Medial amygdala nucleus

There are major differences between centrifugal inputs to MOB and AOB. First, centrifugal inputs to AOB arise from far fewer brain regions than inputs to MOB. The major afferents to AOB are from the bed nucleus of the stria terminalis, the nucleus of the accessory olfactory tract, the medial amygdala nucleus and the posteromedial cortical amygdala nucleus (De Olmos et al. 1978 Shipley and Adamek, 1984). A restricted part of the medial division of AON sends a dense projection to the granule cell layer of AOB (Rizvi et al. 1992), but all other divisions of AON lack connections with AOB. 

Fig. 2.19 Central pathways and nuclei, (a) Frog AOS Pl/Pm = lateral and medial pallium EP = post, olfactory eminence and nSm = medial Septal nucleus (from Kratskin, 1995). Reptiles and mammals-—afferent pathways from AOB to amygdala nuclei (Cortical C3 and Medial M), with tertiary connections to other central nuclei in hypothalamus (MPOA, VMH and PMN) (from Johnston, 2000). (b) Snake AOS Second-order projection of accessory fibres nAOT - nucleus of AOT AM = anterior amygdala and nSph = nucleus Sphericus. (c) Mammal AOS Projection sites of vomeronasal fibres in cortex and hypothalamus (from Johnston, 1998).

Limbic system amygdala (central, anterior, medial, and basolateral nuclei), medial and lateral septal nuclei medial septal nucleus... 

Fig. 35.1 Simplified diagram of chemosensory circuit in amygdala. Vomeronasal input via accessory olfactory bulb (VNO/ AOB) is analyzed in anterior and posterior medial amygdala (MeA, MeP). MeP appears to be inhibited by intercalated nucleus (ICNc) for heterospecific and artificial stimuli. MOE/ MOB Main olfactory epithelium/Main olfactory bulb. ACN Anterior Cortical Nucleus. PC Piriform Cortex. BLA Basolateral amygdala. ICNr rostral part of medial intercalated nucleus. ICNc caudal part of ICN. MPOA Medial Preoptic Area. VMH Ventro-medial hypothalamus...

Basal forebrain cholinergic nuclei project to all cerebral cortical areas and the amygdala (nbM), hippocampal formation, cingulate, and hypothalamus (medial septal nucleus and vertical limb of the diagonal band), and the olfac-... 

The nonapeptide vasopressin (AVP) is synthesized in the paraventricular nucleus of the hypothalamus (PVN) and the nucleus supraopticus. Besides its role in fluid regulation, AVP is also a key modulator of the HPA system, where it potentiates the effects of CRH on adrenocorticotropic hormone (ACTH) release. Extrahypothalamic AVP-containing neurons are localized in the medial amygdala and the bed nucleus of the stria terminalis. AVP applied intracere-broventricularly or to the lateral septum has been shown to affect cognition, social behavior, and anxiety-like behavior in rodents (Insel et al. 2001). 

Fig. 7. Anatomical organization of dopamine Di mRNA expression in the adult human brain (whole hemisphere horizontal images) at a dorsal (A) and ventral (B) level. Notice strong cortical expression of this dopamine receptor subtype in addition to the intense expression levels in the striatum (CN, Pu and NAc). Adapted from Hurd et al. (2001). aCg, anterior cingulate Amy, amygdala Cb, cerebellum cc, corpus callosum CN, caudate nucleus Cun, cuneus F, frontal lobe Hip, hippocampus hyp, hypothalamus I, insular cortex mPFC, medial prefrontal cortex mm, medial mammillary nucleus NAc, nucleus accumbens O, occipital lobe Phg, parahippocampal gyrus Pu, putamen SN, substantia nigra T, temporal lobe U, uncal gyrus.

Fig. 3 Vomeronasal system. Schematic representation of a rodent nasal cavity and brain (lateral view). Accessory olfactory bulb (AOB) mitral cells project to vomeronasal and extended amygdala. Inset The VNO is a bilateral tubular structure located at the base of the nasal septum. VSNs that express the same V1R or V2R converge on a small number of glomeruli in the AOB. Sensory neurons located in the apical layer of the epithelium project to the anterior part of the AOB, whereas those present in the basal layer project to the posterior part. MOE main olfactory epithelium, MOB main olfactory bulb, BSTMPM posteromedial bed nucleus of the stria terminalis, MEA medial amygdaloid nucleus, BACfF bed nucleus of the accessory olfactory tract, PMCO posteromedial cortical amygdaloid area...

F/g. 9. The distribution of NR3A mRNA in the adult rat brain (X-ray film autoradiographs, coronal sections), am, amygdala cm, centromedial thalamic nucleus hy, hypothalamus Co, superior colliculus mg, medial geniculate nucleus pn, pontine nucleus pv, paraventricular thalamic nucleus rt, reticular thalamus. Scale bar, 1 mm (Ciabarra et al., 1995). 

Studies of c-fos expression in the accessory olfactory system have been performed almost exclusively in the context of sexual behavior of animals (Fiber, Adames Swann, 1993 Schellinck, Smyth, Brown Wilkinson, 1993 Baum, Brown, Kica, Rubin, Johnson Papaioannou, 1994 Femandez-Fewell and Meredith, 1994 Rajendren and Moss, 1994 Bressler and Baum, 1996). Many studies show that c-fos is expressed in the vomeronasal projection circuit (i.e. the anterior olfactory bulb, the medial amygdala, the posterior medial bed nucleus of the stria terminalis, or the medial preoptic area) after mating behavior. Importantly, there have been no reports of specific c-fos expression in the VNO. 

Figure 7.1 Dopamine neuronal pathways. AMYG, amygdala CN, caudate nucleus MFB, medial forebrain bundle NcA, nucleus accumbers OT, olfactory tubercle PUT, putamen SN, substantia nigra. For full details see text and Moore and Bloom (1978) and Lindvall and Bjorkland (1978)...

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