Local interneurons in the murine visual thalamus have diverse receptive fields and can provide feature selective inhibition to relay cells.

By influencing the type and quality of information that relay cells transmit, local interneurons in thalamus have a powerful impact on cortex. To define the sensory features that these inhibitory neurons encode, we mapped receptive fields of optogenetically identified cells in the murine dorsolateral geniculate nucleus. Although few in number, local interneurons had diverse types of receptive fields, like their counterpart relay cells. This result differs markedly from visual cortex, where inhibitory cells are typically less selective than excitatory cells. To explore how thalamic interneurons might converge on relay cells, we took a computational approach. Using an evolutionary algorithm to search through a library of interneuron models generated from our results, we show that aggregated output from different groups of local interneurons can simulate the inhibitory component of the relay cell's receptive field. Thus, our work provides proof-of-concept that groups of diverse interneurons can supply feature-specific inhibition to relay cells.

A transducible nuclear/nucleolar protein, mLLP, regulates neuronal morphogenesis and synaptic transmission.

Cell-permeable proteins are emerging as unconventional regulators of signal transduction and providing a potential for therapeutic applications. However, only a few of them are identified and studied in detail. We identify a novel cell-permeable protein, mouse LLP homolog (mLLP), and uncover its roles in regulating neural development. We found that mLLP is strongly expressed in developing nervous system and that mLLP knockdown or overexpression during maturation of cultured neurons affected the neuronal growth and synaptic transmission. Interestingly, extracellular addition of mLLP protein enhanced dendritic arborization, demonstrating the non-cell-autonomous effect of mLLP. Moreover, mLLP interacts with CCCTC-binding factor (CTCF) as well as transcriptional machineries and modulates gene expression involved in neuronal growth. Together, these results illustrate the characteristics and roles of previously unknown cell-permeable protein mLLP in modulating neural development.

Economic Impact of Atopic Dermatitis in Korean Patients.

BACKGROUND: Atopic dermatitis is a global public health concern owing to its increasing prevalence and socioeconomic burden. However, few studies have assessed the economic impact of atopic dermatitis in Korea. OBJECTIVE: We conducted a cost analysis of atopic dermatitis and evaluated its economic impacts on individual annual disease burden, quality of life, and changes in medical expenses with respect to changes in health related-quality of life. METHODS: The cost analysis of atopic dermatitis was performed by reviewing the home accounting records of 32 patients. The economic impact of the disease was evaluated by analyzing questionnaires. To handle uncertainties, we compared the results with the data released by the Health Insurance Review & Assessment Board on medical costs claimed by healthcare facilities. RESULTS: The direct cost of atopic dermatitis per patient during the 3-month study period was 541,280 Korean won (KRW), and expenditures on other atopic dermatitis-related products were 120,313 KRW. The extrapolated annual direct cost (including expenditures on other atopic dermatitis-related products) per patient was 2,646,372 KRW. The estimated annual indirect cost was 1,507,068 KRW. Thus, the annual cost of illness of atopic dermatitis (i.e., direct+indirect costs) was estimated to be 4,153,440 KRW. CONCLUSION: The annual total social cost of atopic dermatitis on a national level is estimated to be 5.8 trillion KRW.

Effects of PI3Kγ overexpression in the hippocampus on synaptic plasticity and spatial learning.

Previous studies have shown that a family of phosphoinositide 3-kinases (PI3Ks) plays pivotal roles in the brain; in particular, we previously reported that knockout of the γ isoform of PI3K (PI3Kγ) in mice impaired synaptic plasticity and reduced behavioral flexibility. To further examine the role of PI3Kγ in synaptic plasticity and hippocampus-dependent behavioral tasks we overexpressed p110γ, the catalytic subunit of PI3Kγ, in the hippocampal CA1 region. We found that the overexpression of p110γ impairs NMDA receptor-dependent long-term depression (LTD) and hippocampus-dependent spatial learning in the Morris water maze (MWM) task. In contrast, long-term potentiation (LTP) and contextual fear memory were not affected by p110γ overexpression. These results, together with the previous knockout study, suggest that a critical level of PI3Kγ in the hippocampus is required for successful induction of LTD and normal learning.

Effect of Food Deprivation on a Delayed Nonmatch-to-place T-maze Task.

Food deprivation can affect performance on difficult cognitive task, such as the delayed nonmatch-to-place T-maze task (DNMT). The importance of food deprivation on maintaining high motivation for DNMT task has been emphasized, but not many studies have investigated the optimal conditions for depriving rodents to maximize performance. Establishing appropriate conditions for food deprivation is necessary to maintain DNMT task motivation. We applied different conditions of food deprivation (1-h food restriction vs. 1.5-g food restriction; single caging vs. group caging) and measured body weight and the number of correct choices that 8-week-old C57BL/6J mice made during the DNMT task. The 1.5-g food restriction group maintained 76.0±0.6% of their initial body weight, but the final body weight of the 1-h food restriction condition group was reduced to 62.2±0.8% of their initial body weight. These results propose that 1.5-g food restriction condition is effective condition for maintaining both body weight and motivation to complete the DNMT task.

