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We live on a planet that is bathed in daily and seasonal sunlight cycles. In this context, terrestrial life forms have evolved mechanisms that directly harness light energy (plants) or decode light information for adaptive advantage. In animals, the main light sensors are a family of G protein–coupled receptors called opsins. Opsin function is best described for the visual sense. However, most animals also use opsins for extraocular light sensing for seasonal behavior and camouflage. While it has long been believed that mammals do not have an extraocular light sensing capacity, recent evidence suggests otherwise. Notably, encephalopsin (OPN3) and neuropsin (OPN5) are both known to mediate extraocular light sensing in mice. Examples of this mediation include photoentrainment of circadian clocks in skin (by OPN5) and acute light-dependent regulation of metabolic pathways (by OPN3 and OPN5). This review summarizes current findings in the expanding field of extraocular photoreception and their relevance for human physiology. Expected final online publication date for the Annual Review of Vision Science, Volume 9 is September 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The mesolimbic dopamine system is an evolutionarily conserved set of brain circuits that play a role in attention, appetitive behavior, and reward processing. In this circuitry, ascending dopaminergic projections from the ventral midbrain innervate targets throughout the limbic forebrain, such as the ventral striatum/nucleus accumbens (NAc). Dopaminergic signaling in the NAc has been widely studied for its role in behavioral reinforcement, reward prediction error encoding, and motivational salience. Less well characterized is the role of dopaminergic neurotransmission in the response to surprising or alerting sensory events. To address this, we used the genetically encoded dopamine sensor dLight1 and fiber photometry to explore the ability of striatal dopamine release to encode the properties of salient sensory stimuli in mice, such as threatening looming discs. Here, we report that lateral NAc (LNAc) dopamine release encodes the rate and magnitude of environmental luminance changes rather than the visual stimulus threat level. This encoding is highly sensitive, as LNAc dopamine could be evoked by light intensities that were imperceptible to human experimenters. We also found that light-evoked dopamine responses are wavelength-dependent at low irradiances, independent of the circadian cycle, robust to previous exposure history, and involve multiple phototransduction pathways. Thus, we have further elaborated the mesolimbic dopamine system’s ability to encode visual information in mice, which is likely relevant to a wide body of scientists employing light sources or optical methods in behavioral research involving rodents.

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PDF file - 1920K, S2: Assessment of Vegfa and Notch target gene expression in flow sorted vascular endothelial cells.

PDF file - 2729K, S1: Flow sorting of human and mouse tumor-associated macrophages.

Axon regeneration after spinal cord injury (SCI) is limited by both a decreased intrinsic ability of neurons to grow axons and the growth-hindering effects of extrinsic inhibitory molecules expressed around the lesion. Deletion ofphosphatase and tensin homolog(Pten) augments mechanistic target of rapamycin (mTOR) signaling and enhances the intrinsic regenerative response of injured corticospinal neurons after SCI. Because of the variety of growth-restrictive extrinsic molecules, it remains unclear how inhibition of conserved inhibitory signaling elements would affect axon regeneration and rewiring after SCI. Moreover, it remains unknown how a combinatorial approach to modulate both extrinsic and intrinsic mechanisms can enhance regeneration and rewiring after SCI. In the present study, we deletedRhoAandRhoC, which encode small GTPases that mediate growth inhibition signals of a variety of extrinsic molecules, to remove global extrinsic pathways.RhoA/RhoCdouble deletion in mice suppressed retraction or dieback of corticospinal axons after SCI. In contrast,Ptendeletion increased regrowth of corticospinal axons into the lesion core. Although deletion of bothRhoAandPtendid not promote axon regrowth across the lesion or motor recovery, it additively promoted rewiring of corticospinal circuits connecting the cerebral cortex, spinal cord, and hindlimb muscles. Our genetic findings, therefore, reveal that a combinatorial approach to modulate both intrinsic and extrinsic factors can additively promote neural circuit rewiring after SCI.SIGNIFICANCE STATEMENTSCI often causes severe motor deficits because of damage to the corticospinal tract (CST), the major neural pathway for voluntary movements. Regeneration of CST axons is required to reconstruct motor circuits and restore functions; however, a lower intrinsic ability to grow axons and extrinsic inhibitory molecules severely limit axon regeneration in the CNS. Here, we investigated whether suppression of extrinsic inhibitory cues by genetic deletion ofRhoas well as enhancement of the intrinsic pathway by deletion ofPtencould enable axon regrowth and rewiring of the CST after SCI. We show that simultaneous elimination of extrinsic and intrinsic signaling pathways can additively promote axon sprouting and rewiring of the corticospinal circuits. Our data demonstrate a potential molecular approach to reconstruct motor pathways after SCI.

Here we investigate mechanisms underlying spontaneous phasic contractions (SPCs) and sympathetic control of contractility in the rat epididymis, a long tubular duct involved in transportation and maturation of sperm. Longitudinal contractions of short segments (~ 1.5 mm) of rat proximal and distal caudal epididymal duct were measured + / − nerve stimulation. The extent of sympathetic innervation of these duct regions was determined by immunohistochemistry. Proximal caudal duct segments (150–300 μm dia.) exhibited SPCs, while distal segments (350–500 μm) were quiescent in ~ 80% of preparations. SPC amplitude and frequency were reduced by the L-type voltage-dependent Ca2+ channel (LVDCC) blocker nifedipine (1 μM), with the T-type voltage-dependent Ca2+ channel (TVDCC) blocker ML218 (1 μM) specifically decreasing SPC frequency. SPCs were inhibited upon blockade of the SR/ER Ca2+-ATPase (CPA 10 μM). SPCs were also inhibited by caffeine (1 μM), 2-APB (100 μM), niflumic acid (100 μM), or by lowering extracellular [Cl−] from 134.4 to 12.4 mM but not by ryanodine (25 μM) or tetracaine (100 μM). Electrical field stimulation (EFS) at 2 Hz for 60 s caused a sustained α1-adrenoceptor-sensitive contraction in distal segments and enhanced and/or induced α2-adrenoceptor-sensitive oscillatory phasic contractions in proximal and distal segments, the latter mimicked by application of the α2-adrenoceptor agonist clonidine. We hypothesise that SPCs in the proximal cauda are triggered by pacemaker mechanisms involving rhythmic IP3 receptor–operated SR/ER store Ca2+ release and resultant activation of CaCC with TVDCCs and possibly LVDCCs subserving in this process. Sympathetic nerve-released noradrenaline induces α2-adrenoceptor-mediated phasic contractions in the proximal and distal cauda. These findings provide new pharmacological targets for male infertility and contraception.

