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Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers.

Brus M, Meurisse M, Keller M, Lévy F - Front Behav Neurosci (2014)

Bottom Line: In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures.We showed that the postpartum period was associated with a decrease in olfactory and hippocampal adult neurogenesis.Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 85, Physiologie de la Reproduction et des Comportements Nouzilly, France ; CNRS, UMR 7247 Nouzilly, France ; Université François Rabelais Tours, France ; IFCE Nouzilly, France.

ABSTRACT
New neurons are continuously added in the dentate gyrus (DG) and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal maturation, the percentage of neuroblasts and new mature neurons in the olfactory bulb and the DG was compared between groups of parturient ewes which could interact or not with their lamb, and virgins. In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures. We showed that the postpartum period was associated with a decrease in olfactory and hippocampal adult neurogenesis. In the olfactory bulb, the suppressive effect on neuroblasts was dependent on interactions with the young whereas in the DG the decrease in new mature neurons was associated with parturition. In addition, dendritic length and number of nodes of neuroblasts were significantly enhanced by interactions with the lamb in the olfactory bulb but not in the DG. Because interactions with the young involved learning of the olfactory signature of the lamb, we hypothesize that this learning is associated with a down-regulation in olfactory neurogenesis and an enhancement of olfactory neuroblast maturation. Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

No MeSH data available.


Related in: MedlinePlus

Effects of parturition and/or interactions with the young on cell proliferation. Densities of Ki67+ cells in the MOB (A) and in the DG (B) in the “Virgin”, “No Lamb” and “With Lamb” groups, represented as median and interquartile ranges. In both structures, the density of Ki67+ cells was significantly lower in the two parturient groups compared to “Virgin” group. * p ≤ 0.05, ** p < 0.01.
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Figure 5: Effects of parturition and/or interactions with the young on cell proliferation. Densities of Ki67+ cells in the MOB (A) and in the DG (B) in the “Virgin”, “No Lamb” and “With Lamb” groups, represented as median and interquartile ranges. In both structures, the density of Ki67+ cells was significantly lower in the two parturient groups compared to “Virgin” group. * p ≤ 0.05, ** p < 0.01.

Mentions: To evaluate the influence of parturition and interactions with the young on cell proliferation, a single immunolabeling was performed against the Ki67 protein, an endogen marker of cell division, in the MOB and the DG (Figure 5). In both the MOB and the DG, the density of Ki67+ cells significantly differed between groups (MOB: H = 6.13, p = 0.025, Figure 5A; DG: H = 7.59, p = 0.01, Figure 5B). For both structures, in the two parturient groups, the density of Ki67+ cells in the MOB was significantly lower compared to the “Virgin” group (MOB: “With Lamb” vs. “Virgin” groups: U = 2, p = 0.01; “No Lamb” vs. “Virgin” groups: U = 7, p = 0.04; DG “With Lamb” and the “Virgin” groups: U = 1, p = 0.01; “No Lamb” group vs. “Virgin” groups: U = 8, p = 0.05).


Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers.

Brus M, Meurisse M, Keller M, Lévy F - Front Behav Neurosci (2014)

Effects of parturition and/or interactions with the young on cell proliferation. Densities of Ki67+ cells in the MOB (A) and in the DG (B) in the “Virgin”, “No Lamb” and “With Lamb” groups, represented as median and interquartile ranges. In both structures, the density of Ki67+ cells was significantly lower in the two parturient groups compared to “Virgin” group. * p ≤ 0.05, ** p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927075&req=5

Figure 5: Effects of parturition and/or interactions with the young on cell proliferation. Densities of Ki67+ cells in the MOB (A) and in the DG (B) in the “Virgin”, “No Lamb” and “With Lamb” groups, represented as median and interquartile ranges. In both structures, the density of Ki67+ cells was significantly lower in the two parturient groups compared to “Virgin” group. * p ≤ 0.05, ** p < 0.01.
Mentions: To evaluate the influence of parturition and interactions with the young on cell proliferation, a single immunolabeling was performed against the Ki67 protein, an endogen marker of cell division, in the MOB and the DG (Figure 5). In both the MOB and the DG, the density of Ki67+ cells significantly differed between groups (MOB: H = 6.13, p = 0.025, Figure 5A; DG: H = 7.59, p = 0.01, Figure 5B). For both structures, in the two parturient groups, the density of Ki67+ cells in the MOB was significantly lower compared to the “Virgin” group (MOB: “With Lamb” vs. “Virgin” groups: U = 2, p = 0.01; “No Lamb” vs. “Virgin” groups: U = 7, p = 0.04; DG “With Lamb” and the “Virgin” groups: U = 1, p = 0.01; “No Lamb” group vs. “Virgin” groups: U = 8, p = 0.05).

Bottom Line: In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures.We showed that the postpartum period was associated with a decrease in olfactory and hippocampal adult neurogenesis.Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 85, Physiologie de la Reproduction et des Comportements Nouzilly, France ; CNRS, UMR 7247 Nouzilly, France ; Université François Rabelais Tours, France ; IFCE Nouzilly, France.

ABSTRACT
New neurons are continuously added in the dentate gyrus (DG) and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal maturation, the percentage of neuroblasts and new mature neurons in the olfactory bulb and the DG was compared between groups of parturient ewes which could interact or not with their lamb, and virgins. In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures. We showed that the postpartum period was associated with a decrease in olfactory and hippocampal adult neurogenesis. In the olfactory bulb, the suppressive effect on neuroblasts was dependent on interactions with the young whereas in the DG the decrease in new mature neurons was associated with parturition. In addition, dendritic length and number of nodes of neuroblasts were significantly enhanced by interactions with the lamb in the olfactory bulb but not in the DG. Because interactions with the young involved learning of the olfactory signature of the lamb, we hypothesize that this learning is associated with a down-regulation in olfactory neurogenesis and an enhancement of olfactory neuroblast maturation. Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

No MeSH data available.


Related in: MedlinePlus