Neonatal Handling Affects Durably Bonding and Social Development

The neonatal period in humans and in most mammals is characterized by intense mother-young interactions favoring pair bonding and the adaptation of neonates to their new environment. However, in many post-delivery procedures, human babies commonly experience combined maternal separation and intense handling for about one hour post-birth. Currently, the effects of such disturbances on later attachment and on the development of newborns are still debated: clearly, further investigations are required. As animals present good models for controlled experimentation, we chose domestic horses to investigate this issue. Horses, like humans, are characterized by single births, long lactating periods and selective mother-infant bonds. Routine postnatal procedures for foals, as for human babies, also involve intense handling and maternal separation. In the present study, we monitored the behavior of foals from early stages of development to “adolescence”, in a normal ecological context (social groups with adults and peers). Experimental foals, separated from their mothers and handled for only 1 hour post-birth, were compared to control foals, left undisturbed after birth. Our results revealed short- and long-term effects of this unique neonatal experience on attachment and subsequent social competences. Thus, experimental foals presented patterns of insecure attachment to their mothers (strong dependence on their mothers, little play) and impaired social competences (social withdrawal, aggressiveness) at all ages. We discuss these results in terms of mother-young interactions, timing of interactions and relationships between bonding and subsequent social competences. Our results indicate that this ungulate species could become an interesting animal model. To our knowledge, this is the first clear demonstration that intervention just after birth affects bonding and subsequent social competences (at least until “adolescence”). It opens new research directions for studies on both humans and other animals

Absence of Both IL-7 and IL-15 Severely Impairs the Development of CD8+ T Cell Response against Toxoplasma gondii

CD8+ T cells play an essential role in the protection against both acute as well as chronic Toxoplasma gondii infection. Although the role of IL-15 has been reported to be important for the development of long-term CD8+ T cell immunity against the pathogen, the simultaneous roles played by both IL-15 and related γ-chain family cytokine IL-7 in the generation of this response during acute phase of infection has not been described. We demonstrate that while lack of IL-7 or IL-15 alone has minimal impact on splenic CD8+ T cell maturation or effector function development during acute Toxoplasmosis, absence of both IL-7 and IL-15 only in the context of infection severely down-regulates the development of a potent CD8+ T cell response. This impairment is characterized by reduction in CD44 expression, IFN-γ production, proliferation and cytotoxicity. However, attenuated maturation and decreased effector functions in these mice are essentially downstream consequences of reduced number of antigen-specific CD8+ T cells. Interestingly, the absence of both cytokines did not impair initial CD8+ T cell generation but affected their survival and differentiation into memory phenotype IL-7Rαhi cells. Significantly lack of both cytokines severely affected expression of Bcl-2, an anti-apoptotic protein, but minimally affected proliferation. The overarching role played by these cytokines in eliciting a potent CD8+ T cell immunity against T. gondii infection is further evidenced by poor survival and high parasite burden in anti IL-7 treated IL-15−/− mice. These studies demonstrate that the two cytokines, IL-7 and IL-15, are exclusively important for the development of protective CD8+ T cell immune response against T. gondii. To the best of our knowledge this synergism between IL-7 and IL-15 in generating an optimal CD8+ T cell immunity against intracellular parasite or any other infectious disease model has not been previously reported

10 mu m ethylene: spectroscopy, intensities and a planetary modeler's atlas

FTS and TDL spectra of ethylene in the 10 mum region have been observed, measured, calibrated, assigned and intensities have been measured. The ultimate goal of this work is the production of a planetary modeler's atlas. A spectrum taken in double-pass configuration at the McMath-Pierce FTS instrument at Kitt Peak National Observatory has been frequency calibrated using CO2 laser bands. Results of a previous analysis (Cauuet et al., J Mol Spectrosc 1990;139:191) have enabled the assignment of the FTS spectrum wherein we have measured over 500 line intensities in the 900-1000 cm(-1) region. These FTS intensities have been calibrated against 13 isolated transitions, taken as secondary intensity standards. These standard lines have been measured independently using TDL (tunable-diode-laser) spectrometers at University of Tennessee and Goddard Space Flight Center. A calculated spectrum, including mixing coefficients for v(4), v(7), v(10) and v(12), and calculated relative intensities, and the TDL-calibrated FTS line intensities were used as data in a non-linear regression analysis to determine the 296 K vibrational band intensities of S-0-7(v) = 321.69 +/- 0.36 cm(-1)/cm atm, S-0-10(v) = 1.16 +/- 0.47 cm(-1)/cm atm, and S-0-12(v) = 31.60 +/- 9.80 cm(-1)/cm atm. These vibrational band intensities combined with the theoretical spectral-line atlas make possible the generation of an ethylene spectrum at an arbitrary temperature. Such spectra prove useful to the planetary-atmosphere modeling-community. A web site is available where an individual can interact with the model and download a custom atlas. The URL is http://aurora.phys.utk.edu/(similar to)blass/ethyatl/. (C) 2001 Elsevier Science Ltd. All rights reserved