Dorsal Neck Research Articles

Sex Differences in Thermal Behavior During Exercise Recovery

PurposeFemales (F) more rapidly withdraw heat loss thermoeffectors post‐exercise compared to males (M), prolonging elevations in core temperature (Tcore). Thermal behavior may compensate for this response, but it is not known if thermal behavior differs between M and F. We tested the hypothesis that thermal behavior remains engaged post‐exercise for a longer time in F than M.MethodsIn a 24°C (43% RH) environment, 17 adults (9 F, 22 ± 2 y) cycled for 60 min, followed by 60 min seated recovery. Mean skin temperature (Tskin, 10 site), Tcore (intestinal) and mean skin wetness (wskin, 4 site) were measured continually. Subjects controlled the temperature of their dorsal neck to perceived thermal comfort using a custom made fluid filled device. Neck device temperature (Tdevice) provided an index of thermal behavior. A linear regression was performed with Tskin, Tcore, and wskin as independent variables and Tdevice as the dependent variable. Standardized beta coefficients were used to determine the relative contribution of each variable to Tdevice.ResultsMetabolic heat production did not differ between sexes during exercise (M: 133 ± 5, F: 123 ± 8 W/m2, P=0.40). Tskin (P=0.80), Tcore (P=0.97), wskin (P=0.76), and Tdevice (P=0.13) did not differ between sexes during exercise or recovery. During exercise, Tskin increased in F (Pre‐Exercise (PreEx): 29.6 ± 0.7°C; End‐Exercise (EndEx): 30.4 ± 0.6°C, P≤0.02), and decreased in recovery (End‐Recovery (EndRec): 29.7 ± 0.6°C, P≤0.01). Tskin did not change throughout in M (PreEx: 29.5 ± 0.6; EndEx: 30.0 ± 0.8, EndRec: 29.5 ± 0.7°C, P≥0.42). Tcore increased in F (PreEx: 37.3 ± 0.3, EndEx: 38.1 ± 0.2°C, P<0.01) and M (PreEx: 37.0 ± 0.3; EndEx: 37.5 ± 0.3°C, P<0.01) during exercise, remaining elevated until 40 min recovery (F: 37.5 ± 0.2, P=0.20; M: 37.3 ± 0.4°C, P=0.08). wskin increased in F (PreEx: 0.21 ± 0.06; EndEx: 0.25 ± 0.03 a.u., P=0.01) and M (PreEx: 0.17 ± 0.06; EndEx: 0.22 ± 0.05 a.u., P=0.03) during exercise, remaining elevated during recovery (F ‐ EndRec: 0.27 ± 0.04, P<0.01, M ‐ EndRec: 0.21 ± 0.05 a.u., P≤0.03). Tdevice decreased in F (Pre: 27.4 ± 0.9; EndEx: 6.1 ± 6.1°C, P≤0.01) and M (Pre: 27.3 ± 1.5; EndEx: 11.8 ± 10.5°C, P≤0.01) during exercise, returning to PreEx 20 min into recovery (F: 20.1 ± 8.0, P≥0.09; M: 19.1 ± 9.2°C, P≥0.06). During exercise, Tcore (51 ± 25%) contributed to Tdevice more than Tskin in M (13 ± 8%, P=0.05), but neither were different to wskin (36 ± 25%, P≥0.37). In F, Tcore (31 ± 26%), Tskin (35 ± 31%) and wskin (34 ± 24%) contributed equally to Tdevice (P≥0.98). During recovery, Tcore (55 ± 21%) contributed more than Tskin (17 ± 13%, P=0.02) in F, but neither were different to wskin (28 ± 20%, P≥0.15). In M, Tcore (37 ± 35%), Tskin (27 ± 23%) and wskin (36 ± 22%) contributed equally to Tdevice (P≥0.84).ConclusionsThermal behavior during and post‐exercise does not differ between M and F. However, Tcore contributes more to thermal behavior during exercise in M and post‐exercise in F. These findings may be related to temporal differences in Tskin during and following exercise.Support or Funding InformationSupported by lululemon athletica inc.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Differential thermal behavioral response to heat vs. cold stress in humans

