PurposeA connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings.MethodsWe acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database.ResultsExploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive axonal veto synapses. (3) Chains of conventional synapses were very common, with intercalated glycinergic-GABAergic chains and very long chains associated with starburst amacrine cells. Glycinergic amacrine cells clearly play a major role in ON-OFF crossover inhibition. (4) Molecular and excitation mapping clearly segregates ultrastructurally defined bipolar cell groups into different response clusters. (5) Finally, low-resolution electron or optical imaging cannot reliably map synaptic connections by process geometry, as adjacency without synaptic contact is abundant in the retina. Only direct visualization of synapses and gap junctions suffices.ConclusionsConnectome assembly and analysis using conventional transmission electron microscopy is now practical for network discovery. Our surveys of volume RC1 demonstrate that previously studied systems such as the AII amacrine cell network involve more network motifs than previously known. The AII network, primarily considered a scotopic pathway, clearly derives ribbon synapse input from photopic ON and OFF cone bipol...

1. The objectives of this study were to evaluate the pharmacokinetics and metabolism of fimasartan in rats. 2. Unlabeled fimasartan or radiolabeled [(14)C]fimasartan was dosed by intravenous injection or oral administration to rats. Concentrations of unlabeled fimasartan in the biological samples were determined by a validated LC/MS/MS assay. Total radioactivity was quantified by liquid scintillation counting and the radioactivity associated with the metabolites was analyzed by using the radiochemical detector. Metabolite identification was conducted by product ion scanning using LC/MS/MS. 3. After oral administration of [(14)C]fimasartan, total radioactivity was found primarily in feces. In bile duct cannulated rats, 58.8 ± 14.4% of the radioactive dose was excreted via bile after oral dosing. Major metabolites of fimasartan including the active metabolite, desulfo-fimasartan, were identified, yet none represented more than 7.2% of the exposure of the parent drug. Fimasartan was rapidly and extensively absorbed and had an oral bioavailability of 32.7-49.6% in rats. Fimasartan plasma concentrations showed a multi-exponential decline after oral administration. Double peaks and extended terminal half-life were observed, which was likely caused by enterohepatic recirculation. 4. These results provide better understanding on the pharmacokinetics of fimasartan and may aid further development of fimasartan analogs.

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Small molecule HAT inhibitors are useful tools to unravel the role of histone acetyltransferases (HATs) in the cell and have relevance for oncology. We synthesized a series of N-acylanthranilic acids (11-16) and of N-acyl-5-hydroxyanthranilic acids (17-22) bearing C6, C8, C10, C12, C14, along with C16 acyl chain at the 2-amino position of anthranilic acid or 5-hydroxyanthranilic acid. Enzyme inhibition of these compounds was investigated, using in vitro PCAF HAT assays. All synthesized compounds (65-76%) showed similar inhibitory activity to anacardic acid (68%) at 100 μM. The cytotoxicity, against one normal cell line (HSF) and eight cancer cell lines (HT-29, HCT-116, MDA-231, A-549, Hep3B, Caski, HeLa and Caki), were evaluated by the SRB method.

The synthesis and aromatase inhibitory activity of androst-4-en-, androst-5-en-, 1β,2β-epoxy- and/or androsta-4,6-dien-, 4β,5β-epoxyandrostane-, and 4-substituted androst-4-en-17-oxime derivatives are described. Inhibition activity of synthesized compounds was assessed using aromatase enzyme and [1β-3H]androstenedione as substrate. Most of the compounds displayed similar to or more aromatase inhibitory activity than formestane (74.2%). 4-Chloro-3β-hydroxy-4-androsten-17-one oxime (14, 93.8%) showed the highest activity, while 4-azido-3β-hydroxy-4-androsten-17-one oxime (17, 32.8%) showed the lowest inhibitory activity for aromatase.