The Stress System
Len Wisneski in The Scientific Basis of Integrative Health, 2017
The fact that both the afferent fibers into and the efferent projections out of the subiculum extend widely from or to cortical and subcortical areas, respectively, indicates that what happens in that small structure has far-reaching network influence. Recent work supports the budding theory that the subiculum actually has a dorsal/ventral separation of function, with the dorsal portion involved in processing information that relates not only to memory retrieval, but to spatial orientation/navigation and movement, features already discussed (Esclassan et al., 2009; O’Mara, 2005). Curiously, the ventral sector is implicated in the regulation and inhibition of the HPA axis and fear, via GABA-ergic neurons that inhibit the stress response. Thus, when a lesion is made in the ventral subiculum, the HPA response to stress is ameliorated (Mueller et al., 2004).
Discussions (D)
Terence R. Anthoney in Neuroanatomy and the Neurologic Exam, 2017
On gross anatomical grounds, the hippocampus proper, the dentate gyrus, and the subiculum are contiguous and jointly make up the cortical structures buried within the hippocampal sulcus. By location, by larger size, and by relationship to the nearby alveus and fimbria, these structures are easily differentiable from other derivatives of the embryologic hippocampal formation, such as the indusium griseum. The hippocampus proper and the subiculum also have in common that they contribute efferent fibers to the fornix (e.g., C&S, p. 630; Nolt, p. 299). Indeed, Nauta and Feirtag state that “on that ground it [the ‘subiculum’] is a part of the hippocampus”—the “subiculum hippocampi” (1986, p. 275).
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
NEOCORTEX and the limbic system. The projection to the mammillary body via the FORNIX has been found to arise in the subiculum, and not in the hippocampus as originally thought. The mammillothalamic tract has been confirmed, but the anterior thalamic nuclei have been found to project to the subiculum, rather than to the hippocampus proper. The subiculum in turn projects to the entorhinal cortex, the origin of the perforant path to the hippocampus. The subiculum also has reciprocal connections with association areas of the neocortex. Thus, like the entorhinal cortex, the subiculum is an important link between the neocortex and the limbic system.
Sectorization of the hippocampal formation: Cytoarchitectonics, topography, or vulnerability to hypoxia?
Published in Journal of the History of the Neurosciences, 2022
Régis Olry
But the terminology related to these structures also shows some discrepancies: for example, the term hippocampal formation designates either the hippocampal complex to which is added the subiculum (Nieuwenhuys, Voogd, and van Huijzen 2008, 372) or all of these structures plus the entorhinal cortex (Standring 2016, 387). The Terminologia Anatomica, which is supposed to simplify the nomenclature and to clarify once and for all the meaning of terms used in morphological sciences, is unfortunately of very little help. It includes under the term “Hippocampus” the hippocampus proper (or Ammon’s horn, formed by regions I–IV or sectors CA1-C4), the subiculum and its subdivisions (why apart from the prosubiculum?), the fimbria, the layers of hippocampus, and the dentate gyrus with its layers (Federative Committee on Anatomical Terminology, 1998, 128).
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).
Related Knowledge Centers
- Entorhinal Cortex
- Lateral Hypothalamus
- Nucleus Accumbens
- Pyramidal Cell
- Septal Area
- Prefrontal Cortex
- Hippocampus
- Hippocampal Formation
- Hippocampus Proper
- Nucleus Reuniens