PurposeData from non‐human endotherms indicate that thermal behavioral responses to increases in core temperature (Tcore) are more robust when compared to similar reductions in Tcore. These observations have been interpreted as a protective response, owing to the proximity of the endothermic Tcore to the upper lethal limit compared to the lower lethal limit. In resting humans, thermal behavior is mostly initiated by changes in skin temperature (Tskin). There is some evidence that thermal behavior in humans is more sensitive to increases in Tskin vs. decreases. On the contrary, it is often posited that skin cooling evokes a greater thermoregulatory response compared to equivalent increases in Tskin because of the greater density of cold receptors in the skin. Based on this uncertainty, we tested the hypothesis that thermal behavior is more sensitive during heat vs. cold stress.MethodsWearing a water perfused suit, twelve healthy adults (23 ± 2 y, 6 F) underwent 60 min of heat (HEAT) and cold (COLD) stress that induced gradual changes in mean body temperature (Tbody). Using a custom‐made device, subjects controlled the temperature of their dorsal neck to perceived thermal comfort. Thus, neck temperature provided an index of thermal behavior. Neck temperature, weighted Tskin (6 site), and Tcore (intestinal) were measured continually. Tbody, the integrated stimulus for thermal behavior, was calculated as the unweighted average of Tskin and Tcore. Neck temperature was analyzed using segmental regression analysis, providing an analysis of thermal behavior relative to changes in Tbody. This analysis provided two parameters: a) threshold, which is indicative of the activation of thermal behavior as a function of Tbody, and b) gain, which is the slope of the thermal behavioral response to continued changes in Tbody after the threshold. To permit direct comparisons between HEAT and COLD, data were analyzed as absolute values and the gain was normalized to the maximum change within a trial and subject.ResultsIn HEAT, Tskin increased by 3.7 ± 0.4°C through 36 min (P<0.01) and an increase in Tskin of 4.1 ± 0.2°C was maintained thereafter. Elevations in Tcore occurred at 36 min, with Tcore maximally increasing by 0.9 ± 0.3°C (P<0.01). In HEAT, neck temperature was decreased at 40 min (P=0.03) with a maximal reduction of 7.9 ± 4.6°C. In COLD, Tskin decreased throughout, dropping by 6.0 ± 0.6°C (P<0.01), while Tcore did not change (P=0.10). In COLD, neck temperature was increased at 32 min (P=0.01) with a maximal increase of 4.3 ± 1.9°C. The threshold change in Tbody upon which thermal behavior was initiated was lower in COLD (0.8 ± 0.7 vs. 1.3 ± 0.7°C, P=0.04). However, the relative gain of the response after the threshold was greater in HEAT (3.8 ± 3.1 vs. 1.4 ± 0.9 a.u., P=0.02).ConclusionsCompared to cold stress, thermal behavior during heat stress is initiated following greater changes in Tbody. However, after activation the relative sensitivity of thermal behavior to continued changes in Tbody is greater during heat stress. These findings are consistent with a higher density of cold receptors in the skin, yet also support that thermal behavior more robustly defends increases in Tbody after thermal behavior is initiated.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Independent suboesophageal neuronal innervation of the defense gland and longitudinal muscles in the stick insect (Peruphasma schultei) prothorax

This study investigates the neuroanatomy of the defense gland and a related muscle in the stick insect Peruphasma schultei with axonal tracing and histological sections. The gland is innervated by three neurons through the Nervus anterior of the suboesophageal ganglion (SOG), the ipsilateral neuron (ILN), the contralateral neuron (CLN) and the prothoracic intersegmental neuron (PIN). The ILN has a large soma which is typical for motoneurons that cause fast contraction of large muscles and its dendrites are located in motor-sensory and sensory neuropile areas of the SOG. The CLN might be involved in the coordination of bilateral or unilateral discharge as its neurites are closely associated to the ILN of the contralateral gland. Close to the ejaculatory duct of the gland lies a dorsal longitudinal neck muscle, musculus pronoto-occipitalis (Idlm2), which is likely indirectly involved in gland discharge by controlling neck movements and, therefore, the direction of discharge. This muscle is innervated by three ventral median neurons (VMN). Thus, three neuron types (ILN, CLN, and PIN) innervate the gland muscle directly, and the VMNs could aid secretion indirectly. The cytoanatomy of motorneurons innervating the defense gland and neck muscle are discussed regarding the structure and functions of the neuropile in the SOG. As a basis for the neuroanatomical study on the defense gland we assembled a map of the SOG in Phasmatodea.

