Ethanol Produces Corticotropin‐Releasing Factor Receptor‐Dependent Enhancement of Spontaneous Glutamatergic Transmission in the Mouse Central Amygdala. (7th October 2015)

• Record Type: Journal Article
• Authors: Silberman, Yuval; Fetterly, Tracy L.; Awad, Elias K.; Milano, Elana J.; Usdin, Ted B.; Winder, Danny G.
• Is Part Of: Alcoholism. Volume 39:Number 11(2015:Nov.)
• Page Start: 2154
• Page End: 2162
• Publication Date: 2015-10-07
• Subjects: Central Nucleus of the Amygdala -- CRF Reporter Mice -- Whole‐Cell Patch‐Clamp Electrophysiology -- Diphtheria Toxin -- Selective Deletion; Alcoholism -- Periodicals; Alcoholism -- Periodicals; Alcoolisme; Electronic journals; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.861005
• DOI: 10.1111/acer.12881
• Languages: English
• ISSNs: 0145-6008

Abstract

Abstract : Background: Ethanol (EtOH) modulation of central amygdala (CeA) neurocircuitry plays a key role in the development of alcoholism via activation of the corticotropin‐releasing factor (CRF) receptor (CRFR) system. Previous work has predominantly focused on EtOH × CRF interactions on the CeA GABA circuitry; however, our laboratory recently showed that CRF enhances CeA glutamatergic transmission. Therefore, this study sought to determine whether EtOH modulates CeA glutamate transmission via activation of CRF signaling. Methods: The effects of EtOH on spontaneous excitatory postsynaptic currents (sEPSCs) and basal resting membrane potentials were examined via standard electrophysiology methods in adult male C57BL/6J mice. Local ablation of CeA CRF neurons (CRF CeAhDTR ) was achieved by targeting the human diphtheria toxin receptor (hDTR) to CeA CRF neurons with an adeno‐associated virus. Ablation was quantified post hoc with confocal microscopy. Genetic targeting of the diphtheria toxin active subunit to CRF neurons (CRF DTA mice) ablated CRF neurons throughout the central nervous system, as assessed by quantitative reverse transcriptase polymerase chain reaction quantification of CRF mRNA. Results: Acute bath application of EtOH significantly increased sEPSC frequency in a concentration‐dependent manner in CeA neurons, and this effect was blocked by pretreatment of co‐applied CRFR1 and CRFR2 antagonists. In experiments utilizing a CRF‐ tomato reporter mouse, EtOH did not significantly alter the basal membrane potential of CeA CRF neurons. The ability of EtOH to enhance CeA sEPSC frequency was not altered in CRF CeAhDTR mice despite a ~78% reduction in CeA CRF cell counts. The ability of EtOH to enhance CeA sEPSC frequency was also not altered in the CRF DTA mice despite a 3‐fold reduction in CRF mRNA levels. Conclusions: These findings demonstrate that EtOH enhances spontaneous glutamatergic transmission in the CeA via a CRFR‐dependent mechanism. Surprisingly, our data suggest that this action may not require endogenous CRF.