Background and aimsThe intestinal stem cell niche is exquisitely sensitive to changes in diet, with high fat diet, caloric restriction, and fasting resulting in altered crypt metabolism and intestinal stem cell function. Unlike cells on the villus, cells in the crypt are not immediately exposed to the dynamically changing contents of the lumen. We hypothesized that enteroendocrine cells (EECs), which sense environmental cues and in response release hormones and metabolites, are essential for relaying the nutrient status of the animal to cells deep in the crypt.MethodsWe used the tamoxifen-inducible VillinCreERT2 mouse model to deplete EECs (Neurog3fl/fl) from adult intestinal epithelium and we generated human intestinal organoids from wild-type and NEUROG3-null human pluripotent stem cells. We used indirect calorimetry, 1H-NMR metabolomics, mitochondrial live imaging, and the Seahorse bioanalyzer to assess metabolism. Intestinal stem cell activity was measured by proliferation and enteroid-forming capacity. Transcriptional changes were assessed using 10X Genomics single-cell sequencing.ResultsLoss of EECs resulted in increased energy expenditure in mice, an abundance of active mitochondria, and a shift of crypt metabolism to fatty acid oxidation. Crypts from mouse and human intestinal organoids lacking EECs displayed increased intestinal stem cell activity and failed to activate phospho-S6 ribosomal protein, a marker for activity of the master metabolic regulator mammalian target of rapamycin (mTOR). These phenotypes were similar to those observed when wild-type mice were deprived of nutrients.ConclusionsDeletion of EECs recapitulated a fasting phenotype despite normal levels of ingested nutrients. These data suggest that EECs are required to relay nutritional information to the stem cell niche and are essential regulators of intestinal metabolism.

The mesolimbic dopamine system is an evolutionarily conserved set of brain circuits that plays a role in attention, appetitive behavior, and reward processing. In this circuitry, ascending dopaminergic projections from the ventral midbrain innervate targets throughout the limbic forebrain, such as the ventral striatum/nucleus accumbens (NAc). Dopaminergic signaling in the NAc has been widely studied for its role in behavioral reinforcement, reward prediction error encoding, and motivational salience. Less well characterized is the role of dopaminergic neurotransmission in the response to surprising or alerting sensory events. To address this, we used the genetically encoded dopamine sensor dLight1 and fiber photometry to explore the ability of striatal dopamine release in to encode the properties of salient sensory stimuli in mice, such as threatening looming discs. Here, we report that NAc lateral shell (LNAc) dopamine release encodes the rate and magnitude of environmental luminance changes rather than visual stimulus threat level. This encoding is highly sensitive, as LNAc dopamine could be evoked by light intensities that were imperceptible to human experimenters. We also found that light-evoked dopamine responses are wavelength-dependent at low irradiances, independent of the circadian cycle, robust to previous exposure history, and involve multiple phototransduction pathways. Thus, we have further elaborated the mesolimbic dopamine system’s ability to encode visual information in mice, which is likely relevant to a wide body of scientists employing light sources or optical methods in behavioral research involving rodents.

The COVID 19 pandemic placed unprecedented strain on healthcare systems and workers, likely also impacting patient safety and outcomes. This study aimed to understand how teamwork climate changed during that pandemic and how these changes affected safety culture and workforce well-being.This cross-sectional observational study of 50,000 healthcare workers (HCWs) in 3 large U.S. health systems used scheduled culture survey results at 2 distinct time points: before and during the first year of the COVID 19 pandemic. The SCORE survey measured 9 culture domains: teamwork climate, safety climate, leadership engagement, improvement readiness, emotional exhaustion, emotional exhaustion climate, thriving, recovery, and work-life balance.Response rate before and during the pandemic was 75.45% and 74.79%, respectively. Overall, HCWs reporting favorable teamwork climate declined (45.6%-43.7%, P0.0001). At a facility level, 35% of facilities saw teamwork climate decline, while only 4% saw an increase in teamwork climate. Facilities with decreased teamwork climate had associated decreases in every culture domain, while facilities with improved teamwork climate maintained well-being domains and saw improvements in every other culture domain.Healthcare worker teamwork norms worsened during the COVID-19 pandemic. Teamwork climate trend was closely associated with other safety culture metrics. Speaking up, resolving conflicts, and interdisciplinary coordination of care were especially predictive. Facilities sustaining these behaviors were able to maintain other workplace norms and workforce well-being metrics despite a global health crisis. Proactive team training may provide substantial benefit to team performance and HCW well-being during stressful times.

