Immediate and Long-Term Effects of Tibial Nerve Stimulation on the Sexual Behavior of Female Rats.

OBJECTIVES: There are limited treatment options for female sexual dysfunction (FSD). Percutaneous tibial nerve stimulation (PTNS) has shown improvements in FSD symptoms in neuromodulation clinical studies, but the direct effects on sexual function are not understood. This study evaluated the immediate and long-term effects of PTNS on sexual motivation and receptivity in a rat model of menopausal women. Our primary hypothesis was that long-term PTNS would yield greater changes in sexual behavior than short-term stimulation. MATERIALS AND METHODS: In two experiments, after receiving treatment, we placed ovariectomized female rats in an operant chamber in which the female controls access to a male by nose poking. We used five treatment conditions, which were with or without PTNS and no, partial, or full hormone priming. In experiment 1, we rotated rats through each condition twice with behavioral testing immediately following treatment for ten weeks. In experiment 2, we committed rats to one condition for six weeks and tracked sexual behavior over time. We quantified sexual motivation and sexual receptivity with standard measures. RESULTS: No primary comparisons were significant in this study. In experiment 1, we observed increased sexual motivation but not receptivity immediately following PTNS with partial hormone priming, as compared with priming without PTNS (linear mixed effect models; initial latency [p = 0.34], inter-interval latency [p = 0.77], nose poke frequency [p = 0.084]; eight rats). In experiment 2, we observed trends of increased sexual receptivity (linear correlation for weekly group means; mounts [p = 0.094 for trendline], intromissions [p = 0.073], lordosis quotient [p = 0.58], percent time spent with a male [p = 0.39], decreased percent time alone [p = 0.024]; four rats per condition), and some sexual motivation metrics (linear correlation for weekly group means; nose pokes per interval [p = 0.050], nose poke frequency [p = 0.039], decreased initial latency [p = 0.11]; four rats per condition) when PTNS was applied long-term with partial hormone priming, as compared with hormone-primed rats without stimulation. CONCLUSIONS: PTNS combined with hormone priming shows potential for increasing sexual motivation in the short-term and sexual receptivity in the long-term in rats. Further studies are needed to examine variability in rat behavior and to investigate PTNS as a treatment for FSD in menopausal women.

Expectancy for Adderall influences subjective mood and drug effects regardless of concurrent caffeine ingestion: A randomized controlled trial.

RATIONALE: Nonmedical prescription stimulant use (NPS; use without a prescription or in ways other than prescribed) is common among college students. Despite the potential for negative consequences, students continue engaging in NPS for cognitive enhancement purposes, which may be maintained by expectancy and placebo effects. OBJECTIVES: This study examined if a placebo administered under the guise of Adderall influenced subjective mood/drug effects and cognitive performance. Furthermore, this study examined if concurrent caffeine ingestion incrementally enhanced Adderall-related placebo effects. METHODS: Undergraduate students with features that put them at elevated risk for NPS (N = 121) completed measures of mood and drug effects and cognitive assessments on two separate laboratory visits in this parallel randomized controlled trial. Visit 1 was a baseline control visit, on which no drug was expected or received. On visit 2, subjects were randomized to: (1) expect/receive no drug (control); (2) expect Adderall/receive placebo; or (3) expect Adderall/receive 200 mg caffeine. RESULTS: There were several significant condition × visit interactions for subjective effects, including amphetamine effects, energy and efficiency effects, and feeling high. In most cases, participants who expected Adderall reported greater positive subjective effects on visit 2 compared to controls; however, there were generally not incremental enhancements for those ingesting caffeine compared to placebo. There were no significant effects for any cognitive tests. CONCLUSIONS: Expectation for prescription stimulant effects influenced subjective outcomes in a sample of high-risk college students. These findings may inform expectancy challenge interventions to reduce NPS. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03648684.

Tibial nerve stimulation increases vaginal blood perfusion and bone mineral density and yield load in ovariectomized rat menopause model.

