Peripheral sensitisation and central sensitisation are implicated in the development of neuropathic pain with neuroplasticity occurring at multiple levels of the pain pathway. Hypersensitivity of the spinothalamic tract has been described in neuropathic animal models of diabetes. Spinal dorsal horn neurones of diabetic rats exhibit abnormally high spontaneous firing, suggesting an imbalance between excitatory and inhibitory signals converging within this structure. GABAergic neurones within the spinal cord and thalamus are crucial for the transmission of painful stimuli to higher centres of the brain that are involved in pain perception. GABAA receptors (GABAARs) are an important target for many clinical drugs, and certain endogenous neurosteroids act as potent allosteric modulators of these receptors. A developmental change in the rate of exponential decay of GABAergic synaptic events has been observed in other types of neurones and this may be related in part to fluctuations in endogenous neurosteroid tone. The objective of this study was to investigate changes to inhibitory neurotransmission with development in three levels of the pain pathway and to explore potential mechanisms underlying diabetic neuropathy. The whole-cell patch-clamp technique was used on slices of neural tissue. Electrophysiological recordings were obtained from wild type mice between the ages of 6 and 80 days in lamina II of the spinal cord, the nucleus reticularis (nRT) of the thalamus and the cerebral cortex. Recordings were also obtained from mice with diabetic neuropathy (ob/ob and db/db) between the ages of 60 and 80 days. Neurosteroids and their precursors were employed along with compounds that prevented their activity at the GABAAR such as ?-cyclodextrin, which is a barrel-shaped cyclic oligosaccharide with a lipophilic interior that sequesters neurosteroids. Behavioural experiments were also performed using von Frey filaments and the tail flick test to examine mechanical and thermal nociception. Recordings from the spinal cord, the thalamus and the cerebral cortex revealed that the decay time of miniature inhibitory postsynaptic currents are significantly reduced with development. The neurosteroids allopregnanolone and ganaxolone were significantly more effective in neurones from the older mice. In contrast, ?-cyclodextrin had significantly less effect in neurones from the older mice. In mature diabetic mice (ob/ob mice), the endogenous neurosteroid tone is reduced compared to control mice, but certain neurosteroid compounds have a greater effect on the GABAARs of these diabetic mice. In addition, the diabetic mice exhibit mechanical allodynia and hyperalgesia, which is responsive to exogenously applied neurosteroids. These results are consistent with the hypothesis that a dramatic reduction in endogenous neurosteroid tone occurs as development progresses and that this impacts on the exponential decay time of GABAergic mIPSCs within neurones of the pain pathway. The higher neurosteroid tone in the youngest mice may confer a degree of neural protection over the nervous system as it develops. The reduction of endogenous neurosteroid tone in diabetic mice may be associated with their hypersensitivity. It is possible that pregnane-derived neurosteroids may exert analgesic effects in pathological pain states by attempting to restore the physiological GABAergic inhibitory tone that is observed in immature animals.

Background: Despite a lack of consensus on its utility, clinicians have traditionally relied on plantar pressure (PP) to predict ulcer risk and prescribe interventions in individuals with diabetic peripheral neuropathy (DPN). Joint kinematics and kinetics have the potential to contribute to DPN assessment and treatment, however previous studies have not accounted for walking speed nor integrated a full-body analysis with a detailed foot model. Purpose: To assess PP and gait alterations in DPN by controlling walking speed and incorporating a multisegment foot model into a full-body gait analysis. We hypothesize that hip and ankle kinetics will be altered consistent with distal muscle weakness. Methods: Ten subjects with DPN (height: 178.79 ± 8.55 cm, weight: 108.78 ± 16.67 kg, age: 61.5 ± 13.53 years), and 10 healthy matched controls (height: 180 ± 6.37 cm, weight: 92.87 ± 14.5 kg, age: 59.4 ± 7.5 years) participated in this cross-sectional study. Fifty-six reflective markers were attached to each subject according to a full-body model, including a multisegment foot. Subjects walked at a controlled speed (1 m/s) while plantar pressure, kinematic and kinetic data were collected. Functional data analysis was used to compare kinematic and kinetic data between groups, while independent t-tests and a Benjamini-Hochburg procedure was used to compare plantar pressure and joint work metrics. Results: Individuals with DPN presented with a delayed transition from hip extension to hip flexion moment and a decrease in peak hip flexion moment. There were no major changes found at the knee. There was an increase in peak dorsiflexion angle and delayed power generation in both the ankle and midtarsal joints. DPN subjects also showed a decreased midtarsal positive work. The only significant PP metric found was a decrease in peak PP under the lateral toes. Conclusion: Findings demonstrated that individuals with DPN use a hip compensation mechanism to overcome distal muscle weakness. Ankle and midfoot alterations are consistent with muscle weakness, requiring proximal compensations. Joint mechanics were more informative than PP measurements and may provide additional insight into DPN assessment and treatment.

