Browsing by Subject "Amygdala"

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    Radial derivatives of the mouse ventral pallium traced with Dbx1-LacZ reporters
    (Elsevier, 2015-12-31) Puelles, Luis; Medina, Loreta; Borello, Ugo; Teissier, Anne; Pierani, Alessandra; Rubenstein, John L.R.; Legaz Pérez, Isabel; Ciencias Sociosanitarias
    The progeny of Dbx1-expressing progenitors was studied in the developing mouse pallium, using two transgenic mouse lines: (1) Dbx1nlslacZ mice, in which the gene of the β-galactosidase reporter (LacZ) is inserted directly under the control of the Dbx1 promoter, allowing short-term lineage tracing of Dbx1-derived cells; and (2) Dbx1CRE mice crossed with a Cre-dependent reporter strain (ROSA26loxP-stop-loxP-LacZ), in which the Dbx1-derived cells result permanently labeled (Bielle et al., 2005). We thus examined in detail the derivatives of the postulated longitudinal ventral pallium (VPall) sector, which has been defined among other features by its selective ventricular zone expression of Dbx1 (the recent ascription by Puelles, 2014 of the whole olfactory cortex primordium to the VPall was tested). Earlier notions about a gradiental caudorostral reduction of Dbx1 signal were corroborated, so that virtually no signal was found at the olfactory bulb and the anterior olfactory area. The piriform cortex was increasingly labeled caudalwards. The only endopiriform grisea labeled were the ventral endopiriform nucleus and the bed nucleus of the external capsule. Anterior and basolateral parts of the whole pallial amygdala also were densely marked, in contrast to the negative posterior parts of these pallial amygdalar nuclei (leaving apart medial amygdalar parts ascribed to subpallial or extratelencephalic sources of Dbx1-derived GABAergic and non-GABAergic neurons). Alternative tentative interpretations are discussed to explain the partial labeling obtained of both olfactory and amygdaloid structures. This includes the hypothesis of an as yet undefined part of the pallium, potentially responsible for the posterior amygdala, or the hypothesis that the VPall may not be wholly characterized by Dbx1 expression (this gene not being necessary for VPall molecular distinctness and histogenetic potency), which would leave a dorsal Dbx1-negative VPall subdomain of variable size that might contribute partially to olfactory and posterior amygdalar structures.
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    Regulation of glial markers expression in the rat basolateral amygdala and hippocampus during morphine aversive memory retrieval and its extinction
    (2025-12-15) Franco García, Aureliio; Gómez Murcia, Victoria; Núñez Parra, Cristina; Farmacología
    Background Opioid use disorder is driven by neurobehavioral adaptations where environmental cues trigger relapse. Consequently, extinction therapy (ET) aims to modify drug-associated memories but has limited long-term efficacy. Recently, evidence suggested that glial cells may contribute to neuroplasticity phenomena in addiction. In this sense, this study examined whether aversive memories of morphine withdrawal and their extinction induce transcriptional changes in glial markers (gfap, aif1, itgam, klf4) in key memory-related regions: the basolateral amygdala (BLA) and hippocampus (dentate gyrus [DG] and CA1). Results Using the conditioned place aversion (CPA) paradigm in rats, we assessed avoidance behavior after naloxone-precipitated withdrawal and its extinction. Transcriptional analyses did not reveal major changes in the BLA. However, in CA1, downregulation of microglial markers cooccurred with aversive memory retrieval and restored after extinction. Moreover, one of the microglial markers, klf4, was reduced concomitantly with extinction memory retrieval in the DG. Correlation analyses showed negative associations between microglial markers and aversive memory strength, suggesting glial involvement in withdrawal-related learning. Conclusions These findings might indicate that microglial activity in CA1 plays a role in opioid withdrawal-associated memories, and extinction training might be returning these effects to basal levels. Therefore, targeting glial responses could provide new therapeutic strategies to prevent relapse.
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    Transient structures of the human fetal brain: Subplate, thalamic reticular complex, ganglionic eminence
    (Murcia : F. Hernández, 2000) Ulfig, N.; Neudorfer, F.; Bohl, J.
    Morphological features of the subplate, the thalamic reticular complex and the ganglionic eminence, which represent three major transient structures of the human fetal forebrain, are summarized with special reference to their functional roles. The subplate harboring various neuronal types is an outstandingly wide zone subjacent to the cortical plate in the human fetal brain. Within the subplate various cortical afferents establish synaptic contacts for a prolonged period before entering the cortical plate. Therefore, the subplate is regarded as a "waiting compartment" which is required for the formation of mature cortical connections. Next to the thalamic reticular nucleus, within the fibers of internal capsule, the perireticular nucleus is located which has been established as a distinct entity during development. Its various neuronal types express a number of different neuroactive substances. Perinatally, the perireticular nucleus is drastically reduced in size. It is involved in the guidance of corticofugal and thalamocortical fibers. The ganglionic eminence is a conspicuous proliferative area that persists throughout nearly the entire fetal period. In the human fetal brain it extends medially upon the dorsal thalamic nuclei which receive precursor cells from the ganglionic eminence. Postmitotic cells in the marginal zone of the ganglionic eminence serve as an intermediate target for growing axons. On the whole, all three structures establish transient neural circuitries that may be essential for the formation of adult projections. The characteristics of the three transient structures are particularly relevant for developmental neuropathology as these structures may be damaged in disorders that preferentially occur in preterm infants.