Neurons in the hypothalamic preoptic area (POA) regulate multiple homeostatic processes, including thermoregulation and sleep, by sensing afferent input and modulating sympathetic nervous system output. The POA has an autonomous circadian clock and may also receive circadian signals indirectly from the suprachiasmatic nucleus. We have previously defined a subset of neurons in the POA termed QPLOT neurons that are identified by the expression of molecular markers (Qrfp, Ptger3, LepR, Opn5, Tacr3) that suggest receptivity to multiple stimuli. Because Ptger3, Opn5, and Tacr3 encode G-protein coupled receptors (GPCRs), we hypothesized that elucidating the G-protein signaling in these neurons is essential to understanding the interplay of inputs in the regulation of metabolism. Here, we describe how the stimulatory Gs-alpha subunit (Gnas) in QPLOT neurons regulates metabolism in mice. We analyzed Opn5cre; Gnasfl/fl mice using indirect calorimetry at ambient temperatures of 22°C (a historical standard), 10°C (a cold challenge), and 28°C (thermoneutrality) to assess the ability of QPLOT neurons to regulate metabolism. We observed a marked decrease in nocturnal locomotion of Opn5cre; Gnasfl/fl mice at both 28°C and 22°C, but no overall differences in energy expenditure, respiratory exchange, or food and water consumption. To analyze daily rhythmic patterns of metabolism, we assessed circadian parameters including amplitude, phase, and MESOR. Loss-of-function GNAS in QPLOT neurons resulted in several subtle rhythmic changes in multiple metabolic parameters. We observed that Opn5cre; Gnasfl/fl mice show a higher rhythm-adjusted mean energy expenditure at 22°C and 10°C, and an exaggerated respiratory exchange shift with temperature. At 28°C, Opn5cre; Gnasfl/fl mice have a significant delay in the phase of energy expenditure and respiratory exchange. Rhythmic analysis also showed limited increases in rhythm-adjusted means of food and water intake at 22°C and 28°C. Together, these data advance our understanding of Gαs-signaling in preoptic QPLOT neurons in regulating daily patterns of metabolism.

Long-term impacts of diet have been well studied; however, the immediate response of the intestinal epithelium to a change in nutrients remains poorly understood. We use physiological metrics and single-cell transcriptomics to interrogate the intestinal epithelial cell response to a high-fat diet (HFD). Within 1 day of HFD exposure, mice exhibit altered whole-body physiology and increased intestinal epithelial proliferation. Single-cell transcriptional analysis on day 1 reveals a cell-stress response in intestinal crypts and a shift toward fatty acid metabolism. By 3 days of HFD, computational trajectory analysis suggests an emergence of progenitors, with a transcriptional profile shifting from secretory populations toward enterocytes. Furthermore, enterocytes upregulate lipid absorption genes and show increased lipid absorption in vivo over 7 days of HFD. These findings demonstrate the rapid intestinal epithelial response to a dietary change and help illustrate the essential ability of animals to adapt to shifting nutritional environments.

SummaryWhile the systemic impacts of overnutrition are well-known to cause obesity and metabolic syndrome over the course of months, the immediate adaptive response of the intestinal epithelium to dietary changes remains poorly understood. Here we used physiological metrics and single cell analyses to interrogate the adaptive response of intestinal epithelial cells when moved to a high fat diet (HFD). Within 1 day of HFD exposure, mice exhibited altered feeding behavior, an increase in energy expenditure and an increase in intestinal epithelial proliferation. Single cell transcriptional analysis demonstrated several acute cellular changes on day 1, including a cell-stress response in intestinal crypts, de-granularization of Paneth cells, and a shift towards fatty acid cellular metabolism. By 3 days of HFD, there was an emergence of uncommitted progenitors with a transcriptional profile indicative of a shift from secretory populations and towards an absorptive fate. In enterocytes, genes regulating lipid transport and absorption increased over the first 3 days which paralleled a functional increase in lipid absorption in vivo over the course of 7 days on HFD. These findings demonstrate that intestinal epithelial cell populations respond rapidly to changes in diet through initial changes in cellular function followed by a shift in cellular composition.

The opsin family of G-protein-coupled receptors are used as light detectors in animals. Opsin 5 (also known as neuropsin or OPN5) is a highly conserved opsin that is sensitive to visible violet light1,2. In mice, OPN5 is a known photoreceptor in the retina3 and skin4 but is also expressed in the hypothalamic preoptic area (POA)5. Here we describe a light-sensing pathway in which POA neurons that express Opn5 regulate thermogenesis in brown adipose tissue (BAT). We show that Opn5 is expressed in glutamatergic warm-sensing POA neurons that receive synaptic input from several thermoregulatory nuclei. We further show that Opn5 POA neurons project to BAT and decrease its activity under chemogenetic stimulation. Opn5-null mice show overactive BAT, increased body temperature, and exaggerated thermogenesis when cold-challenged. Moreover, violet photostimulation during cold exposure acutely suppresses BAT temperature in wild-type mice but not in Opn5-null mice. Direct measurements of intracellular cAMP ex vivo show that Opn5 POA neurons increase cAMP when stimulated with violet light. This analysis thus identifies a violet light-sensitive deep brain photoreceptor that normally suppresses BAT thermogenesis. Mice possess neurons in the preoptic area of the hypothalamus that are sensitive to violet light; these deep brain neurons sense light via OPN5 and regulate adaptive thermogenesis in brown fat.

Aims As PDGFRα (+) cells appear not to suppress the excitability of detrusor smooth muscle by generating SK3-dependent hyperpolarising as proposed in the gastrointestinal tract, we further explored the functional roles of PDGFRα (+) cells in regulating the spontaneous activity of urogenital tissues. Methods Using PDGFRα-eGFP mice, intracellular Ca2+ signaling in PDGFRα (+) cells of the bladder lamina propria, renal pelvis, and seminal vesicle were visualized using Cal-590 fluorescence. The distribution and SK3 expression of PDGFRα (+) cells were also examined by immunohistochemistry. Results In the bladder lamina propria, SK3 (-) PDGFRα (+) cells exhibited spontaneous Ca2+ transients and responded to stimulation of P2Y1 purinoceptors with MRS2365 (100 nM) or adenosine diphosphate (ADP) (100 μM) by developing Ca2+ transients. In the proximal renal pelvis, PDGFRα (+) cells were distributed in the mucosal, muscular and serosal layers but did not express SK3 immunoreactivity. PDGFRα (+) cells in the musculature resembling atypical smooth muscle cells generated spontaneous Ca2+ transients that were partially suppressed upon P2Y1-stimulation, while vigorously responding to human angiotensin II (100 nM). In the seminal vesicle, PDGFRα (+) cells in the musculature but not mucosa expressed SK3 immunoreactivity. In the mucosa, the P2Y1 stimulation evoked Ca2+ transients in both PDGFRα (+) cells and PDGFRα (-) cells. Conclusion PDGFRα (+) cells in spontaneously active urogenital tissues display heterogeneity in terms of their SK3 expression and P2Y1-induced Ca2+ responses. Muscular PDGFRα (+) cells in the renal pelvis and mucosal PDGFRα (+) cells in the seminal vesicle may generate depolarizing signals to drive smooth muscle cells.

