The amygdala controls emotional and social behavior and regulates instinctive reflexes such as defense and reproduction by way of descending projections to the hypothalamus and brainstem. The descending amygdalar projections are suggested to show a cortico-striato-pallidal organization similar to that of the basal ganglia (Swanson [2000] Brain Res 886:113-164). To test this model we investigated the embryological origin and molecular properties of the mouse centromedial and extended amygdalar subdivisions, which constitute major sources of descending projections. We analyzed the distribution of key regulatory genes that show restricted expression patterns within the subpallium (Dlx5, Nkx2.1, Lhx6, Lhx7/8, Lhx9, Shh, and Gbx1), as well as genes considered markers for specific subpallial neuronal subpopulations. Our results indicate that most of the centromedial and extended amygdala is formed by cells derived from multiple subpallial subdivisions. Contrary to a previous suggestion, only the central--but not the medial--amygdala derives from the lateral ganglionic eminence and has striatal-like features. The medial amygdala and a large part of the extended amygdala (including the bed nucleus of the stria terminalis) consist of subdivisions or cell groups that derive from subpallial, pallial (ventral pallium), or extratelencephalic progenitor domains. The subpallial part includes derivatives from the medial ganglionic eminence, the anterior peduncular area, and possibly a novel subdivision, called here commissural preoptic area, located at the base of the septum and related to the anterior commissure. Our study provides a molecular and morphological foundation for understanding the complex embryonic origins and adult organization of the centromedial and extended amygdala.

We studied the lateral and ventral pallial divisions of the claustroamygdaloid complex by means of analysis of expression patterns of the developmental regulatory genes Tbr1, Dbx1, Neurogenin 2, Emx1, Cadherin 8, and Semaphorin 5A in mouse developing telencephalon, from embryonic day 12.5 until birth. Our results indicate that these genes help to distinguish distinct lateral and ventral pallial histogenetic divisions in the embryonic telencephalon. Tbr1 is broadly expressed in both lateral and ventral pallial histogenetic divisions (the lateroventral migratory stream plus the mantle) during early and intermediate embryonic development; its signal becomes weak in parts of the mantle during late embryonic development. Dbx1 is strongly and specifically expressed in progenitor cells (ventricular zone) of the ventral pallium during early embryonic development, but there is no signal of this gene in the rest of the pallium nor the subpallium. Neurogenin 2 and Semaphorin 5A are both expressed in a ventral subdivision of the lateroventral migratory stream (called by us the ventral migratory stream). Further, specific nuclei of the claustral complex and pallial amygdala show strong expression of Neurogenin 2 and/or Semaphorin 5A, including the ventromedial claustrum and endopiriform nuclei, the lateral and basomedial amygdalar nuclei, the anterior and posteromedial cortical amygdalar areas, plus the amygdalo-hippocampal area. We interpret these nuclei or areas of the claustroamygdaloid complex as possible derivatives of the ventral pallium. In contrast, during embryonic development the dorsolateral claustrum, the basolateral amygdalar nucleus, and the posterolateral cortical amygdalar area do not express or show weak expression of Neurogenin 2 or Semaphorin 5A, but express selectively and strongly Cadherin 8 plus Emx1, and may be derivatives of the lateral pallium. The lateral pallial and ventral pallial divisions of the claustroamygdaloid complex appear to have some different sets of connections, although this requires further investigation.

Dysfunctions in emotional control and social behavior are behind human neuropsychiatric disorders, some of which are associated with an alteration of amygdalar development. The medial extended amygdala is a key telencephalic center for control of social behavior, but very little is known about its development. We used in vitro migration assays for analyzing the origin of the neurons of the medial extended amygdala in mouse embryos (E13.5-E16.5). We compared the migration assays with immunofluorescence/immunohistochemistry for calbindin and radial glial fibers and with mRNA expression of several genetic markers of distinct forebrain subdivisions. We provide experimental evidence for multiple embryonic origins of the principal neurons of the medial extended amygdala. In particular, we provide novel evidence indicating that a major part of the neurons derives from a caudoventral pallidal subdivision (previously called or included as part of the anterior peduncular area), forming a cell corridor with similar molecular features (expression of Lhx6 and calbindin), connectivity, and function, which relates to reproductive behavior. We also provide novel experimental evidence indicating that the ventral pallium produces some neurons for the medial amygdala, which correlates with data from Lhx9 expression. Our results also confirm that some neurons of the medial extended amygdala originate in the preoptic area (our results indicate that these cells specifically originate in its commissural subdivision) and the supraoptoparaventricular domain of the hypothalamus. Our study helps to set up the foundations for a better understanding of medial amygdalar control of behavior in normal and abnormal conditions.