INTRODUCTION AND HYPOTHESIS: Human menopause transition and post-menopausal syndrome, driven by reduced ovarian activity and estrogen levels, are associated with an increased risk for symptoms including but not limited to sexual dysfunction, metabolic disease, and osteoporosis. Current treatments are limited in efficacy and may have adverse consequences, so investigation for additional treatment options is necessary. Previous studies have demonstrated that percutaneous tibial nerve stimulation (PTNS) and electro-acupuncture near the tibial nerve are minimally invasive treatments that increase vaginal blood perfusion or serum estrogen in the rat model. We hypothesized that PTNS would protect against harmful reproductive and systemic changes associated with menopause. METHODS: We examined the effects of twice-weekly PTNS (0.2 ms pulse width, 20 Hz, 2× motor threshold) under ketamine-xylazine anesthesia in ovariectomized (OVX) female Sprague-Dawley rats on menopause-associated physiological parameters including serum estradiol, body weight, blood glucose, bone health, and vaginal blood perfusion. Rats were split into three groups (n = 10 per group): (1) intact control (no stimulation), (2) OVX control (no stimulation), and (3) OVX stimulation (treatment group). RESULTS: PTNS did not affect serum estradiol levels, body weight, or blood glucose. PTNS transiently increased vaginal blood perfusion during stimulation for up to 5 weeks after OVX and increased areal bone mineral density and yield load of the right femur (side of stimulation) compared to the unstimulated OVX control. CONCLUSIONS: PTNS may ameliorate some symptoms associated with menopause. Additional studies to elucidate the full potential of PTNS on menopause-associated symptoms under different experimental conditions are warranted.

Expectation for stimulant type modifies caffeine's effects on mood and cognition among college students.

Caffeine is regularly used by college students to enhance mood and academic performance. Although high doses confer risk for negative consequences, moderate doses of caffeine may lead to acute improvements in mood and cognitive functioning. Notably, the pharmacological effects of caffeine may be enhanced by expectancy effects. College students may also engage in nonmedical prescription stimulant use for similar purposes, as students expect strong cognitive enhancement from prescription stimulants and consider them to be more efficacious than caffeine. The purpose of the current study was to examine whether the pharmacological effects of caffeine on mood/drug effects and cognitive performance are enhanced when expecting a conceivably stronger stimulant (i.e., Adderall) compared to when expecting caffeine. Sixty-five undergraduate students were randomized to condition across two variables: drug ingested (placebo or 200 mg caffeine) and drug expected (caffeine or Adderall). Participants completed self-report measures of mood and drug effects pre- and post-drug, as well as cognitive assessments post-drug. There were significant main effects of drug ingested and drug expected on several post-drug measures. Subjects receiving caffeine reported feeling more high, stimulated, anxious, and motivated than subjects receiving placebo. Further, subjects expecting Adderall reported stronger amphetamine effects and feeling more high, and performed better on a working memory test, than those expecting caffeine. Effects tended to be strongest in participants receiving caffeine and expecting Adderall. Modifying expectancies, in conjunction with the pharmacological properties of caffeine at moderate doses, may be one mechanism by which college students may experience differential effects of caffeine. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Implantable brain-computer interface for neuroprosthetic-enabled volitional hand grasp restoration in spinal cord injury.

Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in one 21-year-old male subject with complete cervical quadriplegia (C5 American Spinal Injury Association Impairment Scale A) using a portable fully implanted brain-computer interface within the home environment. The brain-computer interface consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic activity. Movement-intent was used to trigger functional electrical stimulation of the dominant hand during an initial 29-weeks laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement-intent information could be decoded consistently throughout the 29-weeks in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy of various upper extremity tasks, including lifting small objects and transferring objects to specific targets. At-home decoding accuracy during open-loop trials reached an accuracy of 91.3% (range 80-98.95%) and an accuracy of 88.3% (range 77.6-95.5%) during closed-loop trials. Importantly, the temporal stability of both the functional outcomes and decoder metrics were not explored in this study. A fully implanted brain-computer interface can be safely used to reliably decode movement-intent from motor cortex, allowing for accurate volitional control of hand grasp.

Relations among protective behavioral strategies, biological sex, and ADHD symptoms on alcohol use and related problems: Who benefits most, and from what type of strategy?