Symptomatic cervical spondylosis is a progressive degenerative condition of the cervical spine commonly resulting in functionally-limiting pain, weakness, and/or limited dexterity. Symptomatic cervical spondylosis is believed to occur at higher rates in military aviators than civilian counterparts and is a disqualifying condition for all Navy and Marine Corps aircrew. This condition is non-waiverable for tactical jet (ejection-seat-based) aviators. Medical attrition of experienced tactical jet aircrew from the military aviation community results in substantial cost to the U.S. Government, reduces fleet combat capability, and adversely impacts career progression and retention. The clinical maturation of cervical total disc replacement (TDR) technology over the last 2 decades has revolutionized the treatment of symptomatic cervical spondylosis and enabled a return to duty for hundreds of military service members in non-aviation fields. TDR studies demonstrate equal or superior functional outcomes, rates of symptom resolution, reduced complication and reoperation rates, and lower long-term cost compared to traditional Anterior Cervical Discectomy and Fusion (ACDF). Although initial computational modeling studies have evaluated cervical arthroplasty performance during rotary-wing crash impacts, safety within the dynamic tactical jet environment has not yet been established. The purpose of this article is to review factors relevant to TDR safety and outcomes and to propose a framework to evaluate the safety of TDR in Navy and Marine Corps tactical jet aircrew, to ultimately inform aeromedical algorithms regarding return to flight after TDR.

Light stimuli from the external environment serves as a signal. Photoreceptors receive photons at the outer nuclear layer of the retina. Non-visual photoreceptors, such as opsin5 (also known as OPN5 or neuropsin), are expressed in the retinal ganglion cells (RGCs) and hypothalamus to regulate the circadian cycle and body temperature. Here, we show that violet light (VL) stimuli received by OPN5-positive RGCs are transmitted to the habenula brain region. VL improves memory in aged mice and simultaneously increases neural architecture-related genes such as oligodendrocyte-related genes in the hippocampus. In addition, VL improves depressive-like behaviors in the social defeat stress model in an OPN5 dependent manner. Following VL exposure, cFos activation is observed at the nucleus accumbens (NAc) and the paraventricular thalamic nucleus (PVT). Taken together, the results indicate that violet light modulates brain function such as memory and mood by transmitting the signal from RGCs to the habenula region in the brain.

PURPOSE: Cancer is a severe delayed effect of acute radiation exposure. Total-body irradiation has been associated with an increased risk of solid cancer and leukemia in Japanese atomic bomb survivors, and secondary malignancies, such as sarcoma, are a serious consequence of cancer radiation therapy. The radiation late effects cohort (RLEC) of rhesus macaques (Macaca mulatta) is a unique resource of more than 200 animals for studying the long-term consequences of total-body irradiation in an animal model that closely resembles humans at the genetic and physiologic levels. METHODS AND MATERIALS: Using clinical records, clinical imaging, histopathology, and immunohistochemistry, this retrospective study characterized the incidence of neoplasia in the RLEC. RESULTS: Since 2007, 61 neoplasms in 44 of 239 irradiated animals were documented (18.4% of the irradiated population). Only 1 neoplasm was diagnosed among the 51 nonirradiated controls of the RLEC (2.0%). The most common malignancies in the RLEC were sarcomas (38.3% of diagnoses), which are rare neoplasms in nonirradiated macaques. The most common sarcomas included malignant nerve sheath tumors and malignant glomus tumors. Carcinomas were less common (19.7% of diagnoses), and consisted primarily of renal cell and hepatocellular carcinomas. Neoplasia occurred in most major body systems, with the skin and subcutis being the most common site (40%). RNA analysis showed similarities in transcriptional profiles between RLEC and human malignant nerve sheath tumors. CONCLUSIONS: This study indicates that total-body irradiation is associated with an increased incidence of neoplasia years following irradiation, at more than double the incidence described in aging, nonirradiated animals, and promotes tumor histotypes that are rarely observed in nonirradiated, aging rhesus macaques.

During mouse postnatal eye development, the embryonic hyaloid vascular network regresses from the vitreous as an adaption for high-acuity vision. This process occurs with precisely controlled timing. Here, we show that opsin 5 (OPN5; also known as neuropsin)-dependent retinal light responses regulate vascular development in the postnatal eye. In Opn5-null mice, hyaloid vessels regress precociously. We demonstrate that 380-nm light stimulation via OPN5 and VGAT (the vesicular GABA/glycine transporter) in retinal ganglion cells enhances the activity of inner retinal DAT (also known as SLC6A3; a dopamine reuptake transporter) and thus suppresses vitreal dopamine. In turn, dopamine acts directly on hyaloid vascular endothelial cells to suppress the activity of vascular endothelial growth factor receptor 2 (VEGFR2) and promote hyaloid vessel regression. With OPN5 loss of function, the vitreous dopamine level is elevated and results in premature hyaloid regression. These investigations identify violet light as a developmental timing cue that, via an OPN5-dopamine pathway, regulates optic axis clearance in preparation for visual function.

Opsin-3 (Opn3, encephalopsin) was the first nonvisual opsin gene discovered in mammals. Since then, severalOpn3functions have been described, and in two cases (adipose tissue, smooth muscle) light sensing activity is implicated. In addition to peripheral tissues,Opn3is robustly expressed within the central nervous system, for which it derives its name. Despite this expression, no studies have investigated developmental or adult CNS consequences ofOpn3loss-of-function. Here, the behavioral consequences of mice deficient inOpn3were investigated.Opn3-deficient mice perform comparably to wild-type mice in measures of motor coordination, socialization, anxiety-like behavior, and various aspects of learning and memory. However,Opn3-deficient mice have an attenuated acoustic startle reflex (ASR) relative to littermates. This deficit is not because of changes in hearing sensitivity, although Opn3 was shown to be expressed in auditory and vestibular structures, including cochlear outer hair cells. Interestingly, the ASR was not acutely light-dependent and did not vary between daytime and nighttime trials, despite known functions ofOpn3in photoreception and circadian gene amplitude. Together, these results demonstrate the first role ofOpn3on behavior, although the role of this opsin in the CNS remains largely elusive.

