Bursty spike trains of antennal thermo- and bimodal hygro-thermoreceptor neurons encode noxious heat in elaterid beetles.

The main purpose of this study was to explain the internal fine structure of potential antennal thermo- and hygroreceptive sensilla, their innervation specifics, and responses of the sensory neurons to thermal and humidity stimuli in an elaterid beetle using focused ion beam scanning electron microscopy and electrophysiology, respectively. Several essential, high temperature induced turning points in the locomotion were determined using automated video tracking. Our results showed that the sensilla under study, morphologically, are identical to the dome-shaped sensilla (DSS) of carabids. A cold-hot neuron and two bimodal hygro-thermoreceptor neurons, the moist-hot and dry-hot neuron, innervate them. Above 25-30 °C, all the three neurons, at different threshold temperatures, switch from regular spiking to temperature dependent spike bursting. The percentage of bursty DSS neurons on the antenna increases with temperature increase suggesting that this parameter of the neurons may encode noxious heat in a graded manner. Thus, we show that besides carabid beetles, elaterids are another large group of insects with this ability. The threshold temperature of the beetles for onset of elevated locomotor activity (OELA) was lower by 11.9 °C compared to that of critical thermal maximum (39.4 °C). Total paralysis occurred at 41.8 °C. The threshold temperatures for spike bursting of the sensory neurons in DSS and OELA of the beetles coincide suggesting that probably the spike bursts are responsible for encoding noxious heat when confronted. In behavioural thermoregulation, spike bursting DSS neurons serve as a fast and firm three-fold early warning system for the beetles to avoid overheating and death.

Encoding noxious heat by spike bursts of antennal bimodal hygroreceptor (dry) neurons in the carabid Pterostichus oblongopunctatus.

Despite thermosensation being crucial in effective thermoregulation behaviour, it is poorly studied in insects. Very little is known about encoding of noxious high temperatures by peripheral thermoreceptor neurons. In carabids, thermo- and hygrosensitive neurons innervate antennal dome-shaped sensilla (DSS). In this study, we demonstrate that several essential fine structural features of dendritic outer segments of the sensory neurons in the DSS and the classical model of insect thermo- and hygrosensitive sensilla differ fundamentally. Here, we show that spike bursts produced by the bimodal dry neurons in the antennal DSS may contribute to the sensation of noxious heat in P. oblongopunctatus. Our electrophysiological experiments showed that, at temperatures above 25 °C, these neurons switch from humidity-dependent regular spiking to temperature-dependent spike bursting. Five out of seven measured parameters of the bursty spike trains, the percentage of bursty dry neurons, the CV of ISIs in a spike train, the percentage of bursty spikes, the number of spikes in a burst and the ISIs in a burst, are unambiguously dependent on temperature and thus may precisely encode both noxious high steady temperatures up to 45 °C as well as rapid step-changes in it. The cold neuron starts to produce temperature-dependent spike bursts at temperatures above 30-35 °C. Thus, the two neurons encode different but largely overlapping ranges in noxious heat. The extent of dendritic branching and lamellation of the neurons largely varies in different DSS, which might be the structural basis for their variation in threshold temperatures for spike bursting.

Behavioural effects of the neonicotinoid insecticide thiamethoxam on the predatory insect Platynus assimilis.

