Abstract
Previous studies revealed that oxytocin release is increased by various forms of stress. Hypertonic saline injection, immobilization, and several other stressors elevated the blood level of oxytocin in rats. However, the mechanism of the stress-induced oxytocin release in human is not elucidated yet. Although numerous studies indicate that catecholamines play a pivotal role in modulating the release of oxytocin, there is a lack of data regarding the morphological substrate of this phenomenon. In order to reveal putative juxtapositions between tyrosine hydroxylase–immunoreactive (TH–IR) catecholaminergic and the oxytocinergic systems in the human hypothalamus, we utilized double-label immunohistochemistry in the present study. Numerous TH–IR axon varicosities abutted on oxytocin–IR neurons in the supraoptic and paraventricular nuclei, forming synapse-like associations. Close examination of these juxtapositions with high magnification failed to reveal any gaps between the contacting elements. In summary, the intimate associations between the TH–IR and oxytocin–IR elements may be functional synapses and may represent the morphological substrate of stress-influenced oxytocin release. The finding that several oxytocin–IR perikarya did not receive apparent TH innervation suggests that additional mechanisms may play significant roles in the oxytocin modulation by stressors.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.