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Although increasing research is focusing on age-related comorbidities (ARC) among people living with HIV (PLHIV), no studies have concomitantly assessed non-HIV age-related neurological disorders (e.g., Alzheimer’s dementia). A total of 254 PLHIV and 69 HIV-negative controls completed baseline medical history and cognitive testing. ARC data were collected from medical records over the subsequent 9-10 years and included all types of strokes, all types of dementia, mild cognitive impairment, Parkinson's disease, motor neuron disease (grouped into a non-HIV age-related neurological category), cardiovascular disease, chronic kidney disease, chronic liver disease, chronic lung disease, non-AIDS cancers, osteoporosis, and diabetes. Kaplan–Meier curves assessed differences in the incident rates (per 1000 person year) of groups of ARC as defined above and combined ARC (i.e., development of any of the ARC) among younger (baseline age < 50) and older (baseline age ≥ 50) PLHIV and younger and older controls. Cox-proportional hazard models assessed the individual and interaction effects of HIV status and chronological age, in addition to a range of demographic and clinical variables including historical and baseline HIV brain involvement on the risk of developing combined ARC. Older PLHIV had a higher incidence of cardiovascular disease, osteoporosis, and combined ARC compared to other groups (p < 0.05). Incident rate of non-HIV age-related neurological disorders was 2.3 [0.93, 4.79] per 1000 person year. While this incident rate was higher in older PLHIV (5.37 [1.97, 11.92]) than older HIV-negative participants (3.58 [0.18-17.67]), this was not significant. In multivariate analyses, HIV status and chronological age, but not their interaction, and smoking were associated with higher risk of combined ARC (p < 0.05). In analyses focusing on PLHIV, older age and taking abacavir/efavirenz/atazanavir/darunavir containing antiretroviral treatments at the time of diagnosis were associated with greater ARC (p < 0.05). Non-HIV age-related neurological disorders are uncommon in older PLHIV, where the majority were < 70 years of age at the end of follow-up. However, the greater burden of ARC among older PLHIV, most of which are established dementia risk factors, warrants the establishment of commensurate prevention strategies and greater attention to neurocognitive screening.

Changes to how gay, bisexual, and other men who have sex with men (GBM) connect with each other and with their communities have implications for HIV prevention. Social engagement with gay men (defined as having friends who are gay men and spending time with them) has been associated with HIV related outcomes over time among Australian GBM. Using data collected in national, repeated, cross-sectional surveys of GBM between 1998 and 2020 (N = 161,117), analyses of trends in the prevalence of gay social engagement (GSE) in Australia were conducted using linear regression. To assess changing associations with GSE at different time points in the HIV epidemic, three cross-sectional analyses were conducted on factors associated with high and low GSE in 1999/2000, 2009/2010, and 2019/2020 using bivariate and multivariable logistic regression. GSE (scored from 0 to 7) declined among all participants from 4.76 in 1998 to 4.04 in 2020 (p p

IntroductionStigma is a significant contributor to the HIV diagnosis disparities experienced among migrants who are gay and bisexual men (GBM) living in high-income countries.MethodsWe conducted interviews with 24 migrant GBM in Australia diagnosed with HIV from 2017 onwards, who since their diagnosis had become well-connected to sexual health services and participation in research. Interviews were conducted between October 2018 and December 2019. We aimed to identify how HIV and sexual identity stigmas were barriers to accessing HIV testing and prevention.ResultsThese stigmas were deeply embedded into social, cultural, and institutional settings in participants’ countries of origin, resulting in poor HIV literacy, reluctance to access HIV-related services, including HIV testing, and fears of being identified as gay/bisexual publicly. Underpinned by internalised stigma, these fears and poor outcomes often persisted after moving to Australia. Other barriers to accessing HIV-related services in Australia included apprehension about a potential HIV-positive result and the possibility of visa cancellation, concerns about confidentiality, and a lack of confidence and support in navigating the healthcare system, including how to access pre-exposure prophylaxis.ConclusionAddressing these multifaceted HIV testing and prevention barriers requires policies, systems, and interventions that increase health literacy about HIV testing, prevention, and treatment; build trust and confidence when navigating Australian health services; and reduce the impacts of HIV and sexual identity stigmas in migrants’ countries of origin on their experiences in Australia.

