Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro

Z. Z. Pan, M. W. Wessendorf, John Williams

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Nucleus raphe magnus contains a large population of raphe-spinal serotonergic neurons that are thought to be involved in descending control of pain transmission and the modulation of opioid analgesia. Intracellular recordings were made from nucleus raphe magnus neurons in the slice preparation. Cells were divided into two groups, primary and secondary cells, based on the action potential waveform and response to opioids, as reported previously. In some experiments, cells were filled with biocytin and 5-hydroxytryptamine-containing cells were identified immunohistochemically. Of the primary cells that were filled with biocytin, 93% stained for 5-hydroxytryptamine; 90% of biocytin-filled secondary cells were unlabeled for 5-hydroxytryptamine. Previous studies have shown that primary cells are disinhibited by opioids; the finding that most primary cells are serotonergic suggests that at least some 5-hydroxytryptamine-containing neurons in the nucleus raphe magnus are excited by opioid analgesics. 5-Hydroxytryptamine hyperpolarized cells in both primary and secondary cell groups. The 5-hydroxytryptamine agonists (±)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide and 5-carboxamidotryptamine mimicked this action of 5-hydroxytryptamine, indicating that the 5-hydroxytryptamine1A-subtype mediated this hyperpolarization. The hyperpolarization was mediated by an increase in potassium conductance that rectified inwardly. Local electrical stimulation of afferents evoked an inhibitory postsynaptic potential in primary cells. The inhibitory postsynaptic potential reversed polarity at the potassium equilibrium potential and was blocked by 5-hydroxytryptamine1A receptor antagonists. It is proposed that the 5-hydroxytryptamine1A receptor on serotonergic primary cells may function as an autoreceptor to regulate the activity. The role of the 5-hydroxytryptamine1A receptor on non-serotonergic secondary cells is unclear.

Original languageEnglish (US)
Pages (from-to)421-429
Number of pages9
JournalNeuroscience
Volume54
Issue number2
DOIs
StatePublished - 1993

Fingerprint

Serotonin
Neurons
Opioid Analgesics
Inhibitory Postsynaptic Potentials
Nucleus Raphe Magnus
In Vitro Techniques
Potassium
Serotonergic Neurons
Autoreceptors
Serotonin Receptor Agonists
Analgesia
Electric Stimulation
Action Potentials
Pain

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro. / Pan, Z. Z.; Wessendorf, M. W.; Williams, John.

In: Neuroscience, Vol. 54, No. 2, 1993, p. 421-429.

Research output: Contribution to journalArticle

Pan, Z. Z. ; Wessendorf, M. W. ; Williams, John. / Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro. In: Neuroscience. 1993 ; Vol. 54, No. 2. pp. 421-429.
@article{5d2446384adf48a49a1b89093cb48387,
title = "Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro",
abstract = "Nucleus raphe magnus contains a large population of raphe-spinal serotonergic neurons that are thought to be involved in descending control of pain transmission and the modulation of opioid analgesia. Intracellular recordings were made from nucleus raphe magnus neurons in the slice preparation. Cells were divided into two groups, primary and secondary cells, based on the action potential waveform and response to opioids, as reported previously. In some experiments, cells were filled with biocytin and 5-hydroxytryptamine-containing cells were identified immunohistochemically. Of the primary cells that were filled with biocytin, 93{\%} stained for 5-hydroxytryptamine; 90{\%} of biocytin-filled secondary cells were unlabeled for 5-hydroxytryptamine. Previous studies have shown that primary cells are disinhibited by opioids; the finding that most primary cells are serotonergic suggests that at least some 5-hydroxytryptamine-containing neurons in the nucleus raphe magnus are excited by opioid analgesics. 5-Hydroxytryptamine hyperpolarized cells in both primary and secondary cell groups. The 5-hydroxytryptamine agonists (±)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide and 5-carboxamidotryptamine mimicked this action of 5-hydroxytryptamine, indicating that the 5-hydroxytryptamine1A-subtype mediated this hyperpolarization. The hyperpolarization was mediated by an increase in potassium conductance that rectified inwardly. Local electrical stimulation of afferents evoked an inhibitory postsynaptic potential in primary cells. The inhibitory postsynaptic potential reversed polarity at the potassium equilibrium potential and was blocked by 5-hydroxytryptamine1A receptor antagonists. It is proposed that the 5-hydroxytryptamine1A receptor on serotonergic primary cells may function as an autoreceptor to regulate the activity. The role of the 5-hydroxytryptamine1A receptor on non-serotonergic secondary cells is unclear.",
author = "Pan, {Z. Z.} and Wessendorf, {M. W.} and John Williams",
year = "1993",
doi = "10.1016/0306-4522(93)90263-F",
language = "English (US)",
volume = "54",
pages = "421--429",
journal = "Neuroscience",
issn = "0306-4522",
publisher = "Elsevier Limited",
number = "2",

}

TY - JOUR

T1 - Modulation by serotonin of the neurons in rat nucleus raphe magnus in vitro

AU - Pan, Z. Z.