Thermal behavior remains engaged following exercise despite autonomic thermoeffector withdrawal

We tested the hypothesis that thermal behavior during the exercise recovery compensates for elevated core temperatures despite autonomic thermoeffector withdrawal. In a thermoneutral environment, 6 females and 6 males (22 ± 1 y) cycled for 60 min (225 ± 46 W metabolic heat production), followed by 60 min passive recovery. Mean skin and core temperatures, skin blood flow, and local sweat rate were measured continually. Subjects controlled the temperature of their dorsal neck to perceived thermal comfort using a custom-made neck device. Neck device temperature provided an index of thermal behavior. Mean body temperature, calculated as the average of mean skin and core temperatures, provided an index of the stimulus for thermal behavior. To isolate the independent effect of exercise on thermal behavior during recovery, data were analyzed post-exercise the exact minute mean body temperature recovered to pre-exercise levels within a subject. Mean body temperature returned to pre-exercise levels 28 ± 20 min into recovery (Pre: 33.5 ± 0.2, Post: 33.5 ± 0.2 °C, P = 0.20), at which point, mean skin temperature had recovered (Pre: 29.6 ± 0.4, Post: 29.5 ± 0.5 °C, P = 0.20) and core temperature (Pre: 37.3 ± 0.2, Post: 37.5 ± 0.3 °C, P = 0.01) remained elevated. Post-exercise, skin blood flow (Pre: 59 ± 78, Post: 26 ± 25 PU, P = 0.10) and local sweat rate (Pre: 0.05 ± 0.25, Post: 0.13 ± 0.14 mg/cm2 min−1, P = 0.09) returned to pre-exercise levels, while neck device temperature was depressed (Pre: 27.4 ± 1.1, Post: 21.6 ± 7.4 °C, P = 0.03). These findings suggest that thermal behavior compensates for autonomic thermoeffector withdrawal in the presence of elevated core temperatures post-exercise.

Variability of peripheral and central organ activity patterns of mice in an elevated plus maze

Elevated plus maze (EPM) tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials of the prefrontal cortex and hippocampus, electrocardiograms from the intercostal muscle, electromyograms from the dorsal neck muscle, and respiratory signals from the olfactory bulb in individual mice that were repeatedly exposed to EPM tests. Heart rates of the mice were higher in the open arms. In the closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity (LP) states of peripheral signals. The LP states were observed only when the animals were in the closed arms, and the frequencies of the LP states increased as the testing days proceeded. The periods of LP states corresponded with those having significant lower amplitudes of electromyogram. The state more likely occurred in the distal part of the closed arms, which indicates that mice with LP states showed less locomotor activity. During the low-activity states, the delta and theta powers of cortical local field potentials were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables an accurate evaluation of rodent mental states.

Transdermal Drug Delivery of Asiatic Acid Influences Renal Function and Electrolyte Handling in <i>Plasmodium berghei</i> - Infected Sprague-Dawley Male Rats

