From Antenna to Antenna: Lateral Shift of Olfactory Memory Recall by Honeybees

Honeybees, Apis mellifera, readily learn to associate odours with sugar rewards and we show here that recall of the olfactory memory, as demonstrated by the bee extending its proboscis when presented with the trained odour, involves first the right and then the left antenna. At 1–2 hour after training using both antennae, recall is possible mainly when the bee uses its right antenna but by 6 hours after training a lateral shift has occurred and the memory can now be recalled mainly when the left antenna is in use. Long-term memory one day after training is also accessed mainly via the left antenna. This time-dependent shift from right to left antenna is also seen as side biases in responding to odour presented to the bee's left or right side. Hence, not only are the cellular events of memory formation similar in bees and vertebrate species but also the lateralized networks involved may be similar. These findings therefore seem to call for remarkable parallel evolution and suggest that the proper functioning of memory formation in a bilateral animal, either vertebrate or invertebrate, requires lateralization of processing

Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids

Background While bilaterality is a defining characteristic of triploblastic animals, several assemblages have managed to break this symmetry in order to exploit the adaptive peaks garnered through the lateralization of behaviour or morphology. One striking example of an evolved asymmetry in vertebrates comes from a group of scale-eating cichlid fishes from Lake Tanganyika. Members of the Perissodini tribe of cichlid fishes have evolved dental and craniofacial asymmetries in order to more effectively remove scales from the left or right flanks of prey. Here we examine the evolution and development of craniofacial morphology and laterality among Lake Tanganyika scale-eating cichlids. Results Using both geometric and traditional morphometric methods we found that the craniofacial evolution in the Perissodini involved discrete shifts in skeletal anatomy that reflect differences in habitat preference and predation strategies. Further, we show that the evolutionary history of the Perissodini is characterized by an accentuation of craniofacial laterality such that certain taxa show elaborate sided differences in craniofacial shape consistent with the sub-partitioning of function between sides of the head during attacks. Craniofacial laterality in the scale-eating specialist Perissodus microlepis was found to be evident early in development and exhibited a unimodal distribution, which is contrary to the adult condition where jaw laterality has been described as a discrete, bimodal antisymmetry. Finally, using linkage and association analyses we identified a conserved locus for jaw handedness that segregates among East African cichlids. Conclusions We suggest that, during the evolution of the Perissodini, selection has accentuated a latent, genetically determined handedness of the craniofacial skeleton, enabling the evolution of jaw asymmetries in order to increase predation success. Continued work on the developmental genetic basis of laterality in the Perissodini will facilitate a better understanding of the evolution of this unique group of fishes, as well as of left-right axis determination among vertebrates in general

Treatment of pregnancy-related pelvic girdle and/or low back pain after delivery design of a randomized clinical trial within a comprehensive prognostic cohort study [ISRCTN08477490]

<p>Abstract</p> <p>Background</p> <p>Pregnancy-related pelvic girdle and/or low back pain is a controversial syndrome because insight in etiology and prognosis is lacking. The controversy relates to factors eliciting pain and some prognostic factors such as the interpretation of pain at the symphysis. Recent research about treatment strategies also reflects those various opinions, in fact suggesting there is professional uncertainty about the optimal approach. Currently, physiotherapists often prescribe a pain-contingent treatment regime of relative rest and avoiding several day-to-day activities. Additionally, treatment more often includes an exercise program to guide rectification of the muscle imbalance and alignment of the pelvic girdle. Effectiveness of those interventions is not proven and the majority of the studies are methodologically flawed. Investigators draw particular attention to biomedical factors but there is growing evidence that important prognostic issues such as biopsychosocial factors appear to be even more important as point of action in a treatment program.</p> <p>Methods/design</p> <p>This pragmatic randomized controlled trial is designed to evaluate the effectiveness of a tailor-made treatment program with respect to biopsychosocial factors in primary care. The effect of the experimental intervention and usual care are evaluated as they are applied in primary health care. The trial is embedded in a cohort study that is designed as a longitudinal, prospective study, which studies prevalence, etiology, severity and prognosis during pregnancy until one year after delivery. The present paper focuses on choices regarding recruitment procedures, in-/exclusion criteria and the development of a well-timed intervention.</p> <p>Discussion</p> <p>This section briefly discusses the actions taken to minimize bias in the design, the proper time-window for the experimental intervention and the contrast between the experimental intervention and usual care.</p

Additional tracer injection to improve the technical success rate of lymphoscintigraphy for sentinel node biopsy in breast cancer

BACKGROUND: Sentinel node (SN) biopsy has become the standard of care in the treatment of breast cancer. The aim of this study is to determine the value of additional tracer injection to increase the technical success rate of the SN procedure and to identify factors that influence the ability to visualize hotspots. METHODS: From February 1997 to August 2007, 1,208 clinically node-negative breast cancer patients underwent lymphatic mapping for SN biopsy. The technique involved the injection of 370 MBq (10 mCi) Tc-99 m-nanocolloid peritumorally. In case of insufficient or absent visualization of hotspots 37 MBq (1 mCi) of additional tracer was given intracutaneously above the tumor. RESULTS: In 93 patients (7.7%) visualization of hotspots on initial lymphoscintigraphy was insufficient (41 patients) or absent (52 patients). The first 14 patients did not receive additional tracer injection. In five patients, additional tracer did not result in successful lymphoscintigraphy, which is correlated with massive nodal tumor infiltration. In 33 patients with negative initial lymphoscintigraphy, additional tracer injection resulted in secondary SN visualization. In 41 patients with faint hotspots on initial lymphoscintigraphy, additional tracer injection, by increasing nodal uptake, simplified accurate SN biopsy. Decreased radiotracer uptake in this group was associated with older age and high body mass index (BMI). CONCLUSIONS: Additional tracer injection following initial scan failure increases the success rate of lymphoscintigraphy during lymphatic mapping in breast cancer, without compromising accuracy. If additional tracer injection does not result in secondary SN visualization, gross nodal tumor involvement is often present and axillary lymph node dissection (ALND) is mandatory

Conserved effects of salinity acclimation on thermal tolerance and hsp70 expression in divergent populations of threespine stickleback (Gasterosteus aculeatus)

In natural environments, organisms must cope with complex combinations of abiotic stressors. Here, we use threespine stickleback (Gasterosteus aculeatus) to examine how changes in salinity affect tolerance of high temperatures. Threespine stickleback inhabit a range of environments that vary in both salinity and thermal stability making this species an excellent system for investigating interacting stressors. We examined the effects of environmental salinity on maximum thermal tolerance (CTMax) and 70 kDa heat shock protein (hsp70) gene expression using divergent stickleback ecotypes from marine and freshwater habitats. In both ecotypes, the CTMax of fish acclimated to 20 ppt was significantly higher compared to fish acclimated to 2 ppt. The effect of salinity acclimation on the expression of hsp70-1 and hsp70-2 was similar in both the marine and freshwater stickleback ecotype. There were differences in the expression profiles of hsp70-1 and hsp70-2 during heat shock, with hsp70-2 being induced earlier and to a higher level compared to hsp70-1. These data suggest that the two hsp70 isoforms may have functionally different roles in the heat shock response. Lastly, acute salinity challenge coupled with heat shock revealed that the osmoregulatory demands experienced during the heat shock response have a larger effect on the hsp70 expression profile than does the acclimation salinity