Glial cells are essential for functionality of the nervous system. Growing evidence underscores the importance of astrocytes; however, analogous astroglia in peripheral organs are poorly understood. Using confocal time-lapse imaging, fate mapping, and mutant genesis in a zebrafish model, we identify a neural crest–derived glial cell, termed nexus glia, which utilizes Meteorin signaling via Jak/Stat3 to drive differentiation and regulate heart rate and rhythm. Nexus glia are labeled with gfap, glast, and glutamine synthetase, markers that typically denote astroglia cells. Further, analysis of single-cell sequencing datasets of human and murine hearts across ages reveals astrocyte-like cells, which we confirm through a multispecies approach. We show that cardiac nexus glia at the outflow tract are critical regulators of both the sympathetic and parasympathetic system. These data establish the crucial role of glia on cardiac homeostasis and provide a description of nexus glia in the PNS.

Objectives: We give an overview of the current state of cerebellopontine angle (CPA) surgery, based on the recent evidence, and describe our center’s experience in surgical approaches to these lesions. Methods: Retrospective review of cases who underwent surgery for CPA lesions at our hospital during the past 17 years (1996-2013), with focus on the description of the currently most used technique-extended retrosigmoid. We also conducted a brief review of the literature on CPA surgery, comparing the different approaches, their indications and complications. Results: During this period, 203 patients underwent surgery for CPA. The most frequent indication was vestibular schwannoma (84.7%). Other indications were meningiomas (8.4%), epidermoids (1%), vestibular neurectomies (1.5%), arteriovenous malformations (1%), anterior inferior cerebellar artery–posterior inferior cerebellar artery aneurysms (1%), trigeminal microscopic decompression (0.5%), and other more rare tumors (2%). The most used approach was extended retrosigmoid (71.9%), followed by the translabyrinthine (26.1%) and middle fossa approach (2%). Until 2004, the most used approach was the translabyrinthine; after 2004, the most used was the extended retrosigmoid. Conclusions: Currently, the preferred surgical approach used by our team is the extended retrosigmoid, because it allows a complete exposition of sigmoid sinus from the transverse sinus to the jugular bulb, enhances CPA vision, avoids cerebellar retraction, and is a simple way to get a wide route to the CPA. It also allows good functional outcomes (hearing and facial nerve preservation) in most cases. However, indications for approaches depend on the size of the lesion, its location and the quality of preoperative hearing, as well as a necessary familiarity with all approaches.

Poster PresentationsP163 at 2 hours after irradiation. EGR-1 knock-down cells displayed decreased radiation-induced apoptosis, compared with control cells in cell apoptosis assay. Cleaved caspase 3, cleaved caspase 7, cleaved PARP, and Bax activation was decreased by EGR-1 knock-down after irradiation.Conclusions: EGR-1 had abundant expression in human HNSCC tissue. EGR-1 knock-down decreased radiationinduced apoptosis through caspase 3, caspase, 7, PARP, and Bax. EGR-1 may play an important role in treatment response after radiation therapy in human HNSCC.