| Autor: |
Ghimire, Madan, Rui Cai, Lynne Ling, Hackett, Troy A., Caspary, Donald M. |
| Předmět: |
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| Zdroj: |
Journal of Neuroscience; 7/22/2020, Vol. 40 Issue 30, p5724-5739, 16p |
| Abstrakt: |
The presence of novel or degraded communication sounds likely results in activation of basal forebrain cholinergic neurons increasing release of ACh onto presynaptic and postsynaptic nAChRs in primary auditory cortex (Al). nAChR subtypes include high-affinity heteromeric nAChRs commonly composed of α4 and (S2 subunits and low-affinity homomeric nAChRs composed of α7 subunits. In young male FBN rats, we detail the following: (1) the distribution/expression of nAChR subunit transcripts in excitatory (VGluTl) and inhibitory (VGAT) neurons across Al layers; (2) heteromeric nAChR binding across Al layers; and (3) nAChR excitability in Al layer (L) 5 cells. In aged rats, we detailed the impact of aging on Al nAChR subunit expression across layers, heteromeric nAChR receptor binding, and nAChR excitability of Al L5 cells. A majority of Al cells coexpressed transcripts for β2 and α4 with or without ot7, while dispersed subpopulations expressed β2 and α7 or a 7 alone. nAChR subunit transcripts were expressed in young excitatory and inhibitory neurons across L2-L6. Transcript abundance varied across layers, and was highest for β2 and α4. Significant age-related decreases in nAChR subunit transcript expression (message) and receptor binding (protein) were observed in L2-6, most pronounced in infragranular layers. Iti vitro patch-clamp recordings from L5B pyramidal output neurons showed age-related nAChR subunit-selective reductions in postsynaptic responses to ACh. Age-related losses of nAChR subunits likely impact ways in which Al neurons respond to ACh release. While the elderly require additional resources to disambiguate degraded speech codes, resources mediated by nAChRs may be compromised with aging. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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