Supracapsular bed nucleus of the stria terminalis contains central and medial extended amygdala elements: Evidence from anterograde and retrograde tracing experiments in the rat

Abstract

Neurons that accompany the stria terminalis as it loops over the internal capsule have been termed collectively the supracapsular bed nucleus of the stria terminalis (BSTS). They form two cell columns, a lateral column and a considerably smaller medial column. The lateral column merges rostrally with the lateral bed nucleus of the stria terminalis and caudally with the central amygdaloid nucleus (central extended amygdala components). The medial column is continuous with the medial bed nucleus of the stria terminalis and the medial amygdaloid nucleus (medial extended amygdala districts). The connections of the BSTS were investigated in the rat by placing injections of Phaseolus vulgaris-leucoagglutinin (PHA-L) or retrograde tracers in different parts of the extended amygdala or in structures related to the extended amygdala. BSTS inputs and outputs were identified, respectively, by the presence of varicose fibers and retrogradely labeled neurons within the stria terminalis. The results suggest that the medial-to-lateral compartmentalization of BSTS neurons reflects their close alliance with the medial and central divisions of the extended amygdala. The medial BSTS contains primarily elements that correspond to the posterodorsal part of the medial amygdaloid nucleus and the medial column of the posterior division of the medial bed nucleus of the stria terminalis, and the lateral BSTS contains elements that correspond to the medial and lateral parts of the central amygdaloid nucleus and lateral bed nucleus of the stria terminalis. These results add strong support to the concept of the extended amygdala as a ring-like macrostructure around the internal capsule, and they are of theoretical interest for the understanding of the organization of the basal forebrain.

The Ventral Striatopallidum and Extended Amygdala in Huntington Disease

“…The neurons of the medial division of the supracapsular bed nucleus of the stria terminalis form a cell continuum that follows the stria terminalis and penetrates the dorsal part of the internal capsule. This subnucleus receives afferents from the medial (endocrine-associated) hypothalamus (Shammah-Lagnado et al, 2000).…”

Development of the amygdalohypothalamic projection in the mouse embryonic forebrain

“…The organization of the ST in the adult brain has been extensively studied and some comparative aspects have also been discussed (Berkelbach van der Sprenkel 1926;Heimer and Nauta 1969;de Olmos and Ingram 1972;Krettek and Price 1978;Amaral et al 1982;Price et al 1991;Martinez-Garcia et al 1993;Lanuza et al 1997;Alheid et al 1998;Shammah-Lagnado et al 2000), but the developmental aspects of the ST have not been studied adequately in any animal models. The present study is, to our knowledge, the first demonstration of the According to our DiI-tracing experiments, fiber connections of the amygdala in the mouse embryonic forebrain include: (1) LOT, (2) ST and (3) ventral amygdalofugal pathway (VAF).…”

“…The mammalian ST is considered to be involved in transfer of the emotion-related information integrated in the amygdaloid complex to the hypothalamus, interacting with each part of the BNST along the trajectory (Alheid et al 1998;Shammah-Lagnado et al 2000). Thus, ST is involved in the output of the evaluation of external sensory stimuli to the autonomic and endocrine center, the hypothalamus, and in the control of adaptive responses as revealed by anatomical, physiological and behavioral findings (Heimer et al 1991) Though the functional aspects of the amygdaloid complex have been extensively investigated, only a few studies have focused on the developmental mechanisms of the amygdala and related structures, namely birth date studies of the amygdaloid neurons (Bayer 1980;McConnell and Angevine 1983;Bayer 1987), the immunohistochemical examination of developing amygdala and BNST in the rodent and chick (Song and Harlan 1994;Al-Shamma and De Vries 1996;Han and De Vries 1999;Jurkevich et al 1999), and morphological analysis of the human fetal amygdala (Johnston 1923;Ulfig et al 1998;Ulfig 2002).…”

Obesity-inducing amygdala lesions: examination of anterograde degeneration and retrograde transport

“…As with the degeneration in the shell of the accumbens (discussed previously), this degeneration is likely to arise from extrinsic sources such as the basomedial nucleus (81), the posterior basolateral amygdaloid nucleus (56,67,88,92,93), or the amygdalopiriform transition area (67,94), whose axons might have been inadvertently damaged by our lesions.…”