Little information is available regarding sublethal effects of neonicotinoids on insect predators, many of which perform important roles in ecosystem functioning and biocontrol. In this study, dose-dependent sublethal effects of a dietary administered neonicotinoid insecticide thiamethoxam on two basic behaviours, locomotion and feeding, were quantified in the carabid Platynus assimilis (Coleoptera, Carabidae) using automated video-tracking and weighing of consumed food, respectively. Acute toxicity tests showed that, when orally administered, the LD50 of thiamethoxam for P. assimilis beetles was 114.5 ng/g. Thiamethoxam at 108.1 ng/g caused a short-term locomotor hyperactivity within several hours of treatment. Next day after exposure to the insecticide, all the beetles were in a state of locomotor hypoactivity independent of the administered dose ranging from 1.1 to 108.1 ng/g. Reduction in clean food consumption rate (CFCR) is another altered behavioural endpoint of poisoned insect predators as first demonstrated in this study. On the first day of thiamethoxam administration, a remarkable reduction in feeding only occurred in beetles treated at 108.1 ng/g but on the next day, this negative effect appeared even at doses ten to a hundred-fold lower. Recovery from locomotion abnormalities and reduced feeding took several days. Both locomotor activity and CFCR are sensitive and valuable ecotoxicological biomarkers of carabids which should be taken into account in Integrated Pest Management programs where optimal combination of reduced insecticide use and biological control by predatory insects is crucial to achieve best results.

The opening-closing rhythms of the subelytral cavity associated with gas exchange patterns in diapausing Colorado potato beetle, Leptinotarsa decemlineata.

The opening-closing rhythms of the subelytral cavity and associated gas exchange patterns were monitored in diapausing Leptinotarsa decemlineata beetles. Measurements were made by means of a flow-through CO2 analyser and a coulometric respirometer. Under the elytra of these beetles there is a more or less tightly enclosed space, the subelytral cavity (SEC). When the cavity was tightly closed, air pressure inside was sub-atmospheric, as a result of oxygen uptake into the tracheae by the beetle. In about half of the beetles, regular opening-closing rhythms of the SEC were observed visually and also recorded; these beetles displayed a discontinuous gas exchange pattern. The SEC opened at the start of the CO2 burst and was immediately closed. On opening, a rapid passive suction inflow of atmospheric air into the SEC occurred, recorded coulometrically as a sharp upward peak. As the CO2 burst lasted beyond the closure of the SEC, we suggest that most of the CO2 was expelled through the mesothoracic spiracles. In the remaining beetles, the SEC was continually semi-open, and cyclic gas exchange was exhibited. The locking mechanisms and structures between the elytra and between the elytra and the body were examined under a stereomicroscope and by means of microphotography. We conclude that at least some of the L. decemlineata diapausing beetles were able to close their subelytral cavity tightly, and that the cavity then served as a water-saving device.

Low doses of the common alpha-cypermethrin insecticide affect behavioural thermoregulation of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

Sub-lethal effects of pesticides on behavioural endpoints are poorly investigated in non-targeted beneficial carabids. Conspicuous changes in locomotor activity of carabids exposed to sub-lethal doses of neurotoxic insecticides suggest that many other behaviours of these insects might be severely injured as well. We hypothesize that behavioural thermoregulation of carabids may be affected by low doses of neurotoxic pyrethroid insecticide alpha-cypermethrin which may have direct deleterious consequences for the fitness and populations of the beetles in the field. Automated video tracking of the carabid beetle Platynus assimilis Paykull (Coleoptera: Carabidae) on an experimental thermal mosaic arena using EthoVision XT Version 9 software (Noldus Information Technology, Wageningen, The Netherlands) showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations (0.1-10mgL(-1)) drastically reduces the ability of the beetles for behavioural thermoregulation. At noxious high temperature, a considerable number of the beetles died due to thermo-shock. Other intoxicated beetles that survived exposure to high temperature displayed behavioural abnormalities. During heating of the arena from 25 to 45°C, insecticide treated beetles showed a significant fall in tendency to hide in a cool shelter (20°C) and prolonged exposure to noxious high temperatures, accompanied by changes in locomotor activity. Next day after insecticide treatment the beetles recovered from behavioural abnormalities to a large extent but they still were considerably longer exposed to noxious high temperatures compared to the negative control beetles. Our results demonstrated that behavioural thermoregulation is a sensitive and important etho-toxicological biomarker in ground-dwelling carabids. Prolonged exposure to unfavourably high temperatures has an array of negative effects decreasing fitness and survival of these insects at elevated thermal conditions with deep temperature gradients, typical of agricultural habitats. These results may have importance in IPM programs promoting reduced insecticide use.