Attention-deficit/hyperactivity disorder (ADHD) symptoms among college students are associated with high rates of alcohol use and alcohol-related consequences. Use of protective behavioral strategies (PBS) is generally related to lower levels of alcohol use and problems; however, it is unclear how effectively students with ADHD symptoms can implement PBS, and whether certain types of PBS use may yield better outcomes. This study examined relations between PBS type and ADHD symptoms on both alcohol use and consequences, and whether these relations varied by biological sex. Participants were 875 college student drinkers from three universities who completed measures of ADHD symptoms, PBS, past-month alcohol use, and alcohol-related consequences. There were significant moderation effects of ADHD symptoms, such that the relation between PBS use and alcohol use was more pronounced for students high in inattention, and the relation between PBS use and alcohol-related consequences was more pronounced for students high in either inattention or hyperactivity/impulsivity symptoms. These relations were found for both manner of drinking and stopping/limiting drinking PBS, and they tended to be strongest for male students. There were no significant interaction effects that included serious harm reduction PBS; for all students, increased use of this type of PBS was associated with fewer problems. These results suggest that PBS are likely effective for students with ADHD symptoms. Interventions that provide explicit instruction in employing PBS, particularly related to manner of drinking and stopping/limiting drinking strategies, are recommended for students with ADHD symptoms.

ADHD Symptoms and Sex Moderate the Relation Between Protective Behavioral Strategies and Alcohol Use Among Treatment-Mandated College Students.

College students with attention deficit/hyperactivity disorder are likely to engage in alcohol use and experience alcohol-related problems. Use of protective behavioral strategies is related to fewer alcohol-related consequences. However, this association has not been sufficiently examined in relation to attention deficit/hyperactivity disorder symptoms, which could alter the likelihood of utilizing protective behavioral strategies. This study examined whether attention deficit/hyperactivity disorder symptoms moderate the relationship between protective behavioral strategies and alcohol use, and whether this differs by sex. Participants were 125 treatment-mandated college students (58.6% male; Mage = 19.50 years) who completed measures of attention deficit/hyperactivity disorder symptoms, protective behavioral strategies, and past-2-week drinking. There was a significant 3-way interaction such that drinking was highest when protective behavioral strategy use was low and hyperactivity/impulsivity symptoms were high, but only for women. There was also a significant protective behavioral strategy by inattention interaction, as students with high inattention and low protective behavioral strategy use consumed the most drinks. Interventions to enhance use of protective behavioral strategies may effectively decrease alcohol use for college students with attention deficit/hyperactivity disorder symptoms, particularly women.

Ultracompliant Carbon Nanotube Direct Bladder Device.

The bladder, stomach, intestines, heart, and lungs all move dynamically to achieve their purpose. A long-term implantable device that can attach onto an organ, sense its movement, and deliver current to modify the organ function would be useful in many therapeutic applications. The bladder, for example, can suffer from incomplete contractions that result in urinary retention with patients requiring catheterization. Those affected may benefit from a combination of a strain sensor and electrical stimulator to better control bladder emptying. The materials and design of such a device made from thin layer carbon nanotube (CNT) and Ecoflex 00-50 are described and demonstrate its function with in vivo feline bladders. During bench-top characterization, the resistive and capacitive sensors exhibit stability throughout 5000 stretching cycles under physiology conditions. In vivo measurements with piezoresistive devices show a high correlation between sensor resistance and volume. Stimulation driven from platinum-silicone composite electrodes successfully induce bladder contraction. A method for reliable connection and packaging of medical grade wire to the CNT device is also presented. This work is an important step toward the translation of low-durometer elastomers, stretchable CNT percolation, and platinum-silicone composite, which are ideal for large-strain bioelectric applications to sense or modulate dynamic organ states.

"Not for Human Consumption": A Descriptive Investigation into User Characteristics, Motives, and Consequences Associated with Bath Salt Use.

