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Subfornical Organ Neurons Integrate Cholecystokinin and Angiotensin II Signals
Author(s) -
Cancelliere Nicole Mariantonia,
Ferguson Alastair V
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1234.7
Subject(s) - subfornical organ , angiotensin ii , depolarization , endocrinology , medicine , cholecystokinin , membrane potential , chemistry , neuron , electrophysiology , receptor , neuroscience , biology , biochemistry
The subfornical organ (SFO) is a sensory circumventricular organ implicated in the regulation of energy and fluid balance. SFO neurons have been shown to express receptors for and respond to both cholecystokinin (CCK) and angiotensin II (ANG)‐hormones traditionally classified as energy and fluid balance signals, respectively. The purpose of this study was to investigate whether neurons that respond to CCK could also respond to ANG. SFO neurons were micro‐dissected from Sprague‐Dawley rats (21–28 day), dissociated into individual neurons, and incubated at 5mM glucose. Using the perforated patch clamp electrophysiology technique, effects on membrane potential were assessed after isolated SFO neurons were bath applied with CCK‐8S [10nM] followed by ANG II [10nM], allowing for successful washout of the hormone and recovery of the neuron (if responsive) between applications. Our results show that 25% of SFO neurons tested respond to both CCK and ANG directly, causing a depolarization of the membrane potential in response to bath application of both peptides (CCK= + 6.5 mV ± 1.7 mV; ANG= + 7.0 mV ± 1.7 mV; n=2/8), and 38% of neurons tested did not respond to either CCK or ANG (CCK= + 0.2 mV ± 1.4 mV; ANG= + 0.04 mV ± 0.03 mV; n=3/8). A separate population of neurons (38%) did not respond to CCK, and depolarized after ANG application (CCK= − 0.4 mV ± 0.5 mV; ANG= + 9.2 mV ± 4.5 mV; n=3/8). These preliminary data demonstrate that there is a subpopulation of SFO neurons which respond to both CCK and ANG, suggesting that single SFO neurons are able to integrate both of these traditionally classified energy and fluid balance signals. Support or Funding Information This work was supported by the Canadian Institutes of Health Research (CIHR)