Mind bomb-1 is an essential modulator of long-term memory and synaptic plasticity via the Notch signaling pathway.

BACKGROUND: Notch signaling is well recognized as a key regulator of the neuronal fate during embryonic development, but its function in the adult brain is still largely unknown. Mind bomb-1 (Mib1) is an essential positive regulator in the Notch pathway, acting non-autonomously in the signal-sending cells. Therefore, genetic ablation of Mib1 in mature neuron would give valuable insight to understand the cell-to-cell interaction between neurons via Notch signaling for their proper function. RESULTS: Here we show that the inactivation of Mib1 in mature neurons in forebrain results in impaired hippocampal dependent spatial memory and contextual fear memory. Consistently, hippocampal slices from Mib1-deficient mice show impaired late-phase, but not early-phase, long-term potentiation and long-term depression without change in basal synaptic transmission at SC-CA1 synapses. CONCLUSIONS: These data suggest that Mib1-mediated Notch signaling is essential for long-lasting synaptic plasticity and memory formation in the rodent hippocampus.

Grape seed proanthocyanidin extract inhibits glutamate-induced cell death through inhibition of calcium signals and nitric oxide formation in cultured rat hippocampal neurons.

BACKGROUND: Proanthocyanidin is a polyphenolic bioflavonoid with known antioxidant activity. Some flavonoids have a modulatory effect on [Ca²âº]i. Although proanthocyanidin extract from blueberries reportedly affects Ca²âº buffering capacity, there are no reports on the effects of proanthocyanidin on glutamate-induced [Ca²âº]i or cell death. In the present study, the effects of grape seed proanthocyanidin extract (GSPE) on glutamate-induced excitotoxicity was investigated through calcium signals and nitric oxide (NO) in cultured rat hippocampal neurons. RESULTS: Pretreatment with GSPE (0.3-10 µg/ml) for 5 min inhibited the [Ca²âº]i increase normally induced by treatment with glutamate (100 µM) for 1 min, in a concentration-dependent manner. Pretreatment with GSPE (6 µg/ml) for 5 min significantly decreased the [Ca²âº]i increase normally induced by two ionotropic glutamate receptor agonists, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). GSPE further decreased AMPA-induced response in the presence of 1 µM nimodipine. However, GSPE did not affect the 50 mM K+-induced increase in [Ca²âº]i. GSPE significantly decreased the metabotropic glutamate receptor agonist (RS)-3,5-Dihydroxyphenylglycine-induced increase in [Ca²âº]i, but it did not affect caffeine-induced response. GSPE (0.3-6 µg/ml) significantly inhibited synaptically induced [Ca²âº]i spikes by 0.1 mM [Mg²âº]o. In addition, pretreatment with GSPE (6 µg/ml) for 5 min inhibited 0.1 mM [Mg²âº]o- and glutamate-induced formation of NO. Treatment with GSPE (6 µg/ml) significantly inhibited 0.1 mM [Mg²âº]o- and oxygen glucose deprivation-induced neuronal cell death. CONCLUSIONS: All these data suggest that GSPE inhibits 0.1 mM [Mg²âº]o- and oxygen glucose deprivation-induced neurotoxicity through inhibition of calcium signals and NO formation in cultured rat hippocampal neurons.

Prognosis of heart failure patients with reduced and preserved ejection fraction and coexistent chronic obstructive pulmonary disease.

AIMS: The long-term prognosis of patients with heart failure with preserved left ventricular ejection fraction (HFPEF) and coexistent chronic obstructive pulmonary disease (COPD) has not been previously investigated. The primary aim of this study was to determine whether the long-term prognosis of HFPEF patients with COPD differs from that of heart failure patients with reduced left ventricular ejection fraction (HFREF) and COPD. The secondary aim was to identify independent predictors of event-free survival in patients with HF and COPD. METHODS AND RESULTS: We investigated 184 patients with coexistent HF and COPD. Heart failure with preserved left ventricular ejection fraction was present in 98 cases (53%) and HFREF in the remaining 86 cases (47%). Mean follow-up time was 731±369 days. Cardiovascular/pulmonary hospitalization or mortality occurred in 71 patients (39%). No significant difference was observed between the two study groups in terms of event-free survival (P=0.457), but event-free survival was found to be independently associated with New York Heart Association (NYHA) class [III vs. I, hazard ratio (HR) 2.92, 95% confidence interval (CI) 1.09-7.82], Global initiative for chronic Obstructive Lung Disease (GOLD) stage (III vs. I, HR 3.20, 95% CI 1.33-7.68), systemic hypertension (SHT; HR 2.99, 95% CI 1.41-6.33), and pulmonary hypertension (PH; HR 4.35, 95% CI 1.95-9.68). CONCLUSION: In HF patients with coexisting COPD, cardiovascular and pulmonary event-free survival of HFPEF was found to be similar to that of HFREF over 3 years follow-up. Furthermore, severe NYHA class, severe GOLD stage, SHT, and PH were found to be independent predictors of event-free survival.