Oxygen convective uptakes in gas exchange cycles in early diapause pupae of Pieris brassicae.

Oxygen convective uptakes in gas exchange cycles were directly recorded in early diapause pupae of Pieris brassicae L. (Lepidoptera; Pieridae) by means of O2 coulometric respirometry. This method was combined with flow-through CO2 respirometry, the two systems being switchable one to the other. During recording with both systems, measurements were also taken with infrared actography. The pupae displayed short discontinuous gas exchange cycles lasting 40-70 min. No true C phase was found by flow-through measurements; instead, flutter opening of the spiracles with discrete convective O2 uptakes began shortly after the O phase whereas CO2 release was suppressed by the inward directed passive suction ventilation. The F phase was characterized by a series of small CO2 bursts (flutter events). Between these bursts, novel sub-phase `miniflutter' was observed, which consisted of six to 10 miniature inspirations without any CO2 emission. During the flow-through measurements, oxygen convective uptakes were indirectly recorded by the infrared actograph as sudden extensions (lengthening) of the abdominal segments at each spiracular microopening.

Neural Code for Ambient Heat Detection in Elaterid Beetles.

Environmental thermal conditions play a major role at all levels of biological organization; however, there is little information on noxious high temperature sensation crucial in behavioral thermoregulation and survival of small ectothermic animals such as insects. So far, a capability to unambiguously encode heat has been demonstrated only for the sensory triad of the spike bursting thermo- and two bimodal hygro-thermoreceptor neurons located in the antennal dome-shaped sensilla (DSS) in a carabid beetle. We used extracellular single sensillum recording in the range of 20-45°C to demonstrate that a similar sensory triad in the elaterid Agriotes obscurus also produces high temperature-induced bursty spike trains. Several parameters of the bursts are temperature dependent, allowing the neurons in a certain order to encode different, but partly overlapping ranges of heat up to lethal levels in a graded manner. ISI in a burst is the most useful parameter out of six. Our findings consider spike bursting as a general, fundamental quality of the classical sensory triad of antennal thermo- and hygro-thermoreceptor neurons widespread in many insect groups, being a flexible and reliable mode of coding unfavorably high temperatures. The possible involvement of spike bursting in behavioral thermoregulation of the beetles is discussed. By contrast, the mean firing rate of the neurons in regular and bursty spike trains combined does not carry useful thermal information at the high end of noxious heat.

Potential of Colorado Potato Beetle (Coleoptera: Chrysomelidae) to Adapt to Alternative Host Plants.

Twelve selected cultivated or wild solanaceae (Solanum dulcamara, Solanum nigrum, Solanum villosum, Solanum lycopersicum, Solanum muricatum, Solanum melongena, Datura innoxia, Datura metel, Physalis spp., Capsicum annuum, Nicotiana alata, and Petunia spp.) (all species Solanales: Solanaceae) were tested as potential alternative host plants against Solanum tuberosum for a local population of the Colorado potato beetle Leptinotarsa decemlineata Say (CPB) in Estonia. Some CPB populations in America and southern Europe accept most of these plants. However, geographically isolated populations of beetles can differ in their acceptance of new host plants. Migrants from the southern Europe supplement Estonian beetle population regularly, so individuals may differ in their host plant preferences. S. melongena and S. dulcamara were well accepted by the beetles, Lycopersicum spp. (Solanales: Solanaceae) and N. alata were intermediate, and S. villosum and S. nigrum were least accepted. The beetles rejected S. muricatum, Physalis spp., C. annuum, Petunia spp., and D. metel. First-instar larvae completed a full life cycle only on S. dulcamara, N. alata, S. lycopesicum, S. melongena, although their development rate was slower, mortality was higher and emerging adults were underweight relative to those that fed on S. tuberosum. The fourth-instar larvae were less sensitive in relation to food. We found that S. dulcamara as a native plant could provide resources for CPB during early and late season. At the same time, the cultivated S. melongena would be suitable plant species for further testing as dead-end crop for integrated pest management.

