Synapsin II Regulation of GABAergic Synaptic Transmission Is Dependent on Interneuron Subtype.

Synapsins are epilepsy susceptibility genes that encode phosphoproteins reversibly associated with synaptic vesicles. Synapsin II (SynII) gene deletion produces a deficit in inhibitory synaptic transmission, and this defect is thought to cause epileptic activity. We systematically investigated how SynII affects synchronous and asynchronous release components of inhibitory transmission in the CA1 region of the mouse hippocampus. We found that the asynchronous GABAergic release component is diminished in SynII-deleted (SynII(-)) slices. To investigate this defect at different interneuron subtypes, we selectively blocked either N-type or P/Q-type Ca2+ channels. SynII deletion suppressed the asynchronous release component at synapses dependent on N-type Ca2+ channels but not at synapses dependent on P/Q-type Ca2+ channels. We then performed paired double-patch recordings from inhibitory basket interneurons connected to pyramidal neurons and used cluster analysis to classify interneurons according to their spiking and synaptic parameters. We identified two cell subtypes, presumably parvalbumin (PV) and cholecystokinin (CCK) expressing basket interneurons. To validate our interneuron classification, we took advantage of transgenic animals with fluorescently labeled PV interneurons and confirmed that their spiking and synaptic parameters matched the parameters of presumed PV cells identified by the cluster analysis. The analysis of the release time course at the two interneuron subtypes demonstrated that the asynchronous release component was selectively reduced at SynII(-) CCK interneurons. In contrast, the transmission was desynchronized at SynII(-) PV interneurons. Together, our results demonstrate that SynII regulates the time course of GABAergic release, and that this SynII function is dependent on the interneuron subtype.SIGNIFICANCE STATEMENT Deletion of the neuronal protein synapsin II (SynII) leads to the development of epilepsy, probably due to impairments in inhibitory synaptic transmission. We systematically investigated SynII function at different subtypes of inhibitory neurons in the hippocampus. We discovered that SynII affects the time course of GABA release, and that this effect is interneuron subtype specific. Within one of the subtypes, SynII deficiency synchronizes the release and suppresses the asynchronous release component, while at the other subtype SynII deficiency suppresses the synchronous release component. These results reveal a new SynII function in the regulation of the time course of GABA release and demonstrate that this function is dependent on the interneuron subtype.

Synapsin II and Rab3a cooperate in the regulation of epileptic and synaptic activity in the CA1 region of the hippocampus.

Some forms of idiopathic epilepsy in animals and humans are associated with deficiency of synapsin, a phosphoprotein that reversibly associates with synaptic vesicles. We have previously shown that the epileptic phenotype seen in synapsin II knock-out mice (SynII(-)) can be rescued by the genetic deletion of the Rab3a protein. Here we have examined the cellular basis for this rescue using whole-cell recordings from CA1 hippocampal pyramidal cells in brain slices. We find that SynII(-) neurons have increased spontaneous activity and a reduced threshold for the induction of epileptiform activity by 4-aminopyridine (4-AP). Using selective recordings of glutamatergic and GABAergic activity we show that in wild-type neurons low concentrations of 4-AP facilitate glutamatergic and GABAergic transmission in a balanced way, whereas in SynII(-) neurons this balance is shifted toward excitation. This imbalance reflects a deficit in inhibitory synaptic transmission that appears to be secondary to reduced Ca(2+) sensitivity in SynII(-) neurons. This suggestion is supported by our finding that synaptic and epileptiform activity at SynII(-) and wild-type synapses is similar when GABAergic transmission is blocked. Deletion of Rab3a results in glutamatergic synapses that have a compromised responsiveness to either low 4-AP concentrations or elevated extracellular Ca(2+). These changes mitigate the overexcitable phenotype observed in SynII(-) neurons. Thus, Rab3a deletion appears to restore the excitatory/inhibitory imbalance observed in SynII(-) hippocampal slices indirectly, not by correcting the deficit in GABAergic synaptic transmission but rather by impairing excitatory glutamatergic synaptic transmission.

Adesão a terapêutica anti-retroviral (TARV): Experiência dos Serviços Farmacêuticos do Hospital Central de Maputo / Adherence to antiretroviral therapy (ART): Experience of Pharmaceutical Services of the Maputo Central Hospital

