Faculty Bibliography

OBJECTIVE:To evaluate urinalysis testing patterns within the Veterans Health Administration (VHA), estimate the proportion and likelihood of patients who completed a urinalysis to have microscopic hematuria (MH), and explore how urinalysis testing patterns may influence MH detection. METHODS:This was a retrospective cross-sectional study using VHA data. We identified adult patients without a known urologic cancer history who had at least 1 outpatient visit at any VHA site and at least 1 interpretable urinalysis performed in 2015. The factors associated with the number or urinalyses performed on each patient and associations with the presence of MH were investigated. RESULTS:Among 5,719,966 adults, 39% completed a urinalysis. Variation in the proportion of patients who completed urinalyses was highest by age, among patients with hypertension and diabetes, and by region. Of patients who underwent urinalysis and had no prior genitourinary cancer history, 54% did not have an interpretable urinalysis result. Among patients with at least one interpretable microscopic urinalysis, 37% had MH. This was more common among older patients, females, current smokers, and patients with more comorbidities. Variation in the likelihood of patients having MH remained after adjusting for multiple factors and when contextualized by urinalysis completion and interpretability patterns. CONCLUSION/CONCLUSIONS:The number of urinalyses performed in the VHA system is remarkably high. Detection of MH is influenced by the frequency of urinalysis testing and interpretability of results. The presence and detection of MH varies by factors which should be considered when adjudicating the need for further evaluation of MH.

Beyond the vast array of functional roles attributed to serotonin (5-HT) in the brain, changes in 5-HT levels have been shown to accompany changes in behavioral states, including WAKE, NREM, and REM sleep. Whether 5-HT dynamics at shorter time scales can be seen to delineate substates within these larger brain states remains an open question. Here, we performed simultaneous recordings of extracellular 5-HT using a recently developed G-Protein-Coupled Receptor-Activation-Based 5-HT sensor (GRAB5-HT3.0) and local field potential in the hippocampal CA1 of mice, which revealed the presence of prominent ultraslow (<0.05 Hz) 5-HT oscillations both during NREM and WAKE states. Interestingly, the phase of these ultraslow 5-HT oscillations was found to distinguish substates both within and across larger behavioral states. Hippocampal ripples occurred preferentially on the falling phase of ultraslow 5-HT oscillations during both NREM and WAKE, with higher power ripples concentrating near the peak specifically during NREM. By contrast, hippocampal-cortical coherence was strongest, and microarousals and intracranial EMG peaks were most prevalent during the rising phase in both wake and NREM. Overall, ultraslow 5-HT oscillations delineate substates within the larger behavioral states of NREM and WAKE, thus potentially temporally segregating internal memory consolidation processes from arousal-related functions.

Decreased brain levels of coenzyme Q₁₀ (CoQ₁₀), an endogenously synthesized lipophilic antioxidant^1,2, underpin encephalopathy in primary CoQ₁₀ deficiencies^3,4 and are associated with common neurodegenerative diseases and the ageing process^5,6. CoQ₁₀ supplementation does not increase CoQ₁₀ pools in the brain or in other tissues. The recent discovery of the mammalian CoQ₁₀ headgroup synthesis pathway, in which 4-hydroxyphenylpyruvate dioxygenase-like protein (HPDL) makes 4-hydroxymandelate (4-HMA) to synthesize the CoQ₁₀ headgroup precursor 4-hydroxybenzoate (4-HB)⁷, offers an opportunity to pharmacologically restore CoQ₁₀ synthesis and mechanistically treat CoQ₁₀ deficiencies. To test whether 4-HMA or 4-HB supplementation promotes CoQ₁₀ headgroup synthesis in vivo, here we administered 4-HMA and 4-HB to Hpdl^-/- mice, which model an ultra-rare, lethal mitochondrial encephalopathy in humans. Both 4-HMA and 4-HB were incorporated into CoQ₉ and CoQ₁₀ in the brains of Hpdl^-/- mice. Oral treatment of Hpdl^-/- pups with 4-HMA or 4-HB enabled 90-100% of Hpdl^-/- mice to live to adulthood. Furthermore, 4-HB treatment stabilized and improved the neurological symptoms of a patient with progressive spasticity due to biallelic HPDL variants. Our work shows that 4-HMA and 4-HB can modify the course of mitochondrial encephalopathy driven by HPDL variants and demonstrates that CoQ₁₀ headgroup intermediates can restore CoQ₁₀ synthesis in vivo.

Sharp wave-ripples (SPW-Rs) are critical to hippocampal function, and the same is true of gonadal steroids, but the interactions are unclear. We find that surgical removal of the gonads greatly reduces SPW rates in both sexes. Ripples are greatly reduced also. Testosterone treatment rescues SPW and ripple rates in males, and 17β-estradiol restores SPW rates in females. We also find that male SPW rates are higher than females but have less power. Furthermore, in intact females, SPW rates fluctuate with the stage of the ovarian cycle. These data demonstrate that hippocampal SPWs are significantly affected by gonadal removal, testosterone, and 17β-estradiol. In addition, there are sex differences. The data are consistent with past demonstrations that testosterone and 17β-estradiol play central roles in hippocampus and significantly expand the views of hormone action and SPW-Rs.