Significance The increasing prevalence of myopia is a significant public health concern. Unfortunately, the mechanisms driving myopia remain elusive, limiting effective treatment options. This report identifies a refractive development pathway that requires Opn5-expressing retinal ganglion cells (RGCs). Stimulation of Opn5 RGCs with short-wavelength violet light prevented experimental myopia in mice. Furthermore, this effect was dependent on the time of day, with evening exposure being sufficient to protect against experimental myopia. Thus, these studies suggest Opn5 RGCs may contribute to the mechanisms of emmetropization and identify the OPN5 pathway as a potential target for the treatment of myopia., Myopia has become a major public health concern, particularly across much of Asia. It has been shown in multiple studies that outdoor activity has a protective effect on myopia. Recent reports have shown that short-wavelength visible violet light is the component of sunlight that appears to play an important role in preventing myopia progression in mice, chicks, and humans. The mechanism underlying this effect has not been understood. Here, we show that violet light prevents lens defocus–induced myopia in mice. This violet light effect was dependent on both time of day and retinal expression of the violet light sensitive atypical opsin, neuropsin (OPN5). These findings identify Opn5-expressing retinal ganglion cells as crucial for emmetropization in mice and suggest a strategy for myopia prevention in humans.

Here we investigate mechanisms underlying spontaneous phasic contractions (SPCs) and sympathetic control of contractility in the rat epididymis, a long tubular duct involved in transportation and maturation of sperm. Longitudinal contractions of short segments (~ 1.5 mm) of rat proximal and distal caudal epididymal duct were measured + / - nerve stimulation. The extent of sympathetic innervation of these duct regions was determined by immunohistochemistry. Proximal caudal duct segments (150-300 μm dia.) exhibited SPCs, while distal segments (350-500 μm) were quiescent in ~ 80% of preparations. SPC amplitude and frequency were reduced by the L-type voltage-dependent Ca

Opsin 3 (Opn3) is highly expressed in the adult brain, however, information for spatial and temporal expression patterns during embryogenesis is significantly lacking. Here an Opn3-eGFP reporter mouse line was utilized to monitor cell body expression and axonal projections during embryonic and early postnatal to adult stages. By applying 2D and 3D fluorescence imaging techniques, we have identified the onset of Opn3 expression, which predominantly occurred during embryonic stages, in various structures during brain/head development. In addition, this study defines over twenty Opn3-eGFP positive neural structures never reported before. Opn3-eGFP was first observed at E9.5 in neural regions, including the ganglia that will ultimately form the trigeminal, facial and vestibulocochlear cranial nerves. As development proceeds, expanded Opn3-eGFP expression coincided with the formation and maturation of critical components of the central and peripheral nervous systems, including various motor-sensory tracts, such as the dorsal column-medial lemniscus sensory tract, and olfactory, acoustic and optic tracts. The widespread, yet distinct, detection of Opn3-eGFP already at early embryonic stages suggests that Opn3 might play important functional roles in the developing brain and spinal cord to regulate multiple motor and sensory circuitry systems, including proprioception, nociception, ocular movement and olfaction, as well as memory, mood and emotion. This study presents a crucial blueprint from which to investigate autonomic and cognitive opsin-dependent neural development and resultant behaviors under physiological and pathophysiological conditions.Significance StatementThe expression of the mammalian Opsin 3 (Opn3) has only recently been characterized in adults, with no significant study during embryonic development. This study utilized an Opn3-eGFP mouse line to identify Opn3-related development of the CNS and PNS. 2D and 3D fluorescence imaging revealed cell body and axonal Opn3-eGFP expression, which indicated an early onset of Opn3-eGFP in cranial and spinal nerve ganglia, and sensory organs. Embryonic expression of Opn3-eGFP was also identified in the brainstem, cerebellum, hypothalamus and thalamus, whereas Opn3-eGFP expression in the cerebral cortex and associated limbic system regions were observed postnatally. The presence of Opn3, a short-wavelength-sensitive photopigment, in many brain regions during embryogenesis is of great interest when investigating autonomic and cognitive photo-dependent neural development.

Retinal ganglion cells (RGCs) serve as a crucial communication channel from the retina to the brain. In the adult, these cells receive input from defined sets of presynaptic partners and communicate with postsynaptic brain regions to convey features of the visual scene. However, in the developing visual system, RGC interactions extend beyond their synaptic partners such that they guide development before the onset of vision. In this Review, we summarize our current understanding of how interactions between RGCs and their environment influence cellular targeting, migration and circuit maturation during visual system development. We describe the roles of RGC subclasses in shaping unique developmental responses within the retina and at central targets. Finally, we highlight the utility of RNA sequencing and genetic tools in uncovering RGC type-specific roles during the development of the visual system., Summary: This Review summarizes the extensive roles of retinal ganglion cell interactions in shaping cell migration, vascular development, circuit formation and behavior, before the onset of vision in mammals.

Recently, we characterized blue light-mediated relaxation (photorelaxation) of airway smooth muscle (ASM) and implicated the involvement of opsin 3 (OPN3), an atypical opsin. In the present study, we characterized the cellular signaling mechanisms of photorelaxation. We confirmed the functional role of OPN3 in blue light photorelaxation using trachea from OPN3 null mice (maximal relaxation 52 ± 13% compared with wild-type mice 90 ± 4.3%

Striatin, a subunit of the serine/threonine phosphatase PP2A, is a core member of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complexes. The protein is expressed in the cell junctions between epithelial cells, which play a role in maintaining cell-cell junctional integrity. Since adhesion is crucial for the function of the mammalian inner ear, we examined the localization and function of striatin in the mouse cochlea. Our results show that in neonatal mice, striatin is specifically expressed in the cell-cell junctions of the inner hair cells, the receptor cells in the mammalian cochlea. Auditory brainstem response measurements of striatin-deficient mice indicated a progressive, high-frequency hearing loss, suggesting that striatin is essential for normal hearing. Moreover, scanning electron micrographs of the organ of Corti revealed a moderate degeneration of the outer hair cells in the middle and basal regions, concordant with the high-frequency hearing loss. Importantly, striatin-deficient mice show aberrant ribbon synapse maturation that may lead to the observed auditory impairment. Together, these results suggest a novel function for striatin in the mammalian auditory system.

