Neuro-immune crosstalk and food allergy: Focus on enteric neurons and mucosal mast cells

The nervous system and the immune system individually play important roles in regulating the processes necessary to maintain physiological homeostasis, respond to acute stress and protect against external threats. These two regulating systems for maintaining the living body had often been assumed to function independently. Allergies develop as a result of an overreaction of the immune system to substances that are relatively harmless to the body, such as food, pollen and dust mites. Therefore, it has been generally supposed that the development and pathogenesis of allergies can be explained through an immunological interpretation. Recently, however, neuro-immune crosstalk has attracted increasing attention. Consequently, it is becoming clear that there is close morphological proximity and physiological and pathophysiological interactions between neurons and immune cells in various peripheral tissues. Thus, researchers are now beginning to appreciate that neuro-immune interactions may play a role in tissue homeostasis and the pathophysiology of immune-mediated disease, but very little information is available on the molecular basis of these interactions. Mast cells are a part of the innate immune system implicated in allergic reactions and the regulation of host–pathogen interactions. Mast cells are ubiquitous in the body, and these cells are often found in close proximity to nerve fibers in various tissues, including the lamina propria of the intestine. Mast cells and neurons are thought to communicate bidirectionally to modulate neurophysiological effects and mast cell functions, which suggests that neuro-immune interactions may be involved in the pathology of allergic diseases.     

A pilot trial of RNS60 in amyotrophic lateral sclerosis

Introduction: RNS60 is a novel immune-modulatory agent that has shown neuroprotective effects in amytrophic lateral sclerosis (ALS) preclinical models. RNS60 is administered by weekly intravenous infusion and daily nebulization. The objective of this pilot open-label trial was to test the feasibility, safety, and tolerability of long-term RNS60 administration in ALS patients. Methods: The planned treatment duration was 23 weeks and the primary outcomes were safety and tolerability. Secondary outcomes included PBR28 positron emission tomography (PET) imaging and plasma biomarkers of inflammation. Results: Sixteen participants with ALS received RNS60 and 13 (81%) completed 23 weeks of RNS60 treatment. There were no serious adverse events and no participants withdrew from the trial due to drug-related adverse events. There were no significant changes in the biomarkers. Discussion: Long-term RNS60 administration was safe and well-tolerated. A large, multicenter, phase II trial of RNS60 is currently enrolling participants to test the effects of RNS60 on ALS biomarkers and disease progression. Muscle Nerve 59 :303–308, 2019     

Chronic Stress Remodels Synapses in an Amygdala Circuit–Specific Manner

Background

Chronic stress exposure increases the risk of developing various neuropsychiatric illnesses. The behavioral sequelae of stress correlate with dendritic hypertrophy and glutamate-related synaptic remodeling at basolateral amygdala projection neurons (BLA PNs). Yet, though BLA PNs are functionally heterogeneous with diverse corticolimbic targets, it remains unclear whether stress differentially impacts specific output circuits.

Subjective tinnitus: lesion-induced pathological central homeostasis remodeling

Subjective tinnitus is the most common type of tinnitus, which is the manifestation of pathological activities in the brain. It happens in a substantial portion of the general population and brings significant burden to the society. Severe subjective tinnitus can lead to depression and insomnia and severely affects patients’ quality of life. However, due to poor understanding of its etiology and pathogenesis, treatment of subjective tinnitus remains challenging. In recent decades, a growing number of studies have shown that subjective tinnitus is related to lesion-induced neural plasticity of auditory and non-auditory central systems. This article reviews cellular mechanisms of neural plasticity in subjective tinnitus to provide further understanding of its pathogenesis.     

New advances in Amyotrophic Lateral Sclerosis genetics: Towards gene therapy opportunities for familial and young cases

Due to novel gene therapy opportunities, genetic screening is no longer restricted to familial cases of ALS (FALS) cases but also aplies to the sporadic populations (SALS). Screening of four main genes (C9orf72, SOD1, TARDBP and FUS) identified the causes in 15% of Amyotrophic Lateral Sclerosis (ALS) patients (two third of the familial cases and 8% of the sporadic ones) but their respective contribution to ALS phenotype varies according the age of disease onset. The genetic overlap between ALS and other diseases is expanding and includes frontotemporal dementia, Paget's Disease of Bone, myopathy for adult cases, HSP and CMT for young cases highlighing the importance of retrieving the exhaustive familial history for each indivdual with ALS. Incomplete disease penetrance, diversity of the possible phenotypes, as well as the lack of confidence concerning the pathogenicity of most identified variants and/or possible oligogenic inheritance are burdens of ALS genetic counseling to be delivered to patients and at risk individuals. The multitude of rare ALS genetic causes identifed seems to converge to similar cellular pathways leading to inapropriate response to stress emphacising new potential therapeutic options for the disease.     

大鼠腹侧被盖区多巴胺能神经元介导食欲素促进全麻后觉醒效应

目的:研究大鼠腹侧被盖区(VTA)多巴胺能神经元是否介导食欲素(orexin)的促进全麻后觉醒效应。方法:将兴奋性光遗传病毒注射至Hcrt-cre大鼠的orexin阳性神经元所在的下丘脑外侧穹隆周区(PeFLH),同时在VTA区注射抑制性化学遗传病毒及带有酪氨酸羟化酶(TH)-cre的混合病毒抑制多巴胺能神经元,并在VTA区植入光纤。观察通过化学遗传抑制VTA区多巴胺能神经元后,光遗传兴奋VTA区的orexin阳性神经投射终末是否仍能引起促进异氟醚麻醉后觉醒的效应。结果:与对照组相比,用化学遗传技术预先抑制VTA区多巴胺能神经元,阻断了光遗传兴奋VTA区orexin阳性神经投射终末所产生的缩短大鼠1.4%异氟醚麻醉后觉醒时间的作用;并阻断了光遗传兴奋VTA区orexin阳性神经投射终末所产生的降低大鼠1.4%异氟醚麻醉中脑电图爆发抑制率(BSR)效应。用Fos染色法验证了化学遗传法抑制多巴胺能神经元的可靠性。结论:抑制VTA区的多巴胺能神经元能够阻断兴奋大鼠VTA区orexin阳性神经末梢所产生的促进大鼠异氟醚后觉醒的效应,提示VTA区的多巴胺神经神经元介导了orexin调控VTA区产生的促进觉醒效应。     

Neuronal chemo‐architecture of the entorhinal cortex: A comparative review

The identification of neuronal markers, that is, molecules selectively present in subsets of neurons, contributes to our understanding of brain areas and the networks within them. Specifically, recognizing the distribution of different neuronal markers facilitates the identification of borders between functionally distinct brain areas. Detailed knowledge about the localization and physiological significance of neuronal markers may also provide clues to generate new hypotheses concerning aspects of normal and abnormal brain functioning. Here, we provide a comprehensive review on the distribution within the entorhinal cortex of neuronal markers and the morphology of the neurons they reveal. Emphasis is on the comparative distribution of several markers, with a focus on, but not restricted to rodent, monkey and human data, allowing to infer connectional features, across species, associated with these markers, based on what is revealed by mainly rodent data. The overall conclusion from this review is that there is an emerging pattern in the distribution of neuronal markers in the entorhinal cortex when aligning data along a comparable coordinate system in various species.