Background: Malaria is one of the most important infectious inflammatory diseases worldwide which affects vital organs including gastrointestinal and kidneys. Higher prevalence of malaria related renal failure, current malaria drugs nephrotoxicity and drug resistance to malaria calls for continued research in anti-parasitic as well as anti-disease inflammatory pharmaceuticals. Asiatic acid, a plant phytochemical extract, has antioxidant, pro-oxidant and diuretic properties. Here we report influence of Asiatic acid-pectin hydrogel matrix patch application in P. berghei-infected Sprague Dawley rats on renal function and electrolyte handling. Materials and Methods: Asiatic acid (5mg/kg)-pectin patch was applied on the dorsal neck region of the rat on day 7 post infection and monitored for parasitaemia, and physicochemical changes. Urine and blood were collected for measuring various biochemical parameters to estimate renal function and electrolyte handling. Results: Asiatic acid-pectin patch application had significant influence on food and water intake as well as weight changes, urine electrolytes, glomerular filtration rate, and antioxidant markers together with hormonal changes of aldosterone and vasopressin. Conclusion: Application of the once-off Asiatic acid (5mg/kg)-pectin patch influence renal function and renal electrolyte handling while ameliorating, biochemical and hormonal derangements induced by malaria. Novelty of the Work Here we show for the first time a) the efficacy of Asiatic acid (AA) in suppressing murine malaria by way of administering the phytochemical using the amidated pectin hydrogel matrix patch transdermal drug delivery system, b) diminution of asiatic acid dose applied from 10mg/kg oral to 5mg/kg by transdermal, c) reduction of time once-off patch application from five days to three days, d) attenuation of oxidative and hormonal derangements in malaria and e) the amelioration of renal function together with improvement in renal electrolyte handling. The results may be of benefit in patient care replacing the multiple dosing approaches used in malaria management.

Alterations in the Mechanical Response of Deep Dorsal Neck Muscles in Individuals Experiencing Whiplash-Associated Disorders Compared to Healthy Controls: An Ultrasound Study.

The aim of this study was to investigate and compare the mechanical responses of dorsal neck muscles in individuals with whiplash-associated disorders (WAD) versus healthy individuals. This study included 36 individuals with WAD (26 women and 10 men) and 36 healthy controls (26 women and 10 men). Ultrasound imaging with speckle tracking was used to measure deformation and deformation rate in five dorsal neck muscles during a neck extension task. Compared with controls, individuals with WAD showed higher deformations of the semispinalis cervicis (P = 0.02) and multifidus (P = 0.002) muscles and higher deformation rates (P = 0.03 and 0.0001, respectively). Among individuals with WAD, multifidus deformation and deformation rate were significantly associated with pain, disability, and fatigue (r = 0.31-0.46, P = 0.0001-0.01). These findings indicate that the mechanical responses of the deep dorsal neck muscles differ between individuals with WAD and healthy controls, possibly reflecting that these muscles use altered strategies while performing a neck extension task. This finding provides new insight into neck muscles pathology in patients with chronic WAD and may help improve rehabilitation programs. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Summarize the mechanical responses of dorsal neck muscles during loading of the neck muscles via an extension task in individuals with chronic whiplash associated disorders and healthy volunteers; (2) Differentiate mechanical responses between five dorsal neck muscles while loading the neck via an extension task; and (3) Describe the relationships between the mechanical responses of the dorsal neck muscles with the patients' perception of neck pain, disability, and fatigue. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Neck Vibration Proprioceptive Postural Response Intact in Progressive Supranuclear Palsy unlike Idiopathic Parkinson's Disease.

Progressive supranuclear palsy (PSP) and late-stage idiopathic Parkinson’s disease (IPD) are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Postural responses to sensory anteroposterior tilt illusion by bilateral dorsal neck vibration were probed in both groups versus healthy controls on a static recording posture platform. Three distinct anteroposterior body mass excursion peaks (P1–P3) were observed. 18 IPD subjects exhibited well-known excessive response amplitudes, whereas 21 PSP subjects’ responses remained unaltered to 22 control subjects. Neither IPD nor PSP showed response latency deficits, despite brainstem degeneration especially in PSP. The observed response patterns suggest that PSP brainstem pathology might spare the involved proprioceptive pathways and implies viability of neck vibration for possible biofeedback and augmentation therapy in PSP postural instability.