Angiogenesis and vascular remodeling are essential for the establishment of vascular networks during organogenesis. Here we show that the Hippo signaling pathway effectors YAP and TAZ are required, in a gene dosage-dependent manner, for the proliferation and migration of vascular endothelial cells (ECs) during retinal angiogenesis. Intriguingly, nuclear translocation of YAP and TAZ induced by Lats1/2-deletion blocked endothelial migration and phenocopied Yap/Taz-deficient mutants. Furthermore, overexpression of a cytoplasmic form of YAP (YAPS127D) partially rescued the migration defects caused by loss of YAP and TAZ function. Finally, we found that cytoplasmic YAP positively regulated the activity of the small GTPase CDC42, deletion of which caused severe defects in endothelial migration. These findings uncover a previously unrecognized role of cytoplasmic YAP/TAZ in promoting cell migration by activating CDC42 and provide insight into how Hippo signaling in ECs regulates angiogenesis.

The prostate is a gland whose secretions contribute to the seminal fluids ejaculated upon activation of autonomic sympathetic nerves. In elder males, the prostate undergoes an increase in stroma mass and myogenic tone, leading to benign prostatic hyperplasia that occludes the proximal urethra and the presentation of various lower urinary tract symptoms that decrease their quality of life. This review summarises the role of prostatic interstitial cells (PICs) in the generation of the spontaneous tone in the prostate. It presents current knowledge of the role of Ca2+ plays in PIC pacemaking, as well as the mechanisms by which this spontaneous activity triggers slow wave generation and stromal contraction. PICs display a small T-type Ca2+ current (ICaT) and a large L-type Ca2+ current (ICaL). In contrast to other interstitial cells in the urinary and gastrointestinal tracts, spontaneous Ca2+ signalling in PICs is uniquely dependent on Ca2+ influx through ICaL channels. A model of prostatic pacemaking is presented describing how ICaL can be triggered by an initial membrane depolarization evoked upon the selective opening of Ca2+-activated Cl– channels by Ca2+ flowing only through ICaT channels. The resulting current flow through ICaL results in release of Ca2+ from internal stores and the summation of Cl–-selective spontaneous transient depolarizations (STDs) to form pacemaker potentials that propagate passively into the prostatic stroma to evoke regenerative action potentials and excitation-contraction coupling.

Typical and atypical smooth muscle cells (TSMCs and ASMCs, respectively) and interstitial cells (ICs) within the pacemaker region of the mouse renal pelvis were examined using focused ion beam scanning electron (FIB SEM) tomography, immunohistochemistry and Ca2+ imaging. Individual cells within 500–900 electron micrograph stacks were volume rendered and associations with their neighbours established. ‘Ribbon-shaped’, Ano1 Cl− channel immuno-reactive ICs were present in the adventitia and the sub-urothelial space adjacent to the TSMC layer. ICs in the proximal renal pelvis were immuno-reactive to antibodies for CaV3.1 and hyperpolarization-activated cation nucleotide-gated isoform 3 (HCN3) channel sub-units, while basal-epithelial cells (BECs) were intensely immuno-reactive to Kv7.5 channel antibodies. Adventitial to the TSMC layer, ASMCs formed close appositions with TSMCs and ICs. The T-type Ca2+channel blocker, Ni2+ (10–200 μM), reduced the frequency while the L-type Ca2+ channel blocker (1 μM nifedipine) reduced the amplitude of propagating Ca2+ waves and contractions in the TSMC layer. Upon complete suppression of Ca2+ entry through TSMC Ca2+ channels, ASMCs displayed high-frequency (6 min−1) Ca2+ transients, and ICs distributed into two populations of cells firing at 1 and 3 min−1, respectively. IC Ca2+ transients periodically (every 3–5 min−1) summed into bursts which doubled the frequency of ASMC Ca2+ transient firing. Synchronized IC bursting and the acceleration of ASMC firing were inhibited upon blockade of HCN channels with ZD7288 or cell-to-cell coupling with carbenoxolone. While ASMCs appear to be the primary pacemaker driving pyeloureteric peristalsis, it was concluded that sub-urothelial HCN3(+), CaV3.1(+) ICs can accelerate ASMC Ca2+ signalling.

Rhythmic contractions of the renal pelvis transport urine from the kidneys into the ureter. Specialized pacemaker cells, termed atypical smooth muscle cells (ASMCs), are thought to drive the peristaltic contractions of typical smooth muscle cells (TSMCs) in the renal pelvis. Interstitial cells (ICs) in close proximity to ASMCs and TSMCs have been described, but the role of these cells is poorly understood. The presence and distributions of platelet-derived growth factor receptor-α(+) (PDGFRα(+)) ICs in the pelvis-kidney junction (PKJ) and distal renal pelvis were evaluated. We found PDGFRα(+) ICs in the adventitial layers of the pelvis and in the muscle layer of the PKJ and in the adventitia of the distal pelvis. PDGFRα(+) ICs were distinct from c-Kit(+) ICs in the renal pelvis. c-Kit(+) ICs are a minor population of ICs in murine renal pelvis. The majority of c-Kit(+) cells were mast cells. PDGFRα(+) cells in the PKJ co-expressed smMHC and several other smooth muscle gene transcripts, indicating these cells are ASMC, and PDGFRα is a novel biomarker for ASMC. PDGFRα(+) cells also express Ano1, which encodes a Ca(2+)activated Cl(−) conductance that serves as a primary pacemaker conductance in ICs of the GI tract. Spontaneous Ca(2+) transients were observed in c-Kit(+) ICs, smMHC(+) PDGFRα cells and smMHC(−) PDGFRα cells using genetically-encoded Ca(2+) sensors. A reporter strain of mice with eGFP driven by the endogenous promotor for Pdgfra was shown to be a powerful new tool for isolating and characterizing the phenotype and functions of these cells in the renal pelvis.

