SUMMARYThe successful planning and execution of adaptive behaviors in mammals may require long-range coordination of neural networks throughout cerebral cortex. The neuronal implementation of signals that could orchestrate cortex-wide activity remains unclear. Here, we develop and apply methods for cortex-wide Ca2+ imaging in mice performing decision-making behavior and identify a global cortical representation of task engagement encoded in the activity dynamics of both single cells and superficial neuropil distributed across the majority of dorsal cortex. The activity of multiple molecularly defined cell types was found to reflect this representation with type-specific dynamics. Focal optogenetic inhibition tiled across cortex revealed a crucial role for frontal cortex in triggering this cortex-wide phenomenon; local inhibition of this region blocked both the cortex-wide response to task-initiating cues and the voluntary behavior. These findings reveal cell-type-specific processes in cortex for globally representing goal-directed behavior and identify a major cortical node that gates the global broadcast of task-related information.
BACKGROUND Male circumcision significantly reduced the incidence of human immunodeficiency virus (HIV) infection among men in three clinical trials. We assessed the efficacy of male circumcision for the prevention of herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) infections and syphilis in HIV-negative adolescent boys and men. METHODS We enrolled 5534 HIV-negative, uncircumcised male subjects between the ages of 15 and 49 years in two trials of male circumcision for the prevention of HIV and other sexually transmitted infections. Of these subjects, 3393 (61.3%) were HSV-2–seronegative at enrollment. Of the seronegative subjects, 1684 had been randomly assigned to undergo immediate circumcision (intervention group) and 1709 to undergo circumcision after 24 months (control group). At baseline and at 6, 12, and 24 months, we tested subjects for HSV-2 and HIV infection and syphilis, along with performing physical examinations and conducting interviews. In addition, we evaluated a subgroup of subjects for HPV infection at baseline and at 24 months. RESULTS At 24 months, the cumulative probability of HSV-2 seroconversion was 7.8% in the intervention group and 10.3% in the control group (adjusted hazard ratio in the intervention group, 0.72; 95% confidence interval [CI], 0.56 to 0.92; P = 0.008). The prevalence of high-risk HPV genotypes was 18.0% in the intervention group and 27.9% in the control group (adjusted risk ratio, 0.65; 95% CI, 0.46 to 0.90; P = 0.009). However, no significant difference between the two study groups was observed in the incidence of syphilis (adjusted hazard ratio, 1.10; 95% CI, 0.75 to 1.65; P = 0.44). CONCLUSIONS In addition to decreasing the incidence of HIV infection, male circumcision significantly reduced the incidence of HSV-2 infection and the prevalence of HPV infection, findings that underscore the potential public health benefits of the procedure.
Water deprivation produces a drive to seek and consume water. How neural activity creates this motivation remains poorly understood. We used activity-dependent genetic labeling to characterize neurons activated by water deprivation in the hypothalamic median preoptic nucleus (MnPO). Single-cell transcriptional profiling revealed that dehydration-activated MnPO neurons consist of a single excitatory cell type. After optogenetic activation of these neurons, mice drank water and performed an operant lever-pressing task for water reward with rates that scaled with stimulation frequency. This stimulation was aversive, and instrumentally pausing stimulation could reinforce lever-pressing. Activity of these neurons gradually decreased over the course of an operant session. Thus, the activity of dehydration-activated MnPO neurons establishes a scalable, persistent, and aversive internal state that dynamically controls thirst-motivated behavior.
Objective-To assess effects of male circumcision on female genital symptoms, and vaginal infections.Methods-HIV-negative men enrolled in a trial were randomized to immediate or delayed circumcision (control arm). Genital symptoms, BV and trichomonas were assessed in HIV-negative wives of married participants. Adjusted prevalence risk ratios (adjPRR) and 95% confidence intervals (95%CI) were assessed by multivariable log-binomial regression, intent-to-treat analyses.Results-783 wives of control and 825 wives of intervention arm men were comparable at enrollment. BV at enrollment was higher in control (38.3%) than intervention arm spouses (30.5%, p=0.001). At one year follow up, intervention arm wives reported lower rates of genital ulceration (adjPRR 0.78, 95%CI 0.63-0.97), but there were no differences in vaginal discharge or dysuria. The risk of trichomonas was reduced in intervention arm wives (adjPRR 0.52, 95%CI 0.05-0.98), as were the risks of any BV (adjPRR 0.60, 95%CI 0.38-0.94) and severe BV (PRR = 0.39, 95%CI 0.24-0.64).Conclusions-Male circumcision reduces the risk of ulceration, trichomonas and BV in female partners.
