Nicotine but not saline self-administering or yoked control conditions produces sustained neuroadaptations in the accumbens shell

IntroductionUsing yoked animals as the control when monitoring operant drug-self-administration is considered the golden standard. However, instrumental learning per se recruits several neurocircuits that may produce distinct or overlapping neuroadaptations with drugs of abuse. The aim of this project was to assess if contingent responding for nicotine or saline in the presence of a light stimulus as a conditioned reinforcer is associated with sustained neurophysiological adaptations in the nucleus accumbens shell (nAcS), a brain region repeatedly associated with reward related behaviors.MethodsTo this end, nicotine-or saline-administrating rats and yoked-saline stimulus-unpaired training conditions were assessed in operant boxes over four consecutive weeks. After four additional weeks of home cage forced abstinence and subsequent cue reinforced responding under extinction conditions, ex vivo electrophysiology was performed in the nAcS medium spiny neurons (MSNs).ResultsWhole cell recordings conducted in voltage and current-clamp mode showed that excitatory synapses in the nAcS were altered after prolonged forced abstinence from nicotine self-administration. We observed an increase in sEPSC amplitude in animals with a history of contingent nicotine SA potentially indicating higher excitability of accumbal MSNs, which was further supported by current clamp recordings. Interestingly no sustained neuroadaptations were elicited in saline exposed rats from nicotine associated visual cues compared to the yoked controls.ConclusionThe data presented here indicate that nicotine self-administration produces sustained neuroadaptations in the nAcS while operant responding driven by nicotine visual stimuli has no long-term effects on MSNs in nAcS

The genomic landscape of balanced cytogenetic abnormalities associated with human congenital anomalies

Despite the clinical significance of balanced chromosomal abnormalities (BCAs), their characterization has largely been restricted to cytogenetic resolution. We explored the landscape of BCAs at nucleotide resolution in 273 subjects with a spectrum of congenital anomalies. Whole-genome sequencing revised 93% of karyotypes and demonstrated complexity that was cryptic to karyotyping in 21% of BCAs, highlighting the limitations of conventional cytogenetic approaches. At least 33.9% of BCAs resulted in gene disruption that likely contributed to the developmental phenotype, 5.2% were associated with pathogenic genomic imbalances, and 7.3% disrupted topologically associated domains (TADs) encompassing known syndromic loci. Remarkably, BCA breakpoints in eight subjects altered a single TAD encompassing MEF2C, a known driver of 5q14.3 microdeletion syndrome, resulting in decreased MEF2C expression. We propose that sequence-level resolution dramatically improves prediction of clinical outcomes for balanced rearrangements and provides insight into new pathogenic mechanisms, such as altered regulation due to changes in chromosome topology

Molecular surveillance of traditional and emerging pathogens associated with canine infectious respiratory disease

A molecular survey for traditional and emerging pathogens associated with canine infectious respiratory disease (CIRD) was conducted in Italy between 2011 and 2013 on a total of 138 dogs, including 78 early acute clinically ill CIRD animals, 22 non-clinical but exposed to clinically ill CIRD dogs and 38 CIRD convalescent dogs. The results showed that canine parainfluenza virus (CPIV) was the most commonly detected CIRD pathogen, followed by canine respiratory coronavirus (CRCoV), Bordetella bronchiseptica, Mycoplasma cynos, Mycoplasma canis and canine pneumovirus (CnPnV). Some classical CIRD agents, such as canine adenoviruses, canine distemper virus and canid herpesvirus 1, were not detected at all, as were not other emerging respiratory viruses (canine influenza virus, canine hepacivirus) and bacteria (Streptococcus equi subsp. zooepidemicus). Most severe forms of respiratory disease were observed in the presence of CPIV, CRCoV and M. cynos alone or in combination with other pathogens, whereas single CnPnV or M. canis infections were detected in dogs with no or very mild respiratory signs. Interestingly, only the association of M. cynos (alone or in combination with either CRCoV or M. canis) with severe clinical forms was statistically significant. The study, while confirming CPIV as the main responsible for CIRD occurrence, highlights the increasing role of recently discovered viruses, such as CRCoV and CnPnV, for which effective vaccines are not available in the market

COVID-19 as a Paradigmatic Model of the Heterogeneous Disease Presentation in Older People: Data from the GeroCovid Observational Study

COVID-19 may have a heterogeneous onset, especially in older age. However, whether and how COVID-19 signs and symptoms may present and aggregate together according to sociodemographic and health factors is unclear, as well as their prognostic value. This study included 981 COVID-19 inpatients who participated in the GeroCovid Observational study. Signs/symptoms at disease onset, sociodemographic, health, cognitive status, and mobility were systematically recorded. Clusters of signs/symptoms were identified through agglomerative hierarchical clustering. The associations of single signs/symptoms and symptom clusters with longer hospitalization (>= 16 days) and in-hospital mortality were explored through logistic and Cox regressions. The signs/symptoms most reported in our sample (age 78.3 +/- 9.39 years; 49.4% women) were fever (62.5%), cough (45.5%), and dyspnea (62.7%). Atypical symptoms were reported by up to one-third of patients, and delirium by 9.1%. Atypical symptoms were more frequent with advancing age and with lower pre-COVID-19 cognitive and mobility levels. Older men more likely reported respiratory symptoms than women. Dyspnea (hazard ratio [HR] = 1.47, 95% confidence interval [CI]: 1.02-2.12), tachypnea (HR = 1.53, 95% CI: 1.14-2.07), low oxygen saturation (HR = 1.95, 95% CI: 1.32-2.88) and delirium (HR = 1.60, 95% CI: 1.13-2.28) were associated with higher in-hospital mortality. Four symptom clusters were identified. Compared with the mild respiratory symptoms cluster, the severe clinical impairment cluster was associated with higher mortality (HR = 2.57, 95% CI: 1.58-4.18). The severe clinical impairment and aspecific symptoms clusters were associated with longer hospitalization (odds ratio [OR] = 2.38, 95% CI: 1.56-3.63, and OR = 1.75, 95% CI: 1.08-2.83, respectively). Multiple health aspects influence COVID-19 clinical presentation. A symptom clusters approach may help predict adverse health outcomes in older patients. In addition to respiratory symptoms, delirium is independently associated with mortality risk.ClinicalTrials.gov (NCT04379440)