Editorial: Interactions of the nervous system with bacteria

Recent evidence that microbes influence mood and behavior via the gut-brain axis has opened up new avenues for research into neurological disorders. Hence, many studies now employ multidisciplinary approaches assessing for changes in microbial diversity, neuroinflammation as well as alterations in neuronal circuitry that impact brain function in health and disease. Such collaborative research was virtually unheard of in previous decades but holds remarkable promise for identifying novel pathways and therapeutic targets within the gastrointestinal tract to treat brain disorders. This editorial highlights these exciting developments in neuroscience, microbiology, and immunological research by examining 13 articles focused on how the nervous system interacts with bacteria in preclinical and clinical settings. A common theme is the dissection of complex interactions between the nervous system and bacteria as well as the resulting influences on inflammatory pathways, symptoms, or behavior in patient studies and mouse models. Specifically, neuronal-microbial interactions in the context of nervous system disorders ranging from autism, Attention Deficit Hyperactivity Disorder, Alzheimer’s Disease and Major Depressive Disorder to migraine and epilepsy are investigated. Overall, we propose that via leveraging our understanding of the gut-brain axis, the modulation of gut microbes leading to significant benefits for brain health can become a reality

Inflammatory complications of CGRP monoclonal antibodies: a case series

Background: Calcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response. Cases: We present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy. Conclusion: This case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward.</p