As the development of dual-ion batteries (DIBs) is limited by the capacity of anions intercalation, we put forward an innovative design idea of DIB. Compared with the traditional graphite cathodes, few-layered reduced graphene oxide (rGO) has a large specific surface area and can greatly improve the utilization ratio of carbon layers for fast redox reaction process. In addition, the carbon paper current collector with porous network structure facilitates the uniform distribution of active materials, rapid penetration of electrolyte and fast migration of ions, and also relieves the volume strain caused by PF6− intercalation/de-intercalation. Under the effects of the above two aspects, the lithium-rGO DIB demonstrates significantly enhanced electrochemical performance compared with conventional DIBs. It possesses an ultra-high discharge capacity of 405 mA h g−1 with a coulombic efficiency of > 98% after 1000 cycles at 1 A g−1 in the voltage range of 3.0–5.0 V. The detailed mechanism of electrochemical performance enhancement is also discussed.

Increasing HIV testing frequency in gay and bisexual men (GBM) is critical to reducing the time between HIV infection and diagnosis. Using anonymous national behavioural surveillance data (2013–2018) from 43,753 surveys of Australian GBM, we examined HIV testing frequency trends and factors differentiating PrEP-users, non-PrEP-users reporting two or more tests in the previous year, and non-PrEP-users reporting less frequent testing. The proportion tested at least annually increased from 64.4% in 2013 to 70.8% in 2018 (p-trend

In Australia, HIV testing services have become increasingly available in non-traditional settings such as peer-led, community-based services to expand access and increase uptake of HIV testing among gay and bisexual men (GBM). This study aimed to compare the socio-demographic and behavioural characteristics of GBM whose last HIV test was conducted at a community-based service to GBM whose last test was at a traditional clinical setting. We analysed behavioural surveillance data collected from 5988 participants in seven states and territories in the period 2016-2017. We found that non-HIV-positive GBM who attended community-based services were largely similar to men attending clinic-based settings, particularly in terms of sexual practice and risk of HIV. However, non-HIV-positive GBM who were younger, born in Asia, more socially engaged with other gay men but who had not recently used PrEP were more likely to attend community-based services for their last HIV test. This study points to the successful establishment of community-based HIV testing services in Australia as a way to attract subgroups of GBM at potentially higher risk of HIV.

Lithium-sulfur (Li-S) batteries exhibit the high specific capacity and energy density, but prevented by the low coulombic efficiency and weak cycle life. Herein, we fabricate reduced graphene oxide (r-GO) three-dimensional (3D) foams encapsulating polar mesoporous zinc sulfide (ZnS) nanosheets and subsequently utilize the ZnS/r-GO foams to load sulfur (ZnS/r-GO/S) as cathodes for improving the performance of Li-S batteries. The mesoporous diameter of the ZnS nanosheets is approximately 10~30 nm and lots of pores in the 3D foams are observed. The porous structure provides abundant sites to adsorb and accommodate sulfur species. The cathode of the ZnS/r-GO/S exhibits 1259 mA h g−1 of initial capacity and 971.9 mA h g−1 of the reversible capacity after 200 cycles at 0.1 C (1 C = 1675 mA g−1). At 1 C, it still exhibits the tiny capacity decay rate of 0.019% per cycle after 300 cycles. This work may be adopted to combine the nonpolar and polar materials as a 3D network structure for high-performance Li-S batteries.

The metabotropic glutamate (mGlu) receptor 5 is a G protein-coupled receptor and is densely expressed in the mammalian brain. Like other glutamate receptors, mGlu5 receptors are tightly regulated by posttranslational modifications such as phosphorylation, although underlying mechanisms are incompletely investigated. In this study, we investigated the role of a prime kinase, extracellular signal-regulated kinase 1 (ERK1), in the phosphorylation and regulation of mGlu5 receptors in vitro and in striatal neurons. We found that recombinant ERK1 proteins directly bound to the C-terminal (CT) tail of mGlu5 receptors in vitro. Endogenous ERK1 also interacted with mGlu5 receptor proteins in adult rat striatal neurons in vivo. The kinase showed the ability to phosphorylate mGlu5 receptors. A serine residue in the distal region of mGlu5 CT was found to be a primary phosphorylation site sensitive to ERK1. In functional studies, we found that pharmacological inhibition of ERK with an inhibitor U0126 reduced the efficacy of mGlu5 receptors in stimulating production of cytoplasmic inositol-1,4,5-triphosphate, a major downstream conventional signaling event, in striatal neurons under normal conditions. These results identify mGlu5 as a new biochemical substrate of ERK1. The kinase can interact with and phosphorylate an intracellular domain of mGlu5 receptors in striatal neurons and thereby control its signaling efficacy.