Prepubertal circumcision may reduce male HIV acquisition in a general population, but the protective effects are confounded by cultural and behavioral factors in Muslims. In discordant couples, circumcision reduces HIV acquisition and transmission. The assessment of circumcision for HIV prevention is complex and requires randomized trials.
Neuron activity across the brain How is it that groups of neurons dispersed through the brain interact to generate complex behaviors? Three papers in this issue present brain-scale studies of neuronal activity and dynamics (see the Perspective by Huk and Hart). Allen et al. found that in thirsty mice, there is widespread neural activity related to stimuli that elicit licking and drinking. Individual neurons encoded task-specific responses, but every brain area contained neurons with different types of response. Optogenetic stimulation of thirst-sensing neurons in one area of the brain reinstated drinking and neuronal activity across the brain that previously signaled thirst. Gründemann et al. investigated the activity of mouse basal amygdala neurons in relation to behavior during different tasks. Two ensembles of neurons showed orthogonal activity during exploratory and nonexploratory behaviors, possibly reflecting different levels of anxiety experienced in these areas. Stringer et al. analyzed spontaneous neuronal firing, finding that neurons in the primary visual cortex encoded both visual information and motor activity related to facial movements. The variability of neuronal responses to visual stimuli in the primary visual area is mainly related to arousal and reflects the encoding of latent behavioral states. Science , this issue p. eaav3932 , p. eaav8736 , p. eaav7893 ; see also p. 236
Background Randomized trials show that medical male circumcision (MC) reduces high-risk human papillomavirus (HR-HPV) infection in men. We assessed the efficacy of MC to reduce HR-HPV in female partners. Methods HIV-negative men were randomized to immediate MC (intervention) or MC delayed for 24 months (control). HIV-uninfected female partners of married men (648 intervention and 597 control arm) were simultaneously enrolled and provided interview information and self-collected vaginal swabs at baseline, 12 and 24 months. Female HPV infection was a secondary trial end point. Vaginal swabs were evaluated for HR-HPV by Roche HPV Linear Array. An intention-to-treat analysis estimated prevalence risk and incident rate ratios (PRR and IRR) and 95% confidence intervals (95%CI) of HR-HPV by Poisson multiple regression. In women with pre-existing HR-HPV, we estimated the risk ratio (RR) of cleared infection (i.e., loss of detection). The trials were registered with ClinicalTrials.gov, NCT00425984 and NCT00124878.) Findings Female characteristics and HPV prevalence were similar between arms at enrollment. Two year retention rates were 84.7% (549/648) in intervention arm and 84.1% (502/597) in control arm spouses. Year 2 female HR-HPV prevalence was 27.8% (151/544) in the intervention and 38.7% (189/488) in the control arm (PRR=0.72, 95%CI 0.60–0.85, p=0.001). HR-HPV incidence was 20.7/100py in the intervention arm and 26.9/100py in the control arm wives (IRR=0.77, 95%CI 0.63-0.93, p=0.008). HR-HPV incidence was lower in intervention than control arm wives for 13 of 14 (92.9%) HR-HPV genotypes and in most demographic/behavioral subgroups. Genotype specific HR-HPV clearance was higher in the wives of men in the intervention arm (66.2%, 376/568) than the control arm (59.2%, 339/573, RR=1.12, 95%CI 1.02-1.22). Interpretation MC reduces the prevalence and incidence and increases clearance of HR-HPV infections in female partners. Funding Bill & Melinda Gates Foundation with additional laboratory and training support from National Institutes of Health and Fogarty International Center.
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