Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat
Neurotensin (NT) is an endogenous neuropeptide that exerts potent opioid-independent analgesic effects, most likely via the type 2 NT receptor (NTR2). Previous morphological and electrophysiological studies suggested that the NT-NTR2 system is primarily localized in structures that constitute the de...
Main Authors: | , , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Frontiers Media S.A.
2014-10-01
|
Series: | Frontiers in Neuroanatomy |
Subjects: | |
Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnana.2014.00112/full |
_version_ | 1818299942291111936 |
---|---|
author | Jian eWang Hua eZhang Yu-Peng eFeng Hua eMeng Li-Ping eWu Wen eWang Hui eLi Ting eZhang Jin-Shan eZhang Yun-Qing eLi |
author_facet | Jian eWang Hua eZhang Yu-Peng eFeng Hua eMeng Li-Ping eWu Wen eWang Hui eLi Ting eZhang Jin-Shan eZhang Yun-Qing eLi |
author_sort | Jian eWang |
collection | DOAJ |
description | Neurotensin (NT) is an endogenous neuropeptide that exerts potent opioid-independent analgesic effects, most likely via the type 2 NT receptor (NTR2). Previous morphological and electrophysiological studies suggested that the NT-NTR2 system is primarily localized in structures that constitute the descending pain control pathway, such as the periaqueductal gray (PAG), the rostral ventromedial medulla (RVM), and the spinal dorsal horn (SDH). However, relevant morphological evidence for this neurotensinergic (NTergic) circuit is lacking. Thus, the aim of the present study was to morphologically elucidate the potential sites and connections in the NT-NTR2 system that are involved in the descending pain control pathway. Based on light and electron microscopy combined with anterograde and retrograde tracing, we found evidence that NTR2-immunoreactive (IR) neurons in the RVM receive NT-IR projections originating from the PAG; express NT, serotonin (5-HT), or both; and send projections that terminate in laminae I and II of the SDH. These results suggest that NTR2 may contribute to pain control by binding to NT in the PAG-RVM-SDH pathway. In conclusion, our data provide morphological evidence for an NTergic PAG-RVM-SDH pathway, implicating novel mechanisms of NT-induced analgesia. |
first_indexed | 2024-12-13T04:59:14Z |
format | Article |
id | doaj.art-63fab38e93374d3c9c493a6959e3e5a1 |
institution | Directory Open Access Journal |
issn | 1662-5129 |
language | English |
last_indexed | 2024-12-13T04:59:14Z |
publishDate | 2014-10-01 |
publisher | Frontiers Media S.A. |
record_format | Article |
series | Frontiers in Neuroanatomy |
spelling | doaj.art-63fab38e93374d3c9c493a6959e3e5a12022-12-21T23:58:50ZengFrontiers Media S.A.Frontiers in Neuroanatomy1662-51292014-10-01810.3389/fnana.2014.00112108594Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in ratJian eWang0Hua eZhang1Yu-Peng eFeng2Hua eMeng3Li-Ping eWu4Wen eWang5Hui eLi6Ting eZhang7Jin-Shan eZhang8Yun-Qing eLi9The Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityThe Fourth Military Medical UniversityNeurotensin (NT) is an endogenous neuropeptide that exerts potent opioid-independent analgesic effects, most likely via the type 2 NT receptor (NTR2). Previous morphological and electrophysiological studies suggested that the NT-NTR2 system is primarily localized in structures that constitute the descending pain control pathway, such as the periaqueductal gray (PAG), the rostral ventromedial medulla (RVM), and the spinal dorsal horn (SDH). However, relevant morphological evidence for this neurotensinergic (NTergic) circuit is lacking. Thus, the aim of the present study was to morphologically elucidate the potential sites and connections in the NT-NTR2 system that are involved in the descending pain control pathway. Based on light and electron microscopy combined with anterograde and retrograde tracing, we found evidence that NTR2-immunoreactive (IR) neurons in the RVM receive NT-IR projections originating from the PAG; express NT, serotonin (5-HT), or both; and send projections that terminate in laminae I and II of the SDH. These results suggest that NTR2 may contribute to pain control by binding to NT in the PAG-RVM-SDH pathway. In conclusion, our data provide morphological evidence for an NTergic PAG-RVM-SDH pathway, implicating novel mechanisms of NT-induced analgesia.http://journal.frontiersin.org/Journal/10.3389/fnana.2014.00112/fullAnalgesiaNeurotensinNociceptionPeriaqueductal gray matterRostral Ventromedial Medulla (RVM)NTR2 |
spellingShingle | Jian eWang Hua eZhang Yu-Peng eFeng Hua eMeng Li-Ping eWu Wen eWang Hui eLi Ting eZhang Jin-Shan eZhang Yun-Qing eLi Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat Frontiers in Neuroanatomy Analgesia Neurotensin Nociception Periaqueductal gray matter Rostral Ventromedial Medulla (RVM) NTR2 |
title | Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat |
title_full | Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat |
title_fullStr | Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat |
title_full_unstemmed | Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat |
title_short | Morphological evidence for a neurotensinergic periaqueductal gray-rostral ventromedial medulla-spinal dorsal horn descending pathway in rat |
title_sort | morphological evidence for a neurotensinergic periaqueductal gray rostral ventromedial medulla spinal dorsal horn descending pathway in rat |
topic | Analgesia Neurotensin Nociception Periaqueductal gray matter Rostral Ventromedial Medulla (RVM) NTR2 |
url | http://journal.frontiersin.org/Journal/10.3389/fnana.2014.00112/full |
work_keys_str_mv | AT jianewang morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT huaezhang morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT yupengefeng morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT huaemeng morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT lipingewu morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT wenewang morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT huieli morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT tingezhang morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT jinshanezhang morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat AT yunqingeli morphologicalevidenceforaneurotensinergicperiaqueductalgrayrostralventromedialmedullaspinaldorsalhorndescendingpathwayinrat |