Modulation of subfornical organ neurons by neurotensin

Simple item page
dc.contributor.authorBelyea, M Megan
dc.contributor.examiningcommitteeStecina, Katinka (Max Rady College of Medicine)
dc.contributor.examiningcommitteeJeffries, Ken (Biological Sciences)
dc.contributor.supervisorFry, Mark
dc.date.accessioned2024-01-04T15:14:12Z
dc.date.available2024-01-04T15:14:12Z
dc.date.issued2023-12-22
dc.date.submitted2023-12-22T18:17:13Zen_US
dc.degree.disciplineBiological Sciencesen_US
dc.degree.levelMaster of Science (M.Sc.)
dc.description.abstractNeurotensin (NT) is a 13 amino-acid peptide which is both a hormone and neuromodulator. Through its 3-4 known receptors, NT is shown to influence several physiological responses including autonomic output, hydromineral balance, and cardiovascular regulation. Recent transcriptomic studies have revealed that the subfornical organ (SFO) expresses a high abundance of neurotensin receptors (NTSR), specifically NTSR2 and NTSR3, with levels comparable to other prominent neuromodulators that act in this region. The SFO is known for its involvement in cardiovascular regulation, sympathetic output, and hydromineral balance. As a circumventricular organ, it lacks the blood brain barrier, providing a direct interface with peptides in circulation, in addition to centrally released signals in cerebrospinal fluid. Both NT and the SFO have been found to influence satiety and water intake; thus, the SFO, through various peptides, and NT as a peptide have both been found to play a key role in hydromineral balance; which, in turn, plays a role in cardiovascular regulation. Due to their intersecting areas of influence, and as the SFO is a major integration center for peripheral and central signals, we hypothesized that this neuropeptide modulates neurons in this region to elicit physiological responses. Whole-cell patch-clamp recordings from this study demonstrate that NT (1µM) modulates synaptic activity in 54% (34/63) of SFO neurons tested, in acutely prepared brain slices. Specifically, we found that NT significantly increased excitability of SFO neurons by depolarizing the resting membrane potential, and that NT decreased the amplitude of EPSCs, but not EPSC interevent interval. By also treating 35/63 cells previously tested for NT, with Ang II, we found that there appears to be a subpopulation of SFO neurons sensitive to both NT and Ang II. Most of these cells exhibited a decrease in EPSC amplitude to both peptides, suggesting that they may operate through this region of the CNS to affect the same homeostatic mechanisms.
dc.description.noteFebruary 2024
dc.identifier.urihttp://hdl.handle.net/1993/37921
dc.language.isoeng
dc.rightsopen accessen_US
dc.subjectSubfornical Organ
dc.subjectNeurotensin
dc.subjectCircumventricular Organs
dc.subjectSFO
dc.subjectNT
dc.subjectCVO
dc.titleModulation of subfornical organ neurons by neurotensin
dc.typemaster thesisen_US
local.subject.manitobano
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Thesis
Size:
1.99 MB
Format:
Adobe Portable Document Format
Description:
A 12 month embargo has been applied for journal publication.
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
770 B
Format:
Item-specific license agreed to upon submission
Description:
Download
Collections
FGS - Electronic Theses and Practica