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Reduced function of the serotonin transporter (SERT) is associated with increased susceptibility to anxiety and depression and with type-2 diabetes, which is especially true in older women. Preference for a “Western diet” (WD), enriched with saturated fat, cholesterol, and sugars, may aggravate these conditions. In previous studies, decreased glucose tolerance, central and peripheral inflammation, dyslipidemia, emotional, cognitive, and social abnormalities were reported in WD-fed young female mice. We investigated the metabolic, molecular, and behavioral changes associated with a 3-week-long dietary regime of either the WD or control diet in 12-month-old female mice with three different Sert genotypes: homozygous (Slc6a4) gene knockout (Sert−/−: KO), heterozygous (Sert+/−: HET), or wild-type mice (Sert+/+: WT). In the WT-WD and KO-WD groups, but not in HET-WD-fed mice, most of changes induced by the WD paralleled those found in the younger mice, including brain overexpression of inflammatory marker Toll-like receptor 4 (Tlr4) and impaired hippocampus-dependent performance in the marble test. However, the 12-month-old female mice became obese. Control diet KO mice exhibited impaired hippocampal-dependent behaviors, increased brain expression of the serotonin receptors Htr2c and Htr1b, as well as increased Tlr4 and mitochondrial regulator, peroxisome proliferator-activated receptor gamma-coactivator-1a (Ppargc1a). Paradoxically, these, and other changes, were reversed in KO-WD mutants, suggesting a complex interplay between Sert deficiency and metabolic factors as well as potential compensatory molecular mechanisms that might be disrupted by the WD exposure. Most, but not all, of the changes in gene expression in the brain and liver of KO mice were not exhibited by the HET mice fed with either diet. Some of the WD-induced changes were similar in the KO-WD and HET-WD-fed mice, but the latter displayed a “rescued” phenotype in terms of diet-induced abnormalities in glucose tolerance, neuroinflammation, and hippocampus-dependent performance. Thus, complete versus partial Sert inactivation in aged mice results in distinct metabolic, molecular, and behavioral consequences in response to the WD. Our findings show that Sert+/− mice are resilient to certain environmental challenges and support the concept of heterosis as evolutionary adaptive mechanism. © Copyright © 2020 Veniaminova, Cespuglio, Chernukha, Schmitt-Boehrer, Morozov, Kalueff, Kuznetsova, Anthony, Lesch and Strekalova. 01EW1602B, 01EW1902, 602805 Deutsche Forschungsgemeinschaft, DFG: CRC TRR 58 A1/A5 Horizon 2020 Framework Programme, H2020: Eat2beNICE, 728018, 643051 Russian Science Foundation, RSF: 16-16-10073 Seventh Framework Programme, FP7 I.M. Sechenov First Moscow State Medical University, MSMU Deutsche Forschungsgemeinschaft, DFG We thank Collette Rousset and Donia Amrouni from C. Bernard University, Anna Gorlova from Sechenov University, and Anastasiya Kibitkina and Galina Tolmacheva from the Gorbatov Research Center for their valuable contribution to this work. Funding. The authors? work reported here was supported by the Deutsche Forschungsgemeinschaft (DFG: CRC TRR 58 A1/A5), the European Union?s Seventh Framework Programme (FP7/2007?2013) under Grant No. 602805 (Aggressotype), ERA-Net NEURON/RESPOND, No. 01EW1602B and ERA-Net NEURON/DECODE, No. 01EW1902 (to K-PL), the Horizon 2020 Research and Innovation Programme under Grant No. 728018 (Eat2beNICE) and Grant No. 643051 (MiND), 5-100 Russian Academic Excellence Project (to K-PL and TS), the Russian Science Foundation (RSF) Project No. 16-16-10073 (to IC and OK), and the University of W?rzburg in the funding programme Open Access Publishing (to KP-L).