The landscape of HIV testing has changed significantly in recent years following the rise in importance of the 'treatment as prevention' strategy and advancements in new HIV testing and prevention technologies. This review provides a synthesis of qualitative research findings published since 2010 on preferences and practices of men who have sex with men (MSM) surrounding HIV testing in high-income settings. MSM are one of the hardest groups to reach with standard or conventional HIV testing approaches. To develop innovative testing strategies for this particular group, a good understanding of their concerns, barriers and facilitators of accessing HIV testing is needed. This updated review provides valuable information for improving existing programs and designing new testing services for MSM.

Several Src family kinase (SFK) members are expressed in the mammalian brain and serve as key kinases in the regulation of a variety of cellular and synaptic events. These SFKs may be subject to the modulation by dopamine, although this topic has been investigated incompletely. In this study, we explored whether dopamine D2 receptors (D2Rs) regulate SFKs in adult rat brains in vivo. We investigated the role of D2Rs in two forebrain areas, the medial prefrontal cortex (mPFC) and hippocampus, since dopamine plays a pivotal role in regulating activity of mPFC and hippocampal neurons and D2Rs are expressed in these regions. We found that a systemic injection of a D2R selective antagonist eticlopride elevated phosphorylation of SFKs at a conserved autophosphorylation site, an event correlated with activation of SFKs, in the mPFC. Similarly, antagonism of D2Rs by haloperidol increased SFK phosphorylation. In contrast, eticlopride and haloperidol did not alter SFK phosphorylation in the hippocampus. The effect of eticlopride was time-dependent and relatively delayed. Among two common SFK members enriched at synaptic sites, eticlopride selectively altered phosphorylation of Fyn but not Src. Our data suggest that D2Rs exert an inhibitory effect on the activity-related phosphorylation of Fyn in the mPFC under normal conditions.

Acetylcholine (ACh) is a key transmitter in the mesocorticolimbic circuit. By interacting with muscarinic ACh receptors (mAChR) enriched in the circuit, ACh actively regulates various neuronal and synaptic activities. The extracellular signal-regulated kinase (ERK) is one of members of the mitogen-activated protein kinase family and is subject to the regulation by dopamine receptors, although the regulation of ERKs by limbic mAChRs is poorly understood. In this study, we investigated the role of mAChRs in the regulation of ERK phosphorylation (activation) in the mesocorticolimbic system of adult rat brains in vivo. We targeted a sub-pool of ERKs at synaptic sites. We found that a systemic injection of the mAChR antagonist scopolamine increased phosphorylation of synaptic ERKs in the striatum (caudate putamen and nucleus accumbens) and medial prefrontal cortex (mPFC). Increases in ERK phosphorylation in both forebrain regions were rapid and transient. Notably, pretreatment with a dopamine D1 receptor (D1R) antagonist SCH23390 blocked the scopolamine-stimulated ERK phosphorylation in these brain regions, while a dopamine D2 receptor antagonist eticlopride did not. Scopolamine and SCH23390 did not change the amount of total ERK proteins. These results demonstrate that mAChRs inhibit synaptic ERK phosphorylation in striatal and mPFC neurons under normal conditions. Blockade of this inhibitory mAChR tone leads to the upregulation of ERK phosphorylation likely through a mechanism involving the level of D1R activity.

