Anatomy of the Hippocampus

In a recent study, Turner and Schwartzkroin (1980) attempted to estimate the voltage and current transfer between the soma and dendrites of CAl pyramidal cells of the guinea pig hippocampus, by recording from the cells intracellularly and then injecting HRP to visualize the detailed anatomy of the dendritic tree. All of the cells were oriented within the transverse plane of the slice and almost completely contained within one 75-pm section cut parallel to the surface of the slice. Although a few processes were found in adjacent sections, the major part of the tree was extremely flat and only 25-50 pm thick. 

FIGURE 26-5 Immunohistochemical localization of type I corticosteroid receptor (mineralocorticoid receptor) in the rat hippocampus. (A) Mineralocorticoid immunoreactivity is concentrated in pyramidal cell fields of the cornu ammonis (CA2). (B) High-power photomicrograph shows that steroid-bound mineralocorticoid receptors are primarily localized to neuronal cell nuclei. (Courtesy of Dr James P. Herman, Department of Anatomy and Neurobiology, University of Kentucky.)... 

Unusually high levels of dysbindin-1 are found in neuronal and neuropil components of this brain area, which consists of the dentate gyrus (DG), hippocampus proper (i.e., cornu ammonis [CA] fields 1-3]), and the subiculum ( Figures 2.2-13c—d and O 2.2-14V). As in the case of the basal ganglia, an anatomical introduction clarifies the functional implications of dysbindin-1 found in the hippocampal formation ( Figures 2.2-13-2.2-18). For a detailed review of its anatomy, see Amaral and Lavenex (2007). 

Van Hoesen GW, Hyman BT (1990) Hippocampal formation anatomy and the patterns of pathology in Alzheimer s disease. Prog Brain Res 83 445-457 Van Hoesen GW, Hyman BT, Damasio AR (1991) Entorhinal cortex pathology in Alzheimer s disease. Hippocampus 1 1-8... 

The determination of fhe embryonic "critical period of development" for the brain structures involved in learning and memory processes in mice is based on the original work by Rodier (1976). This study identified fhe embryonic time frames for peak neurogenesis and neuroepithelial proliferation for cerebral corfex, hippocampus, septum, amygdala, corpus striatum, thalamus, hypothalamus, cerebellum, and olfactory bulb as the period from embryonic day E14 fhrough E17. Rodier documented almost 40 years ago that the specific time of the central nervous system (CNS) insult is an important factor in subsequent effects on both anatomy and behavior. Therefore, this early work established what we refer to as the embryonic "critical period of development." The report suggested that the behavioral effects of toxicants such as benzo(a)pyrene (B(a)P) are similar in both rats and mice. This study was one of the first to demonstrate that mice could be used successfully as subjects in a variety of behavioral evaluation experiments. 

Fig. 13. Artistic demonstration of the vascular anatomy to the amygdala, hippocampus and parahippocampus...

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