Different Fear States Engage Distinct Networks within the Intercalated Cell Clusters of the Amygdala

Exposure to a fearful context during periods of memory plasticity impairs extinction via hyperactivation of frontal-amygdalar circuits

“…In contrast, delayed extinction-whether it followed conditioning or retrieval-increased the proportion of main nucleus (In) c-Fos + neurons relative to medial paracapsular (ImP) neurons. This finding is consistent with studies indicating that activation of these two neuronal populations competes during learning, with the paracapsular cluster (ImP) more active during both acquisition and extinction and the main nucleus (In) activated preferentially during fear extinction (Whittle et al 2010;Busti et al 2011;Manko et al 2011).…”

“…We distinguished c-Fos + neurons in the main nucleus (In) and the medial paracapsular (ImP) using methods identical to those used by Busti et al (2011) to evaluate Zif268 expression in these nuclei as well as in other studies of ITC populations (Hefner et al 2008). Briefly, these nuclei were distinguished from other amygdalar nuclei as their activation patterns cluster together and the background staining produced by our IHC technique allows for distinction from other nuclei (Supplemental Fig.…”

“…Current theoretical accounts require that the relative effects of these distinct ITC masses are considered when evaluating their functional output. We therefore calculated the proportion of active In to ImP neurons to account for their combined role in mitigating the effect of extinction recency in a way consistent with current amygdala functional findings (Whittle et al 2010;Busti et al 2011;Manko et al 2011;Palomares-Castillo et al 2012;Pare and Duvarci 2012).…”

“…In addition, studies of the amygdala and medial prefrontal cortex have begun to show some of the substrates that underlie immediate extinction (Mao et al 2006;Clem and Huganir 2010;Kim et al 2010;Xue et al 2012). One brain region that is strongly linked with the prefrontal cortex and controls different aspects of fear expression and extinction is the intercalated cell masses (ITC) within the amygdala (Hefner et al 2008;Likhtik et al 2008;Busti et al 2011;Manko et al 2011). However, little is known about how these specific neuronal populations may be engaged in response to extinction contingencies that result in differential response loss (e.g., immediate or delayed extinction).…”

Oxytocin und die suchterhaltenden Mechanismen der Alkoholabhängigkeit

“…Die CRF-Neurone in der Amygdala besitzen Glucocorticoidrezeptoren, weshalb sie möglicherweise zusätzlich durch die Nebennierenrinde mittels einer Rückkoppelungs-schleife moduliert werden [16]. Furcht (Reaktion auf bestimmte Reize) und Angst (im Sinne eines Zustandes; ungerichtet) werden maßgeblich über die 2 Oxytocin und die suchterhaltenden Mechanismen der Alkoholabhängigkeit K review Amygdala vermittelt und reguliert [16][17][18][19][20][21]. Furchtund angstrelevante neuronale Efferenzen entspringen den zentralen [22], lateralen und basolateralen (basalen) Kerngebieten der Amygdala [17,19].…”