Tuesday, January 19, 2016 1:04:23 PM
http://www.ncbi.nlm.nih.gov/pubmed/26049209
>>> Biol Psychiatry. 2015 May 2. pii: S0006-3223(15)00357-1. doi: 10.1016/j.biopsych.2015.04.019. [Epub ahead of print]
Naltrexone Facilitates Learning and Delays Extinction by Increasing AMPA Receptor Phosphorylation and Membrane Insertion.
Kibaly C1, Kam AY2, Loh HH2, Law PY2.
Abstract
BACKGROUND:
The opioid antagonists naloxone/naltrexone are involved in improving learning and memory, but their cellular and molecular mechanisms remain unknown. We investigated the effect of naloxone/naltrexone on hippocampal a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) trafficking, a molecular substrate of learning and memory, as a probable mechanism for the antagonists activity.
METHODS:
To measure naloxone/naltrexone-regulated AMPAR trafficking, pHluorin-glutamate A1 (GluA1) imaging and biochemical analyses were performed on primary hippocampal neurons. To establish the in vivo role of GluA1-Serine 845 (S845) phosphorylation on the behavioral effect induced by inhibition of the endogenous µ-opioid receptor (MOR) by naltrexone, MOR knockout, and GluA1-S845A mutant (in which Ser845 was mutated to Ala) mice were tested in a water maze after chronic naltrexone administration. Behavioral responses and GluA1 levels in the hippocampal postsynaptic density in wild-type and GluA1-S845A mutant mice were compared using Western blot analysis.
RESULTS:
In vitro prolonged naloxone/naltrexone exposure significantly increased synaptic and extrasynaptic GluA1 membrane expression as well as GluA1-S845 phosphorylation. In the MOR knockout and GluA1-S845A mutant mice, naltrexone did not improve learning, which suggests that naltrexone acts via inhibition of endogenous MOR action and alteration of GluA1 phosphorylation. Naltrexone-treated wild-type mice had significantly increased phosphorylated GluA1-S845 and GluA1 levels in their hippocampal postsynaptic density on the third day of acquisition, which is the time when naltrexone significantly improved learning.
CONCLUSIONS:
The beneficial effect of naltrexone on spatial learning and memory under normal conditions appears to be the result of increasing GluA1-S845 phosphorylation-dependent AMPAR trafficking. These results can be further explored in a mouse model of memory loss.
Published by Elsevier Inc.
KEYWORDS:
AMPA receptors; GluA1; GluA1-S845; GluA1-S845A mutant; Naltrexone; Spatial memory
<<<
Recent RSPI News
- Form 8-K - Current report • Edgar (US Regulatory) • 02/02/2024 01:30:27 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 01/22/2024 01:45:38 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 12/11/2023 01:45:18 PM
- Form 10-Q - Quarterly report [Sections 13 or 15(d)] • Edgar (US Regulatory) • 11/17/2023 09:06:03 PM
- Form NT 10-Q - Notification of inability to timely file Form 10-Q or 10-QSB • Edgar (US Regulatory) • 11/14/2023 09:05:14 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 10/12/2023 01:00:21 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 10/02/2023 12:45:26 PM
- Form 10-Q - Quarterly report [Sections 13 or 15(d)] • Edgar (US Regulatory) • 08/21/2023 08:05:55 PM
- Form NT 10-Q - Notification of inability to timely file Form 10-Q or 10-QSB • Edgar (US Regulatory) • 08/14/2023 08:15:24 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 08/09/2023 12:52:24 PM
Bantec Reports an Over 50 Percent Increase in Sales and Profits in Q1 2024 from Q1 2023 • BANT • Apr 25, 2024 10:00 AM
Cannabix's Breath Logix Alcohol Device Delivers Positive Impact to Private Monitoring Agency in Montana, USA • BLO • Apr 25, 2024 8:52 AM
Kona Gold Beverages, Inc. Announces Name Change to NuVibe, Inc. and Initiation of Ticker Symbol Application Process • KGKG • Apr 25, 2024 8:30 AM
Axis Technologies Group and Carbonis Forge Ahead with New Digital Carbon Credit Technology • AXTG • Apr 24, 2024 3:00 AM
North Bay Resources Announces Successful Equipment Test at Bishop Gold Mill, Inyo County, California • NBRI • Apr 23, 2024 9:41 AM
Epazz, Inc.: CryObo, Inc. solar Bitcoin operations will issue tokens • EPAZ • Apr 23, 2024 9:20 AM