Orientador: Ana Cláudia Moreira Almeida Verdu / Banca: Edson Massayuki Huziwara / Banca: Nassim Chamel Elias / Resumo: Considerando a necessidade de delinear e sistematizar condições de ensino de comportamento verbal a pessoas com repertório verbal mínimo e o uso crescente do Multiple Exemplar Instruction (MEI), estratégia que coloca diferentes topografias de operantes verbais e seus controles de estímulos em rotatividade, com potencial para integrar operantes verbais, o presente trabalho realizou três estudos. O Estudo 01 apresenta uma revisão de literatura com os descritores "multiple exemplar instruction" OR "multiple exemplar training", no Web of Science, Scopus e Pubmed, sem restrição de ano. Visou sistematizar o uso dos termos Multiple Exemplar Instruction (MEI) e Multiple Exemplar Training (MET), identificar e descrever sob quais arranjos de procedimento o MEI tem sido usado e seus resultados. Foram selecionadas 65 publicações e MET foi o termo mais frequentemente usado; em relação ao MEI, a população mais frequentemente envolvida nos estudos foram crianças com Transtorno do Espectro Autista (TEA), no entanto outros diagnósticos demonstraram menor exigência de exposição ao MEI. Discute-se a aproximação entre os termos MEI e MET na literatura e elementos de distinção. O Estudo 02 apresenta um estudo de caso que explorou os efeitos do MEI sobre a integração entre operantes de ouvir e falar e sobre variabilidade no desempenho de uma criança com Desordem do Espectro da Neuropatia Auditiva (DENA). O participante tinha sete anos de idade, usuário de implante coclear (IC) unilateral há um ano... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Considering the need to delineate and to systematize verbal behavior teaching, the Multiple Exemplar Instruction (MEI) has been frequently applied as a teaching strategy for people with minimal verbal repertoire. The MEI consist in rotation on stimulus controls and different topographies responses, and it has the potential to integrate verbal operants. The present thesis conducted three studies. Study 01 presents a literature review with the descriptors "multiple exemplar instruction" OR "multiple exemplar training" in the Web of Science, Scopus, and Pubmed, without year restriction. The objective was to systematize the use of the terms Multiple Exemplar Instruction (MEI) and Multiple Exemplar Training (MET), and also to identify and to describe the MEI arrangements and their results. 65 publications were selected. The most used term was MET. The most frequent population in the studies with MEI were children with Autism Spectrum Disorder (ASD). Children with other diagnoses needed few exposures to MEI. The approximations and distinctions between the terms MEI and MET in the literature were discussed. Study 02 presents a case study that evaluated the effects of MEI on the integration between listening and speaking operants and on performance variability in a child with Spectrum Disorder of Auditory Neuropathy (SDAN). The participant was seven years old, and he received unilateral cochlear implant (CI) at one year and four months ago. In the tests, the participant showed the hi... (Complete abstract click electronic access below) / Mestre

Paclitaxel, vincristine, oxaliplatin, and bortezomib are cancer chemotherapy drugs with adverse effects that include chemotherapy-induced neuropathic pain (CINP) as well as depression of behavior and mood. In the clinical setting, opioids are often used concurrently with or following chemotherapy to treat pain related to the cancer or CINP, but repeated opioid exposure can also increase the risk of opioid abuse. This dissertation evaluated the effect of chemotherapy treatment on motivated behaviors and opioid reward in rats. The main findings of this evaluation are as follows: (1) Chemotherapy, at doses that produce robust and sustained mechanical hypersensitivity produce only weak or nonexistent depression of positively reinforced operant responding maintained either by electrical brain stimulation in an assay of intracranial self-stimulation or by food pellets in an assay of food-maintained responding. (2) There was no correlation between the expression of mechanical hypersensitivity and depression of motivated behaviors across individual animals, suggesting that these two effects of chemotherapy do not share common mechanisms of action. (3) Mechanical hypersensitivity, but not behavioral depression could be reversed with morphine. (4) The class of chemotherapeutic used in preclinical models is a determinant of the severity of effects on neuropathy-related endpoints and on the time course of these effects. (5) Chemotherapy does not protect against the rewarding effects of repeated morphine administration and does not alter the time course of the enhancement of reward with repeated morphine exposure. These findings suggest that administration of chemotherapy to rats induces mechanical hypersensitivity while failing to decrease behaviors dependent on mesolimbic dopamine signaling or protecting against morphine abuse-related effects. While apparent that chemotherapy can produce peripheral neuropathy, the data in this dissertation does not support the hypothesis that chemotherapy can produce behavioral depressant manifestations of chemotherapy-induced neuropathic pain (CINP) in rats.

