Shape transformations of lipid vesicles by insertion of bulky-head lipids

Lipid vesicles, in particular Giant Unilamellar Vesicles (GUVs), have been increasingly important as compartments of artificial cells to reconstruct living cell-like systems in a bottom-up fashion. Here, we report shape transformations of lipid vesicles induced by polyethylene glycol-lipid conjugate (PEG lipids). Statistical analysis of deformed vesicle shapes revealed that shapes vesicles tend to deform into depended on the concentration of the PEG lipids. When compared with theoretically simulated vesicle shapes, those shapes were found to be more energetically favorable, with lower membrane bending energies than other shapes. This result suggests that the vesicle shape transformations can be controlled by externally added membrane molecules, which can serve as a potential method to control the replications of artificial cells

ラット ソクザカク ノ IPSP ニ タイスル アデノシン ト カンナビノイド ニヨル ダツブンキョク ユウドウ ヨクセイ ノ ユウドウ

A short period of depolarization evokes transient suppression of neurotransmitter release (Depolarization-induced Suppression of IPSP: DSI). Recent studies suggest that cannabinoids are candidates for the retrograde messenger required to induce DSI in the hippocampal CA1 area. A G protein-coupled process and inhibition of N-type calcium channels at the presynaptic terminals are believed to be involved in the induction mechanism. We examined DSI induction in the nucleus accumbens in which inputs from multiple sites in the telencephalon, including the hippocampus and basolateral amygdala, converge. Using whole-cell recording from a horizontal slice preparation of nucleus accumbens from the rat brain, we monitored the effect of endogenous cannabinoids on DSI induction and found that 300 nM AM281, a selective cannabinoid CB1 receptor antagonist, resulted in blockade of DSI. Adenosine is reported to suppress neurotransmitter release by inhibiting N-type calcium channels, which is a similar mechanism to that reported for cannabinoid-induced DSI. We therefore examined the effect of endogenous adenosine on DSI induction using DPCPX, a selective A1 receptor antagonist, and found that DSI induction was blocked in the presence of 100 nM DPCPX. These results suggest that cooperative activation of CB1 and A1 receptors contributes to DSI induction in the rat nucleus accumbens.　Key words: Nucleus accumbens, DSI, Cannabinoid, Adenosine, Whole-cell recording短時間の脱分極は一過性に伝達物質の放出を抑制する（脱分極誘導 IPSP 抑制：DSI）。最近の研究によればカンナビノイドは海馬 CA1 領域における DSI 誘導に関わる逆行性伝達物質であることが示されている。誘導のメカニズムとしてはＧ蛋白に結合した過程やＮ型のカルシウムチャンネルが関与していると考えられている。我々は、海馬・基底外側扁桃体などを含んだ終脳における多くの部位からの入力を統合している場所である側座核において、DSI の誘導を検討した。側座核の水平断薄切標本を用いて whole cell recording を行い、DSI誘導に関する内因性カンナビノイドの影響を調べたところ、選択的 CB1 カンナビノイド受容体阻害薬である 300nM の AM281 が DSI の誘導を阻害した。アデノシンはＮ型カルシウムチャンネルを阻害することによって伝達物質の放出を抑制することが報告されているが、この効果はカンナビノイドの効果と類似している。それ故我々は選択的な A1 アデノシン受容体の阻害薬である DPCPX を用いて、DSI 誘導に関する内因性アデノシンの効果を調べてみた。その結果、100nM の DPCPX が DSI の誘導を阻害することがわかった。これらの結果から CB1 と A1 受容体活性が側座核における DSI の誘導に関わっていることが示された。　キーワード：側座核、DSI 、カンナビノイド、アデノシン、whole-cell recordin

Comparative Analysis of Proximal and Distal Determinants for the Acceptance of Coercive Charging Policies in the UK and Japan

Coercive policies, such as road pricing or environmental taxation, are policies of an authority that charges or restricts its subjects in order to protect or restore common goods. Studies have shown it is important to understand the acceptability of such policies to the general public to guarantee long-term success. Our analysis, based on a limited survey of British and Japanese students, investigates well-established psychological factors that determine acceptability of road pricing directly or indirectly, such as perceived effectiveness, fairness, or problem awareness, as well as the role of a general trust in the government and a belief in "absolute values

Cooperative Binding of Ferrocenylnaphthalene Diimide Carrying β-Cyclodextrin Converts Double-Stranded DNA to a Rod-Like Structure

Ferrocenylnaphthalene diimide carrying β-cyclodextrin (β-CD), 1, intercalated into double-stranded DNA with a binding affinity of K = (6.6 ± 0.8) × 104 M–1 and a binding site size of n = 4, with a high positive cooperative parameter of ω = 14. β-CD and ferrocene moieties of the compound contributed to the formation of the intermolecular inclusion complex on DNA. Binding of 1 resulted in conversion of the DNA duplex to a rod-like form, which was cleaved upon adamantylamine addition