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Abstract The TRPM8 channel is a principal cold transducer that is expressed on some primary afferents of the somatic and cranial sensory systems. However, it is uncertain whether TRPM8-expressing afferent neurons have the ability to convey innocuous and noxious cold stimuli with sensory discrimination between the two sub-modalities. Using rat dorsal root ganglion (DRG) neurons and the patch-clamp recording technique, we characterized membrane and action potential properties of TRPM8-expressing DRG neurons at 24°C and 10°C. TRPM8-expressing neurons could be classified into TTX-sensitive (TTXs/TRPM8) and TTX-resistant (TTXr/TRPM8) subtypes based on the sensitivity to tetrodotoxin (TTX) block of their action potentials. These two subtypes of cold-sensing cells displayed different membrane and action potential properties. Voltage-activated inward Na+ currents were highly susceptible to cooling temperature and abolished by ~95% at 10°C in TTXs/TRPM8 DRG neurons, but remained substantially large at 10°C in TTXr/TRPM8 cells. In both TTXs/TRPM8 and TTXr/TRPM8 cells, voltage-activated outward K+ currents were substantially inhibited at 10°C, and the cooling-sensitive outward currents resembled A-type K+ currents. TTXs/TRPM8 neurons and TTXr/TRPM8 neurons were shown to fire action potentials at innocuous and noxious cold temperatures respectively, demonstrating sensory discrimination between innocuous and noxious cold by the two subpopulations of cold-sensing DRG neurons. The effects of cooling temperatures on voltage-gated Na+ channels and A-type K+ currents are likely to be contributing factors to sensory discrimination of cold by TTXs/TRPM8 and TTXr/TRPM8 afferent neurons.

Abstract Menthol-sensitive/capsaicin-insensitive neurons (MS/CI) and menthol-sensitive/capsaicin-sensitive neurons (MS/CS) are thought to represent two functionally distinct populations of cold-sensing neurons that use TRPM8 receptors to convey innocuous and noxious cold information respectively. However, TRPM8-mediated responses have not been well characterized in these two neuron populations. Using rat dorsal root ganglion neurons, here we show that MS/CI neurons had larger menthol responses with greater adaptation. In contrast, MS/CS neurons had smaller menthol responses with less adaptation. All menthol-sensitive neurons showed significant reduction of menthol responses following the treatment of cells with the protein kinase C (PKC) activator PDBu (Phorbol 12,13-dibutyrate). PDBu-induced reduction of menthol responses was completely abolished in the presence of PKC inhibitors BIM (bisindolylmaleimide) or staurosporine. When menthol responses were examined in the presence of protein kinase inhibitors, it was found that the adaptation was significantly attenuated by either BIM or staurosporine and also by the Ca2+/calmodulin-dependent protein kinase (CamKII) inhibitor KN62 (N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine) in MS/CI neurons. In contrast, in MS/CS neurons menthol response was not affected significantly by BIM, staurosporine or KN62. In both MS/CI and MS/CS neurons, the menthol responses were not affected by PKA activators forskolin and 8-Br-cAMP (8-Bromoadenosine-3', 5'-cyclic monophosphate) or by protein kinase A (PKA) inhibitor Rp-cAMPs (Rp-Adenosine-3',5'-cyclic monophosphorothioate). Taken together, these results suggest that TRPM8-mediated responses are significantly different between non-nociceptive-like and nociceptive-like neurons.