Mitogen-activated protein kinases (MAPKs) are expressed in postmitotic neurons and act as important regulators in intracellular signaling. In addition to their nuclear distribution and roles in regulating gene expression, MAPKs, especially the extracellular signal-regulated kinase (ERK) subclass, reside in peripheral dendritic spines and synapses, including the postsynaptic density (PSD) microdomain. This peripheral pool of MAPKs/ERKs is either constitutively active or sensitive to changing synaptic input. Active MAPKs directly interact with and phosphorylate local substrates to alter their trafficking and subcellular/subsynaptic distributions, through which MAPKs regulate function of substrates and contribute to long-lasting synaptic plasticity. A number of physiologically relevant substrates of MAPKs have been identified at synaptic sites. Central among them are key synaptic scaffold proteins (PSD-95 and PSD-93), cadherin-associated proteins (δ-catenin), Kv4.2 K+ channels, and metabotropic glutamate receptors. Through a reversible phosphorylation event, MAPKs rapidly and efficiently modulate the function of these substrates and thus determine the strength of synaptic transmission. This review summarizes the recent progress in cell biology of synaptic MAPKs and analyzes roles of this specific pool of MAPKs in regulating local substrates and synaptic plasticity.

The use of antiretroviral therapy to prevent HIV transmission is now advocated in many settings, yet little research has documented the views of people with HIV. Semi-structured interviews were conducted in Australia between 2012 and 2014 with 27 HIV-positive people not using treatment at the time of interview. Thematic analysis of views on treatment-as-prevention found that while many participants recognised potential prevention benefits, only a minority was in support of initiating treatment solely to achieve those benefits. A range of uncertain or critical views were expressed regarding who would benefit, risk reduction, and changing treatment norms. Participants resisted responsibility narratives that implied treatment should be used for the public good, in favour of making considered decisions about their preferred approach to managing HIV. Engaging communities in dialogue and debate regarding the risks and benefits of treatment will be critical if this new prevention strategy is to engender public trust.

Neuroadaptations of glutamatergic transmission in the limbic reward circuitry are linked to persistent drug addiction. Accumulating data have demonstrated roles of ionotropic glutamate receptors and group I and II metabotropic glutamate receptors (mGluRs) in this event. Emerging evidence also identifies Gαi/o-coupled group III mGluRs (mGluR4/7/8 subtypes enriched in the limbic system) as direct substrates of drugs of abuse and active regulators of drug action. Auto- and heteroreceptors of mGluR4/7/8 reside predominantly on nerve terminals of glutamatergic corticostriatal and GABAergic striatopallidal pathways, respectively. These presynaptic receptors regulate basal and/or phasic release of respective transmitters to maintain basal ganglia homeostasis. In response to operant administration of common addictive drugs, such as psychostimulants (cocaine and amphetamine), alcohol and opiates, limbic group III mGluRs undergo drastic adaptations to contribute to the enduring remodeling of excitatory synapses and to usually suppress drug seeking behavior. As a result, a loss-of-function mutation (knockout) of individual group III receptor subtypes often promotes drug seeking. This review summarizes the data from recent studies on three group III receptor subtypes (mGluR4/7/8) expressed in the basal ganglia and analyzes their roles in the regulation of dopamine and glutamate signaling in the striatum and their participation in the addictive properties of three major classes of drugs (psychostimulants, alcohol, and opiates).

Injecting drug use is commonly reported among gay and bisexual men in Australia. We examined the prevalence and covariates of injecting drug use among men participating in the Sydney Gay Community Periodic Survey between 2004-06 and 2011. In 2004-06, data was collected about which drugs were injected, while in 2011, data was collected about hepatitis C (HCV) and esoteric sexual practices. In 2004-06, 5.6 % of men reported injecting drugs in the previous 6 months; 3.4 % reported methamphetamine injection and 0.4 % heroin injection. In 2011, men who injected drugs were less likely to be employed full-time, and more likely to be HCV-positive, HIV-positive, to have used party drugs for sex, and to have engaged in esoteric sexual practices. The strong associations between injecting drug use, sexual risk practices and blood-borne virus infection suggests the need for combined sexual health and harm reduction services for gay and bisexual men who inject drugs.

Our aim was to clarify the role of alcohol and other drug (AOD) use in major depression among gay men attending general medical practices. A secondary analysis was conducted on survey data collected from 531 gay men attending high-HIV-caseload general practices in Adelaide and Sydney, Australia. The survey contained demographic, social, behavioural and AOD variables. Participants were classified into those with (n = 130) and without major depression (n = 401) using the PHQ-9 screening tool. Although rates of drug use were very high in the sample, multivariate logistic regression analysis showed that the majority of variables independently associated with major depression were social and behavioural factors. Only one AOD variable was associated with major depression: the use of three or more drug types in the past 6 months. Attending to specific patterns of AOD use may assist in the identification of gay men most at risk of major depression.