Multiple Identified Neurons and Peripheral Nerves Innervating the Prothoracic Defense Glands in Stick Insects Reveal Evolutionary Conserved and Novel Elements of a Chemical Defense System

The defense glands in the dorsal prothorax are an important autapomorphic trait of stick insects (Phasmatodea). Here, we study the functional anatomy and neuronal innervation of the defense glands in Anisomorpha paromalus (Westwood, 1859) (Pseudophasmatinae), a species which sprays its defense secretions when disturbed or attacked. We use a neuroanatomical approach to identify the nerves innervating the gland muscles and the motoneurons with axons in the different nerves. The defense gland is innervated by nerves originating from two segments, the suboesophageal ganglion and the prothoracic ganglion. Axonal tracing confirms the gland innervation via the anterior suboesophageal nerve, and two intersegmental nerves, the posterior suboesophageal nerve and the anterior prothoracic nerve. Axonal tracing of individual nerves reveals eight identified neuron types in the suboesophageal or prothoracic ganglion. The strongest innervating nerve of the gland is the anterior suboesophageal nerve, which also supplies dorsal longitudinal thorax muscles (neck muscles) by separate nerve branches. Tracing of individual nerve branches reveals different sets of motoneurons innervating the defense gland (one ipsilateral and one contralateral suboesophageal neuron) or the neck muscle (ventral median neurons). The ipsilateral and contralateral suboesophageal neurons have no homologs in related taxa like locusts and crickets, and thus evolved within stick insects with the differentiation of the defense glands. The overall innervation pattern suggests that the longitudinal gland muscles derived from dorsal longitudinal neck muscles. In sum, the innervating nerves for dorsal longitudinal muscles are conserved in stick insects, while the neuronal control system was specialized with conserved motoneurons for the persisting neck muscles, and evolutionarily novel suboesophageal and prothoracic motoneurons innervating the defense gland.

Anatomical basis for simultaneous block of greater and third occipital nerves, with an ultrasound-guided technique.

In some headache disorders, for which the greater occipital nerve block is partly effective, the third occipital nerve is also suggested to be involved. We aimed to establish a simple technique for simultaneously blocking the greater and third occipital nerves. We performed a detailed examination of dorsal neck anatomy in 33 formalin-fixed cadavers, and deduced two candidate target points for blocking both the greater and third occipital nerves. These target points were tested on three Thiel-fixed cadavers. We performed ultrasound-guided dye injections into these points, examined the results by dissection, and selected the most suitable injection point. Finally, this target point was tested in three healthy volunteers. We injected 4ml of local anesthetic and 1ml of radiopaque material at the selected point, guided with a standard ultrasound system. Then, the pattern of local anesthetic distribution was imaged with computed tomography. We deduced that the most suitable injection point was the medial head of the semispinalis capitis muscle at the C1 level of the cervical vertebra. Both nerves entered this muscle, in close proximity, with little individual variation. In healthy volunteers, an anesthetic injected was confined to the muscle and induced anesthesia in the skin areas innervated by both nerves. The medial head of the semispinalis capitis muscle is a suitable landmark for blocking the greater and third occipital nerves simultaneously, by which occipital nerve involvement in various headache disorders may be rapidly examined and treated.

Orderly recruitment of thermoeffectors in resting humans.

The recruitment of thermoeffectors, including thermoregulatory behavior, relative to changes in body temperature has not been quantified in humans. We tested the hypothesis that changes in skin blood flow, behavior, and sweating or metabolic rate are initiated with increasing changes in mean skin temperature (Tskin) in resting humans. While wearing a water-perfused suit, 12 healthy young adults underwent heat (Heat) and cold stress (Cold) that induced gradual changes in Tskin. Subjects controlled the temperature of their dorsal neck to their perceived thermal comfort. Thus neck skin temperature provided an index of thermoregulatory behavior. Neck skin temperature (Tskin), core temperature (Tcore), metabolic rate, sweat rate, and nonglabrous skin blood flow were measured continually. Data were analyzed using segmental regression analysis, providing an index of thermoeffector activation relative to changes in Tskin. In Heat, increases in skin blood flow were observed with the smallest elevations in Tskin ( P < 0.01). Thermal behavior was initiated with an increase in Tskin of 2.4 ± 1.3°C (mean ± SD, P = 0.04), while sweating was observed with further elevations in Tskin (3.4 ± 0.5°C, P = 0.04), which coincided with increases in Tcore ( P = 0.98). In Cold, reductions in skin blood flow occurred with the smallest decrease in Tskin ( P < 0.01). Thermal behavior was initiated with a Tskin decrease of 1.5 ± 1.3°C, while metabolic rate ( P = 0.10) and Tcore ( P = 0.76) did not change throughout. These data indicate that autonomic and behavioral thermoeffectors are recruited in coordination with one another and likely in an orderly manner relative to the comparative physiological cost.