The use of local ecological knowledge (LEK) has been advocated for biodiversity monitoring and management. To date, however, it has been underused in studying wild populations of animals and, particularly, in obtaining quantitative abundance estimates. We evaluated LEK as a tool for collecting extensive data on local animal abundance and population trends. We interviewed shepherds in southeastern Spain, asking them to estimate the local abundance of the terrestrial tortoise Testudo graeca. We quantified reliability of abundance estimates derived from interviews by comparing them with those obtained from standard field-sampling protocols (distance sampling). We also explored the complementarity of these 2 approaches. LEK provided high-quality and low-cost information about both distribution and abundance of T. graeca. Interviews with shepherds yielded abundance estimates in a much wider range than linear transects, which only detected the species in the upper two-thirds of its abundance range. Abundance estimates from both methodologies showed a close relationship. Analysis of confidence intervals indicated local knowledge could be used to estimate mean local abundances and to detect mean population trends. A cost analysis determined that the information derived from LEK was 100 times cheaper than that obtained through linear-transect surveys. Our results should further the use of LEK as a standard tool for sampling the quantitative abundance of a great variety of taxa, particularly when population densities are low and traditional sampling methods are expensive or difficult to implement.

We compared the combinatorial expression patterns of several LIM domain-containing regulatory genes in the ventrolateral pallium of mouse and chicken, in order to identify the homologues of the ventral pallial amygdala and other olfactory structures in birds. Lmo3, Lmo4, Lhx2, and Lhx9 showed comparable expression patterns in the telencephalon of mouse and chicken, which allowed distinction of the ventrolateral pallium and, particularly, the ventral pallial amygdala and entorhinal cortex. Lmo3 was expressed in most of the ventrolateral pallium in both species, including, in chicken, the piriform cortex and dorsal ventricular ridge (mesopallium, nidopallium, and arcopallium) and, in mouse, the piriform cortex, most of the claustral complex, and the pallial amygdala. Lhx9 was differentially expressed in the ventral pallium, where it was restricted to its rostral (olfactory bulb) and caudal (amygdalar and entorhinal) poles. In the caudal pole, expression of Lhx9 overlapped that of its paralog Lhx2. According to these expression patterns, the chicken ventral pallial amygdala appears to include the caudal dorsolateral pallium, the caudal nidopallium, and the whole arcopallium, and each one relates to a distinct ventricular sector. Finally, the combinatorial expression patterns of Lmo3, Lhx9, and Lmo4 distinguished four distinct subdivisions in the superficial, olfactorecipient area of the chicken ventral pallium, which appear comparable to the piriform, entorhinal, amygdalopiriform, and amygdalar cortices of mammals. The results are discussed in the context of the two existing, opposite views on the homology of the dorsal ventricular ridge of sauropsids and in terms of the evolution of pallial derivatives.

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Should a species be translocated? Uncertainty regarding the necessity and feasibility of many translocations complicates answering this question. Here, we review translocation projects, both published and unpublished. Our results indicate that most projects (1) addressed fewer than half of the basic criteria established for translocations and (2) were either unjustifiable from a conservation perspective or inadequately designed to guarantee success or preclude negative consequences. We propose a hierarchical decision‐making system – an explicit method that integrates existing guidelines, thereby covering a key gap in conservation science – to reduce ambiguity when deciding whether to implement a given translocation project. This method will improve the likelihood of success in translocation projects and contribute to the efficient use of the limited resources available for these conservation efforts.

A socioecological approach to biodiversity conservation has recently been encouraged. We examined farmer perceptions of ecosystem services provided by scavenging vertebrates in Spain through face-to-face surveys with farmers in seven large extensive livestock systems. Scavenging services (i.e., carrion consumption) was the most perceived benefit whereas the role of some scavengers as predators was the most recognized damage. The most beneficial scavengers perceived were vultures. Overall, we detected a "Dr. Jekyll and Mr. Hyde" paradox as the same species and species within the same guild can be dually perceived as beneficial or harmful. Our findings provide evidence that traditional extensive farming linked to experience-based and local ecological knowledge drives positive perceptions of scavengers and their consideration as ecosystem services providers. Research on social perceptions can contribute to the conservation of scavengers by raising awareness about the ecosystem services provided by this functional group.