Protein-protein interactions represent an important mechanism for posttranslational modifications of protein expression and function. In brain cells, surface-expressed and membrane-bound neurotransmitter receptors are common proteins that undergo dynamic protein-protein interactions between their intracellular domains and submembranous regulatory proteins. Recently, the Gα(i/o)-coupled muscarinic M4 receptor (M4R) has been revealed to be one of these receptors. Through direct interaction with the intracellular loops or C-terminal tails of M4Rs, M4R interacting proteins (M4RIPs) vigorously regulate the efficacy of M4R signaling. A synapse-enriched protein kinase, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), exemplifies a prototype model of M4RIPs, and is capable of binding to the second intracellular loop of M4Rs. Through an activity- and phosphorylation-dependent mechanism, CaMKII potentiates the M4R/Gα(i/o)-mediated inhibition of M4R efficacy in inhibiting adenylyl cyclase and cAMP production. In striatal neurons where M4Rs are most abundantly expressed, M4RIPs dynamically control M4R activity to maintain a proper cholinergic tone in these neurons. This is critical for maintaining the acetylcholine-dopamine balance in the basal ganglia, which determines the behavioral responsiveness to dopamine stimulation by psychostimulants.

Using two cohort studies (Health in men-HIM and positive health-PH) and repeated large cross-sectional surveys (Gay Community Periodic Survey-GCPS) of gay men in Sydney, Australia, we examined the association between viral load and unprotected anal intercourse (UAI) between HIV sero-discordant regular partners. Between 2001 and 2007, we conducted 243 interviews with 102 HIV-negative gay men in HIM and 148 interviews with 99 HIV-positive gay men in PH who were in regular relationships with HIV sero-discordant partners. During the same time period, 437 HIV positive men with HIV sero-discordant regular partners completed questionnaires for the GCPS. All completed interviews or questionnaires during that time period were used for these analyses. Amongst the HIV-negative respondents, sero-discordant UAI was more likely to be reported when the men believed their HIV-positive regular partner had an undetectable rather than a detectable viral load (P = 0.002). Amongst the HIV-positive respondents, sero-discordant UAI was as likely to be reported when they themselves reported having an undetectable or a detectable viral load. Use of viral load in negotiating condom use between sero-discordant gay couples may be understood very differently by the HIV-negative and HIV-positive men within those partnerships.

Group I mGluRs (mGluR1/5) are G-protein-coupled receptors and are abundantly expressed in most of medium spiny projection neurons in the striatum. Recent evidence demonstrates that group I mGluRs are among essential regulators for constitutive and inducible gene expression in host neurons. Upon activation, mGluR1/5 signals activate extracellular signal-regulated kinases (ERKs) which in turn phosphorylate transcription factors such as cAMP response element-binding protein (CREB) and Elk-1, and thereby facilitate immediate early gene and opioid peptide gene expression. The conventional mGluR1/5 signaling cascade (phosphoinositide hydrolysis and intracellular Ca(2+) release) participates in linking mGluR1/5 to ERK. Additionally, the prominent mGluR1/5 adaptor protein Homer contributes to assemble an efficient signaling apparatus connecting mGluR1/5 to gene expression. The mGluR1/5 linkage to transcription also functions in dopamine-stimulated gene expression. Together, the mGluR1/5-mediated gene expression constitutes a transcription-dependent mechanism underlying molecular adaptations and plasticity related to the pathogenesis of various mental illnesses.

In recent years, increases in both risk behavior and in seroconversion among homosexually active men have been noted in a number of parts of the world. Data were available from 903 HIV negative homosexual men regarding number of acts of unprotected anal intercourse (UAI), separated into receptive and insertive UAI, with and without ejaculation, with steady and with casual partners. Partners were classified according to serostatus as reported by respondents. Men (N = 325) reported 13,692 UAI acts, most of which were with steady partners, of whom most were reported to be HIV-negative. With HIV-positive partners, both steady and casual, and with casual partners of unknown serostatus, receptive UAI with ejaculation was relatively rare. Insertive UAI without ejaculation was relatively common with casual partners of unknown serostatus. Patterns of UAI suggest that risk of transmission may be greater with steady partners. Men appear to modify practice according to both the nature of the relationship (steady or casual) and (assumed) serostatus of partner.