Intraocular pressure (IOP) is regulated by the resistance to outflow of the eye's aqueous humor. Elevated resistance raises IOP and can cause glaucoma. Despite the importance of outflow resistance, its site and regulation are unclear. The small size, complex geometry, and relative inaccessibility of the outflow pathway have limited study to whole animal, whole eye, or anterior-segment preparations, or isolated cells. We now report measuring elemental contents of the heterogeneous cell types within the intact human trabecular outflow pathway using electron-probe X-ray microanalysis. Baseline contents of Na+, K+, Cl−, and P and volume (monitored as Na+K contents) were comparable to those of epithelial cells previously studied. Elemental contents and volume were altered by ouabain to block Na+-K+-activated ATPase and by hypotonicity to trigger a regulatory volume decrease (RVD). Previous results with isolated trabecular meshwork (TM) cells had disagreed whether TM cells express an RVD. In the intact tissue, we found that all cells, including TM cells, displayed a regulatory solute release consistent with an RVD. Selective agonists of A1 and A2 adenosine receptors (ARs), which exert opposite effects on IOP, produced similar effects on juxtacanalicular (JCT) cells, previously inaccessible to functional study, but not on Schlemm's canal cells that adjoin the JCT. The results obtained with hypotonicity and AR agonists indicate the potential of this approach to dissect physiological mechanisms in an area that is extremely difficult to study functionally and demonstrate the utility of electron microprobe analysis in studying the cellular physiology of the human trabecular outflow pathway in situ.

Aqueous humor is secreted by the bilayered ciliary epithelium. Solutes and water enter the pigmented ciliary epithelial (PE) cell layer, cross gap junctions into the nonpigmented ciliary epithelial (NPE) cell layer, and are released into the aqueous humor. Electrical measurements suggest that heptanol reduces transepithelial ion movement by interrupting PE-NPE communication and that gap junctions may be a regulatory site of aqueous humor formation. Several lines of evidence also suggest that net ciliary epithelial transport is strongly region dependent. Divided rabbit iris-ciliary bodies were incubated in chambers under control and experimental conditions, quick-frozen, cryosectioned, and freeze-dried. Elemental intracellular contents of NPE and PE cells were determined by electron probe X-ray microanalysis. With or without heptanol, ouabain produced concentration- and time-dependent changes more markedly in anterior than in posterior epithelium. Without heptanol, there were considerable cell-to-cell variations in Na gain and K loss. However, contiguous NPE and PE cells displayed similar changes, even when nearby cell pairs were little changed by ouabain in aqueous, stromal, or both reservoirs. In contrast, with heptanol present, ouabain added to aqueous or both reservoirs produced much larger changes in NPE than in PE cells. The results indicate that 1) heptanol indeed interrupts PE-NPE junctions, providing an opportunity for electron microprobe analysis of the sidedness of modification of ciliary epithelial secretion; 2) Na and K undergo faster turnover in anterior than in posterior epithelium; and 3) PE-NPE gap junctions differ from PE-PE and NPE-NPE junctions in permitting ionic equilibration between adjoining ouabain-stressed cells.

We teach medical and other health professional students “human physiology,” so one might wonder at the title of this editorial. One definition of humanize is “to make something friendlier to humans. Humanizing makes things more civilized, refined, and understandable” (

The β-adrenergic antagonist timolol reduces ciliary epithelial secretion in glaucomatous patients. Whether inhibition is mediated by reducing cAMP is unknown. Elemental composition of rabbit ciliary epithelium was studied by electron probe X-ray microanalysis. Volume of cultured bovine pigmented ciliary epithelial (PE) cells was measured by electronic cell sizing; Ca2+activity and pH were monitored with fura 2 and 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, respectively. Timolol (10 μM) produced similar K and Cl losses from ciliary epithelia in HCO[Formula: see text]/CO2solution but had no effect in HCO[Formula: see text]/CO2-free solution or in HCO[Formula: see text]/CO2solution containing the carbonic anhydrase inhibitor acetazolamide. Inhibition of Na+/H+exchange by dimethylamiloride in HCO[Formula: see text]/CO2solution reduced Cl and K comparably to timolol. cAMP did not reverse timolol's effects. Timolol (100 nM, 10 μM) and levobunolol (10 μM) produced cAMP-independent inhibition of the regulatory volume increase (RVI) in PE cells and increased intracellular Ca2+and pH. Increasing Ca2+with ionomycin also blocked the RVI. The results document a previously unrecognized cAMP-independent transport effect of timolol. Inhibition of Cl−/HCO[Formula: see text] exchange may mediate timolol's inhibition of aqueous humor formation.