The serotonergic raphe nuclei are involved in regulating brain states over time-scales of minutes and hours. We examined more rapid effects of serotonergic activation on two classes of principal neurons in the mouse olfactory bulb, mitral and tufted cells, which send olfactory information to distinct targets. Brief stimulation of the raphe nuclei led to excitation of tufted cells at rest and potentiation of their odor responses. While mitral cells at rest were also excited by raphe activation, their odor responses were bidirectionally modulated, leading to improved pattern separation of odors. In vitro whole-cell recordings revealed that specific optogenetic activation of raphe axons affected bulbar neurons through dual release of serotonin and glutamate. Therefore, the raphe nuclei, in addition to their role in neuromodulation of brain states, are also involved in fast, sub-second top-down modulation, similar to cortical feedback. This modulation can selectively and differentially sensitize or decorrelate distinct output channels.

4.

OBJECTIVEPublication metrics such as the Hirsch index (h-index) are often used to evaluate and compare research productivity in academia. The h-index is not a field-normalized statistic and can therefore be dependent on overall rates of publication and citation within specific fields. Thus, a metric that adjusts for this while measuring individual contributions would be preferable. The National Institutes of Health (NIH) has developed a new, field-normalized, article-level metric called the “relative citation ratio” (RCR) that can be used to more accurately compare author productivity between fields. The mean RCR is calculated as the total number of citations per year of a publication divided by the average field-specific citations per year, whereas the weighted RCR is the sum of all article-level RCR scores over an author’s career. The present study was performed to determine how various factors, such as academic rank, career duration, a Doctor of Philosophy (PhD) degree, and sex, impact the RCR to analyze research productivity among academic neurosurgeons.METHODSA retrospective data analysis was performed using the iCite database. All physician faculty affiliated with Accreditation Council for Graduate Medical Education (ACGME)–accredited neurological surgery programs were eligible for analysis. Sex, career duration, academic rank, additional degrees, total publications, mean RCR, and weighted RCR were collected for each individual. Mean RCR and weighted RCR were compared between variables to assess patterns of analysis by using SAS software version 9.4.RESULTSA total of 1687 neurosurgery faculty members from 125 institutions were included in the analysis. Advanced academic rank, longer career duration, and PhD acquisition were all associated with increased mean and weighted RCRs. Male sex was associated with having an increased weighted RCR but not an increased mean RCR score. Overall, neurological surgeons were highly productive, with a median RCR of 1.37 (IQR 0.93–1.97) and a median weighted RCR of 28.56 (IQR 7.99–85.65).CONCLUSIONSThe RCR and its derivatives are new metrics that help fill in the gaps of other indices for research output. Here, the authors found that advanced academic rank, longer career duration, and PhD acquisition were all associated with increased mean and weighted RCRs. Male sex was associated with having an increased weighted, but not mean, RCR score, most likely because of historically unequal opportunities for women within the field. Furthermore, the data showed that current academic neurosurgeons are exceptionally productive compared to both physicians in other specialties and the general scientific community.

Inflammatory bowel disease (IBD) is a chronic condition involving the inflammation of the colon and small intestine. IBD affects as many as 1.4 million people in the U.S. alone and costs the health care industry over $1.7 billion annually. Managing IBD normally requires invasive and often discomforting diagnostic tests. In an effort to alleviate the painful and costly nature of traditional diagnosis, there has been increasing research initiative focused on noninvasive biomarkers. PubMed, provided by the United States National Library of Medicine (NLM) at the National Institutes of Health, was utilized with the following search terms: 1) myeloperoxidase (MPO) 2), inflammatory bowel disease (IBD), and 3) neutrophils. The following terms were used interchangeably with search terms 1-3: 4) costs, 5) biomarkers, 6) review, and 7) etiology. In the context of IBD, myeloperoxidase (MPO), a lysosomal protein found in neutrophils, may serve as a viable biomarker for assessing disease status. Several studies demonstrated increased levels of neutrophils in patients with active IBD. Furthermore, studies have found significantly higher levels of MPO in patients with active IBD compared to patients without IBD as well as patients with inactive IBD. MPO is also expressed in higher concentrations in patients with more severe forms of IBD. When measuring treatment efficacy, MPO levels are indicative of the quality of response. MPO may serve as an important diagnostic and prognostic tool in assessing IBD status.