We have recently found that nicotine (Nic) enhances object recognition memory (ORM) in the novel object recognition test (NOR) via stimulation of α4β2 and α7 nicotinic acetylcholine receptors (nAChRs) in the medial prefrontal cortex (mPFC) of mice. Additionally, in vitro electrophysiological analyses revealed that Nic increases firing activity of mPFC layer V pyramidal neurons, which was occluded by 4-aminopyridine (4-AP), a non-selective voltage-dependent potassium (Kv) channel inhibitor, or XE-991, a selective Kv7 channel inhibitor. According to these findings, we hypothesized that Nic increases mPFC neuronal activity by suppressing Kv channels, resulting in the enhancement of ORM. To test this hypothesis, we first observed that c-Fos expression is increased in the mPFC after systemic Nic administration and that suppression of mPFC neuronal activity with inhibitory DREADD significantly inhibits the Nic-induced ORM enhancement, indicating the importance of mPFC neuronal activity in ORM enhancement. Moreover, we found that intra-mPFC injection of 4-AP or XE-991, as well as Nic, enhances ORM. Since one of the targets of 4-AP is Kv4.3 channels, we tested the effects of NS5806, a Kv4.3 channel activator, on Nic-induced ORM enhancement and found that intra-mPFC injection of NS5806 suppressed the Nic-induced ORM enhancement. Similarly, a Kv7 channel activator retigabine also attenuated Nic-induced ORM enhancement. These data suggest that Nic enhances ORM via activation of mPFC neurons through the suppression of Kv4.3 and Kv7 channels.