New promising work has indicated oxytocin (OXT) receptor activation is blunted in
cardiovascular diseases (CVDs) and OXT receptor activation may be a novel target to
increase parasympathetic activity to the heart and treat cardiac autonomic imbalance.
This study tests the hypotheses that the release of OXT from hypothalamic paraventricular
(PVN) neurons onto cardiac vagal neurons (CVNs) is diminished with chronic intermittent
hypoxia-hypercapnia (CIH/H), an animal model of Obstructive Sleep Apnea (OSA) and
furthermore that selective activation of PVN OXT neurons can reduce adverse cardiovascular
consequences that occur with CIH/H. Optogenetic stimulation of channelrhodopsin expressing
PVN fibers evoked large transient increases in Ca2+ in CHO cells stably transfected to express the human recombinant OXT receptor and
the red fluorescent calcium indicator, R-GECO1, dispersed adjacent to CVNs. The release
of OXT onto CVNs upon photoactivation of PVN fibers was blunted in animals exposed
to 21 days of CIH/H. To examine if restoration of OXT neuron activity can prevent the in
vivo cardiovascular effects of CIH/H, we selectively expressed excitatory DREADDs
in PVN OXT neurons, and implanted animals with telemetry devices to monitor blood
pressure (BP) and EKG activity. Selective chronic activation of PVN OXT neurons decreased
resting BP and HR, and more importantly chronic PVN OXT neuron activation prevented
the elevations in BP and HR that with CIH/H. These results indicate excitation of
parvocellular PVN fibers releases OXT at brainstem CVN targets, decreases resting
BP and HR, and prevent the elevations in BP and HR that occur after 21 days of CIH/H.
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Autonomic Neuroscience: Basic and ClinicalAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
Article Info
Identification
Copyright
© 2015 Published by Elsevier Inc.