Ultrasonography as a complementary diagnostic method for evaluating the skin of healthy cats.

Ultrasonography is not often used in feline dermatology. The purpose of this study was to assess the usefulness and applicability of ultrasonography for skin evaluation in 21 clinically healthy cats. Ultrasonographic examination was conducted in 4 cutaneous regions (frontal, dorsal neck, sacral, and abdominal) using an 18-MHz linear-sequential-array transducer. Findings were assessed using histomorphometric analysis of skin samples set as reference standards. Morphologic evaluation, thickness measurements, measurement variability, and comparison between regions and genders were carried out. The ultrasonographic pattern of feline skin was characterized by 3 distinct layers of different echogenicity and echostructure. Skin was thickest at the dorsal neck region and thinnest at the abdominal region. Skin at the frontal region and dorsal neck region was thicker in males. Variability was < 10% in all regions. No apparent correspondence was found between ultrasonographic and histometric measurements of skin thickness. Collectively, these findings suggest that ultrasonography is a simple, noninvasive, and reproducible technique that allows cutaneous layers to be identified and accurately measures skin thickness in cats.

Restoration of fresh cat ovarian tissue function by autografting to subcutaneous tissue: A pilot study

Ovarian tissue transplantation could be a valuable technique for the preservation of endangered animals. The domestic cat affords an adequate experimental model for studies aimed at wild felids due to its phylogenetic similarity. Thus, this pilot study evaluated the efficacy of cat ovarian tissue autotransplantation to a peripheral site. Three adult queens were submitted to ovariohysterectomy. The ovaries were fragmented into eight pieces; two were fixed as a control and six were transplanted to subcutaneous tissue of the dorsal neck. Grafts were monitored weekly by ultrasound and fecal samples collected daily in order to monitor estradiol levels. Grafts were recovered on Days: 7, 14, 28, 49 and 63 post-transplantation for histological analyses. One graft was maintained in one animal for 8 months. A total of 2466 ovarian follicles were analyzed: 1406 primordial and 1060 growing follicles. All animals presented antral follicles in one or more of the grafts. The percentage of morphologically normal primordial follicles was always higher than 80%, except for Day 7 transplants. Although the proportion of growing follicles increased after transplantation, there was a general decrease in the percentage of morphologically normal growing follicles from Day 7 onwards. All animals demonstrated at least three estradiol peaks during the 63-day period, and one animal exhibited estrous behaviour on three occasions. Hormonal peaks directly correlated with the visualization of antral follicles (by ultrasound and/or histology) and the observation of estrous behaviour. Long-term results on one female showed the concentration of 37.8 pg/mL of serum estradiol on Day 233 post-grafting and the female exhibited estrous behaviour on several occasions. This graft showed one antral follicle, one luteinized follicle and two preantral follicles. In conclusion, cat ovary autotransplantation to the subcutaneous tissue restored ovarian function, with hormone production and antral follicle development, over both short and long term periods. This could be a valuable technique in the evaluation of ovarian cryopreservation methods in felids. Once the technique is shown successful, it may be applied in allografts or xenografts between different feline species.

