TLR3 deficiency increases voluntary alcohol consumption.

Toll-like receptors (TLRs) are innate immunity-related receptors. Many studies have indicated the involvement of TLRs in neurophysiology and neuropathology. One study showed that TLR3 regulates hippocampal memory and is highly expressed in the mesolimbic dopamine system, suggesting that TLR3 signaling may regulate alcohol consumption. The present study assessed the potential role of TLR3 in alcohol intake pattern. We used adult BalbC wild-type mice and TLR3 knockout mice and tested two-bottle alcohol preference over 15 days and one-bottle 2 or 4 h drinking in the dark over 4 consecutive days. The 10% alcohol consumption rate of TLR3 knockout mice increased on the 24 h free-choice test. Our findings support a potential regulatory role of TLR3 in alcohol consumption.