Precision-targeted ultrasonic neuromodulation offers immense potential for studying brain function and treating neurological diseases. Yet, its application has been limited by challenges in achieving precise spatio-temporal control and monitoring of ultrasound effects on brain circuits. Here we show that transcranial ultrasound elicits direct and highly focal responses, which can be dynamically steered at spatio-temporal scales relevant for neural function. Furthermore, holographic transcranial ultrasound stimulation allows direct control of the stimulated volume and actively modulates local and mid-range network projections, effectively lowering the activation threshold by an order of magnitude. To better understand this previously unexplored excitability regime not fully explained by the conventional pressure-frequency dyad, we developed a dual modelling framework, where both an empirical and a mechanistic model were constructed to capture the intricacies of holographic transcranial ultrasound stimulation. These models achieve qualitative agreement with our experimental results, suggesting that these findings are predominantly driven by putative network interactions. Our results bring insight on the complex interaction mechanisms of ultrasound with neural tissue and highlight its potential for the noninvasive interfacing of distributed brain networks.

OBJECTIVES/OBJECTIVE:To determine the relationships between the number and class of xerogenic medications on whole stimulated salivary flow rates and oral health-related quality of life (OH-QOL) measures in patients who received high-dose external beam radiation therapy (RT) for head and neck cancer (HNC). STUDY DESIGN/METHODS:Complete medication lists were generated using patient electronic health records from every attended study visit for 146 HNC patients. Whole stimulated salivary flow was measured before RT, and 6 and 18-months after RT. Ten single-item questions and two composite scales of swallowing problems and senses problems (taste and smell) were assessed at baseline and at 6-month intervals up to 24 months after RT. Linear mixed-effects models examined associations between the total number and class of medications and stimulated salivary flow and OH-QOL. RESULTS:There was no detected association between the total number of medications and stimulated salivary flow (p-value = .18). Only antidepressant usage was significantly associated with stimulated salivary flow (P = .006). Number of medications, narcotic analgesic, and antidepressant usage were significantly associated with a clinically meaningful decrease in OH-QOL. CONCLUSION/CONCLUSIONS:Antidepressants were associated with reduced stimulated salivary flow, but no cumulative negative effect on whole stimulated salivary flow was identified. Polypharmacy was associated with worse OH-QOL.

Most offspring are born helpless, requiring intense caregiving from parents especially during the first few days of neonatal life. For many species, infant cries are a primary signal used by parents to provide caregiving. Previously we and others documented how maternal left auditory cortex rapidly becomes sensitized to pup calls over hours of parental experience, enabled by oxytocin. The speed and robustness of this maternal plasticity suggests cortical pre-tuning or initial bias for pup call stimulus features. Here we examine the circuit basis of left-lateralized tuning to vocalization features with whole-cell recordings in brain slices. We found that layer 2/3 pyramidal cells of female left auditory cortex show selective suppression of inhibitory inputs with repeated stimulation at the fundamental pup call rate (inter-stimulus interval ∼150 msec) in pup-naïve females and expanded with maternal experience. However, optogenetic stimulation of cortical inhibitory cells showed that inputs from somatostatin-positive and oxytocin-receptor-expressing interneurons were less suppressed at these rates. This suggested that disynaptic inhibition rather than monosynaptic depression was a major mechanism underlying pre-tuning of cortical excitatory neurons, confirmed with simulations. Thus cortical interneuron specializations can augment neuroplasticity mechanisms to ensure fast appropriate caregiving in response to infant cries.

INTRODUCTION/BACKGROUND:Underlying causes of Alzheimer's disease (AD) remain unknown, making it imperative to identify molecular mechanisms driving the pathobiology of AD onset and progression. METHODS:Laser capture microdissection was used to isolate layer III pyramidal neurons from post mortem human prefrontal cortex (Brodmann area 9). Single population RNA sequencing was conducted using tissue from subjects with no cognitive impairment (NCI), mild cognitive impairment (MCI), and AD. Differentially expressed genes (DEGs) were compared across groups. RESULTS:DEGs increased from prodromal (MCI vs. NCI) to progression (AD vs. MCI) to frank AD (AD vs. NCI). The majority of DEGs and pathways shared between prodromal and progression exhibited a change in the direction of dysregulation unlike pathways between progression and frank AD. DISCUSSION/CONCLUSIONS:Candidate genes and pathways were identified that demarcate early-stage AD onset from AD progression, providing a roadmap to study cortical cellular vulnerability and key targets for intervention at early stages of AD. HIGHLIGHTS/CONCLUSIONS:Pyramidal neuron differentially expressed genes (DEGs) are directionally divergent between prodromal, progression, and frank Alzheimer's disease (AD). Pyramidal neuron DEGs are directionally convergent between progression and frank AD. Dysfunctional bioenergetic pathways increased dysregulation as the AD spectrum progressed. Immune response pathways were more dysregulated in frank AD than prodromal stages. DEGs, = biological pathways, and interactomes demarcate specific stages across the AD spectrum.