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Prosomeric organization of the hypothalamus in an elasmobranch, the catshark Scyliorhinus canicula.

Santos-Durán GN, Menuet A, Lagadec R, Mayeur H, Ferreiro-Galve S, Mazan S, Rodríguez-Moldes I, Candal E - Front Neuroanat (2015)

Bottom Line: Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain.Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates.These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigaciones Biológicas, Department of Cell Biology and Ecology, University of Santiago de Compostela Santiago de Compostela, Spain.

ABSTRACT
The hypothalamus has been a central topic in neuroanatomy because of its important physiological functions, but its mature organization remains elusive. Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain. Here we studied the molecular organization of the hypothalamus and neighboring telencephalic domains in a cartilaginous fish, the catshark, Scyliorhinus canicula, focusing on ScFoxg1a, ScShh, ScNkx2.1, ScDlx2/5, ScOtp, and ScTbr1 expression profiles and on the identification α-acetylated-tubulin-immunoreactive (ir), TH-ir, 5-HT-ir, and GFAP-ir structures by means of immunohistochemistry. Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates. These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates.

No MeSH data available.


Schematic representation of various gene expression patterns in the forebrain of mouse (A) and the rostral diencephalon and hypothalamus of S. canicula(B), and their correspondence with the updated prosomeric model (see text for details). Patterns in (A) are illustrated according to Figures 8.9 and 8.16 in Puelles et al. (2012). Patterns in (B) were mapped according to present results. Expression of Nkx2.1 and Otp genes in the telencephalon has not been represented. White, green and blue dots represent non-ventricular ScNkx2.1-, ScDlx2/5-, and ScOtp-expressing cells, respectively. For abbreviations, see list.
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Figure 6: Schematic representation of various gene expression patterns in the forebrain of mouse (A) and the rostral diencephalon and hypothalamus of S. canicula(B), and their correspondence with the updated prosomeric model (see text for details). Patterns in (A) are illustrated according to Figures 8.9 and 8.16 in Puelles et al. (2012). Patterns in (B) were mapped according to present results. Expression of Nkx2.1 and Otp genes in the telencephalon has not been represented. White, green and blue dots represent non-ventricular ScNkx2.1-, ScDlx2/5-, and ScOtp-expressing cells, respectively. For abbreviations, see list.

Mentions: According with the updated prosomeric model (Puelles et al., 2012; see also Figure 6A) the AHy, together with the telencephalon, are the rostral-most regions of the alar plate. The AHy is located ventral to the Foxg1-expressing telencephalon, dorsal to the BHy (which is characterized by the expression of Nkx2.1 in its whole extension except in its caudal-most portion), and rostral to the alar p3 (characterized by the complementary expression of Dlx and Tbr1 genes). Within the territory delimitated by the above-mentioned genes, two longitudinal (dorso-ventrally arranged) histogenetic domains are defined based on the complementary expression of Dlx and Otp genes. The dorsal-most domain is termed paraventricular domain (Pa), and expresses Otp but not Dlx genes. The ventral-most is the subparaventricular domain (SPa), which expresses Dlx genes but not Otp. Dlx is expressed beyond the HDB in the alar p3. The alar HDB is defined by the clear-cut expression among genes restricted to the AHy (Sim1, Otp) or to the alar p3 (Lhx9, Arx, Olig2 among others). The alar p3, besides, includes the prethalamic eminence (PThE) and express genes in a complementary manner (PThE: Tbr1, Lhx9, Gdf10; alar p3: Dlx genes, Arx, Gsh2). Moreover, according with the prosomeric model both, Pa and SPa domains, present terminal (hp2) and peduncular (hp1) domains (TPa, PPa; TSPa, PSPa respectively). However these subdomains cannot be genetically identified without additional markers. Thus, the AHy presents at least four different histogenetic domains although some work on the development of hypothalamic peptidergic cells point to much more subdivision (Figure 6A; see also Morales-Delgado et al., 2011, 2014; Puelles et al., 2012).