<p>Leber´s hereditary optic neuropathy (LHON), a disease affecting vision, is caused by several point mutations in mitochondrial DNA. Mutations leading to a defect NADH ubiquinone oxidoreductase protein will affect the respiratory chain and cause a disturbed ATP production. It is still unknown why this defect leads to the degeneration of retinal ganglion cells and cells in the opticus nerve as well as demyelination of axons in these areas. Analysis of mitochondrial DNA is an important tool in the diagnosis of the disease. At the present time analysis is based on cleavage by restriction enzymes, which only detects two of the most frequent mutations: m.3460G>A and m.11778G>A. This is far too few considering that more than 30 mutations are known to be associated with LHON. Therefore a new analysis method is requested. Here we describe a method based on the sequencing of the mitochondrial genes MT-ND1, MT-ND4 and MT-ND6, which will detect more than 15 different point mutations associated with the disease. To validate the analysis, DNA from 31 patients with LHON symptoms were sequenced; of these 10 were found to be positive for a LHON mutation. This result indicates that the sequencing analysis will be more effective in diagnosis of LHON than restriction enzymes.</p> / <p>Lebers hereditära optikus neuropati (LHON) är en sjukdom som beror på genetiska förändringar i arvsmassan som leder till att cellens energiomsättning rubbas. Detta gör att nervceller i ögat och synnerven bryts ned vilket leder till en synnedsättning. En patient som drabbas av LHON har inga symptom fram till dess att synen börjar försämras. Sjukdomsförloppet går snabbt och på bara några veckor är patienten ofta helt blind. Diagnostik av LHON idag utgörs av flera undersökningar av öga och synfält. Diagnosen bekräftas av en analys av arvsmassan som finns i mitokondrien, cellens energifabrik. Här beskriver vi en ny förbättrad analysmetod baserad på DNA sekvensering, dvs. bestämning av baserna i mitokondriella arvsmassan. För att utvärdera analysen har vi undersökt 31 patienter med misstänkt LHON - av dessa visade sig 10 bära på en sjuklig förändring. Resultatet visar att sekvensering med fördel kan ersätta den tidigare analysmetoden då fler sjukliga förändringar kan påvisas och utförandet av analysen är mer användarvänligt.</p>

Leber´s hereditary optic neuropathy (LHON), a disease affecting vision, is caused by several point mutations in mitochondrial DNA. Mutations leading to a defect NADH ubiquinone oxidoreductase protein will affect the respiratory chain and cause a disturbed ATP production. It is still unknown why this defect leads to the degeneration of retinal ganglion cells and cells in the opticus nerve as well as demyelination of axons in these areas. Analysis of mitochondrial DNA is an important tool in the diagnosis of the disease. At the present time analysis is based on cleavage by restriction enzymes, which only detects two of the most frequent mutations: m.3460G&gt;A and m.11778G&gt;A. This is far too few considering that more than 30 mutations are known to be associated with LHON. Therefore a new analysis method is requested. Here we describe a method based on the sequencing of the mitochondrial genes MT-ND1, MT-ND4 and MT-ND6, which will detect more than 15 different point mutations associated with the disease. To validate the analysis, DNA from 31 patients with LHON symptoms were sequenced; of these 10 were found to be positive for a LHON mutation. This result indicates that the sequencing analysis will be more effective in diagnosis of LHON than restriction enzymes. / Lebers hereditära optikus neuropati (LHON) är en sjukdom som beror på genetiska förändringar i arvsmassan som leder till att cellens energiomsättning rubbas. Detta gör att nervceller i ögat och synnerven bryts ned vilket leder till en synnedsättning. En patient som drabbas av LHON har inga symptom fram till dess att synen börjar försämras. Sjukdomsförloppet går snabbt och på bara några veckor är patienten ofta helt blind. Diagnostik av LHON idag utgörs av flera undersökningar av öga och synfält. Diagnosen bekräftas av en analys av arvsmassan som finns i mitokondrien, cellens energifabrik. Här beskriver vi en ny förbättrad analysmetod baserad på DNA sekvensering, dvs. bestämning av baserna i mitokondriella arvsmassan. För att utvärdera analysen har vi undersökt 31 patienter med misstänkt LHON - av dessa visade sig 10 bära på en sjuklig förändring. Resultatet visar att sekvensering med fördel kan ersätta den tidigare analysmetoden då fler sjukliga förändringar kan påvisas och utförandet av analysen är mer användarvänligt.

