The effect of rearing experience and TPH2 genotype on HPA axis function and aggression in rhesus monkeys: A retrospective analysis

Gene-environment (G × E) interactions contribute to the development of many neuropsychiatric disorders. Tryptophan hydroxylase-2 (TPH2) synthesizes neuronal serotonin and is closely related to the hypothalamic-pituitary-adrenal (HPA) axis, while early life experience is a critical environmental factor programming the HPA axis response to stress. This retrospective study investigated G × E interaction at the TPH2 locus in rhesus monkeys. Twenty-eight adult, male rhesus monkeys of Indian origin, either mother-reared or peer-reared as infants, were involved in this study. These monkeys have been previously genotyped for the functional A2051C polymorphism in rhTPH2, and had been physiologically and behaviorally characterized. rhTPH2 A2051C exerted a significant main effect (CC > AA&AC) on the cerebrospinal fluid (CSF) level of 5-hydroxyindole-3-acetic acid (5-HIAA; F_(1,14) = 6.42, p = 0.024), plasma cortisol level in the morning (F_(1,18) = 14.63, p = 0.002) and cortisol response to ACTH challenge (F_(1,17) = 6.87, p = 0.018), while the rearing experience showed a significant main effect (PR > MR) on CSF CRH (F_(1,20) = 11.66, p = 0.003) and cage shaking behavior (F_(1,27) = 4.45, p = 0.045). The effects of rhTPH2 A2051C on the afternoon cortisol level, plasma ACTH level, dexamethasone suppression of urinary cortisol excretion, and aggression were dependent upon the rearing experience. These results were not confounded by the functional C77G polymorphism in the mu-opioid receptor (MOR). The present study supports the hypothesis that rearing experience and rhTPH2 A2051C interact to influence central 5-HT metabolism, HPA axis function, and aggressive behaviors. Our findings strengthen the involvement of G × E interactions at the loci of serotonergic genes and the utility of the nonhuman primate to model G × E interactions in the development of human neuropsychiatric diseases.     

Development of a novel neodymium compound for in vivo fluorescence imaging.

We developed a novel fluorescent probe that contains the neodymium(III) complex moiety and fluorescein moiety. This probe can emit long-lived near-infrared luminescence derived from a Nd ion through excitation of the fluorescein moiety with visible light (lambda(ex) = 488 nm, lambda(em) = 880 nm, lifetime = 2.3 micros). These results indicate the possibility of the probe as a candidate for in vivo fluorescence molecular imaging.     

Prediction of possible sites for posttranslational modifications in human gamma crystallins: effect of glycation on the structure of human gamma-B-crystallin as analyzed by molecular modeling

Crystallins are recognized as one of the long-lived proteins of lens tissue that might serve as the target for several posttranslational modifications leading to cataract development. We have studied several such sites present in the human gamma-crystallins based either on PROSITE pattern search results or earlier experimental evidences. Their probabilities were examined on the basis of the database analysis of the gamma-crystallin sequences and on their specific locations in the constructed homology models. An N-glycosylation site in human gammaD-crystallin and several phosphorylation sites in all four human gamma-crystallins were predicted by the PROSITE search. Some of these sites were found to be strongly conserved in the gamma-crystallin sequences from different sources. An extensive analysis of these sites was performed to predict their probabilities as potential sites for protein modifications. Glycation studies were performed separately by attaching sugars to the human gammaB-crystallin model, and the effect of binding was analyzed. The studies showed that the major effect of alphaD-glucose (alphaD-G) and alphaD-glucose-6-phosphate (alphaD-G6P) binding was the disruption of charges not only at the surface but also within the molecule. Only a minor alteration in the distances of sulfhydryl groups of cysteines and on their positions in the three-dimensional models were observed, leading us to assume that glycation alone is not responsible for intra- and intermolecular disulfide bond formation.     

Finding meaning in first episode psychosis: experience, agency, and the cultural repertoire

The article examines individuals' attempts to generate meaning following their experiences with psychosis. The inquiry is based on a person-centered ethnographic study of a Danish mental health community program for early intervention in schizophrenia and involves longitudinal interviews with 15 of its participants. The article takes an existential anthropological perspective emphasizing agency and cultural phenomenology to investigate how individuals draw on resources from the cultural repertoire to make sense of personally disturbing experiences during their psychosis. It is suggested that the concept of "system of explanation" has advantages over, for example, "illness narrative" and "explanatory model" when demonstrating how some individuals engage in the creative analytic and theory-building work of bricolage, selecting, adding, and combining various systems of explanation. Delusions are equally derived from the cultural repertoire but are constructed as dogmatic explanations that are idiosyncratic to the individual who holds them.     

New spines, new memories

For more than a century dendritic spines have been a source of fascination and speculation. The long-held belief that these anatomical structures are involved in learning and memory are addressed. Specifically, two lines of evidence that support this claim are reviewed. In the first, we review evidence that experimental manipulations that affect dendritic spine number in the hippocampus also affect learning processes of various sorts. In the second, we review evidence that learning itself affects the presence of dendritic spines in the hippocampus. Based on these observations, we propose that the presence of spines enhances synaptic efficacy and thereby the excitability of the network involved in the learning process. With this scheme, learning is not dependent on changes in spine density but rather changes in the presence of dendritic spines provide anatomical support for the processing of novel information used in memory formation.     

