The role of apelin-13 in object recognition memory in 6-hydroxy dopamine-induced substantia nigra lesion in rats

Parkinson’s disease (PD) is the second common neurodegenerative disorder that affects different areas of the brain, especially induced progressive neurodegeneration in the substantia nigra. Although PD is well known with its motor deficits, the patients often suffer from cognitive dysfunction. Apelin, as the endogenous ligand of the APJ receptor, is prominently expressed in brain regions involved in learning and memory. However, the role of apelin in cognition and cognitive disorders has not been fully clarified. Here, the role of apelin-13 in memory processes was investigated on cognitive disorders in rat parkinsonism experimental model. 6-hydroxydopamine (6-OHDA: 8 μg/2.5 μl) was injected into the right substantia nigra. Apelin-13 (1, 2 and 3 μg/rat) was administered into the substantia nigra one week after the 6-OHDA injection. Novel object recognition and object location tasks were performed one month after the apelin injection. 6-OHDA-treated animals showed a significant impairment in cognitive functions. Apelin-13 (3 μg/rat) significantly ameliorates cognitive impairments in 6-OHDA-treated animals which revealed by the increased in the exploration index in novel object recognition and object location tasks. In conclusion, the data support the pro-cognitive property of apelin-13 in 6-OHDA-induced cognitive deficit and will potentially extend the possible therapeutic aspect of apelin for neurodegenerative disorders.

کلیدواژه ها:

Apelin-13 ، Parkinsonism ، 6-OHDA ، Cognitive impairment ، Learning and memory