Abstract

The locus coeruleus (LC) has previously been implicated in the regulation of vasopressin secretion. To further investigate this issue experiments were done in which extracellular recordings were obtained from functionally identified neurosecretory vasopressin (VP) cells of the rat supraoptic nucleus. Electrolytic lesions of the ipsilateral LC reduced the proportion of VP cells inhibited by carotid baroreceptor activation from 93% to 35%; the inhibitory effect of aortic depressor nerve stimulation was unchanged. Electrical stimulation of the LC altered the discharge probability of 20% of VP cells tested, the predominant effect being excitation. In contrast to the effects of electrolytic lesions and electrical stimulation, neither chemical inhibition nor stimulation of the LC, by local injection of neuroactive amino acids, altered VP cell baroreceptor responsiveness or spontaneous discharge. These data indicate that while fibres of passage in the LC region can influence VP cell excitability, particularly responses to carotid baroreceptor activation, LC cells do not regulate VP cell function or, by implication, the secretion of this vasoactive and antidiuretic hormone.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

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.