Prey selection by experienced and naive juvenile Atlantic salmon

Both in foraging groups and in a sequential prey encounter context, learning had a visible effect on the pattern of selection for three live prey types ( Ecdyonurus larvae, Hydropsyche larvae, and Gammarus ) by juvenile Atlantic salmon Salmo salar . Compared to wild-caught fish, naive, hatchery-reared fish that had not been exposed to natural prey ate Hydropsyche larvae in a remarkably low proportion, and consumed a higher proportion of Gammarus. Ecdyonurus experienced a high and rather steady predation rate across the experience gradient, but after a short period of experience with live prey the consumption rate for Hydropsyche increased drastically, and that of Gammarus decreased, matching the selection pattern exhibited by wild fish. Individual fish offered prey in a sequential encounter context increased consumption rates of all the prey types as they gained experience, but the improvement was higher for the prey that were less consumed initially. Fish became more selective as they approached satiation, conforming to the prediction of optimal foraging theory that higher predator's energy requirements, as well as low food availability, result in reduced selectivity. The results also suggest that fish from distinct populations can differ in the degree of diet selectivity according to their energetic requirements for growth. The fast learning response of Atlantic salmon parr towards novel prey probably allows fish to maintain a high foraging efficiency when faced with frequent changes in the availability of different prey types.     

Sex differences in foraging behaviour and oviposition site preference in an insect predator, Orius sauteri

The effects of patch quality on the foraging behaviour of an anthocorid predator Orius sauteri (Poppius) were compared between sexes. Prior experience in patches was also studied to determine whether this was a factor affecting oviposition decisions. Patch quality affected patch residence time differently for the two sexes; females stayed much longer in a patch with prey (60 Thrips palmi larvae) than a patch without prey, while males did not remain in any patch for extended periods. Most of the females remained in or moved to patches with prey, whereas males dispersed, irrespective of patch quality. Both females released in patches with prey and females released in patches without prey deposited more eggs per hour in patches with prey than in patches without prey. Females released in patches without prey laid eggs in patches with prey at higher rates than did females released in patches with prey. Causes for the sex difference in patch residence time and allocation are discussed in relation to optimal foraging theory. The significance of selective oviposition and the role of experience in oviposition decisions within heterogeneous environments are also discussed.     

Experience of natural prey and feeding efficiency in three-spined sticklebacks (Gasterosteus aculeatus L.)

The possibility that efficiency of feeding on different prey in three-spined sticklebacks ( Gasterosteus aculeatus L.) increases by experience of such items was investigated experimentally by comparing sticklebacks reared with only non-moving prey (frozen brine shrimps) with sticklebacks caught in the wild from localities where a wide range of prey species was available. Fish without experience of natural food scored less well than those from the wild on various components of foraging and so had reduced feeding efficiency. However, feeding efficiency in naive fish improved after just a few days of experience with natural prey. Such experience-induced changes in foraging efficiency will alter the profitability of prey items for individual fish.     

Olfactory Associative Learning of the Pupal Parasitoid Pimpla luctuosa Smith (Hymenoptera: Ichneumonidae)

Laboratory experiments were conducted to determine the role of learning in olfactory host searching by the ichneumonid pupal parasitoid, Pimpla luctuosa Smith. Females learned to associate novel odors such as vanilla and strawberry with hosts when they oviposited in at least several hosts with the odors. Repeated experiences of hosts with an odor increased the response of the experienced odor, and females that had experienced host odor seven times responded to the experienced odors 90% of the time. Although the response by females to a learned odor gradually decreased with increasing host-deprivation time, 60% of the females that had experienced host odor 7 days earlier still responded to the experienced odor. Females also learned two separate odors associated with hosts at a time and responded to both odors without a preference for one odor over the other. When trained two separate odors with hosts, females learned the second odor more quickly than the first odor. After females experienced several stings in simulated hosts with the previously learned odor, they ceased to respond to the learned odor, suggesting that repeated unrewarding experiences cause females to cease to respond to the learned odors.     

Environmental predictability and remating in European blackbirds

We studied mate and site fidelity between years in an Englishpopulation of blackbirds (Turdus merula) from 1985 to 1991.Divorce was observed in 32% of 183 cases where mates had survivedfrom the previous breeding season. After divorces, females tendedto nest farther from their original site than males did, butthere was no sex difference in distance moved after the deathof a mate. The mean annual fledgling production of 60 m x 60m breeding sites was statistically repeatable among years, evenafter accounting for possible differences in reproductive performanceamong site-tenacious individuals. Divorce rates were greatestin low-quality sites. We found no annual fitness cost associatedwith mating with an unfamiliar bird. However, breeding in anew site cost on average one fledgling per year.