Despite widespread concerns about contraceptive side effects among contraceptive users, few studies explore the specific side effects women are told about during contraceptive counseling. It is thus unclear whether women receive appropriate and sufficient information on side effects they may experience. The objective of this study is to describe which specific side effects of hormonal contraception or copper IUD users are counseled on and identify relevant user characteristics associated with receipt of counseling, using nationally representative cross-sectional data from Ethiopia. Data were collected from a nationally representative sample of women between October and December 2019. Analyses were restricted to 2,039 current users of hormonal contraception (implant, injectable, pill, or emergency contraception) or the copper IUD. Descriptive analyses identified the types and number of side effects, across all methods and by the injectable, implant, and pill. Multinomial regression identified factors associated with receipt of counseling on bleeding changes only, non-bleeding changes only, or both, relative to no counseling on side effects, adjusting for method type, source, and socio-economic characteristics. Less than 10% of users were told of at least one bleeding and non-bleeding side effect. Relative to implant users, injectable and other method users were less likely to be told about bleeding changes only (aRRR: 0.65, 95% CI: 0.46-0.93 and aRRR: 0.31, 95% CI: 0.16-0.61, respectively) and users of other methods were less likely to be told about both a bleeding and non-bleeding change (aRRR: 0.43, 95% CI: 0.19-0.93). Users who received their method from a non-public source were less likely to receive counseling on any kind of side effect and nulliparous women were less likely to be told about both kinds of side effects. There is need to improve counseling on the method specific side effects on which women are counseled, particularly in the private sector., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zimmerman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: The focus of reproductive autonomy research has historically been on the experience of unintended pregnancy and use of contraceptive methods. However, this has led to the neglect of a different group of women who suffer from constraints on their reproductive autonomy-women who experience pregnancies later than they desire or who are unable to become pregnant. This study examines the extent of later-than-desired pregnancy among women and evaluates the sociodemographic and reproductive factors associated with this experience in Uganda., Methods: We use data from the Performance Monitoring for Action Uganda 2022 female survey. We restricted the nationally representative sample of reproductive-aged women to those who were currently pregnant or who had ever given birth (n = 3311). We compared the characteristics of women across fertility intention categories (wanted pregnancy earlier, then, later, or not at all) of their current or most recent birth and used multivariable logistic regression to examine factors independently associated with having a pregnancy later than desired compared to at a desired time., Results: Overall, 28.3% of women had a later-than-desired pregnancy. Nearly all sociodemographic and reproductive characteristics were associated with the desired pregnancy timing of women's current or most recent pregnancy. Having higher education [adjusted odds ratio (aOR) 2.41, 95% confidence interval (CI) 1.13-5.13], having sought care for difficulties getting pregnant (aOR 2.12, 95% CI 1.30-3.46), and having less than very good self-rated health (good health aOR 1.74, 95% CI 1.12-2.71; moderate health aOR 1.77, 95% CI 1.09-2.86; very bad health aOR 4.32, 95% CI 1.15-16.26) were all independently significantly associated with increased odds of having a later-than-desired pregnancy. Being nulliparous (aOR 1.98, 95% CI 0.99-3.95) was also borderline significantly associated with having a later-than-desired pregnancy., Conclusions: Identifying those who have later-than-desired pregnancies is essential if we seek to make progress towards supporting women and couples in achieving their reproductive goals, not just preventing pregnancies. Research on desired pregnancy timing in sub-Saharan Africa should be expanded to capture later-than-desired pregnancies, a population which is invisible in existing data. This work has public health implications due to commonalities in the factors associated with mistimed and unintended pregnancies and their link to poorer health and potentially poorer pregnancy outcomes., (© 2024. The Author(s).)

While polycystic ovarian syndrome (PCOS) is one of the most common hormonal endocrine disorders among women of reproductive age, the psychosocial impact of PCOS has not been evaluated across different quality of life (QoL) indicators. We rigorously analyzed available evidence pertaining to the psychosocial burden of PCOS in women of reproductive age and compared validated QoL scores of women with and without PCOS before and after treatment. We searched and considered publications from PubMed, PsychINFO, Embase, and Cochrane Library that evaluated the association between diagnosed PCOS and QoL by standardized and validated questionnaires at baseline and after treatment. Reviewers assessed the risk of bias using established Cochrane and Newcastle-Ottawa Scale guidelines. A total of 33 studies were included in the review: 14 randomized controlled trials and 19 observational studies. The 36-Item Short Form Survey and World Health Organization Quality of Life - BREF questionnaire both revealed that the diagnosis and life experience of PCOS had a disability score that was similar to or surpassed that of heart disease, diabetes mellitus, or breast cancer. QoL scores, associated with mental health issues, infertility, sexual dysfunction, obesity, menstrual disorder, and hirsutism, were lower at the baseline than after treatment in the majority of instruments measuring these variables in women with PCOS. PCOS is associated with significant psychosocial stress and reduced QoL across baseline measures and in comparison, to other diseases. Evidence suggests that treatment with therapy, medications, and lifestyle management decreased psychosocial burdens and alleviated QoL experienced by women with PCOS., (© 2023. The Author(s), under exclusive licence to Society for Reproductive Investigation.)