Functional morphology and neuronal innervation of the prothoracic defence gland in Timema

AbstractTimema is the most basal genus of Phasmatodea and the sister group to the remaining stick and leaf‐insects (Euphasmatodea). An autapomorphy of all phasmids is the paired prothoracic exocrine defence glands. In this study, the anatomy and innervation of the defence glands in Timema petita and Timema chumash are described and compared with the data on Euphasmatodea. In all phasmids, the glands consist of a cuticular epithelium, a secretory epithelium and muscular fibres that compress the lumen. In Timematodea, the muscular part of the gland is less developed than in Euphasmatodea and the ejection of the defence secretion depends on the dorsal longitudinal neck muscles. On the neuroanatomical level, Timema petita and Timema chumash lack neurons that are involved in the independent contraction of the gland in euphasmids. In both studied species of Timema, neck muscles play an active role in the gland function which is not observed in any other phasmid. Considering the basal position of this genus, this supports the hypothesis that in euphasmids, the muscular part of the gland evolved from the dorsal longitudinal neck muscles. Additionally, the same nerves that innervate the dorsal longitudinal neck muscles in all Polyneoptera also innervate the defence glands in phasmids.

Comparison of spatial summation properties at different body sites

Background and aimsThe nociceptive system appears to have evolved a range of protective characteristics that are of great interest in understanding both acute and chronic pain. Spatial summation is one important characteristic, whereby increasing area of a stimulus, or distance between multiple stimuli, results in more intense pain—not only greater area of pain. One of the mysteries of chronic pain is why spinal pain is so prevalent relative to pain at other sites. Since pathological tissue models have failed to fully explain spinal pain, we theorized that body region specific differences in sensory processing—such as a greater propensity for spatial summation—may help to explain its vulnerability. We aimed to examine this by comparing the properties of summation at different body parts: the dorsal forearm, neck, and back. MethodsSpatial summation of pain was investigated using noxious intra-dermal electrical stimuli in healthy pain-free adults (14 males, 6 females), and the perceived pain intensity was rated on a 0–100 pain scale. Area-based stimulation was investigated by doubling the stimulation area with the addition of a second electrode placed adjacent to the first. Distance-based summation was investigated by randomly varying the separation distance between paired noxious electrical stimuli at separations of 0, 10, 15, and 20cm. ResultsThis study demonstrated that the properties of area- and distance-based summation are uniform across the neck, back, and forearm in healthy adults. Spatial summation of pain was also found to be greatest at 15- and 20-cm paired separations for all body regions tested, confirming that noxious information can be integrated over an extensive anatomical area. ConclusionData from this investigation refutes the thesis that spatial summation of pain may be a contributing factor for the reported difference in chronicity rates between spinal and peripheral sites. It remains, however, a potentially important mechanism by which noxious inputs from multi-level pathology might integrate and contribute to pain. ImplicationsWhile data from this project suggest that there are no regional differences in the properties of spatial summation of noxious stimuli, regional differences in other characteristics of the nociceptive system may yet provide insight into why some spinal pain is so highly prevalent; nociceptive distance-based summation may be highly relevant where two or more conditions co-exist in close proximity.

Cutaneous lesions due to Trichosporon jirovecii in a tortoise (Testudo hermanni)

Cutaneous mycoses have been rarely reported in Chelonians. A Testudo hermanni adult male showed a thick erosion of the dorsal neck covered by necrotic material. Trichosporon sp. was cultivated, while arthrospores and hyphae were observed in histological sections. The causative agent was identified as Trichosporon jirovecii by PCR. After a surgical intervention povidone iodine and Iruxol® ointment were daily administered through the drainage for 2 weeks, along with enrofloxacin 5mg diluted in saline 0.5ml via the intracelomatic route. After treatment the ulcer healed with residual scars. No relapse was registered after 12 months. T. jirovecii is considered as a rare yeast pathogen and the presented case is the first report of a dermatomycosis in tortoises caused by this yeast species.

Changes in selected physicochemical properties of horse meat and fat during cold and frozen storage