Diabetic neuropathy is believed to arise due to oxidative stress following hyperglycemic situations. Uncoupling proteins (UCPs) constitute a subgroup of mitochondrial transporter proteins with putative antioxidant properties. By dissipating the proton gradient over the mitochondrial inner membrane, these proteins reduce the mitochondrial inner membrane potential (MMP), and thereby, the mitochondrial production of reactive oxygen species (ROS) is decreased. In this thesis I have examined the regulation of UCP2, UCP3, and UCP4 by the neuroprotective hormone insulin-like growth factor type 1 (IGF-1). I have also investigated the possible involvement of UCP3 in IGF-1-mediated neuroprotection following high glucose treatments. All studies were performed using human neuroblastoma SH-SY5Y cells as an in vitro cell model. The major findings were as follows: i. Native SH-SY5Y cells expressed UCP2, UCP3, and UCP4. ii. UCP3 was upregulated by IGF-1 via activation of the IGF-1 receptor. IGF-1 increased UCP3 mRNA and protein levels primarily via activation of the “classical” anti-apoptotic phosphatidyl inositol 3 (PI3)-kinase signaling pathway, as shown by incubation with specific inhibitors of the PI3-kinase and mitogen activated protein (MAP) kinase signaling pathways. iii. UCP2 and UCP4 protein levels were only marginally or not at all regulated by IGF-1. These UCPs are probably not involved in IGF-1-mediated neuroprotection. iv. High glucose concentrations reduced the UCP3 protein levels in highly differentiated SH-SY5Y cells. Concomitantly, the MMP and the levels of ROS and glutathione increased, whereas the number of neurites per cell was reduced. This supports an antioxidant and neuroprotective role of UCP3 v. IGF-1 prevented the glucose-induced reduction in UCP3 protein levels. In parallel, the effects on MMP, levels of ROS and glutathione, and number of neurites per cell were abolished or significantly reduced. These data suggest that UCP3 is involved in IGF-1-mediated neuroprotection.

El Glucagon-like peptide-1 (GLP-1), un pèptid derivat del processament del proglucagó en les cè_lules L del jejúnum i del colon, inhibeix la secreció àcida gàstrica i el buidament gàstric, a més de reduir la capacitat d'ingesta. Els mecanismes d'acció del GLP-1 no estan clars. Hi ha dades que suggereixen que la inhibició de les funcions gàstriques per part del GLP-1 estan mitjançades pel nervi vagus.L'acomodació o relaxació gàstrica en resposta a la ingesta és un reflex mitjançat pel vagus que dóna lloc a un increment del volum o capacitat gàstrica que impedeix l'increment de la pressió intragàstrica quan mengem, evitant així l'aparició de símptomes. La primera hipòtesi que vàrem plantejar va ser que el GLP-1 inhibeix el reflex d'acomodació gàstrica i que això explicaria en part la reducció de la capacitat d'ingesta que s'observa en administrar el GLP-1. Per provar aquesta hipòtesi vàrem comparar els efectes d'una infusió endovenosa de GLP-1 i placebo, en voluntaris sans, sobre l'acomodació gàstrica postprandial (mesurada amb la tècnica SPECT), l'increment postprandial del polipèptid pancreàtic (marcador de funció vagal abdominal) i el volum d'un nutrient líquid (Ensure®) ingerit fins atansar la sacietat màxima. Els resultats del primer estudi van demostrar que el GLP-1 no inhibeix l'acomodació gàstrica postprandial; al contrari, va augmentar el volum gàstric en dejú i després del menjar. Això es va acompanyar per una marcada inhibició de la secreció de polipèptid pancreàtic, la qual està sota control vagal colinèrgic. Degut a que el to gàstric està mantingut per influència colinèrgica vagal, els resultats obtinguts són compatibles amb la hipòtesi de que el GLP-1 indueix relaxació gàstrica (augment de volum gàstric) per inhibició de les vies colinèrgiques vagals. Si aquesta hipòtesi fos certa, en cas de disfunció vagal o vagotomia, el GLP-1 no produiria relaxació gàstrica (augment de volum gàstric). Per provar aquesta segona hipòtesi, vàrem estudiar l'efecte de la mateixa infusió endovenosa de GLP-1, comparada amb placebo, en els volums gàstrics de subjectes amb neuropatia vagal diabètica. Vàrem comparar també els volums gàstrics dels malalts diabètics que