Vulvovaginitis occurs in mostly reproductive aged women. Recurrent vaginitis affects overall quality of life, with a large financial burden on the patient, family, and health system. This review discusses a clinician's approach to vulvovaginitis with specific attention to the 2021 updated Center for Disease Control and Prevention guidelines. The authors discuss the role of the microbiome in vaginitis and evidence-based approaches for diagnosis and treatment of vaginitis. This review also provides updates on new considerations, diagnosis, management, and treatment of vaginitis. Desquamative inflammatory vaginitis and genitourinary syndrome of menopause are discussed as differential diagnosis of vaginitis symptoms., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Cone photoreceptors scale dynamically the sensitivity of responses to maintain responsiveness across wide range of changes in luminance. Synaptic changes contribute to this adaptation, but how this process is coordinated at the molecular level is poorly understood. Here, we report that a cell adhesion-like molecule, LRIT1, is enriched selectively at cone photoreceptor synapses where it engages in a trans-synaptic interaction with mGluR6, the principal receptor in postsynaptic ON-bipolar cells. The levels of LRIT1 are regulated by the neurotransmitter release apparatus that controls photoreceptor output. Knockout of LRIT1 in mice increases the sensitivity of cone synaptic signaling while impairing its ability to adapt to background light without overtly influencing the morphology or molecular composition of photoreceptor synapses. Accordingly, mice lacking LRIT1 show visual deficits under conditions requiring temporally challenging discrimination of visual signals in steady background light. These observations reveal molecular mechanisms involved in scaling synaptic communication in the retina., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Collagens and hyaluronic acid have long been used in pharmaceuticals and food supplements for the improvement of skin elasticity and hydration. These compounds provide the building blocks of the skin. Ovoderm is an oral supplement obtained from eggshells that contains naturally occurring collagen and glycosaminoglycans, such as hyaluronic acid. We evaluated the efficacy of Ovoderm on skin biophysical parameters related to cutaneous aging such as elasticity, hydration, and pigmentation. Two pilot studies were run to assess the effect of daily oral supplementation with 300 mg Ovoderm on skin parameters. The first consisted of a self-assessment questionnaire intended to perform an assessment on skin, hair, and nail health after 50 days of treatment. The second measured the effect of 5-week treatment on hydration by corneometry, on elasticity with the cutometer, and on pigmentation with the mexameter. In the pilot study 1, participants were predominantly satisfied with the effects obtained on general face (100% volunteers satisfied) and body (94% volunteers satisfied) skin condition and skin properties (100% volunteers satisfied with facial skin softness, 94% with facial skin hydration, and 89% with body skin hydration) and partly with effects on hair (67% volunteers satisfied) and nail (50% volunteers satisfied) condition. The study 2 revealed a statistically significant improvement in skin elasticity (12% increase, p =.0136), a tendency to reduce skin pigmentation (5% decrease), and no significant change in skin hydration. Our study reflects that oral supplementation with Ovoderm is efficacious to reduce the gradual loss of skin elasticity characteristic of aged skin, which helps to improve the appearance of the skin.

Neural circuit wiring relies on selective synapse formation whereby a presynaptic release apparatus is matched with its cognate postsynaptic machinery. At metabotropic synapses, the molecular mechanisms underlying this process are poorly understood. In the mammalian retina, rod photoreceptors form selective contacts with rod ON-bipolar cells by aligning the presynaptic voltage-gated Ca 2+ channel directing glutamate release (Ca V 1.4) with postsynaptic mGluR6 receptors. We show this coordination requires an extracellular protein, α2δ4, which complexes with Ca V 1.4 and the rod synaptogenic mediator, ELFN1, for trans-synaptic alignment with mGluR6. Eliminating α2δ4 in mice abolishes rod synaptogenesis and synaptic transmission to rod ON-bipolar cells, and disrupts postsynaptic mGluR6 clustering. We further find that in rods, α2δ4 is crucial for organizing synaptic ribbons and setting Ca V 1.4 voltage sensitivity. In cones, α2δ4 is essential for Ca V 1.4 function, but is not required for ribbon organization, synaptogenesis, or synaptic transmission. These findings offer insights into retinal pathologies associated with α2δ4 dysfunction., (Copyright © 2017 Elsevier Inc. All rights reserved.)

