Journal article
LC-derived excitatory synaptic transmission to dorsal raphe serotonin neurons is inhibited by activation of alpha2-adrenergic receptors
Neuropsychopharmacology (New York, N.Y.), Vol.49(6), pp.1014-1023
05/2024
DOI: 10.1038/s41386-024-01824-3
PMCID: PMC11039657
PMID: 38368493
Abstract
In the central nervous system, noradrenaline transmission controls the degree to which we are awake, alert, and attentive. Aberrant noradrenaline transmission is associated with pathological forms of hyper- and hypo-arousal that present in numerous neuropsychiatric disorders often associated with dysfunction in serotonin transmission. In vivo, noradrenaline regulates the release of serotonin because noradrenergic input drives the serotonin neurons to fire action potentials via activation of excitatory α1-adrenergic receptors (α1-A
). Despite the critical influence of noradrenaline on the activity of dorsal raphe serotonin neurons, the source of noradrenergic afferents has not been resolved and the presynaptic mechanisms that regulate noradrenaline-dependent synaptic transmission have not been described. Using an acute brain slice preparation from male and female mice and electrophysiological recordings from dorsal raphe serotonin neurons, we found that selective optogenetic activation of locus coeruleus terminals in the dorsal raphe was sufficient to produce an α1-A
-mediated excitatory postsynaptic current (α1-A
-EPSC). Activation of inhibitory α2-adrenergic receptors (α2-A
) with UK-14,304 eliminated the α1-A
-EPSC via presynaptic inhibition of noradrenaline release, likely via inhibition of voltage-gated calcium channels. In a subset of serotonin neurons, activation of postsynaptic α2-A
produced an outward current through activation of GIRK potassium conductance. Further, in vivo activation of α2-A
by systemic administration of clonidine reduced the expression of c-fos in the dorsal raphe serotonin neurons, indicating reduced neural activity. Thus, α2-A
are critical regulators of serotonin neuron excitability.
Details
- Title: Subtitle
- LC-derived excitatory synaptic transmission to dorsal raphe serotonin neurons is inhibited by activation of alpha2-adrenergic receptors
- Creators
- Aleigha Gugel - University of IowaErik A Ingebretsen - University of IowaHolly S Hake - National Institute on Drug AbuseStephanie C Gantz - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Neuropsychopharmacology (New York, N.Y.), Vol.49(6), pp.1014-1023
- DOI
- 10.1038/s41386-024-01824-3
- PMID
- 38368493
- PMCID
- PMC11039657
- NLM abbreviation
- Neuropsychopharmacology
- ISSN
- 0893-133X
- eISSN
- 1740-634X
- Grant note
- DOI: 10.13039/100001024, name: Roy J. Carver Charitable Trust; name: Department of Molecular Physiology and Biophysics
- Language
- English
- Electronic publication date
- 02/17/2024
- Date published
- 05/2024
- Academic Unit
- Molecular Physiology and Biophysics; Iowa Neuroscience Institute
- Record Identifier
- 9984560489602771
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