SummaryAlmost all life forms can decode light information for adaptive advantage. Examples include the visual system, where photoreceptor signals are interpreted as images, and the circadian system, where light entrains a physiological clock. Here we describe a local, non-visual light response in mice that employs encephalopsin (OPN3, a 480 nm, blue light responsive opsin) to regulate the function of adipocytes. Germ line null and adipocyte-specific conditional null mice show a deficit in thermogenesis that is phenocopied in mice under blue-light deficient conditions. We show that blue light stimulation of adipocytes activates hormone sensitive lipase, the rate limiting enzyme in the lipolysis pathway, and that this is OPN3-dependent. Opn3 adipocyte conditional null mice also use reduced levels of fat mass when fasted and cold exposed further suggesting a lipolysis deficit. These data suggest the hypothesis that in mice, a local, OPN3-dependent light response in adipocytes is a mechanism for regulation of energy homeostasis.

Sensory stimulation plays a critical role in the maturation of sensory organs and systems. For example, when deprived of light before birth, foetal mouse pups in utero exhibit altered ocular vascular development. Normal vascular development depends on light excitation of melanopsin, a non-rod, non-cone photopigment that is expressed in a subset of ganglion cells (mRGCs) in the retina. However, there is no direct evidence that mRGCs in foetal eyes are light-responsive. Very little is known about how light absorption leads to excitation in these foetal neurons. Using mRGC-specific expression of the calcium indicators GCaMP3 and GCaMP6, we report that foetal mouse mRGCs respond to light as early as 4 days before birth. Further, two distinct Gq/11-G protein family antagonists, FR9000359 and YM-254890, abolish these light responses. TTX, a blocker of voltage-activated sodium channels, reversibly represses light responses, and FPL6417 and L-cis-diltiazem, which modify L-type calcium channels, respectively increase and reduce light responses. Electrophysiological patch pipette recordings show that embryonic mRGCs respond to light of intensity as low as 2.9 × 1012 photons/cm2/s. The present findings demonstrate a heretofore unproven but postulated light sensitivity in the retinas of foetal mice and identify the transduction pathways involved. Surprisingly, mRGCs do not function as completely independent photoreceptors but are electrotonically coupled with other mRGCs. Given that melanopsin is expressed in foetal human retinas, these findings support the idea that the eyes of foetal and early preterm infants are likely to exhibit functional photosensitivity.Key pointsMelanopsin is a light-excitable photopigment expressed in a subset of ganglion cell neurons (mRGCs) in the retinas of many different species of vertebrates. In mature animals, light activation of mRGCs modulates many visual adaptive functions including pupil constriction, entrainment of circadian rhythms, mood and learning. In neonatal pups at ages prior to the developmental onset of visual signalling from rods and cones, melanopsin cells mediate photoaversive behaviour. In foetal pups, light activation of melanopsin cells accelerates maturation of the ocular vasculature. Here, we describe and physiologically characterize the light responses of melanopsin ganglion cells in the retinas of foetal pups.MRGCs in embryonic retinas respond to light at least four days prior to birth and exhibit responses to light of intensity as low as 3 × 1012 photons/cm2/s.Phototransduction mechanisms include melanopsin activation of Gq/11 – G proteins, voltage-activated sodium currents, and voltage-gated L-type calcium currents.MRGCs are electrotonically coupled to other mRGCs in foetal retinas.We propose that melanopsin-expressing ganglion cells are excited by light while in utero and that this excitation relies, for the most part, on phototransduction pathways that have been described in postnatal retinas. Furthermore, we propose that foetal mRGCs have the requisite properties to modulate light-regulated maturation of the ocular vasculature and, perhaps, the development of visual pathways.

The peristaltic pressure waves in the renal pelvis that propel urine expressed by the kidney into the ureter towards the bladder have long been considered to be 'myogenic', being little affected by blockers of nerve conduction or autonomic neurotransmission, but sustained by the intrinsic release of prostaglandins and sensory neurotransmitters. In uni-papilla mammals, the funnel-shaped renal pelvis consists of a lumen-forming urothelium and a stromal layer enveloped by a plexus of 'typical' smooth muscle cells (TSMCs), in multi-papillae kidneys a number of minor and major calyces fuse into a large renal pelvis. Electron microscopic, electrophysiological and Ca

The ureter acts as a functional syncytium and is controlled by a propagating plateau-type action potential (AP) which gives rise to a wave of contraction (ureteral peristalsis) via a process called excitation-contraction (E-C)coupling. The second messenger Ca2+ activates Ca2+/calmodulin-dependent myosin light chain kinase-dependent phosphorylation of 20-kDa regulatory light chains of myosin which leads to ureteric contraction. Ca2+ entry from the extracellular space via voltage-gated L-type Ca2+ channels (VGCCs) provides the major source of activator Ca2+, responsible for generation of both the AP and a Ca2+ transient that appears as an intercellular Ca2+ wave. The AP, inward Ca2+ current, Ca2+ transient and twitch contraction are all fully blocked by the selective L-type Ca2+ channel blocker nifedipine. Ca2+ entry via VGCCs, coupled to activation of Ca2+-sensitive K+ (KCa) or Cl- (ClCa) channels, acts as a negative or positive feedback mechanism, respectively, to control excitability and the amplitude and duration of the plateau component of the AP, Ca2+ transient and twitch contraction. The ureter, isolated from the pelvis, is not spontaneously active. However, spontaneous activity can be initiated in the proximal and distal ureter by a variety of biological effectors such as neurotransmitters, paracrine, endocrine and inflammatory factors. Applied agonists depolarise ureteric smooth muscles cells to threshold of AP activation, initiating propagating intercellular AP-mediated Ca2+ waves to produce antegrade and/or retrograde ureteric peristalsis. Several mechanisms have been proposed to describe agonist-induced depolarization of ureteric smooth muscle, which include suppression of K+ channels, stimulation of ClCa current and activation of non-selective cation receptor/store operated channels.