A introdução do Tratamento Anti-retroviral (TARV) mostrou-se útil na redução da morbilidade e mortalidade em pacientes infectados por HIV. Contudo, o sucesso do TARV está fortemente dependente duma óptima adesão reportada na literatura como sendo acima de 95%. Vários métodos e recursos foram já utilizados para avaliação da adesão ao TARV em muitas partes do Mundo, incluindo em Moçambique. Para além disso, o papel da Farmácia na adesão ao TARV tem sido também reportado, mas não há referências do seu possível papel na melhoria da adesão ao TARV em Moçambique. Objectivo: Com este estudo, pretendeu-se estimar a adesão ao TARV através dos registos de levantamento dos Anti-retrovirais (ARV) na Farmácia e correlacionar a mesma adesão com as características sócio-demográficas e com o estado de progressão da infecção por HIV, estimada pela contagem de CD4. Também pretendeu recomendar estratégias ao nível da Farmácia para alertar atempadamente o sistema de atenção e cuidados aos pacientes seguidos no Hospital Central Maputo (HCM) para melhorar a adesão ao TARV. Métodos: Trata-se de um estudo observacional transversal que incluiu a revisão dos registos de 300 pacientes seleccionados aleatoriamente do Hospital de Dia do HCM que foram atendidos entre 2006 a 2009. Foi feita a análise descritiva dos dados recolhidos e foi efectuada uma análise retrospectiva de cada um dos pacientes durante um período de 12 meses. Foi elaborada uma ficha para a recolha dos dados na Farmácia. Foram recolhidos dados a partir dos processos clínicos e registos dos reaviamentos de ARVs de 300 pacientes em TARV. Foi efectuada uma análise descritiva dos dados sócio-demográficos e clínico-laboratoriais e estimada a adesão cumulativa de todos os pacientes por cada um dos meses de seguimento. A adesão foi determinada a partir dos registos dos medicamentos levantados e frequência de reaviamentos subsequentes. Resultados: Observou-se um nível de adesão ao TARV entre os pacientes, que se pode considerar "bom"com apenas 12% dos pacientes (36/300) classificados como tendo uma "pobre" adesão (<95%). A média geral de adesão foi de 97.6% com uma mediana de 98.3% (variação de 85.6% a 100% e o desvio padrão de 2.4%). Não revelou qualquer associação entre os factores sócio-demográficos e a adesão ao TARV. O estudo mostra problemas recorrentes de adesão entre os pacientes com 2 ou mais dias de atrasos no reaviamento dos medicamentos. Foi encontrada uma associação significativa entre a adesão e os valores de CD4 após 6 meses de TARV (p = 0,01). Dos 300 pacientes, 150 (50%) tiveram alguma enfermidade ou infecção associada à infecção por HIV como a tuberculose. Não foi encontrada qualquer associação significativa entre a adesão ao TARV e a tuberculose (p = 0,80). Todos os pacientes mostraram melhorias nos valores das contagens de CD4 cerca de 6 meses após terem iniciado o TARV com uma média de 171 células/mm 3 . Conclusões: O estudo conclui que é possível estimar com alguma fiabilidade o nível de adesão ao TARV a partir dos registos da Farmácia. O estudo confirma resultados similares noutros países e mostra que uma boa adesão contribui significativamente para a melhoria dos valores da contagem de CD4. Estudos futuros poderiam buscar respostas em relação às razões que levam a maioria dos pacientes a se atrasarem entre 1,5 dias no reaviamento dos seus medicamentos. O estudo mostra que um sistema de alerta, por exemplo ao nível da Farmácia, poderia ajudar a detectar os pacientes de forma atempada para lembrá-los sobre a necessidade de reaviar os seus medicamentos.

The introduction of Antiretroviral Therapy (ART) has proven useful in reducing morbidity and mortality in patients infected with HIV. However, the success of ART is highly dependent on an optimal adherence reported in the literature as being above 95%. Various methods and resources have been used to evaluate adherence to ART in many parts of the world, including in Mozambique. In addition, the role of Pharmacy in adherence to ART has also been reported, but no references to its possible role in improving adherence to ART in Mozambique. Objective: This study aimed to estimate adherence to ART through the records survey of ART in Pharmacy and correlate the same attachment to the socio-demographic characteristics and the state of progression of HIV infection, estimated by CD4 count. Also to recommend strategies at the pharmacy to alert the system of timely attention and care to patients in the Central Hospital of Maputo (HCM) to improve adherence to ART. Methods: This is a cross sectional observational study that included a review of the records of 300 patients selected randomly from the Day Hospital of HCM who were treated between 2006 to 2009. Descriptive analysis was performed of data collected and carried out a retrospective analysis of each patient over a period of 12 months. Drew up a form for collecting data in the Pharmacy. Data were collected from clinical files and records of 300 patients on ART. We performed a descriptive analysis of socio-demographic and clinical-laboratory and estimated cumulative adherence of all patients for each follow-up. Compliance was determined from the records of the medicines surveyed and frequency of subsequent replenishment. Results: There was a level of adherence to ART among patients, which can be considered "good" with only 12% of patients (36/300) classified as having a "poor" adherence (<95%). The overall average compliance was 97.6% with a median of 98.3% (range 85.6% to 100% and standard deviation of 2.4%). Showed no association between sociodemographic factors and adherence to ART. The study shows persistent problems of adherence among patients with 2 or more days late in replenishment of their medicines. We found a significant association between adherence and CD4 counts after 6 months of ART (p = 0.01). Of the 300 patients, 150 (50%) had some disease or infection associated with HIV infection such as tuberculosis. They found no significant association between adherence to ART and tuberculosis (p = 0.80). All patients showed improvements in the values of CD4 counts about 6 months after starting ART with an average of 171 cells/mm3. Conclusions: The study concludes that it is possible to estimate with any reliability the level of ART adherence from pharmacy records. The study confirms similar findings in other countries and shows that a good adherence contributes significantly to the improvement of the values of CD4 count. Future studies could seek answers regarding the reasons why the majority of patients are delayed from 1.5 days in replenishment of their medicines. The study shows that an alert system, for example at the pharmacy, could help detect patients in a timely manner to remind them about the need for replenishment their medicines