Stress-induced modulation of endocannabinoid signaling leads to delayed strengthening of synaptic connectivity in the amygdala. Proc Natl Acad Sci U S A 2020 Jan 07;117(1):650-655
Date
12/18/2019Pubmed ID
31843894Pubmed Central ID
PMC6955336DOI
10.1073/pnas.1910322116Scopus ID
2-s2.0-85077654645 (requires institutional sign-in at Scopus site) 43 CitationsAbstract
Even a brief exposure to severe stress strengthens synaptic connectivity days later in the amygdala, a brain area implicated in the affective symptoms of stress-related psychiatric disorders. However, little is known about the synaptic signaling mechanisms during stress that eventually culminate in its delayed impact on the amygdala. Hence, we investigated early stress-induced changes in amygdalar synaptic signaling in order to prevent its delayed effects. Whole-cell recordings in basolateral amygdala (BLA) slices from rats revealed higher frequency of miniature excitatory postsynaptic currents (mEPSCs) immediately after 2-h immobilization stress. This was replicated by inhibition of cannabinoid receptors (CB1R), suggesting a role for endocannabinoid (eCB) signaling. Stress also reduced N-arachidonoylethanolamine (AEA), an endogenous ligand of CB1R. Since stress-induced activation of fatty acid amide hydrolase (FAAH) reduces AEA, we confirmed that oral administration of an FAAH inhibitor during stress prevents the increase in synaptic excitation in the BLA soon after stress. Although stress also caused an immediate reduction in synaptic inhibition, this was not prevented by FAAH inhibition. Strikingly, FAAH inhibition during the traumatic stressor was also effective 10 d later on the delayed manifestation of synaptic strengthening in BLA neurons, preventing both enhanced mEPSC frequency and increased dendritic spine-density. Thus, oral administration of an FAAH inhibitor during a brief stress prevents the early synaptic changes that eventually build up to hyperexcitability in the amygdala. This framework is of therapeutic relevance because of growing interest in targeting eCB signaling to prevent the gradual development of emotional symptoms and underlying amygdalar dysfunction triggered by traumatic stress.
Author List
Yasmin F, Colangeli R, Morena M, Filipski S, van der Stelt M, Pittman QJ, Hillard CJ, Teskey GC, McEwen BS, Hill MN, Chattarji SAuthor
Cecilia J. Hillard PhD Associate Dean, Center Director, Professor in the Pharmacology and Toxicology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Administration, OralAmidohydrolases
Animals
Arachidonic Acids
Basolateral Nuclear Complex
Cannabinoid Receptor Antagonists
Disease Models, Animal
Emotions
Endocannabinoids
Enzyme Inhibitors
Excitatory Postsynaptic Potentials
Humans
Male
Polyunsaturated Alkamides
Rats
Receptor, Cannabinoid, CB1
Signal Transduction
Stress, Psychological
