Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold.

Electrical synapses are neuronal gap junction (GJ) channels associated with a macromolecular complex called the electrical synapse density (ESD), which regulates development and dynamically modifies electrical transmission. However, the proteomic makeup and molecular mechanisms utilized by the ESD that direct electrical synapse formation are not well understood. Using the Mauthner cell of zebrafish as a model, we previously found that the intracellular scaffolding protein ZO1b is a member of the ESD, localizing postsynaptically, where it is required for GJ channel localization, electrical communication, neural network function, and behavior. Here, we show that the complexity of the ESD is further diversified by the genomic structure of the ZO1b gene locus. The ZO1b gene is alternatively initiated at three transcriptional start sites resulting in isoforms with unique N-termini that we call ZO1b-Alpha, -Beta, and -Gamma. We demonstrate that ZO1b-Beta and ZO1b-Gamma are broadly expressed throughout the nervous system and localize to electrical synapses. By contrast, ZO1b-Alpha is expressed mainly non-neuronally and is not found at synapses. We generate mutants in all individual isoforms, as well as double mutant combinations in cis on individual chromosomes, and find that ZO1b-Beta is necessary and sufficient for robust GJ channel localization. ZO1b-Gamma, despite its localization to the synapse, plays an auxiliary role in channel localization. This study expands the notion of molecular complexity at the ESD, revealing that an individual genomic locus can contribute distinct isoforms to the macromolecular complex at electrical synapses. Further, independent scaffold isoforms have differential contributions to developmental assembly of the interneuronal GJ channels. We propose that ESD molecular complexity arises both from the diversity of unique genes and from distinct isoforms encoded by single genes. Overall, ESD proteomic diversity is expected to have critical impacts on the development, structure, function, and plasticity of electrical transmission.

Assessing the concern for airway complications introduced by Wendler's glottoplasty.

Objective: Wendler's glottoplasty (WG) is a pitch-elevating surgery performed by laryngologists providing gender-affirming care. The surgery creates an anterior glottic web that could theoretically cause airway concerns, either perioperatively or at the time of future procedures; such concerns are not well-described in the literature. We seek to assess surgeon opinions on airway concerns regarding WG. Method: A survey of laryngologists assessing opinions on airway considerations in glottoplasty. Results: A total of 19 physicians responded, representing approximately 193 surgeries. 52.6% performed glottoplasty and the remainder responded based on experience with anterior glottic webs. Two perioperative airway complications were reported, both mild stridor that did not prevent same-day discharge. No long-term sequela was reported. All surveyed laryngologists endorsed an altered general anesthetic approach for future procedures, with 73.7% advocating for use of a smaller endotracheal tube. 72.2% did not have "major concerns" about future intubations, and only 5.3% thought the immediate risk of airway compromise was a "real concern." 91.9% counsel their patients routinely but briefly on airway concerns. Open-ended comments conveyed themes of concern for post-operative disruption of the web more than of airway compromise. Conclusion: Because glottoplasty is performed in the anterior glottis and does not significantly impact airway patency, the risk of serious airway complications appears to be minimal. Laryngologists believe future intubations require a modified approach with a smaller tube, partly due to concern for glottic web trauma. Based on this pilot study, the topic deserves greater work to standardize care and anesthetic alterations for patients with WG. Level of Evidence: 5.