The peristaltic pressure waves in the renal pelvis that propel urine expressed by the kidney into the ureter towards the bladder have long been considered to be 'myogenic', being little affected by blockers of nerve conduction or autonomic neurotransmission, but sustained by the intrinsic release of prostaglandins and sensory neurotransmitters. In uni-papilla mammals, the funnel-shaped renal pelvis consists of a lumen-forming urothelium and a stromal layer enveloped by a plexus of 'typical' smooth muscle cells (TSMCs), in multi-papillae kidneys a number of minor and major calyces fuse into a large renal pelvis. Electron microscopic, electrophysiological and Ca2+ imaging studies have established that the pacemaker cells driving pyeloureteric peristalsis are likely to be morphologically distinct 'atypical' smooth muscle cells (ASMCs) that fire Ca2+ transients and spontaneous transient depolarizations (STDs) which trigger propagating nifedipine-sensitive action potentials and Ca2+ waves in the TSMC layer. In uni-calyceal kidneys, ASMCs predominately locate on the serosal surface of the proximal renal pelvis while in multi-papillae kidneys they locate within the sub-urothelial space. 'Fibroblast-like' interstitial cells (ICs) located in the sub-urothelial space or adventitia are a mixed population of cells, having regional and species-dependent expression of various Cl-, K+, Ca2+ and cationic channels. ICs display asynchronous Ca2+ transients that periodically synchronize into bursts that accelerate ASMC Ca2+ transient firing. This review presents current knowledge of the architecture of the proximal renal pelvis, the role Ca2+ plays in renal pelvis peristalsis and the mechanisms by which ICs may sustain/accelerate ASMC pacemaking.

UNLABELLED The pathway to military neurosurgical practice can include a number of accession options. This article is an objective comparison of fiscal, tangible, and intangible benefits provided through different military neurosurgery career paths. Neurosurgeons may train through active duty, reserve, or civilian pathways. These modalities were evaluated on the basis of economic data during residency and the initial 3 years afterwards. When available, military base pay, basic allowance for housing and subsistence, variable special pay, board certified pay, incentive pay, multiyear special pay, reserve drill pay, civilian salary, income tax, and other tax incentives were analyzed using publically available data. Civilians had lower residency pay, higher starting salaries, increased taxes, malpractice insurance cost, and increased overhead. Active duty service saw higher residency pay, lower starting salary, tax incentives, increased benefits, and almost no associated overhead including malpractice coverage. Reserve service saw a combination of civilian benefits with supplementation of reserve drill pay in return for weekend drill and the possibility of deployment and activation. Being a neurosurgeon in the military is extremely rewarding. From a financial perspective, ignoring intangibles, this article shows most entry pathways with initially modest differences between the cumulative salaries of active duty and civilian career paths and with higher overall compensation available from the reserve service option. These pathways become increasingly discrepant over time as civilian pay greatly exceeds that of military neurosurgeons. We hope that those curious about or considering serving in the United States military benefit from our accounting and review of these comparative paths. ABBREVIATIONS FAP, Financial Assistance ProgramNADDS, Navy Active Duty Delay for SpecialistsTMS, Training in Medical Specialties.

The microvasculature plays a primary role in the interchange of substances between tissues and the circulation. In visceral organs that undergo considerable distension upon filling, the microvasculature appears to display intrinsic contractile properties to maintain their flow. Submucosal venules in the bladder or gastrointestinal tract generate rhythmic spontaneous phasic constrictions and associated Ca(2+) transients. These events are initiated within either venular pericytes or smooth muscle cells (SMCs) arising from spontaneous Ca(2+) release from the sarcoplasmic reticulum (SR) and the opening of Ca(2+) -activated chloride channels (CaCCs) that trigger Ca(2+) influx through L-type voltage-dependent Ca(2+) channels (VDCCs). L-type VDCCs also play a critical role in maintaining synchrony within the contractile mural cells. In the stomach myenteric layer, spontaneous Ca(2+) transients originating in capillary pericytes appear to spread to their neighbouring arteriolar SMCs. Capillary Ca(2+) transients primarily rely on SR Ca(2+) release, but also require Ca(2+) influx through T-type VDCCs for their synchrony. The opening of T-type VDCCs also contribute to the propagation of Ca(2+) transients into SMCs. In visceral microvasculature, pericytes act as either spontaneously active contractile machinery of the venules or as pacemaker cells generating synchronous Ca(2+) transients that drive spontaneous contractions in upstream arterioles. Thus pericytes play different roles in different vascular beds in a manner that may well depend on the selective expression of T-type and L-type Ca(2+) channels.

SUMMARY Almost all life forms can detect and decode light information for adaptive advantage. Examples include the visual system, in which photoreceptor signals are processed into virtual images, and the circadian system, in which light entrains a physiological clock. Here we describe a light response pathway in mice that employs encephalopsin (OPN3, a 480 nm, blue-light-responsive opsin) to regulate the function of adipocytes. Germline null and adipocyte-specific conditional null mice show a light- and Opn3-dependent deficit in thermogenesis and become hypothermic upon cold exposure. We show that stimulating mouse adipocytes with blue light enhances the lipolysis response and, in particular, phosphorylation of hormone-sensitive lipase. This response is Opn3 dependent. These data establish a key mechanism in which light-dependent, local regulation of the lipolysis response in white adipocytes regulates energy metabolism., Graphical Abstract, In Brief White adipocytes activate the lipolysis pathway to produce the free fatty acids that are used as heating fuel by brown adipose tissue. Nayak et al. show that Opsin 3 is required for blue-light-enhanced activation of the lipolysis pathway. This explains the low body temperature of Opn3 mutant mice.