Evaluation of late blight foliar resistance of potato cultivars in northern Baltic conditions.

The main aim of this study was to evaluate foliar late blight resistance and yield of selected foreign and Estonian potato cultivars to determine the most promising cultivars for the northern Baltic region. We hypothesized that local cultivars have higher late blight (Phytophthora infestans) resistance and yield due to higher blight resistance. Potato late blight observation field trials were carried out in 2012 and 2013 in Einola Farm, Tartu County, Estonia. In both growing seasons, 12 potato cultivars were compared, nine from the Dutch Breeding Company Agrico and three from the Estonian Crop Research Institute. They comprised four early cultivars: Ranomi, Esmee, Romie and Maret, four early-medium cultivars: Toluca, Mariska, Madeleine and Teele and four medium-late/late cultivars: Excellency, Bellefleur, Manitou and Anti. Of these, only two, Anti and Toluca, qualified as highly foliar late blight resistant. This research clearly indicates that, despite unfavourable conditions for the pathogen, late blight is able to destroy potato foliage in most of these cultivars before the end of the growing season in northern Baltic conditions. This reflects local genetic heterogeneity of populations of P. infestans, probably associated with the presence of strains adapted to a wide range of humidity conditions. In 2012 that had late blight favourable weather, the cultivar Toluca showed high foliar blight resistance, as it reached the maximum yield compared to most other cultivars which were susceptible or very susceptible to late blight and had drastically reduced yield. However, although the late blight infection was not recorded in the growing season 2013, the cultivar Toluca did not tolerate the dry weather well and its tuber yield remained significantly lower than that in all other cultivars. Additionally, in 2013, a potato early blight (Alternaria solani) outbreak was recorded with the two most susceptible cultivars being the local cultivar Teele and the Dutch cultivar Excellency.

Electrophysiological responses from neurons of antennal taste sensilla in the polyphagous predatory ground beetle Pterostichus oblongopunctatus (Fabricius 1787) to plant sugars and amino acids.

The responses of antennal contact chemoreceptors, in the polyphagous predatory ground beetle Pterostichus oblongopunctatus, to twelve 1-1,000 mmol l(-1) plant sugars and seven 10-100 mmol l(-1) amino acids were tested. The disaccharides with an alpha-1.4-glycoside linkage, sucrose and maltose, were the two most stimulatory sugars for the sugar-sensitive neuron innervating these contact chemosensilla. The firing rates they evoked were concentration dependent and reached up to 70 impulses/s at 1,000 mmol l(-1). The stimulatory effect of glucose on this neuron was approximately two times lower. This can be partly explained by the fact that glucose exists in at least two anomeric forms, alpha and beta. These two forms interconvert over a timescale of hours in aqueous solution, to a final stable ratio of alpha:beta 36:64, in a process called mutarotation. So the physiologically active alpha-anomere forms only 36% of the glucose solution which was reflected in its relatively low dose/response curve. Due to the partial herbivory of P. oblongopunctatus these plant sugars are probably involved in its search for food, for example, for conifer seeds. Several carbohydrates, in addition to glucose, such as cellobiose, arabinose, xylose, mannose, rhamnose and galactose are known as components of cellulose and hemicelluloses. They are released by brown-rot fungi during enzymatic wood decay. None of them stimulated the antennal sugar-sensitive neuron. They are therefore not implicated in the search for hibernation sites, which include rotting wood, by this beetle. The weak stimulating effect (below 3 impulses/s) of some 100 mmol l(-1) amino acids (methionine, serine, alanine, glutamine) to the 4th chemosensory neuron of these sensilla was characterized as non-specific, or modulating the responses of non-target chemosensory neurons.

Dynamics of Supercooling Ability and Cold Tolerance of the Alder Beetle (Coleoptera: Chrysomelidae).

