Role of satellite cell-derived l-serine in the dorsal root ganglion in paclitaxel-induced painful peripheral neuropathy

Paclitaxel is one of the most commonly used antineoplastic drugs for the treatment of solid tumors. Unfortunately, its use is often associated with dose-limiting painful peripheral neuropathy and subsequent neuropathic pain that is resistant to standard analgesics. However, there are few clinically available drugs or drug classes for the treatment of paclitaxel-induced neuropathy due to a lack of information regarding the mechanisms responsible for it. In this study, we examined the involvement of L-serine in paclitaxel-induced hyperalgesia/allodynia and decrease in sensory nerve conduction velocity (SNCV). We used a preclinical rat model of paclitaxel-induced painful peripheral neuropathy. Response to von Frey filaments, SNCV, 3-phosphoglycerate dehydrogenase (3PGDH) expression, and L-serine concentration were examined. Effects of L-serine administration were also investigated. Paclitaxel treatment induced mechanical allodynia/hyperalgesia and reduction of SNCV. Paclitaxel also decreased the L-serine concentration in the dorsal root ganglion (DRG) but not in the sciatic nerve or spinal cord. In addition, paclitaxel decreased expression of 3PGDH, a biosynthetic enzyme of L-serine, in the DRG. Immunohistochemistry showed that 3PGDH was localized in satellite cells but not in neurons in the DRG. Intraperitoneal administration of L-serine improved both paclitaxel-induced mechanical allodynia/hyperalgesia and the reduction of SNCV. These results suggest that satellite cell-derived L-serine in the DRG plays an important role in paclitaxel-induced painful peripheral neuropathy. These findings may lead to novel strategies for the treatment of paclitaxel-induced painful peripheral neuropathy.ArticleNEUROSCIENCE. 174(0):190-199 (2011)journal articl

Effects of Escitalopram on Sign-Tracking

Sign tracking is a phenomenon in organisms in which they are likely to approach a cue for appetitive stimuli. This behavior is important in drug addiction and likelihood of relapse. The aim of the current 32 study is to examine the sign tracking and goal tracking behaviors of rats when different doses of Escitalopram are administered to them. We hypothesize that sign tracking behaviors will decrease when Escitalopram is administered. Subjects are 31 male Sprague Dawley rats. Sign and goal tracking behaviors are measured using operant chambers. Upon analyzing the data with a repeated measures ANOVA, we found that among the strongest sign trackers, administration of escitalopram reduced their sign tracking as hypothesized. Implications of these findings can be applied to drug addiction rehabilitation and relapse in humans. Further research needs to be done, but SSRIs may be an effective adjunctive treatment for drug addiction

Effects of Memantine on Sign-Tracking

Sign tracking is an organism approaching a signal for an appetitive stimulus. An example of this in humans is an addict interacting with drug paraphernalia when coming across it without consciously understanding why or knowingly intending to get high. This contributes to relapse and finding a pharmaceutical that reduces sign tracking could help addicts in recovery. We replicated this kind of signtracking in rats and administered three different doses of Memantine to test how this affects their signtracking. We first got the rats to associate a lever popping out with a treat pellet being given. We tracked how often the rats interreacted with the lever and food receptacle to determine if they are signtrackers (interact a lot with the lever) goal-trackers (interact a lot with the food receptacle) or Intermediate (Interacted with both).A mixed model ANOVA showed a significant interaction between dose and behavioral phenotype, but post hoc test showed no significant differences between pairs. These results are unusual but promising and more research is needed

Dance Type and Flight Parameters Are Associated with Different Mushroom Body Neural Activities in Worker Honeybee Brains

Background: Honeybee foragers can transmit the information concerning the location of food sources to their nestmates using dance communication. We previously used a novel immediate early gene, termed kakusei, to demonstrate that the neural activity of a specific mushroom body (MB) neuron subtype is preferentially enhanced in the forager brain. The sensory information related to this MB neuron activity, however, remained unclear. Methodology/Principal Findings: Here, we used kakusei to analyze the relationship between MB neuron activity and types of foraging behavior. The number of kakusei-positive MB neurons was higher in the round dancers that had flown a short distance than in the waggle dancers that had flown a long distance. Furthermore, the amount of kakusei transcript in the MBs inversely related to the waggle-phase duration of the waggle dance, which correlates with the flight distance. Using a narrow tunnel whose inside was vertically or axially lined, we manipulated the pattern of visual input, which is received by the foragers during flight, and analysed kakusei expression. The amount of kakusei transcript in the MBs was related to the foraging frequency but not to the tunnel pattern. In contrast, the number of kakusei-positive MB neurons was affected by the tunnel patterns, but not related to foraging frequency. Conclusions/Significance: These results suggest that the MB neuron activity depends on the foraging frequency, whereas the number of active MB neurons is related to the pattern of visual input received during foraging flight. Our results sugges

An Analysis of Uniform Shear Flow Past a Porous Plate Attached to a Plane Surface