Amphetamine is an indirect dopamine receptor agonist and increases glutamate release in the striatum. Activation of group I metabotropic glutamate receptors (mGluRs) upregulates cAMP response element-binding protein (CREB) and Elk-1 phosphorylation via extracellular signal-regulated kinase 1 and 2 (ERK1/2) in the striatum in vivo. In the present study the role of mGluRs in the regulation of ERK1/2 pathways leading to CREB and Elk-1 phosphorylation by amphetamine was investigated using immunohistochemistry and Western blot in the rat dorsal striatum. Acute administration of amphetamine (5 mg/kg, i.p.) caused increases in phosphorylated (p)CREB, pElk-1, and pERK1/2 immunoreactivity. Intrastriatal blockade of group I mGluRs with N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC; 25 nmol) significantly attenuated amphetamine-induced pCREB, pElk-1, pERK1/2, and Fos immunoreactivity in both medial and lateral areas of the striatum. Systemic injection of an mGluR5 antagonist, 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP; 10 mg/kg, i.p.), also blocked the amphetamine induction of these phosphoproteins. In contrast, intrastriatal blockade of group II/III mGluRs with (RS)-alpha-methylserine-o-phosphate monophenyl ester (MSOPPE; 25 nmol) did not affect amphetamine-induced increases in all the four markers. Similarly, intrastriatal dantrolene (2 or 20 nmol) that blocks intracellular Ca(2+) release from ryanodine-sensitive stores did not affect amphetamine effects. Injection of PHCCC, MPEP, MSOPPE, or dantrolene alone did not alter basal levels of the three phosphoproteins and Fos. These data suggest that acute amphetamine is able to facilitate the phosphorylation of CREB, Elk-1, and ERK1/2 signaling proteins and Fos gene expression via a group I mGluR-dependent mechanism in the dorsal striatum.

Atmospheric Pressure Chemical Vapor Deposition (APCVD) and powder spray pyrolysis are both pyrolytic thin film deposition techniques that are used to coat glass with thin films at atmospheric pressure. In the present study, the fluid dynamics of each process was investigated by laser light scattering. For each system, a 193 nm ArF excimer laser pulsed at 7 Hz was used for the analysis. In the case of the APCVD reactor, the difference in Rayleigh scattering between helium injected in the reactor and ambient air was used to characterize the process. For the powder spray process, laser scattering off the sprayed powder was used. The effect of various parameters is discussed.

Fluorine-doped tin oxide films were produced by atmospheric pressure chemical vapor deposition (APCVD) from the reaction of tin tetrachloride, water, and difluoroethanc. Tin oxide films deposited on glass substrates containing high sodium concentrations tended to be of lower quality with higher resistivities than films deposited on low sodium glass. Scanning electron Microscopy (SEM) was used to study the differences in film nucleation on the high and low sodium containing glass substrates. Eiarly in the nuclcation process, individual grains of tin oxide crystals arc observed to be distributed discontinuously over the substrates. As the deposition time was increased the number of nucleation sites increased and the individual grains became larger. The number of nucleation sites was consistently higher on the high sodium glass. However, numerous inclusions of sodium chloride crystals were observed by EDX in the tin oxide films deposited on the high sodium glass. SEM cross sections revealed how the film growth converted from the grains, which initially nucleated on the glass surface, to columns in the direction perpendicular to the substrate surface. Results for tin oxide grown on sodium-containing glass over coated with silica are also be presented.

Suppression of the tail flick response to noxious heat and paw withdrawal response to noxious pressure were produced by electrical stimulation of arcuate nucleus of the hypothalamus (ARH) in pentobarbital anesthetized rats. Systemic administration of naloxone (2 mg/kg) greatly antagonized the ARH stimulation-produced inhibition of both algesic reflexes. The thresholds of stimulation for inhibition of two spinal nociceptive reflexes in the lightly anesthetized state were not significantly different from the thresholds of stimulation at the same ARH sites in the awake state in the same animals. These findings provide evidence establishing the (1) usefulness of the anesthetized rat model for investigation of antinociceptive mechanisms; (2) the involvement of endogenous opioid mechanisms in mediating ARH stimulation-produced analgesia.