rebien placebo amb els dels subjectes sans estudiats en el primer estudi presentat en aquesta tesi. Al contrari del que vàrem observar en subjectes sans, el GLP-1 no va augmentar el volum gàstric en malalts diabètics amb neuropatia vagal. Això suggereix que l'efecte del GLP-1 sobre el volum gàstric està mitjançat pel nervi vagus.Els malalts diabètics avaluats presentaven volums gàstrics, tan en dejú com després del menjar, similars als dels subjectes sans. El nervi vagus participa en el control del to o volum gàstric, però hi ha altres mecanismes que també hi participen. Es més, hi ha evidència de que el to gàstric pot ser controlat adequadament en absència de innervació vagal extrínseca. De manera que la troballa de la existència de volums gàstrics normals en malalts amb neuropatia vagal s'afegeix a la evidència de que, en cas d'alteració del reflex principal vago-vagal, es produeix un mecanisme adaptatiu per preservar la resposta de relaxació gàstrica postprandial. / Glucagon-like peptide-1 (GLP-1), a peptide derived from the processing of the proglucagon molecule in L cells of the jejunum and colon, inhibits gastric acid secretion and gastric emptying rate and it also decreases food consumption. It is still not clear how these effects of GLP-1 are mediated. There are data that suggest that GLP-1 inhibition of upper gastrointestinal functions is mediated through the vagus nerve.The accommodation or relaxation of the stomach in response to meal ingestion is a vagally-mediated reflex that increases gastric volume. This prevents the increase in intragastric pressure when food and fluid enter in the stomach, avoiding the development of symptoms. We hypothesized that GLP-1 inhibits the gastric accommodation reflex and that this effect could partly explain the reduced food consumption with GLP-1. To test this hypothesis, we compared, in healthy volunteers, the effects of intravenous infusion of GLP-1 and placebo, on postprandial gastric accommodation (as measured by the SPECT technique), postprandial response of plasma human pancreatic polypeptide (a surrogate marker of vagal abdominal function) and the volume of a nutrient liquid meal (Ensure_) ingested at maximum satiation. The results of the first study showed that GLP-1 does not inhibit postprandial gastric accommodation; on the contrary, it increased fasting and postprandial gastric volumes. This was accompanied by a marked inhibition of the pancreatic polypeptide release, which is under vagal cholinergic control. Since gastric tone is maintained by vagal cholinergic input, the results observed in our first study suggested that GLP-1 could induce gastric relaxation (increase gastric volume) by inhibition of vagal cholinergic pathways. If this hypothesis were true, one would predict that in the presence of vagal dysfunction or vagotomy, GLP-1 would not induce gastric relaxation (increase gastric volume). To test this second hypothesis we studied the effect of the same intravenous infusion of GLP-1, compared to placebo, on gastric volumes in a sample of subjects with diabetes affected with vagal neuropathy. We also compared gastric volumes in diabetic patients on placebo to those in the healthy subjects who participated in the first study presented in this thesis. In contrast to effects in health, GLP-1 did not increase gastric volume in diabetics with vagal neuropathy. This suggests that the effect of GLP-1 on gastric volume is dependent on vagal function. The diabetic patients evaluated had gastric volumes similar to those of healthy controls. The vagus nerve participates in the control of gastric volume or tone; however, there are other mechanisms involved. Furthermore, there is increasing evidence that gastric tone may be adequately controlled in the absence of extrinsic vagal innervation. Thus, we believe that the normal gastric volume response to a meal observed in the presence of vagal neuropathy adds to the growing evidence of the existence of an adaptive response preserving postprandial gastric relaxation when the main vago-vagal reflex is impaired.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成5年1月28日 平山正昭氏の博士論文として提出された

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