The Central Nucleus of the Amygdaloid Body of the Brain: Cytoarchitectonics, Neuronal Organization, Connections

Abstract

This review considers the questions of the structural-functional organization of the central nucleus (CN) of the amygdaloid body (AB) of the brain in relation to new data on its involvement in the formation of stress reactions and adaptive behavior in animals. Data are presented on the distribution of neuropeptides, neurotransmitters, and modulators in the CN. It is noted that the CN, appearing at the earliest stages of establishment of the AB, is reorganized with it and reflects the evolution of the whole AB. Detailed data are presented on the cytoarchitectonics of the CN of the AB, its heteromorphousness, and subdivision into zones (subnuclei) based on the use of different study methods and assessment criteria. The neuronal organization of the CN and its subnuclei is considered; detailed descriptions of different types of neurons are provided, with consideration of their topographies, sizes, and shapes and of their perikarya, the orientation and type of branching of their dendrites, the organization of the spine apparatus, and axon structure. The characteristics of the development of the CN of the AB in the ontogenesis of mammals and man are discussed. Analysis of published data and our own results supports the role of the CN not only as an intra-amygdalar integrative center, but also as one of the major channels for the afferent and efferent connections of the AB with the rest of the brain.

Chemotherapy agent cisplatin induces 48-h Fos expression in the brain of a vomiting species, the house musk shrew (Suncus murinus)

“…The CeA is a highly differentiated nucleus that has afferent and efferent connections with cortices, PBN, hypothalamus, DVC, and other brain regions (3). In the present study, Fos expression in the CeA paralleled similar effects in the DVC after cisplatin treatment, and pretreatment with palonosetron inhibited Fos cell counts in both areas at 6 h after cisplatin treatment.…”

Ethanol and corticotropin releasing factor receptor modulation of central amygdala neurocircuitry: An update and future directions

“…The CeA can be divided into four major subdivisions, the lateral capsular (CeLC), the lateral (CeL), the medial (CeM), and the intermediate (CeI), subregions that maintain distinct inter-subregion connectivity (Akmaev, Kalimullina, & Sharipova, 2004; Cassell, Freedman, & Shi, 1999; Sah, Faber, Lopez De Armentia, & Power, 2003). In general, the CeL is thought to be the major input subregion and the CeM appears to be the major output subnucleus, while the other subregions can gate inter-regional activity.…”

“…Overall, studies examining the neurocircuit architecture of the CeA may be somewhat limited by the lack of strong boundary demarcations between CeA subregions, and the potential for cell types typical of one subregion to also overlap into others. (For more complete reviews of CeA neuroanatomy, see Akmaev et al, 2004; Cassell et al, 1999). …”

Restraint stress increases serotonin release in the central nucleus of the amygdala via activation of corticotropin-releasing factor receptors

“…Hyperactivity of the amygdala, as observed in individuals suffering from anxiety and depression [17,41], is thought to contribute to the negative cognitive and affective symptoms characterizing such disorders [46]. The central nucleus of the amygdala (CeA) receives highly processed information via the lateral and basolateral amygdala from wide range of cortical and subcortical structures and, in turn, projects to the hypothalamus and brainstem [1,38]. Experimental evidence in rodents suggests both activational and integrative roles for the CeA in responses to stressors.…”