal order pattern separation and associations across time and, computationally, this could involve associations in CA1 between object and timing information that have their origins in the lateral and medial entorhinal cortex respectively (Colgin et al. 2008, Kesner and Rolls 2015).