Background. Cooling and freezing are the most popular methods of meat and fat preservation. During cooling low temperatures do not destroy the structure of meat and fatty tissue or cause big changes in their quality. The freezing of meat and fat causes changes in their quality, which are directly connected with the freezing process followed by frozen storage. The aim of the study was to analyse changes in selected physicochemical properties of horse meat and fat during cold and frozen storage. Material and methods. Samples of the longest dorsal muscle and neck fat collected from 16 horse semi-carcasses were used as the research material. One batch of the meat samples was subjected to laboratory analyses after 48 and 120 h of cold storage. The other three batches were frozen and stored for 1, 3 and 6 months at a temperature of –22°C. Results. The extension of frozen storage of horse meat to 3 months (directly after defrosting) caused colour brightening and reduced thermal dripping, in comparison with the cold-stored raw material. Further extension of storage to 6 months decreased the meat quality by darkening its colour and caused greater thawing dripping (no statistically significant differences) with simultan­eous improvement of thermal dripping. There were statistically significant differences both in peroxide and acid values for cold-stored and frozen neck fat. The values increased during freezing and frozen storage. Conclusions. The study showed that the time of cold and frozen storage determined physicochemical properties of horse meat and fat. Therefore, it seems appropriate to conduct further research on changes in physicochemical properties of horse meat and fat stored under cooling conditions in modified atmosphere.

Effect of Phenibut and Glufimet, a Novel Glutamic Acid Derivative, on Respiration of Heart and Brain Mitochondria from Animals Exposed to Stress against the Background of Inducible NO-Synthase Blockade.

Increased oxygen consumption by heart and brain mitochondria in the absence of ADP and reduced mitochondrial respiration in the presence of ADP were observed in rats exposed to stress simulated by suspension by the dorsal neck skin fold for 24 h, which attests to uncoupling of substrate oxidation and ATP synthesis and can cause electron drain from the respiratory chain, formation of ROS, and oxidative damage to cell structures. Blockade of inducible NO synthase with aminoguanidine (single intraperitoneal dose of 50 mg/kg before stress exposure) increased coupling of respiration and oxidative phosphorylation in heart and brain mitochondria of rats exposed to immobilization-painful stress, which was especially pronounced in cardiomyocytes. The test compounds glufimet (single intraperitoneal dose of 29 mg/kg before stress exposure) and phenibut (single intraperitoneal dose of 50 mg/kg before stress exposure) limited stress-induced mitochondrial damage against the background of inducible NO synthase blockade and without it, which was seen from increased respiratory control ratio in comparison with that in untreated rats exposed to stress (control).

5 背側頸筋刺激に反応する侵害受容ニューロンの機能特性(第515回大阪歯科学会例会)

5 背側頸筋刺激に反応する侵害受容ニューロンの機能特性(第515回大阪歯科学会例会)

Distinct immune and clinical responses to alcohol-soluble vs. salt-soluble wheat proteins in mice

Abstract Food hypersensitivity is a growing global public health problem. Wheat has been linked to distinct types of human hypersensitivities with incompletely understood mechanisms. Although wheat proteins (WP) differ in solubility, it is unknown whether alcohol-soluble (AS) and salt-soluble (SS) WP differ in their immune and disease activation properties. Here we tested the hypothesis that AS and SSWP extracted from soft-wheat will elicit distinct types of immune and clinical responses in inbred mice. Groups of BALB/cJ mice weaned onto a plant-protein free diet received IP injections with AS and SSWP (0.01 mg/mouse) along with alum. The WP-specific (S) IgE, IgG1, IgG2a, IgA and total (T) IgE responses were analyzed. Systemic anaphylaxis and mucosal mast cell degranulation response (MMCR) upon IP challenge were quantified by hypothermia shock response (HSR) and elevation of plasma mMCP-1, respectively. Mice were monitored for dermatitis and alopecia. Spleen tissue extracts were used in measuring immune-activation biomarkers. Whereas the SSWP elicited higher titers of SIgA, the ASWP elicited higher titers of SIgE, SIgG1, SIgG2a and higher TIgE levels. The ASWP elicited significantly higher HSR and MMCR. Only ASWP but not SSWP elicited dorsal neck dermatitis lesions in 44% of mice. Alopecia lesions, without inflammation, were noted in 22% of ASWP- and 33% of SSWP-injected mice. Furthermore, ASWP and SSWP elicited distinct patterns of activation of acute-phase response proteins, chemokines, cytokines, growth factors, matrix proteins and signaling proteins. These data provide the first direct evidence that WP fractions that differ in solubility elicit qualitatively distinct immune and clinical reactions in genetically identical mice.