In the retina, rod and cone photoreceptors form distinct connections with different classes of downstream bipolar cells. However, the molecular mechanisms responsible for their selective connectivity are unknown. Here we identify a cell-adhesion protein, ELFN1, to be essential for the formation of synapses between rods and rod ON-bipolar cells in the primary rod pathway. ELFN1 is expressed selectively in rods where it is targeted to the axonal terminals by the synaptic release machinery. At the synapse, ELFN1 binds in trans to mGluR6, the postsynaptic receptor on rod ON-bipolar cells. Elimination of ELFN1 in mice prevents the formation of synaptic contacts involving rods, but not cones, allowing a dissection of the contributions of primary and secondary rod pathways to retinal circuit function and vision. We conclude that ELFN1 is necessary for the selective wiring of rods into the primary rod pathway and is required for high sensitivity of vision., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In the retina, synaptic transmission between photoreceptors and downstream ON-bipolar neurons (ON-BCs) is mediated by a GPCR pathway, which plays an essential role in vision. However, the mechanisms that control signal transmission at this synapse and its relevance to behavior remain poorly understood. In this study we used a genetic system to titrate the rate of GPCR signaling in ON-BC dendrites by varying the concentration of key RGS proteins and measuring the impact on transmission of signal between photoreceptors and ON-BC neurons using electroretinography and single cell recordings. We found that sensitivity, onset timing, and the maximal amplitude of light-evoked responses in rod- and cone-driven ON-BCs are determined by different RGS concentrations. We further show that changes in RGS concentration differentially impact visually guided-behavior mediated by rod and cone ON pathways. These findings illustrate that neuronal circuit properties can be modulated by adjusting parameters of GPCR-based neurotransmission at individual synapses.

Cooling temperatures may modify action potential firing properties to alter sensory modalities. Herein, we investigated how cooling temperatures modify action potential firing properties in two groups of rat dorsal root ganglion (DRG) neurons, tetrodotoxin-sensitive (TTXs) Na(+) channel-expressing neurons and tetrodotoxin-resistant (TTXr) Na(+) channel-expressing neurons. We found that multiple action potential firing in response to membrane depolarization was suppressed in TTXs neurons but maintained or facilitated in TTXr neurons at cooling temperatures. We showed that cooling temperatures strongly inhibited A-type K(+) currents (IA) and TTXs Na(+) channels but had fewer inhibitory effects on TTXr Na(+) channels and non-inactivating K(+) currents (IK). We demonstrated that the sensitivity of A-type K(+) channels and voltage-gated Na(+) channels to cooling temperatures and their interplay determine somatosensory neuron excitability at cooling temperatures. Our results provide a putative mechanism by which cooling temperatures modify different sensory modalities including pain., (© 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.)

The time course of signaling via heterotrimeric G proteins is controlled through their activation by G-protein coupled receptors and deactivation through the action of GTPase accelerating proteins (GAPs). Here we identify RGS7 and RGS11 as the key GAPs in the mGluR6 pathway of retinal rod ON bipolar cells that set the sensitivity and time course of light-evoked responses. We showed using electroretinography and single cell recordings that the elimination of RGS7 did not influence dark-adapted light-evoked responses, but the concurrent elimination of RGS11 severely reduced their magnitude and dramatically slowed the onset of the response. In RGS7/RGS11 double-knockout mice, light-evoked responses in rod ON bipolar cells were only observed during persistent activation of rod photoreceptors that saturate rods. These observations are consistent with persistently high G-protein activity in rod ON bipolar cell dendrites caused by the absence of the dominant GAP, biasing TRPM1 channels to the closed state.

The cold-sensing channel transient receptor potential melastatin 8 (TRPM8) features Ca(2+)-dependent downregulation, a cellular process underlying somatosensory accommodation in cold environments. The Ca(2+)-dependent functional downregulation of TRPM8 is manifested with two distinctive phases, acute desensitization and tachyphylaxis. Here we show in rat dorsal root ganglion neurons that TRPM8 acute desensitization critically depends on phosphatidylinositol 4,5-bisphosphate (PIP(2)) availability rather than PIP(2) hydrolysis and is triggered by calmodulin activation. Tachyphylaxis, on the other hand, is mediated by phospholipase hydrolysis of PIP(2) and protein kinase C/phosphatase 1,2A. We further demonstrate that PIP(2) switches TRPM8 channel gating to a high-open probability state with short closed times. Ca(2+)-calmodulin reverses the effect of PIP(2), switching channel gating to a low-open probability state with long closed times. Thus, through gating modulation, Ca(2+)-calmodulin provides a mechanism to rapidly regulate TRPM8 functions in the somatosensory system.