This is a good first study on the applicability of the wake-source model to shear flow around and through a screen. Since previous work [4] dealt with uniform flow, the authors have properly chosen shear flow as the next step in extending the work. Moreover, shear flow is probably more important than uniform flow in practical situations, and so this study should be of interest to designers who need quantitative information on the effectiveness of wind breaks and the like. To be truly useful, however, this study should be continued in order to vary plate porosity and wind shear rate. The present experiments were carried out for a single plate and for one upstream velocity profile. The pressure-drop coefficient K for the plate was 18.1, which is higher than values for normal porous materials like woven screens, and the average shear rate G of the velocity profile was 216 s" 1 , which corresponds to a moderate 53 percent change in velocity from the bottom to the top of the screen. These conditions produced a downstream velocity profile that was satisfactorily predicted by the wake-source model, but this tells us little about the accuracy of the model for other conditions. Additional experimental results would not only establish the range of validity of the model but would also provide useful data for design purposes. For the latter, the quantity of interest is likely the reduction of velocity produced by the windbreak, and thus it would be beneficial to have a plot, say, of mean velocity reduction as a function of the screen coefficient K, with G as a free parameter. I hope the present work is the initial step in an endeavour of this sort. The authors do, in fact, infer that the study is being continued and to that end I would suggest several changes in future work. First, the mapping of the velocity field upstream of the plate is presently incomplete and the matching location too arbitrary. It would be interesting to learn, for example, the effect on predicted downstream profile if the matching were carried out at x/h = -1.1, say, and not at x/h = -2.2. Secondly, it should be straightforward to measure the plate's pressure-drop coefficient and so verify the value calculated in the text. Finally, it would be useful to investigate non-uniform shear flows. Uniform shear is the logical case after uniform flow, as mentioned above, but it is not true that the theory demands a uniform shear flow which has a constant vorticity. The model requires only that the flow be inviscid, not irrotational. Consequently the approaching flow may hav

Identification of novel bombyxin genes from the genome of the silkmoth bombyx mori and analysis of their expression

Insulin family peptide members play key roles in regulating growth, metabolism, and reproduction. Bombyxin is an insulin-related peptide of the silkmoth Bombyx mori. We analyzed the full genome of B. mori and identified five novel bombyxin families, V to Z. We characterized the genomic organization and chromosomal location of the novel bombyxin family genes. In contrast to previously identified bombyxin genes, bombyxin-V and -Z genes had intervening introns at almost the same positions as vertebrate insulin genes. We performed reverse transcription-polymerase chain reaction and in situ hybridization in different tissues and developmental stages to observe their temporal and spatial expression patterns. The newly identified bombyxin genes were expressed in diverse tissues: bombyxin-V, -W, and -Y mRNAs were expressed in the brain and bombyxin-X mRNA in fat bodies. Bombyxin-Y gene was expressed in both brain and ovary of larval stages. High level of bombyxin-Z gene expression in the follicular cells may suggest its function in reproduction. The presence of a short C-peptide domain and an extended A chain domain, and high expression of bombyxin-X gene in the fat body cells during non-feeding stages suggest its insulin-like growth factor-like function. These results suggest that the bombyxin genes originated from a common ancestral gene, similar to the vertebrate insulin gene, and evolved into a diverse gene family with multiple functions. © 2011 Zoological Society of Japan

Detection of Neural Activity in the Brains of Japanese Honeybee Workers during the Formation of a “Hot Defensive Bee Ball”

Anti-predator behaviors are essential to survival for most animals. The neural bases of such behaviors, however, remain largely unknown. Although honeybees commonly use their stingers to counterattack predators, the Japanese honeybee (Apis cerana japonica) uses a different strategy to fight against the giant hornet (Vespa mandarinia japonica). Instead of stinging the hornet, Japanese honeybees form a “hot defensive bee ball” by surrounding the hornet en masse, killing it with heat. The European honeybee (A. mellifera ligustica), on the other hand, does not exhibit this behavior, and their colonies are often destroyed by a hornet attack. In the present study, we attempted to analyze the neural basis of this behavior by mapping the active brain regions of Japanese honeybee workers during the formation of a hot defensive bee ball. First, we identified an A. cerana homolog (Acks = Apis cerana kakusei) of kakusei, an immediate early gene that we previously identified from A. mellifera, and showed that Acks has characteristics similar to kakusei and can be used to visualize active brain regions in A. cerana. Using Acks as a neural activity marker, we demonstrated that neural activity in the mushroom bodies, especially in Class II Kenyon cells, one subtype of mushroom body intrinsic neurons, and a restricted area between the dorsal lobes and the optic lobes was increased in the brains of Japanese honeybee workers involved in the formation of a hot defensive bee ball. In addition, workers exposed to 46°C heat also exhibited Acks expression patterns similar to those observed in the brains of workers involved in the formation of a hot defensive bee ball, suggesting that the neural activity observed in the brains of workers involved in the hot defensive bee ball mainly reflects thermal stimuli processing

Motion of a vortex sheet on a sphere with pole vortices

We cons i der the motion of a vortex sheet on the surface of a unit sphere in the presence of point vortices xed on north and south poles.Analytic and numerical research revealed that a vortex sheet in two-dimensional space has the following three properties.First,the vortex sheet is linearly unstable due to Kelvin-Helmholtz instability.Second,the curvature of the vortex sheet diverges in nite time.Last,the vortex sheet evolves into a rolling-up doubly branched spiral,when the equation of motion is regularized by the vortex method.The purpose of this article is to investigate how the curvature of the sphere and the presence of the pole vortices

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries