Indiana University-Purdue University Indianapolis (IUPUI) / Synaptic transmission is coordinated by a litany of protein-protein interactions that rely on the proper localization and function of pre- and post-synaptic Ca2+ channels. The axonal guidance/specification collapsin response mediator protein-2 (CRMP-2) was identified as a potential partner of the pre-synaptic N-type voltage-gated Ca2+ channel (CaV2.2). CRMP-2 bound directly to CaV2.2 in two regions; the channel domain I-II intracellular loop and the distal C-terminus. Both proteins co-localized within presynaptic sites in hippocampal neurons. Overexpression in hippocampal neurons of a CRMP-2 protein fused to EGFP caused a significant increase in Ca2+ channel current density whereas lentivirus-mediated CRMP-2 knockdown abolished this effect. Cell surface biotinylation studies showed an increased number of CaV2.2 at the cell surface in CRMP-2–overexpressing neurons. Both activity- and CRMP-2-phosphoryation altered the interaction between CaV2.2 and CRMP-2. I identified a CRMP-2-derived peptide (called CBD3) that bound CaV2.2 and effectively disrupted the interaction between CaV2.2 and CRMP-2. CBD3 peptide fused to the HIV TAT protein (TAT-CBD3) decreased neuropeptide release from sensory neurons and excitatory synaptic transmission in dorsal horn neurons, and reversed neuropathic hypersensitivity produced by an antiretroviral drug. Unchecked Ca2+ influx via N-methyl-D-aspartate receptors (NMDARs) has been linked to activation of neurotoxic cascades culminating in cell death (i.e. excitotoxicity). CRMP-2 was suggested to affect NMDAR trafficking and possibly involved in neuronal survival following excitotoxicity. Based upon these studies, I hypothesized that a peptide from CRMP2 could preserve neurons in the face of excitotoxic challenges. Lentiviral–mediated CRMP2 knockdown or treatment with TAT-CBD3 blocked neuronal death following glutamate exposure likely via blunting toxicity from NMDAR-mediated delayed calcium deregulation. TAT-CBD3 induced internalization of the NMDAR subunit NR2B in dendritic spines without altering somal surface expression. TAT-CBD3 reduced NMDA-mediated Ca2+-influx and currents in cultured neurons. The presented work validates CRMP-2 as a novel modulator of pre- and post-synaptic Ca2+ channels and provides evidence that the TAT-CBD3 peptide could be useful as a potential therapeutic for both chronic neuropathic pain and excitotoxicity following stroke or other neuronal insults.

The two neuron types that initially degenerate with Alzheimer's Disease are the cholinergic projections from the septum to the hippocampus and from the substantia innominata to the cortex, and the somatostatinergic neurons in the hippocampus and cortex. The functional relationship between these two types of neurons was investigated using folic acid, a neuro-excitant, and cysteamine, a somatostatin depleter. Folic acid causes a neuron to fire at a much higher rate than normal (Spector, 1971). Folic acid was injected into either the septum or the substantia innominata, and the long-term effect of the resulting acute hyperactivity of the cholinergic neurons on somatostatin neurons was measured as somatostatin-like immunoreactivity in the hippocampus and cortex. Glutamic acid decarboxylase activity, a marker for gamma-amino butyric acid (GABA) neurons, was also measured because it has been shown to decrease in the cortex after injection of folic acid into the substantia innominata. The administration of folic acid to the cholinergic neurons did not have a significant long-term effect on somatostatin-like immunoreactivity nor glutamic acid decarboxylase activity; therefore, a hyperactivity of the cholinergic neurons did not result in degeneration of GABAergic nor somatostatinergic neurons. Cysteamine causes a short-term depletion of somatostatin. Cysteamine was injected subcutaneously and the effect of an acute decrease of brain somatostatin on the cholinergic neurons was studied by measuring high affinity choline uptake, an indicator of cholinergic activity. Administration of cysteamine had no measured effect on high affinity choline uptake in the hippocampus or frontal cortex; therefore, a depletion of somatostatin did not effect cholinergic activity. The assay for high affinity choline uptake was tested by injection of pentobarbital, a drug known to decrease high affinity choline uptake. We detected a decrease in high affinity choline uptake after pentobarbital administration, indicating that if cysteamine were decreasing high affinity choline uptake, the assay would have detected it. / Master of Science

La dépression est l’un des troubles mentaux les plus fréquents de nos jours. C’est une maladie liée en général à un déficit en neurotransmetteurs monoaminergiques (sérotonine, noradrénaline et dopamine). Les antidépresseurs actuels agissant via des mécanismes monoaminergiques présentent de nombreux effets secondaires et peuvent conduire à une accoutumance. L’une des approches impliquerait le ciblage des récepteurs mélatoninergiques afin de resynchroniser les rythmes circadiens qui sont perturbés dans certaines pathologies du système nerveux central, notamment la dépression. La conception de ligands non monoaminergiques et possédant des propriétés chronobiotiques constituerait une stratégie prometteuse.L’agomélatine (Valdoxan®) issue d’une collaboration entre le laboratoire de chimie thérapeutique (EA4481 - GRIIOT) et les laboratoires Servier est commercialisée depuis 2009 pour le traitement de la dépression majeure. Ce bioisoster naphtalénique de la mélatonine possède un mécanisme d’action innovant. Elle se distingue par ses propriétés agoniste non sélectif des récepteurs mélatoninergiques MT1 et MT2 et antagoniste des récepteurs 5-HT2c.L’objectif de ce travail réside dans la conception et la synthèse de nouveaux ligands successeurs de l’agomélatine présentant un profil pharmacologique et pharmacocinétique amélioré. Différentes pharmacomodulations ont été réalisées sur l’agomélatine. Les stratégies de «Drug Design» notamment le principe de bioisostérie ont été appliquées, nous permettant ainsi la synthèse de nouvelles familles de composés présentant des profils pharmacologiques intéressants. / Nowadays, depression related to a deficit in nonoaminergic neurotransmitters, is the most frequent mental illness. Available antidepressive drugs acting through monoamnergic mechanisms possess a lot of side effects and can lead to an addiction. One approach involves targeting melatoninergic receptors to resynchronize circadian rhythms, which are known to be perturbed in some pathology related to nervous central system as depression. So conception of non-monoaminergic ligands with chronobiotic properties would constitute a promising strategy.Agomelatine (Valdoxan®) a novel antidepressant developed by Servier and our laboratory (EA4481 - GRIIOT) was granted marketing authorization in 2009 for the treatment of major depressive disorder. This naphthalen analogous of melatonin possess an innovative mechanism. It acts as a non selective melatoninergic MT1/MT2 receptors agonist and a serotonin 5-HT2c receptor antagonist.The aim of this work is to design and synthesize new potential successors of agomelatine with an improved pharmacological and pharmacokinetic profile. Drug Design strategies such as bioisosterism were applied to allow the elaboration of new series of compounds with interesting pharmacological profiles.

O córtex pré-frontal medial (PFCm) é caracterizado por entradas glutamatérgicas e dopaminérgicas que convergem sobre os mesmos neurônios alvos. Devido à escassa informação sobre as bases anatômicas das interações entre a dopamina (DA) e o glutamato (Glu), mapeamos a distribuição de subunidades (Su) de receptores (Rs) de Glu do tipo AMPA, NMDA e kainato no PFCm e investigamos a sua expressão em neurônios contendo a fosfoproteína DARPP-32 e em interneurônios. Os resultados mostram que as Su GluR2/3 dos Rs do tipo AMPA são as mais amplamente distribuídas no PFCm e expressas em todos os neurônios DARPP-32+. GluR2/3 é também amplamente co-localizado com as Su NMDAR1 dos Rs de Glu do tipo NMDA e GluR5/6/7 dos Rs do tipo kainato. Em contraste, as Su GluR1 e GluR4 são somente fracamente expressos no PFCm e não são co-localizados com DARPP-32, porém com GABA ou parvalbumina. Os resultados indicam que as Su GluR2/3, NMDAR1 e GluR5/6/7 são amplamente expressos em neurônios piramidais DARPP-32+ enquanto GluR1 e GluR4 são predominantemente expressos em interneurônios do PFCm. / The medial prefrontal cortex (PFCm) is characterized by glutamatergic and dopaminergic afferents that converge on the same target neurons. Since there is only limited information about the anatomical bases for interactions between dopamine (DA) and glutamate (Glu), we mapped the distribution of AMPA, NMDA and kainate Glu receptor (Rs) subunits (Su) in the PFcm and investigated their expression in neurons containing the phosphprotein DARPP-32 and in interneurons. Results show that the Su GluR2/3 of AMPA type Rs are the most prominently distributed in the PFCm and expressed in all neurons DARPP-32+. GluR2/3 is also widely co-localized with the NMDA type Su NMDAR1 and the Kainate Su GluR5/6/7. In contrast, the Su GluR1 and GluR4 are only weakly expressed in the PFCm and are not colocalized with DARPP-32 but with GABA or parvalbumin. Results indicate that the Su GluR2/3, NMDAR1, and GluR5/6/7 are prominently expressed in DARPP-32+ pyramidal neurons, whereas GluR1 and GluR4 are predominantly expressed by interneurons in the PFC.

A interleucina-2 (IL-2) atua na modulação da atividade dopaminérgica, que influencia o comportamento maternal. Neste estudo observou-se que o estado lactacional reduziu a atividade geral em campo aberto, porém não alterou os níveis de dopamina e seus metabólitos. A administração de IL-2, tanto sistêmica com diretamente no N.Ac não alterou a atividade geral em campo aberto, indicando a ausência de efeito motor da mesma. Além disso, a administração de IL-2 sistêmica e no N.Ac reduziu as porcentagens de ratas que agrupam os filhotes e de filhotes agrupados por rata. A injeção de IL-2 no N.Ac aumentou as latências de busca do primeiro e segundo filhotes e o comportamento agressivo. A administração sistêmica de IL-2 em ratas virgens reduziu somente do valor absoluto de DOPAC (metabólito de dopamina) após 100 e 120. Este achado corrobora a idéia de que o IL-2 altera a atividade dopaminérgica. Os resultados sugerem que a administração sistêmica da dose de IL-2 estudada não influencia de forma significativa os níveis de dopamina e de seus metabólitos no N.Ac. / Interleukin-2 (IL-2) modulates the dopaminergic neurotransmission, that into the nucleus accumbens (N.Ac) plays a role in maternal behavior. The IL-2 dose used in this study does not have motor effects. Both peripheral and central N.Ac injections decreased the percent of mothers grouping pups together and the number of grouped pups. IL-2 injections into the N.Ac resulted in longer latencies to retrieve first and second pups and increased aggressive behavior. In order to test if these behavioral effects would be related to the IL-2 reduced the DOPAC (dopamine metabolite) concentrations in the N.Ac of virgin rats treated with IL-2. This suggests suggest that the IL-2 dose used in this study does not alter so much the dopaminergic transmission by influencing extracellular levels of this neurotransmitter.

Nesse trabalho de duas partes, colunas monolíticas poliméricas foram aplicadas em extração em fase sólida e em nanocromatografia capilar, duas das suas mais importantes aplicações. Na primeira parte foi desenvolvido um monolito para extração em fase sólida dos metais Cd(II), Pb(II) e Cu(II), que foi acoplada on-line com detecção eletroquímica com o auxílio de instrumentação de análise por injeção sequencial (SIA). A coluna usada como suporte sólido para extração em fase sólida foi obtida com a copolimerização entre formador de ligação cruzada etileno dimetacrilato (EDMA) e monômero funcional glicidil metacrilato (GMA), preparada a partir de uma mistura reacional composta de 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol e 20% 1,4- butanodiol, aquecida durante 24 horas à 60°C. Essa composição e condições de polimerização favoreceram a permeabilidade do monolito, o que foi necessário para o acoplamento no SIA. Após a obtenção do monolito base o mesmo foi modificado pela reação do anel epóxi do grupo GMA com ácido iminodiacético (IDA) para garantir propriedades de quelação de metais e maior capacidade de adsorção para a coluna. O monolito foi caracterizado com imagens de microscopia de varredura eletrônica (MEV) e a capacidade de extração foi de 4,4 ± 0,3 mg Cu(II) m-1 obtida com curvas de breakthrough. O método de determinação on-line dos metais operado por SIA, que executou as etapas de carregamento de amostra, limpeza da coluna, eluição dos analitos e recondicionamento dos sítios ativos teve frequência amostral de 6,8 injeções por hora. Os limites de detecção (LD) e quantificação (LQ) para o método foram, respectivamente, de 1,0 e 3,3 µg L-1 para o Cd(II), 0,7 e 2,2 µg L-1 para o Pb(II) e 0,5 e 1,8 µg L-1 para o Cu(II). O método foi aplicado na determinação dos metais em diferentes matrizes de águas naturais, sendo encontrado Cu(II) em algumas amostras. A exatidão do método foi avaliada com estudos de adição e recuperação nessas águas, obtendo-se valores entre 75,5 e 116,6%. Na segunda parte do trabalho foi utilizada uma coluna polar composta da sulfobetaína zwitteriônica N,N-dimetil-N-metacriloil-oxietil-N-(3-sulfopropil) amônio betaína (MEDSA) e do formador de ligações cruzadas dioxietil dimetacrilato (DiEDMA) em Nanocromatografia de Interação Hidrofílica (HILIC) para fazer a separação de Dopamina, Epinefrina, Norepinefrina, L-DOPA, Tiramina, DOPAC e Ácido Homovanílico, neurotransmissores, alguns de seus metabólitos e precursores, compostos polares de baixa massa molecular. A seletividade cromatográfica da coluna foi altamente dependente da composição da fase móvel aquosa:orgânica, apresentando um mínimo de retenção na transição do mecanismo HILIC para a fase reversa (RP). Ajustando os dados experimentais de fatores de retenção em função da composição da fase móvel com o modelo de retenção duplo foi possível prever qual composição de fase móvel promoveria a separação dos analitos da mistura, que foi atingida em torno de 85% acetonitrila e 15% H2O. A coluna foi modificada com o grupo zwitteriônico 2-metacriloil-oxietil fosforilcolina (MPC) por UV grafting e a modificação da metade do comprimento da coluna durante 30 minutos de exposição UV levou às mudanças na seletividade cromatográfica. / In this two parts work, polymeric monolithic columns were applied in solid phase extraction and in capillary nanochromatography, two of their most important applications. In the first part, a monolith for solid phase extraction of Cd(II), Pb(II) and Cu(II) metals was developed and coupled online with electrochemical detection with the aid of sequential injection analysis instrumentation (SIA). The column used as a solid support for solid phase extraction was obtained by copolymerization between the crosslinker ethylene dimethacrylate (EDMA) and the functional monomer glycidyl methacrylate (GMA), prepared from a reaction mixture composed of 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol and 20% 1,4-butanediol, heated at 60 ° C for 24 hours. This composition and polymerization conditions favored monoliths permeability, which was required for the SIA coupling. After obtaining the base monolith, it was modified by reaction of the epoxy ring of the GMA group with the iminodiacetic acid (IDA) to guarantee metals chelating properties and increase adsorption capacity for the column. The monolith was characterized by scanning electron microscopy (SEM) images and extraction capacity was 4.4 ± 0.3 mg Cu(II) m-1, obtained from breakthrough curves. The method for online determination of metals operated by SIA, which performed the steps of sample loading, column cleaning, analyte elution and reconditioning of active sites had a sampling throughput of 6.8 injections per hour. The limits of detection (LD) and quantification (LQ) for the method were, respectively, 1.0 and 3.3 µg L-1 for Cd(II), 0.7 and 2.2 µg L-1 for the Pb(II) and 0.5 and 1.8 µg L-1 for Cu(II). The method was applied for the determination of metals in different natural water matrices, finding Cu(II) in some samples. The accuracy of the method was evaluated with addition and recovery studies in these waters, finding recoveries between 75.5 and 116.6%. In the second part of the work, a polar column composed of the zwitterionic sulfobetaine N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium betaine (MEDSA) and the cross-linker dioxyethyl dimethacrylate (DiEDMA) was used in Hydrophilic Interaction Nanocromatography (HILIC) to separate Dopamine, Epinephrine, Norepinephrine, L-DOPA, Tyramine, DOPAC and Homovanilic Acid, neurotransmitters, some of its metabolites and precursors, which are polar compounds of low molecular mass. The chromatographic selectivity of the column was highly dependent on the composition of the aqueous:organic mobile phase, showing a minimum retention at the transition from the HILIC to the reverse phase (RP) mechanism. By adjusting the experimental data of retention factors as a function of mobile phase composition with the double retention model it was possible to predict which mobile phase composition would promote the separation of the mixed analytes, which was achieved around 85% acetonitrile and 15% H2O. The column was modified with the 2-methacryloyl oxyethyl phosphorylcholine (MPC) zwitterionic group by UV grafting and the modification of half columns length during 30 minutes of UV exposure led to changes in the chromatographic selectivity.

O núcleo acumbens (Acb) é subdividido em core e shell (AcbSh). Há evidências que as divisões do Acb vão além da dicotomia core-shell e que regiões pobres em tirosina hidroxilase (TH) e calretinina (Calr) formam um sistema de corredores no AcbSh. Para detalhar melhor a organização do Acb investigamos a distribuição de TH, Calr, DARPP-32 e do transportador de dopamina (DAT). Em seguida, foi comparada a distribuição destes marcadores com a das subunidades GluA2/3 dos receptores de glutamato do tipo AMPA. Finalmente, exploramos se as aferências pré-frontais são direcionadas à distintos compartimentos do AcbSh. Nossos resultados revelaram que regiões que contém neurônios GluA2/3+ intensamente marcados formam um sistema de corredores no AbSh que coincide com áreas pobres em TH, Calr e DAT. Os experimentos de rastreamento anterógrado indicaram que somente uma pequena parte das aferências pré-frontais é direcionada aos corredores. Nossos resultados delinearam um sistema de corredores no AcbSh que provavelmente constitui um compartimento neuroquímico altamente especializado. / The nucleus accumbens (Acb) is subdivided in core and shell (AcbSh). There is evidence that accumbal subdivisions go beyond this core-shell dichotomy and that regions poor in tyrosine hydroxylase (TH) and calretinin (Calr) form a corridor system in the Acbsh. To better detail accumbal organization, we investigated the distribution of TH, Calr, DARPP-32 and of the dopamine transporter (DAT). Then we compared the distribution of these markers with that of the AMPA-type glutamate receptor subunits GluA2/3. Finally, we explored whether prefrontal afferents are directed to distinct AcbSh compartments. Our findings revealed that regions containing intensely labeled GluA2/3+ neurons form a corridor system in the AcbSh that coincides with regions poor in TH, Calr, and DAT. Anterograde tracing experiments indicated that only a small portion of the prefrontal afferents is specifically related to the corridors. Our findings delineated a complex corridor system in the AcbSh which might constitute a highly specialized neurochemical compartment.

Nesse trabalho de duas partes, colunas monolíticas poliméricas foram aplicadas em extração em fase sólida e em nanocromatografia capilar, duas das suas mais importantes aplicações. Na primeira parte foi desenvolvido um monolito para extração em fase sólida dos metais Cd(II), Pb(II) e Cu(II), que foi acoplada on-line com detecção eletroquímica com o auxílio de instrumentação de análise por injeção sequencial (SIA). A coluna usada como suporte sólido para extração em fase sólida foi obtida com a copolimerização entre formador de ligação cruzada etileno dimetacrilato (EDMA) e monômero funcional glicidil metacrilato (GMA), preparada a partir de uma mistura reacional composta de 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol e 20% 1,4- butanodiol, aquecida durante 24 horas à 60°C. Essa composição e condições de polimerização favoreceram a permeabilidade do monolito, o que foi necessário para o acoplamento no SIA. Após a obtenção do monolito base o mesmo foi modificado pela reação do anel epóxi do grupo GMA com ácido iminodiacético (IDA) para garantir propriedades de quelação de metais e maior capacidade de adsorção para a coluna. O monolito foi caracterizado com imagens de microscopia de varredura eletrônica (MEV) e a capacidade de extração foi de 4,4 ± 0,3 mg Cu(II) m-1 obtida com curvas de breakthrough. O método de determinação on-line dos metais operado por SIA, que executou as etapas de carregamento de amostra, limpeza da coluna, eluição dos analitos e recondicionamento dos sítios ativos teve frequência amostral de 6,8 injeções por hora. Os limites de detecção (LD) e quantificação (LQ) para o método foram, respectivamente, de 1,0 e 3,3 µg L-1 para o Cd(II), 0,7 e 2,2 µg L-1 para o Pb(II) e 0,5 e 1,8 µg L-1 para o Cu(II). O método foi aplicado na determinação dos metais em diferentes matrizes de águas naturais, sendo encontrado Cu(II) em algumas amostras. A exatidão do método foi avaliada com estudos de adição e recuperação nessas águas, obtendo-se valores entre 75,5 e 116,6%. Na segunda parte do trabalho foi utilizada uma coluna polar composta da sulfobetaína zwitteriônica N,N-dimetil-N-metacriloil-oxietil-N-(3-sulfopropil) amônio betaína (MEDSA) e do formador de ligações cruzadas dioxietil dimetacrilato (DiEDMA) em Nanocromatografia de Interação Hidrofílica (HILIC) para fazer a separação de Dopamina, Epinefrina, Norepinefrina, L-DOPA, Tiramina, DOPAC e Ácido Homovanílico, neurotransmissores, alguns de seus metabólitos e precursores, compostos polares de baixa massa molecular. A seletividade cromatográfica da coluna foi altamente dependente da composição da fase móvel aquosa:orgânica, apresentando um mínimo de retenção na transição do mecanismo HILIC para a fase reversa (RP). Ajustando os dados experimentais de fatores de retenção em função da composição da fase móvel com o modelo de retenção duplo foi possível prever qual composição de fase móvel promoveria a separação dos analitos da mistura, que foi atingida em torno de 85% acetonitrila e 15% H2O. A coluna foi modificada com o grupo zwitteriônico 2-metacriloil-oxietil fosforilcolina (MPC) por UV grafting e a modificação da metade do comprimento da coluna durante 30 minutos de exposição UV levou às mudanças na seletividade cromatográfica. / In this two parts work, polymeric monolithic columns were applied in solid phase extraction and in capillary nanochromatography, two of their most important applications. In the first part, a monolith for solid phase extraction of Cd(II), Pb(II) and Cu(II) metals was developed and coupled online with electrochemical detection with the aid of sequential injection analysis instrumentation (SIA). The column used as a solid support for solid phase extraction was obtained by copolymerization between the crosslinker ethylene dimethacrylate (EDMA) and the functional monomer glycidyl methacrylate (GMA), prepared from a reaction mixture composed of 30% GMA, 10% EDMA, 5% H2O, 35% n-propanol and 20% 1,4-butanediol, heated at 60 ° C for 24 hours. This composition and polymerization conditions favored monoliths permeability, which was required for the SIA coupling. After obtaining the base monolith, it was modified by reaction of the epoxy ring of the GMA group with the iminodiacetic acid (IDA) to guarantee metals chelating properties and increase adsorption capacity for the column. The monolith was characterized by scanning electron microscopy (SEM) images and extraction capacity was 4.4 ± 0.3 mg Cu(II) m-1, obtained from breakthrough curves. The method for online determination of metals operated by SIA, which performed the steps of sample loading, column cleaning, analyte elution and reconditioning of active sites had a sampling throughput of 6.8 injections per hour. The limits of detection (LD) and quantification (LQ) for the method were, respectively, 1.0 and 3.3 µg L-1 for Cd(II), 0.7 and 2.2 µg L-1 for the Pb(II) and 0.5 and 1.8 µg L-1 for Cu(II). The method was applied for the determination of metals in different natural water matrices, finding Cu(II) in some samples. The accuracy of the method was evaluated with addition and recovery studies in these waters, finding recoveries between 75.5 and 116.6%. In the second part of the work, a polar column composed of the zwitterionic sulfobetaine N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium betaine (MEDSA) and the cross-linker dioxyethyl dimethacrylate (DiEDMA) was used in Hydrophilic Interaction Nanocromatography (HILIC) to separate Dopamine, Epinephrine, Norepinephrine, L-DOPA, Tyramine, DOPAC and Homovanilic Acid, neurotransmitters, some of its metabolites and precursors, which are polar compounds of low molecular mass. The chromatographic selectivity of the column was highly dependent on the composition of the aqueous:organic mobile phase, showing a minimum retention at the transition from the HILIC to the reverse phase (RP) mechanism. By adjusting the experimental data of retention factors as a function of mobile phase composition with the double retention model it was possible to predict which mobile phase composition would promote the separation of the mixed analytes, which was achieved around 85% acetonitrile and 15% H2O. The column was modified with the 2-methacryloyl oxyethyl phosphorylcholine (MPC) zwitterionic group by UV grafting and the modification of half columns length during 30 minutes of UV exposure led to changes in the chromatographic selectivity.

Students with Attention-Deficit/Hyperactivity Disorder (ADHD) are usually inattentive and disruptive in class, are at high risk for chronic academic achievement difficulties, and may develop problems in relationships with peers, parents, and teachers (DuPaul, Stoner, 2003). One of the primary goals of behavioural treatment for ADHD is to enable a student to develop adequate levels of self-control (Barkley, 1990; DuPaul & Stoner, 1994). Methods are needed in the classroom, which give the child or adolescent with ADHD, control over his or her condition and thus increased independence, more experiences with success, and increased resiliency. Listening to music has many therapeutic applications, including the development of cognitive skills such as attention and memory (Canadian Association for Music Therapy, 2006). Music is accessible to all teachers and students, and is an easy strategy to implement in classrooms. Yet, despite the knowledge that adolescents are active users of music media (North, Hargreaves, & ONeill, 2000), little research on music and ADHD participants has been completed. Through the use of a single subject case study, the purpose of this research was: look at the academic experience that an adolescent male diagnosed with ADHD faced in his life at school; and to gain a better understanding of how music could potentially affect his ability to self-regulate and cope with the detrimental effects of ADHD during in-class seat work and homework. Multiple interviews with one boy, his parents, and teachers across a 14-week period of time provided a primary source of data. Results indicated that the adolescents experiences with listening to music during school and homework increased the time that he was able to attend and concentrate. Unexpected gains included an increase in his ability to recall information during exams, and an increase in motivation, positive attitude, and mood towards school work as a result of enjoying listening to his favourite music. However, the study also involved the unexpected and disheartening discovery of clashing and competing voices that perhaps ultimately rendered the boys positive experiences with music insignificant, given the louder rule-and-order school culture. The pragmatic realities of working within a school context will need to be considered and strategically addressed if students are to benefit from practices that help even though they may be unconventional and not fully understood.

Students with Attention-Deficit/Hyperactivity Disorder (ADHD) are usually inattentive and disruptive in class, are at high risk for chronic academic achievement difficulties, and may develop problems in relationships with peers, parents, and teachers (DuPaul, Stoner, 2003). One of the primary goals of behavioural treatment for ADHD is to enable a student to develop adequate levels of self-control (Barkley, 1990; DuPaul & Stoner, 1994). Methods are needed in the classroom, which give the child or adolescent with ADHD, control over his or her condition and thus increased independence, more experiences with success, and increased resiliency. Listening to music has many therapeutic applications, including the development of cognitive skills such as attention and memory (Canadian Association for Music Therapy, 2006). Music is accessible to all teachers and students, and is an easy strategy to implement in classrooms. Yet, despite the knowledge that adolescents are active users of music media (North, Hargreaves, & ONeill, 2000), little research on music and ADHD participants has been completed. Through the use of a single subject case study, the purpose of this research was: look at the academic experience that an adolescent male diagnosed with ADHD faced in his life at school; and to gain a better understanding of how music could potentially affect his ability to self-regulate and cope with the detrimental effects of ADHD during in-class seat work and homework. Multiple interviews with one boy, his parents, and teachers across a 14-week period of time provided a primary source of data. Results indicated that the adolescents experiences with listening to music during school and homework increased the time that he was able to attend and concentrate. Unexpected gains included an increase in his ability to recall information during exams, and an increase in motivation, positive attitude, and mood towards school work as a result of enjoying listening to his favourite music. However, the study also involved the unexpected and disheartening discovery of clashing and competing voices that perhaps ultimately rendered the boys positive experiences with music insignificant, given the louder rule-and-order school culture. The pragmatic realities of working within a school context will need to be considered and strategically addressed if students are to benefit from practices that help even though they may be unconventional and not fully understood.