ABT-239 is a novel, highly efficacious antagonist belonging to the non-imidazole class of histamine H3 receptor (H3R) antagonists. It also acts as a transient receptor potential vanilloid type 1 (TRPV1) antagonist.

Perfusing the tuberomammillary nucleus (TMN) with ABT-239 selectively activates c-Fos in the nucleus basalis of Meynert (NBM) and cortex. Moreover, when the TMN is perfused with ABT-239 at a concentration of 10 μM, there is an increase in histamine release from the TMN, NBM, and cortex; however, this effect is not observed in either the striatum or the nucleus accumbens (NAcc).

ABT-239, administered intraperitoneally (i.p.) at a dosage of 3 mg/kg, markedly delays seizure onset, diminishes behavioral seizures triggered by KA, and lowers the occurrence of head bobbing and forelimb clonus in mice. Additionally, at this dosage, ABT-239 enhances memory by converting a short-term learning event into a long-lasting memory in wild type (WT) mice, albeit not in those lacking histamine. The compound is also found to significantly reduce all stages of neuronal damage. In conjunction, ABT-239 and TDZD-8 (10 mg/kg, i.p.) notably decrease the quantity of pyknotic neurons in the hippocampi of mice. When ABT-239 (1 mg/kg, i.p.) is combined with a sub-therapeutic dose of SVP (150 mg/kg, i.p.), there is a marked decrease in behaviors associated with distress such as immobility, head bobbing, and forelimb clonus. A higher dose combination of ABT-239 and TDZD-8 exhibits the most significant enhancement of Bcl-2 expression and reduction in Bax levels, indicating improved neuronal survival. Additionally, combined administration of ABT-239 (at doses of 1 and 3 mg/kg, i.p.) with nicotine enhances nicotine's beneficial effects on memory acquisition and consolidation, with further improvements observed at lower concentrations of ABT-239 (0.1 mg/kg, i.p.) and nicotine.