Agelastica alni L. (Coleoptera: Chrysomelidae) is a common beetle pest of alder trees (Alnus incana L.) in forests and parks across Estonia. The supercooling ability and capacity to survive low temperature exposure changes temporally. Relatively high unimodal supercooling point (SCP) levels (with a mean value of -6 to -8°C) were characteristic of the beetles in September during their diapause induction period, in April when the beetles had terminated their diapause development and in May when they started to reproduce. During their deep diapause period the SCPs of beetles had a bimodal distribution. Some beetles decreased their SCPs to -14 to -19°C while others retained a high SCP value of -6 to -8°C. Most vulnerable to low temperature were overwintered active beetles in May; after 1 h exposure their LTemp50 (median lethal temperature) was -6.3°C. In September with the onset of diapause tolerance of beetles started to increase, LTemp50 = -7.7°C. Beetles were most cold tolerant during their deep diapause period with LTemp50 < -12.0°C. A. alni beetles use one of two different strategies for overwintering, some are freeze-tolerant while others are freeze-avoidant. The freeze-avoidant beetles with low SCP (-12 to -15°C) acquired greater cold tolerance than those with higher SCP (-6 to -8°C), with LTemp50 = -13.7°C and LTemp50 = -11°C, respectively.

Are pesticide residues in honey related to oilseed rape treatments?

Pesticide treatments before and during the flowering of honey bee forage crops may lead to residues in honey. In northern regions oilseed rape belongs to the main forage crops that is mostly cultivated by means of intensive agriculture, including several pesticide treatments. However, in addition to the focal forage crops, pesticides from non-forage crops can spread to wild flowers around fields, and thus the residues in honey would reflect the whole range of pesticides used in the agricultural landscape. The aim of our study was to clarify which currently used pesticides are present in honey gathered from heterogeneous agricultural landscapes after the end of flowering of oilseed crops. Honey samples (N = 33) were collected from beehives of Estonia during 2013 and 2014, and analysed for residues of 47 currently used agricultural pesticides using the multiresidue method with HPLC-MS/MS and GC-MS and a single residue method for glyphosate, aminopyralid and clopyralid. Residues of eight different active ingredients with representatives from all three basic pesticide classes were determined. Although no correlation was detected between the cumulative amount of pesticide residues and percent of oilseed crops in the foraging territory, most of the residues are those allowed for oilseed rape treatments. Among all pesticides, herbicide residues prevailed in 2013 but not in 2014. Despite the relatively small agricultural impact of Estonia, the detected levels of pesticide residues sometimes exceeded maximum residue level; however, these concentrations do not pose a health risk to consumers, also acute toxicity to honey bees would be very unlikely.

A new method for electrophysiological identification of antennal pH receptor cells in ground beetles: the example of Pterostichus aethiops (Panzer, 1796) (Coleoptera, Carabidae).

The responses of antennal taste sensilla of the ground beetle Pterostichus aethiops to 100mM Na(+)-salts and their mixtures with 1 and 10mM NaOH were compared. An increase in pH by 0.3-0.6 units in 100mM Na(+)-salt solutions, caused by the content of 1mM NaOH, was too small, except for alkaline Na(2)HPO(4), to influence the firing rate of the cation cell and pH cell significantly. However, different sensitivity of the two cells to increased pH was clearly demonstrated when the concentration of NaOH in 100mM stimulating salt solutions was increased to 10mM. Increasing pH by 1.2-2 units caused the 1st s firing rate to increase by 140-1050% and 0-26% in the pH cell and cation cell, respectively. Compared to the buffer series method used for identification of the pH receptors in ground beetles earlier, considerably stronger responses of the pH cell to a similar increase in pH were observed when the NaOH method was used for testing. At the same time, undesirable changes in salt ions concentration that occur when stimulating solutions differing by 1-2 pH units are prepared were much smaller using the latter method. Behavioural and ecological relevance of the results is discussed.

Responses of the antennal bimodal hygroreceptor neurons to innocuous and noxious high temperatures in the carabid beetle, Pterostichus oblongopunctatus.

