Deficits Of Synaptic Functions In Hippocampal Slices Prepared From Aged Mice Null Î±7 Nicotinic Acetylcholine Receptors
Alpha 7 (Î±7) nicotinic acetylcholine receptor (Î±7-nAChR) is one of most high expressed nAChR subtypes in the brain. The activation of nAChRs enhances animal cognitive, learning and memory abilities. However, the role of genetic knockout (KO) of Î±7-nAChRs in animal cognition-associated behaviors is still obscure. An early report showed that Î±7-nAChR KO mice did not exhibit behavioral phenotypes, concerning the roles of Î±7-nAChRs in normal, cognition-associated behaviors. Later, Î±7-nAChR KO mice were found a deficit in animal spatial discrimination. The roles of Î±7-nAChRs in the alterations of hippocampal synaptic function during aging process are largely unknown. Here, we address this question by examining synaptic function using field potential recording in hippocampal slice preparations from adult (12-14 months old) and aged (22-24 months old) Î±7-nAChR KO and age-matched wild-type (WT) mice. We found that compared to aged WT mice, aged Î±7-nAChR KO mice exhibited significantly reduced size of evoked field synaptic potential and impaired long-term potentiation (LTP) in hippocampal CA3-CA1 synapses. However, adult Î±7-nAChR KO mice did not show a clear deficit in LTP although the basic synaptic transmission was also reduced compared to adult WT mice. In both age groups, there was no significant difference of paired-pulse facilitation between Î±7-nAChR KO and WT mice. Collectively, this study provides direct evidence, for the first time, that the impaired synaptic function occurs in aged Î±7-nAChR KO mice, suggesting an importance of Î±7-nAChRs in maintaining cognitive function during aging process. Â© 2014 Elsevier Ireland Ltd.
Digital Object Identifier (DOI)
Ma, Luyao; Turner, Dharshaun; Zhang, Junfang; Wang, Qingwen; Wang, Michele; Shen, Jianxing; Zhang, Shijiang; and Wu, Jie, "Deficits Of Synaptic Functions In Hippocampal Slices Prepared From Aged Mice Null Î±7 Nicotinic Acetylcholine Receptors" (2014). Neurobiology. 415.