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A comparative analysis shows morphofunctional differences between the rat and mouse melanin-concentrating hormone systems.

Croizier S, Franchi-Bernard G, Colard C, Poncet F, La Roche A, Risold PY - PLoS ONE (2010)

Bottom Line: Sub-populations of neurons producing melanin-concentrating hormone (MCH) are characterized by distinct projection patterns, birthdates and CART/NK3 expression in rat.Evidence for such sub-populations has not been reported in other species.Furthermore, divergences in the distribution of MCH axons were observed, in particular in the ventromedial hypothalamus.

View Article: PubMed Central - PubMed

Affiliation: Faculté de Médecine et de Pharmacie, Université de Franche-Comté, Besançon, France.

ABSTRACT
Sub-populations of neurons producing melanin-concentrating hormone (MCH) are characterized by distinct projection patterns, birthdates and CART/NK3 expression in rat. Evidence for such sub-populations has not been reported in other species. However, given that genetically engineered mouse lines are now commonly used as experimental models, a better characterization of the anatomy and morphofunctionnal organization of MCH system in this species is then necessary. Combining multiple immunohistochemistry experiments with in situ hybridization, tract tracing or BrdU injections, evidence supporting the hypothesis that rat and mouse MCH systems are not identical was obtained: sub-populations of MCH neurons also exist in mouse, but their relative abundance is different. Furthermore, divergences in the distribution of MCH axons were observed, in particular in the ventromedial hypothalamus. These differences suggest that rat and mouse MCH neurons are differentially involved in anatomical networks that control feeding and the sleep/wake cycle.

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MCH neuron genesis in the mouse hypothalamus.(A) Histogram summarizing precedent findings in the rat concerning the genesis of MCH, MCH/CART/NK3 and Hcrt neurons in the hypothalamus [12],[18]. (B–F) A similar study combining BrdU, immunohistochemistry and in situ hybridization was conducted in mouse to compare the birthdates of MCH and Hcrt neurons. (B) Photomicrograph illustrating a neuron double-labeled for BrdU (red immunohistochemistry) and MCH (in situ hybridization). (C) Dual immunofluorescence to identify Hcrt (green) and BrdU in the same neurons. Only neurons displaying a densely BrdU-labeled nucleus were taken into consideration. (D–F) Histograms of MCH/BrdU, NK3/BrdU and Hcrt/BrdU neurons. MCH/BrdU positive neurons are seen from E9 to E14, with a peak at E10 (D). NK3/BrdU positive cells in the zona incerta/LHA were observed only at E11 and E12 (E). On the same material, double labeled Hcrt/BrdU perikarya were observed mainly at E10 (F). LHA: lateral hypothalamic area.
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pone-0015471-g004: MCH neuron genesis in the mouse hypothalamus.(A) Histogram summarizing precedent findings in the rat concerning the genesis of MCH, MCH/CART/NK3 and Hcrt neurons in the hypothalamus [12],[18]. (B–F) A similar study combining BrdU, immunohistochemistry and in situ hybridization was conducted in mouse to compare the birthdates of MCH and Hcrt neurons. (B) Photomicrograph illustrating a neuron double-labeled for BrdU (red immunohistochemistry) and MCH (in situ hybridization). (C) Dual immunofluorescence to identify Hcrt (green) and BrdU in the same neurons. Only neurons displaying a densely BrdU-labeled nucleus were taken into consideration. (D–F) Histograms of MCH/BrdU, NK3/BrdU and Hcrt/BrdU neurons. MCH/BrdU positive neurons are seen from E9 to E14, with a peak at E10 (D). NK3/BrdU positive cells in the zona incerta/LHA were observed only at E11 and E12 (E). On the same material, double labeled Hcrt/BrdU perikarya were observed mainly at E10 (F). LHA: lateral hypothalamic area.

Mentions: Past data obtained in rat showed that the whole MCH population is generated over several gestational stages (from embryonic day 10 (E10) to E16, with a peak at E12/E13) (Figure 4A) [12]. This pattern of MCH genesis was compared to the production of the hypocretin/orexin (Hcrt)-containing neurons; these cells co-localize with MCH neurons, project with a similar pattern throughout the brain and are involved in similar functions [6],[16],[17]. In contrast to MCH, these cells are generated in one sharp peak at E12 in the rat [18]. With regard to MCH sub-populations, it seems that MCH, Hcrt and MCH/CART cell bodies are generated in successive waves: the first wave gives rise to spinally projecting MCH neurons at E11, then Hcrt neurons are generated at E12, and MCH/CART neurons are produced slightly later at E12/E13 [12],[14],[18].


A comparative analysis shows morphofunctional differences between the rat and mouse melanin-concentrating hormone systems.

Croizier S, Franchi-Bernard G, Colard C, Poncet F, La Roche A, Risold PY - PLoS ONE (2010)

MCH neuron genesis in the mouse hypothalamus.(A) Histogram summarizing precedent findings in the rat concerning the genesis of MCH, MCH/CART/NK3 and Hcrt neurons in the hypothalamus [12],[18]. (B–F) A similar study combining BrdU, immunohistochemistry and in situ hybridization was conducted in mouse to compare the birthdates of MCH and Hcrt neurons. (B) Photomicrograph illustrating a neuron double-labeled for BrdU (red immunohistochemistry) and MCH (in situ hybridization). (C) Dual immunofluorescence to identify Hcrt (green) and BrdU in the same neurons. Only neurons displaying a densely BrdU-labeled nucleus were taken into consideration. (D–F) Histograms of MCH/BrdU, NK3/BrdU and Hcrt/BrdU neurons. MCH/BrdU positive neurons are seen from E9 to E14, with a peak at E10 (D). NK3/BrdU positive cells in the zona incerta/LHA were observed only at E11 and E12 (E). On the same material, double labeled Hcrt/BrdU perikarya were observed mainly at E10 (F). LHA: lateral hypothalamic area.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2984507&req=5

pone-0015471-g004: MCH neuron genesis in the mouse hypothalamus.(A) Histogram summarizing precedent findings in the rat concerning the genesis of MCH, MCH/CART/NK3 and Hcrt neurons in the hypothalamus [12],[18]. (B–F) A similar study combining BrdU, immunohistochemistry and in situ hybridization was conducted in mouse to compare the birthdates of MCH and Hcrt neurons. (B) Photomicrograph illustrating a neuron double-labeled for BrdU (red immunohistochemistry) and MCH (in situ hybridization). (C) Dual immunofluorescence to identify Hcrt (green) and BrdU in the same neurons. Only neurons displaying a densely BrdU-labeled nucleus were taken into consideration. (D–F) Histograms of MCH/BrdU, NK3/BrdU and Hcrt/BrdU neurons. MCH/BrdU positive neurons are seen from E9 to E14, with a peak at E10 (D). NK3/BrdU positive cells in the zona incerta/LHA were observed only at E11 and E12 (E). On the same material, double labeled Hcrt/BrdU perikarya were observed mainly at E10 (F). LHA: lateral hypothalamic area.
Mentions: Past data obtained in rat showed that the whole MCH population is generated over several gestational stages (from embryonic day 10 (E10) to E16, with a peak at E12/E13) (Figure 4A) [12]. This pattern of MCH genesis was compared to the production of the hypocretin/orexin (Hcrt)-containing neurons; these cells co-localize with MCH neurons, project with a similar pattern throughout the brain and are involved in similar functions [6],[16],[17]. In contrast to MCH, these cells are generated in one sharp peak at E12 in the rat [18]. With regard to MCH sub-populations, it seems that MCH, Hcrt and MCH/CART cell bodies are generated in successive waves: the first wave gives rise to spinally projecting MCH neurons at E11, then Hcrt neurons are generated at E12, and MCH/CART neurons are produced slightly later at E12/E13 [12],[14],[18].

Bottom Line: Sub-populations of neurons producing melanin-concentrating hormone (MCH) are characterized by distinct projection patterns, birthdates and CART/NK3 expression in rat.Evidence for such sub-populations has not been reported in other species.Furthermore, divergences in the distribution of MCH axons were observed, in particular in the ventromedial hypothalamus.

View Article: PubMed Central - PubMed

Affiliation: Faculté de Médecine et de Pharmacie, Université de Franche-Comté, Besançon, France.

ABSTRACT
Sub-populations of neurons producing melanin-concentrating hormone (MCH) are characterized by distinct projection patterns, birthdates and CART/NK3 expression in rat. Evidence for such sub-populations has not been reported in other species. However, given that genetically engineered mouse lines are now commonly used as experimental models, a better characterization of the anatomy and morphofunctionnal organization of MCH system in this species is then necessary. Combining multiple immunohistochemistry experiments with in situ hybridization, tract tracing or BrdU injections, evidence supporting the hypothesis that rat and mouse MCH systems are not identical was obtained: sub-populations of MCH neurons also exist in mouse, but their relative abundance is different. Furthermore, divergences in the distribution of MCH axons were observed, in particular in the ventromedial hypothalamus. These differences suggest that rat and mouse MCH neurons are differentially involved in anatomical networks that control feeding and the sleep/wake cycle.

Show MeSH
Related in: MedlinePlus