Electrophysiological responses of thermo- and hygroreceptor neurons from antennal dome-shaped sensilla of the carabid beetle Pterostichus oblongopunctatus to different levels of steady temperature ranging from 20 to 35°C and rapid step-changes in it were measured and analysed at both constant relative and absolute ambient air humidity conditions. It appeared that both hygroreceptor neurons respond to temperature which means that they are bimodal. For the first time in arthropods, the ability of antennal dry and moist neurons to produce high temperature induced spike bursts is documented. Burstiness of the spike trains is temperature dependent and increases with temperature increase. Threshold temperatures at which the two neurons switch from regular spiking to spike bursting are lower compared to that of the cold neuron, differ and approximately coincide with the upper limit of preferred temperatures of the species. We emphasise that, in contrast to various sensory systems studied, the hygroreceptor neurons of P. oblongopunctatus have stable and continuous burst trains, no temporal information is encoded in the timing of the bursts. We hypothesise that temperature dependent spike bursts produced by the antennal thermo- and hygroreceptor neurons may be responsible for detection of noxious high temperatures important in behavioural thermoregulation of carabid beetles.

Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

BACKGROUND: Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. RESULTS: Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (< 2 h) locomotor hyperactivity followed by a long-term (>24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. CONCLUSION: Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field.

A pilot study of the use of biocide-impregnated gauze as an adjunct to wound care in a burn population.

The aim of this study was to evaluate the use of a polyhexamethylene biguanide biocide-impregnated gauze (Kerlix™ AMD gauze dressing, Covidien d/b/a Tyco Healthcare Group LP) as an adjuvant to routine burn care and its impact on the incidence of hospital-associated infections in burn population. One hundred eight burn patients admitted to the Burn Treatment Center were prospectively enrolled from August 2008 to June 2009 and matched 1:2 with historic controls who were admitted from March 2006 to July 2008. Clinical care remained otherwise unchanged; however, several hospital initiatives (the national surgical improvement project, the surgical care improvement project, and a central venous line bundle) were initiated before and during the study. There were significantly less infections in the study population (18.52% of case patients vs 28.70% of control patients had infections, P = .047). Although there was a decrease in each infection subtype analyzed, a statistically significant reduction was only reached for pneumonias (1.85% in cases vs 5.86 in controls, P = .042). Implementation of polyhexamethylene biguanide biocide-impregnated gauze was temporally correlated with a significant decrease in healthcare-associated infections in burn population. As there was no corresponding decrease in wound infections, the impact of the gauze on healthcare-associated infections, if any, cannot be conclusively determined by this study. A larger prospective study powered to detect a decrease in wound-related infections is warranted.

Effects of Fastac 50 EC on bumble bee Bombus terrestris L. respiration: DGE disappearance does not lead to increasing water loss.

Sublethal effects of pesticides in insects can be observed through physiological changes, which are commonly estimated by metabolic rate and respiratory patterns, more precisely by the patterns of discontinuous gas-exchange (DGE) cycles. The aim of the present research was to study the effect of some low concentrations of Fastac 50 EC on the cycles of CO(2) release and respiratory water loss rates (WLR) in bumble bee Bombus terrestris L. foragers. Bumble bees were dipped into 0.004% and 0.002% Fastac 50 EC solution. Flow-through respirometry was used to record the respiration and WLR 3h before and after the treatment. The respirometry was combined with infrared actography to enable simultaneous recording of abdominal movements. Our results show that Fastac 50 EC has an after-effect on bumble bee respiratory rhythms and muscle activity but does not affect WLR. Treatment with 0.004% Fastac 50 EC solution resulted in disappearance of the respiration cycles; also the lifespan of treated bumble bees was significantly shorter. Treatment with 0.002% Fastac 50 EC solution had no significant effect on respiration patterns or longevity. We found no evidence for the DGE cycles functioning as a water saving mechanism.

Evaluation of the usefulness of two established pain assessment tools in a burn population.