Synthetic cathinones, commonly referred to as "bath salts," are recreational designer drugs that recently emerged as a drug of abuse. However, little is known about bath salt users, particularly in the United States (US). This descriptive study aims to better characterize users and user behavior, including common motives for and consequences of use. Individuals with a lifetime history of bath salt use (BSU; n = 110) completed an Internet survey. Participants (50.9% male) were aged 18 to 58 (M = 31.21, SD = 10.25) years and were from 32 US states. Most participants reported past-year BSU, via intranasal use, obtained from a friend or acquaintance. Recreational motives (e.g., to get high, experimentation) were commonly reported, as was use due to drug availability. Participants reported experiencing an average of 5.50 consequences, with both physical (e.g., rapid heartbeat) and psychological (e.g., anxiety) negative outcomes commonly reported. This descriptive information on BSU from a small but diverse sample of users may inform efforts to reduce use and negative consequences, such as eliminating riskier routes of administration (e.g., injection) and targeting specific motives for use (e.g., providing alternative methods for mood expansion).

Alcohol-related protective behavioral strategies as a mediator of the relationship between drinking motives and risky sexual behaviors.

Risky sexual behaviors (RSB) frequently occur in the context of alcohol use and are associated with distinct drinking motives among college students. Use of alcohol protective behavioral strategies (PBS) is associated with reductions in alcohol use and related problems, which may extend to alcohol-related RSB. Moreover, as PBS use mediates the relationship between positive reinforcement drinking motives and alcohol-related problems, the same may be true for alcohol-related RSB, specifically. The current study examined whether PBS mediates the relationship between drinking motives and RSB among college students. Participants (N = 2039, 72.8% female, Mage = 19.79) from ten universities across ten U.S. states completed an online survey assessing past-month drinking motivation, alcohol PBS, alcohol consumption, and RSB. To test study aims, a saturated path model in which drinking motives were modeled as predictors of RSB via PBS use subscales and alcohol consumption was conducted. Several double mediation effects were found, such that stronger endorsement of motives (i.e., social, enhancement, conformity, coping for depression) were associated with lower PBS (particularly manner of drinking and serious harm reduction), which was associated with higher alcohol use, which was associated with higher RSB. Multi-group models found the mediation effects to be gender invariant, although several differences in direct associations were found across genders. For college students high in positive reinforcement motives (i.e., social or enhancement) for drinking, interventions that aim to increase PBS use, specifically related to modifying the manner in which one drinks and avoiding very dangerous consequences, may be effective in reducing alcohol-related RSB.

Transcutaneous Electrical Nerve Stimulation to Improve Female Sexual Dysfunction Symptoms: A Pilot Study.

OBJECTIVES: To perform a pilot study using transcutaneous electrical nerve stimulation (TENS) on the dorsal genital nerve and the posterior tibial nerve for improving symptoms of female sexual dysfunction (FSD) in women without bladder problems. We hypothesize that this therapy will be effective at improving genital arousal deficits. MATERIALS AND METHODS: Nine women with general FSD completed the study. Subjects received 12 sessions of transcutaneous dorsal genital nerve stimulation (DGNS; n = 6) or posterior tibial nerve stimulation (PTNS; n = 3). Stimulation was delivered for 30 min at 20 Hz. Sexual functioning was evaluated with the female sexual functioning index (FSFI), and surveys were also given on general health, urological functioning, and the Patients' Global Impression of Change (PGIC) after treatment. Surveys were given before treatment (baseline), after 6 and 12 weeks of treatment, and 6 weeks after the completion of stimulation sessions. RESULTS: The average total FSFI score across all subjects significantly increased from 15.3 ± 4.8 at baseline to 20.3 ± 7.8 after six sessions, 21.7 ± 7.5 after 12 sessions, and 21.3 ± 7.1 at study completion (p < 0.05 for all time points). Increases were observed in both DGNS and PTNS subjects. Significant FSFI increases were seen in the subdomains of lubrication, arousal, and orgasm, each of which is related to genital arousal. Bladder and general health surveys did not change across the study. PGIC had a significant increase. CONCLUSIONS: This study provides evidence that transcutaneous stimulation of peripheral nerves has the potential to be a valuable therapeutic tool for women with FSD.

Tibial Nerve Stimulation to Drive Genital Sexual Arousal in an Anesthetized Female Rat.

