Nicotinic receptor modulation of the default mode network.
Rationale: Previous neuroimaging studies of cognition involving nicotinic acetylcholine receptor (nAChR) agonist administration have repeatedly found enhanced task-induced deactivation of regions of the default mode network (DMN), a group of brain systems that is more active at rest and mediates tas...
| Publicado en: | Psychopharmacology Vol. 238; no. 2; pp. 589 - 598 |
|---|---|
| Autores principales: | , , , , , |
| Formato: | Journal Article |
| Publicado: |
Springer Nature
2021
|
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=148320670&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 148320670 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00333158 EJD jtl: Psychopharmacology issn: 00333158 maglogo: N pubinfo: dt: 2021 vid: 238 iid: 2 pid: 237 pub: Springer Nature place: New York, New York artinfo: ui: 148320670 147210528 10.1007/s00213-020-05711-9 148320670 ppf: 589 ppct: 9 formats: fmt: – @attributes: type: T – @attributes: type: P tig: atl: Nicotinic receptor modulation of the default mode network. aug: au: Hahn, Britta Harvey, Alexander N. Concheiro-Guisan, Marta Huestis, Marilyn A. Ross, Thomas J. Stein, Elliot A. affil: University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. Box 21247, 21228, Baltimore, MD, USA sug: ab: Rationale: Previous neuroimaging studies of cognition involving nicotinic acetylcholine receptor (nAChR) agonist administration have repeatedly found enhanced task-induced deactivation of regions of the default mode network (DMN), a group of brain systems that is more active at rest and mediates task-independent thought processes. This effect may be related to pro-cognitive nAChR agonist effects Objectives: The present study sought to test whether nAChR modulation of the DMN is bi-directional, i.e., whether a nAChR antagonist would reduce task-induced deactivation. Methods: Eighteen healthy non-smokers underwent functional magnetic resonance imaging while performing a letter N-back task. Scans were performed after nicotine administration (7 mg/24 h, transdermally), after administration of the nAChR antagonist mecamylamine (7.5 mg, p.o.), and after double placebo, in counterbalanced sequence. Blood-oxygen-level-dependent (BOLD) signal was analyzed within ventromedial prefrontal cortex (vmPFC) and posterior cingulate cortex (PCC) regions of interest—central hubs of the DMN in which consistent nAChR agonist–induced changes had previously been identified. Results: Nicotine enhanced hit rate in both the 0-back and 2-back condition, while mecamylamine slowed reaction time in the 2-back condition. Mecamylamine reduced task-induced deactivation of vmPFC and PCC. Nicotine had no significant effects on the BOLD signal. Conclusions: The finding that nAChR tone reduction by mecamylamine weakened task-induced DMN deactivation indicates that a constant tone of nAChR activation helps regulate DMN activity in healthy individuals. This suggests that low nAChR tone may play a causal role in DMN dysregulation seen in conditions such as mild cognitive impairment or Alzheimer's disease. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|