Ethanol effects on excitability of corticotropin-releasing factor-expressing neurons in the medial subdivision of the mouse central amygdala nucleus.

BACKGROUND

Corticotropin-releasing factor (CRF) neurons in the medial subdivision of the central amygdala (CeM) are a distinct subpopulation of neurons in a critical brain region modulating ethanol actions. Previous studies have demonstrated enhanced release of GABA and neuropeptides in this brain region in response to acute ethanol exposure.

METHODS

We performed whole-cell patch clamp recordings on identified CRF-containing neurons (CeMCRF) in the CeM and measured intrinsic measures of excitability in response to acute ethanol exposure.

RESULTS

We found that CeMCRF neurons are highly sensitive to actions of acute ethanol exposure, which suppresses neuronal excitability in a dose-dependent manner and shortens spike duration of the CeMCRF neurons during repetitive firing. Ethanol's inhibitory effect on neuronal excitability persists even in synaptically isolated CeMCRF neurons, an indication of a direct action on the intrinsic membrane properties that underlie excitability.

CONCLUSIONS

Our results reveal that ethanol selectively alters intrinsic firing mechanisms of CeMCRF neurons at low dose but broadly suppresses excitability at a higher dose. These findings provide new insight into how alcohol modulates intrinsic membrane properties of these CeMCRF neurons within stress-related amygdala circuits.