BACKGROUND: There is clinical evidence that percutaneous tibial nerve stimulation can positively benefit women with female sexual interest/arousal disorder, yet no studies have explored the potential mechanisms further. AIM: To investigate the effect of tibial nerve stimulation on vaginal blood perfusion (VBP) in an anesthetized rat model. METHODS: 16 ketamine-anesthetized rats were surgically implanted with a nerve cuff electrode on 1 tibial nerve. The tibial nerve was stimulated for 30 minutes continuously or non-continuously at a frequency of 10 to 25 Hz. OUTCOMES: VBP was measured with laser Doppler flowmetry and analyzed using a wavelet transform of time-frequency representations with a focus on the neurogenic energy range (0.076-0.200 Hz). RESULTS: 25 of 33 (75.8%) stimulation periods had at least a 500% increase in laser Doppler flowmetry neurogenic energy compared with baseline. This increase was most common within 20 to 35 minutes after the start of stimulation. There was no statistically significant difference for frequency used or estrous cycle stage. CLINICAL TRANSLATION: The results of this study provide further support for percutaneous tibial nerve stimulation as an alternative treatment option for women with genital arousal aspects of female sexual interest/arousal disorder. STRENGTHS AND LIMITATIONS: This study successfully demonstrates the ability of tibial nerve stimulation to increase VBP. However, further studies to determine parameter optimization and to illuminate neural mechanisms are needed. Further studies also are necessary to determine effects of repeated stimulation sessions. CONCLUSION: Long-duration tibial stimulation was successful at driving increases in the neurogenic component of VBP, providing evidence that tibial nerve stimulation could be used to treat genital arousal aspects of female sexual interest/arousal disorder by improving pelvic blood flow. Zimmerman LL, Rice IC, Berger MB, Bruns TM. Tibial Nerve Stimulation to Drive Genital Sexual Arousal in an Anesthetized Female Rat. J Sex Med 2018;15:296-303.

Time-Frequency Analysis of Increases in Vaginal Blood Perfusion Elicited by Long-Duration Pudendal Neuromodulation in Anesthetized Rats.

OBJECTIVES: Female sexual dysfunction (FSD) affects a significant portion of the population. Although treatment options for FSD are limited, neuromodulation for bladder dysfunction has improved sexual function in some women. A few studies have investigated peripheral neuromodulation for eliciting changes in vaginal blood flow, as a proxy for modulating genital sexual arousal, however results are generally transient. Our central hypothesis is that repeated or extended-duration pudendal nerve stimulation can elicit maintained vaginal blood flow increases. MATERIALS AND METHODS: Under ketamine anesthesia, the pudendal nerve of 14 female rats was stimulated at varying frequencies (1-100 Hz) and durations (0.15-60 min). Vaginal blood perfusion was measured with a laser Doppler flowmetry probe. Changes in blood perfusion were determined through raw signal analysis and increases in the energy of neurogenic (0.076-0.200 Hz) and myogenic (0.200-0.740 Hz) frequency bands through wavelet analysis. Additionally, a convolution model was developed for a carry-over stimulation effect. RESULTS: Each experiment had significant increases in vaginal blood perfusion due to pudendal nerve stimulation. In addition, there were large concurrent increases in neurogenic and myogenic frequency-band energy in 11/14 experiments, with an average maximal response at 31.3 min after stimulation initiation. An effective stimulation model with a 30-min carry-over effect had a stronger correlation to blood perfusion than the stimulation period itself. CONCLUSIONS: Repeated or extended-duration pudendal nerve stimulation can elicit maintained increases in vaginal blood perfusion. This work indicates the potential for pudendal neuromodulation as a method for increasing genital arousal as a potential treatment for FSD.

Neurological complications associated with HIV and AIDS: clinical implications for nursing.

This article provides a clinical nursing update on major neurological complications associated with HIV and AIDS. Life expectancy for those with AIDS has increased as a consequence of antiretroviral therapy, and thus, neurological complications remain a clinical challenge. Four significant diseases associated with HIV and AIDS are addressed: HIV-associated dementia, peripheral neuropathy, cryptococcal meningitis, and toxoplasmosis. Updated statistics, a review of pathophysiology, common manifestations, diagnostic tests, and standard treatments are discussed for each disease. Nursing considerations when caring for this population are reviewed and include assessment, safety, activities of daily living, pain management, and treatment adherence.