マウスにおける外側視床下丘ヒスタミン作動性シグナル伝達を介したピト​​リサントによるアルコール摂取の抑制と離脱症状の陰性感情の改善

Alcohol use disorder (AUD) is a chronic condition marked by compulsive drinking and withdrawal-related negative affect. Histamine (HA) signaling, particularly via the histamine H3 receptor (H3R), may modulate alcohol-related behaviors. We investigated the effects of pitolisant, an FDA-approved H3R antagonist, on ethanol (EtOH)-related behaviors in mice.

Adult male C57BL/6J mice underwent acute or chronic (2 or > 8 weeks) intermittent alcohol exposure. Pitolisant pretreatment was administered, and then pharmacological behavior, histologic, and molecular assays were conducted.

Pitolisant administration reduced acute EtOH-induced locomotor activation, conditioned place preference, and sedative effects, and also curtailed EtOH intake. It alleviated anxiety and depression-like behavior during 24-h withdrawal (Post-EtOH). Mechanistically, the Post-EtOH condition was featured by complicated brain cFos expression mapping, including elevated cFos, [HA] and [glutamine]/[glutamate] ratio in the lateral habenula (LHb). However, systemic pitolisant treatment significantly increased [norepinephrine]/[normetanephrine] ratio, and restored the diminished phosphorylated CREB and BDNF levels in the LHb. Intra-LHb H2R antagonist cimetidine infusion partly blocked the pitolisant therapeutic effect on alcohol-related behavior.

These findings highlight the HAergic system as a critical regulator of alcohol-related behaviors. The LHb HA signaling and norepinephrine neurotransmission might underlie pitolisant's potential novel therapeutic strategy for AUD.