Hypothalamic oxytocinergic magnocellular neurons have a fascinating ability to release peptide from both their axon terminals and from their dendrites. Existing data indicates that the relationship between somatic activity and dendritic release is not constant, but the mechanisms through which this relationship can be modulated are not completely understood. Here we use a combination of electrical and optical recording techniques to quantify activity-induced calcium influx in proximal vs. distal dendrites of oxytocinergic magnocellular neurons located in the paraventricular nucleus of the hypothalamus (OT-MCNs). Results reveal that the dendrites of OT-MCNs are weak conductors of somatic voltage changes, however activity-induced dendritic calcium influx can be robustly regulated by both osmosensitive and non-osmosensitive ion channels located along the dendritic membrane. Overall, this study reveals that dendritic conductivity is a dynamic and endogenously regulated feature of OT-MCNs that is likely to have substantial functional impact on central oxytocin release.
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for all figures.
- Charles J Frazier
- Eric G Krause
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All animal procedures were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Florida (under protocol # 201701866).
- Ryohei Yasuda, Max Planck Florida Institute for Neuroscience, United States
- Received: September 25, 2020
- Accepted: July 11, 2021
- Accepted Manuscript published: July 12, 2021 (version 1)
© 2021, Sheng et al.
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