Prosomeric organization of the hypothalamus in an elasmobranch, the catshark Scyliorhinus canicula.

Santos-Durán GN, Menuet A, Lagadec R, Mayeur H, Ferreiro-Galve S, Mazan S, Rodríguez-Moldes I, Candal E - Front Neuroanat (2015)

Schematic representation of various gene expression patterns in the forebrain of mouse (A) and the rostral diencephalon and hypothalamus of S. canicula(B), and their correspondence with the updated prosomeric model (see text for details). Patterns in (A) are illustrated according to Figures 8.9 and 8.16 in Puelles et al. (2012). Patterns in (B) were mapped according to present results. Expression of Nkx2.1 and Otp genes in the telencephalon has not been represented. White, green and blue dots represent non-ventricular ScNkx2.1-, ScDlx2/5-, and ScOtp-expressing cells, respectively. For abbreviations, see list.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4389657&req=5

Figure 6: Schematic representation of various gene expression patterns in the forebrain of mouse (A) and the rostral diencephalon and hypothalamus of S. canicula(B), and their correspondence with the updated prosomeric model (see text for details). Patterns in (A) are illustrated according to Figures 8.9 and 8.16 in Puelles et al. (2012). Patterns in (B) were mapped according to present results. Expression of Nkx2.1 and Otp genes in the telencephalon has not been represented. White, green and blue dots represent non-ventricular ScNkx2.1-, ScDlx2/5-, and ScOtp-expressing cells, respectively. For abbreviations, see list.
Mentions: According with the updated prosomeric model (Puelles et al., 2012; see also Figure 6A) the AHy, together with the telencephalon, are the rostral-most regions of the alar plate. The AHy is located ventral to the Foxg1-expressing telencephalon, dorsal to the BHy (which is characterized by the expression of Nkx2.1 in its whole extension except in its caudal-most portion), and rostral to the alar p3 (characterized by the complementary expression of Dlx and Tbr1 genes). Within the territory delimitated by the above-mentioned genes, two longitudinal (dorso-ventrally arranged) histogenetic domains are defined based on the complementary expression of Dlx and Otp genes. The dorsal-most domain is termed paraventricular domain (Pa), and expresses Otp but not Dlx genes. The ventral-most is the subparaventricular domain (SPa), which expresses Dlx genes but not Otp. Dlx is expressed beyond the HDB in the alar p3. The alar HDB is defined by the clear-cut expression among genes restricted to the AHy (Sim1, Otp) or to the alar p3 (Lhx9, Arx, Olig2 among others). The alar p3, besides, includes the prethalamic eminence (PThE) and express genes in a complementary manner (PThE: Tbr1, Lhx9, Gdf10; alar p3: Dlx genes, Arx, Gsh2). Moreover, according with the prosomeric model both, Pa and SPa domains, present terminal (hp2) and peduncular (hp1) domains (TPa, PPa; TSPa, PSPa respectively). However these subdomains cannot be genetically identified without additional markers. Thus, the AHy presents at least four different histogenetic domains although some work on the development of hypothalamic peptidergic cells point to much more subdivision (Figure 6A; see also Morales-Delgado et al., 2011, 2014; Puelles et al., 2012).

Bottom Line: Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain.Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates.These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigaciones Biológicas, Department of Cell Biology and Ecology, University of Santiago de Compostela Santiago de Compostela, Spain.

ABSTRACT
The hypothalamus has been a central topic in neuroanatomy because of its important physiological functions, but its mature organization remains elusive. Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain. Here we studied the molecular organization of the hypothalamus and neighboring telencephalic domains in a cartilaginous fish, the catshark, Scyliorhinus canicula, focusing on ScFoxg1a, ScShh, ScNkx2.1, ScDlx2/5, ScOtp, and ScTbr1 expression profiles and on the identification α-acetylated-tubulin-immunoreactive (ir), TH-ir, 5-HT-ir, and GFAP-ir structures by means of immunohistochemistry. Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates. These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates.

No MeSH data available.