Evaluation of burn pain and its successful treatment has proven challenging for all staff who care for burn patients. As successful pain relief is important for full physical and psychological recovery, accurate assessment of burn pain is essential. The authors sought to prospectively evaluate two previously validated pain scales, the Critical Care Pain Observation Tool (CCPOT) and the Adult Nonverbal Scale (ANVS), in our burn population and compare them with patients' reports of pain. Both scales include nonverbal behaviors that are numerically scored and can be used in communicative as well as noncommunicative patients. Thirty-eight patients underwent 225 paired pain assessments. Assessments were compared with patients' self-reports of pain using the numeric rating scale (NRS) and the visual analog scale (VAS). Performance of the scales was evaluated by psychometric analysis. Logistic regression was used to compare pain scores with patient demographics, burn demographics, and administered analgesia. Both CCPOT and ANVS were internally consistent and able to discriminate pain intensity. However, these scales had poor interrater reliability. Furthermore, they correlated poorly with patients' self-reports of pain per the NRS and VAS pain scale scores. By logistic regression, all the pain scales showed a decrease in patient pain corresponding to the length of time after the burn. Otherwise, pain was not related to any patient demographics or evaluator experience. The size of burn was the only burn-related variable significantly associated with the pain scores, and this was only for the scores obtained with the CCPOT scale. In addition, only CCPOT and ANVS scales correlated with administered analgesia during hospitalization. The authors conclude that CCPOT and ANVS do not accurately assess pain in burn patients. However, it seems that the staff may administer analgesia based on several nonverbal clues encompassed in these scales. Future studies should address nonverbal signs of pain in burn patients. These signs could then be used in pain scales to target burn patient pain more effectively.

Electrophysiological identification of hygroreceptor neurons from the antennal dome-shaped sensilla in the ground beetle Pterostichus oblongopunctatus.

This study gives the first electrophysiological evidence of hygroreceptors in carabids. Extracellular recordings from the antennal dome-shaped sensilla of the carabid beetle Pterostichus oblolongopunctatus (Coleoptera, Carabidae) clearly show the presence of moist and dry neuron antagonistically responding to humidity changes. The cold neuron of the same sensillum did not respond to changes in humidity. For the first time, we demonstrate that the binary system of two antagonistic hygroreceptor neurons discriminates differences between steady-state humidity levels more sensitively than either neuron separately. Another advantage of the binary system is that it guarantees immediate and strong phasic-tonic response to rapid humidity changes in either direction. In the hygrosensing system of carabids, this would allow detection of subtle step-changes in humidity with greater sensitivity than differences in steady-state values of humidity. Thus, construction of the hygrosensing system with opposing receptor neurons may allow insects to detect environmental humidity differences critical for their habitat and microhabitat selection, and survival with great precision.

Spike bursts generated by the thermosensitive (cold) neuron from the antennal campaniform sensilla of the ground beetle Platynus assimilis.

Responses of the antennal thermosensitive neuron of the ground beetle Platynus assimilis to warming from 20 to 50 degrees C were measured and analysed. During warming, neurons switched from regular spiking to bursting. ISI analysis showed that the number of spikes in the burst and spike frequency within the burst were temperature dependent and may precisely encode unfavourably or dangerously high temperatures in a graded manner. In contrast, regular spikes of the neuron encode moderate temperatures at 20-30 degrees C. The threshold temperature of spike bursting varied in different neurons from 25 to 47 degrees C. As a result, the number of bursting neurons increased with temperature increase. Therefore, in addition to the burst characteristics, the total number of bursting neurons may also contain useful information on external temperature. A relationship between the spike bursts and locomotor activity of the beetles was found which may have importance in behavioural thermoregulation of the species. At 44.4+/-0.6 degrees C, first indications of partial paralysis (of the hind legs) were observed. We emphasize, that in contrast to various sensory systems studied, the thermoreceptor neuron of P. assimilis has a stable and continuous burst train, no temporal information is encoded in the timing of the bursts.