RESUMO
The function of medial entorhinal cortex layer II (MECII) excitatory neurons has been recently explored. MECII dysfunction underlies deficits in spatial navigation and working memory. MECII neurons comprise two major excitatory neuronal populations, pyramidal island and stellate ocean cells, in addition to the inhibitory interneurons. Ocean cells express reelin and surround clusters of island cells that lack reelin expression. The influence of reelin expression by ocean cells and interneurons on their own morphological differentiation and that of MECII island cells has remained unknown. To address this, we used a conditional reelin knockout (RelncKO) mouse to induce reelin deficiency postnatally in vitro and in vivo. Reelin deficiency caused dendritic hypertrophy of ocean cells, interneurons and only proximal dendritic compartments of island cells. Ca2+ recording showed that both cell types exhibited an elevation of calcium frequencies in RelncKO, indicating that the hypertrophic effect is related to excessive Ca2+ signalling. Moreover, pharmacological receptor blockade in RelncKO mouse revealed malfunctioning of GABAB, NMDA and AMPA receptors. Collectively, this study emphasizes the significance of reelin in neuronal growth, and its absence results in dendrite hypertrophy of MECII neurons.
Assuntos
Moléculas de Adesão Celular Neuronais , Dendritos , Córtex Entorrinal , Proteínas da Matriz Extracelular , Camundongos Knockout , Proteínas do Tecido Nervoso , Proteína Reelina , Serina Endopeptidases , Animais , Córtex Entorrinal/metabolismo , Dendritos/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Moléculas de Adesão Celular Neuronais/genética , Serina Endopeptidases/metabolismo , Serina Endopeptidases/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas da Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/genética , Camundongos , Interneurônios/metabolismo , Neurônios/metabolismo , Sinalização do CálcioRESUMO
OBJECTIVES: This study aimed to assess the knowledge, attitude and practices of patients with type 2 diabetes on insulin regarding insulin therapy. DESIGN: A cross-sectional study. SETTING: This study was conducted at the Dubai Diabetes Center from 1 December 2018 to 1 March 2020. PARTICIPANTS: Face-to-face interviews were conducted for 350 participants with type 2 diabetes at the Dubai Diabetes Center. Interviews followed the structured format of a questionnaire designed to obtain demographic details and score participants on knowledge, attitude and practices. We included patients aged >18 years and receiving insulin therapy. Patients with type 1 diabetes, pregnant women with gestational diabetes, those aged <18 years or those with a history of dementia were excluded. RESULTS: The median age of participants was 61 years (first quartile, 53 years; third quartile, 67 years); 35.7% were male individuals and 64.3% were female individuals. The median percentage scores for knowledge, attitude and practices were 62.5% (62.5%, 75%), 85.7% (71.4%, 100%) and 77.7% (66.6%, 88.8%), respectively. Highly educated participants had a high level of knowledge. Significant negative correlations were found between the percentage knowledge scores and participants' age and between the participants' percentage attitude scores and haemoglobin A1C levels; Spearman's correlations were -0.182 (p<0.001) and -0.14 (p=0.008), respectively. A significant positive Spearman's correlation of 0.123 (p=0.021) was found between the percentage knowledge and percentage practice scores. No correlations were found among knowledge levels, participants' haemoglobin A1c levels and duration of insulin use. CONCLUSION: Patients with type 2 diabetes receiving insulin therapy and attending the Dubai Diabetes Center had adequate knowledge, a positive attitude and correct practice regarding insulin therapy. However, knowledge of specific facts did not always translate into correct behaviours and practices.