The α7-nicotinic acetylcholine receptor (α7-nAChR) is a recognized target for the treatment of dementia associated with aging and certain developmental disorders. This study evaluates memory improvement in a rat model by the effects of polyunsaturated fatty acids EPA and DHA mediated by α7-nAChR, as well as identifying the minimum dose of EPA/DHA required to generate an effect in the improvement of cognition through α7-nAChR in rats. The modified Y-maze and object recognition behavioral tests were performed in scopolamine-induced amnesic rats, in order to study the effects of long-term supplementation (10, 15, 30, and 60 mg/kg) of the two polyunsaturated fatty acids in improving cognitive impairment. Cognitive enhancement by EPA and DHA is mediated through α7-nAChRs, as evidenced by memory recovery after treatment with a selective α7-nAChR antagonist, methyllycaconitine (MLA). Tacrine, a centrally active acetylcholinesterase inhibitor, and PNU282987, an α7-nAChR agonist, are employed as reference standards. Our data demonstrate that 15 mg/kg EPA and DHA can affect cholinergic neurotransmission positively through memory and cognition and, thus, can exert a beneficial action on learning and memory deficits.
Keywords: behavioral memory loss; cognitive improvement; methyllycaconitine; modified Y-maze; neuroprotection; object recognition test (ORT); omega-3; α7-nAChRs.