AU - Wessendorf, M. W.

AU - Williams, John

PY - 1993

Y1 - 1993

N2 - Nucleus raphe magnus contains a large population of raphe-spinal serotonergic neurons that are thought to be involved in descending control of pain transmission and the modulation of opioid analgesia. Intracellular recordings were made from nucleus raphe magnus neurons in the slice preparation. Cells were divided into two groups, primary and secondary cells, based on the action potential waveform and response to opioids, as reported previously. In some experiments, cells were filled with biocytin and 5-hydroxytryptamine-containing cells were identified immunohistochemically. Of the primary cells that were filled with biocytin, 93% stained for 5-hydroxytryptamine; 90% of biocytin-filled secondary cells were unlabeled for 5-hydroxytryptamine. Previous studies have shown that primary cells are disinhibited by opioids; the finding that most primary cells are serotonergic suggests that at least some 5-hydroxytryptamine-containing neurons in the nucleus raphe magnus are excited by opioid analgesics. 5-Hydroxytryptamine hyperpolarized cells in both primary and secondary cell groups. The 5-hydroxytryptamine agonists (±)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide and 5-carboxamidotryptamine mimicked this action of 5-hydroxytryptamine, indicating that the 5-hydroxytryptamine1A-subtype mediated this hyperpolarization. The hyperpolarization was mediated by an increase in potassium conductance that rectified inwardly. Local electrical stimulation of afferents evoked an inhibitory postsynaptic potential in primary cells. The inhibitory postsynaptic potential reversed polarity at the potassium equilibrium potential and was blocked by 5-hydroxytryptamine1A receptor antagonists. It is proposed that the 5-hydroxytryptamine1A receptor on serotonergic primary cells may function as an autoreceptor to regulate the activity. The role of the 5-hydroxytryptamine1A receptor on non-serotonergic secondary cells is unclear.

AB - Nucleus raphe magnus contains a large population of raphe-spinal serotonergic neurons that are thought to be involved in descending control of pain transmission and the modulation of opioid analgesia. Intracellular recordings were made from nucleus raphe magnus neurons in the slice preparation. Cells were divided into two groups, primary and secondary cells, based on the action potential waveform and response to opioids, as reported previously. In some experiments, cells were filled with biocytin and 5-hydroxytryptamine-containing cells were identified immunohistochemically. Of the primary cells that were filled with biocytin, 93% stained for 5-hydroxytryptamine; 90% of biocytin-filled secondary cells were unlabeled for 5-hydroxytryptamine. Previous studies have shown that primary cells are disinhibited by opioids; the finding that most primary cells are serotonergic suggests that at least some 5-hydroxytryptamine-containing neurons in the nucleus raphe magnus are excited by opioid analgesics. 5-Hydroxytryptamine hyperpolarized cells in both primary and secondary cell groups. The 5-hydroxytryptamine agonists (±)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide and 5-carboxamidotryptamine mimicked this action of 5-hydroxytryptamine, indicating that the 5-hydroxytryptamine1A-subtype mediated this hyperpolarization. The hyperpolarization was mediated by an increase in potassium conductance that rectified inwardly. Local electrical stimulation of afferents evoked an inhibitory postsynaptic potential in primary cells. The inhibitory postsynaptic potential reversed polarity at the potassium equilibrium potential and was blocked by 5-hydroxytryptamine1A receptor antagonists. It is proposed that the 5-hydroxytryptamine1A receptor on serotonergic primary cells may function as an autoreceptor to regulate the activity. The role of the 5-hydroxytryptamine1A receptor on non-serotonergic secondary cells is unclear.

UR - http://www.scopus.com/inward/record.url?scp=0027251356&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027251356&partnerID=8YFLogxK

U2 - 10.1016/0306-4522(93)90263-F

DO - 10.1016/0306-4522(93)90263-F

M3 - Article

VL - 54

SP - 421

EP - 429

JO - Neuroscience

JF - Neuroscience

SN - 0306-4522

IS - 2

ER -