当前位置： SCI文献检索 > BEHAVIOURAL BRAIN RESEARCH期刊下所有文献 > Interactions between Aβ oligomers and presynaptic cholinergic signaling: age-dependent effects on attentional capacities.

Interactions between Aβ oligomers and presynaptic cholinergic signaling: age-dependent effects on attentional capacities.

Abstract：

:Substantial evidence suggests that cerebral deposition of the neurotoxic fibrillar form of amyloid precursor protein, β-amyloid (Aβ), plays a critical role in the pathogenesis of Alzheimer's disease (AD). Yet, many aspects of AD pathology including the cognitive symptoms and selective vulnerability of cortically projecting basal forebrain (BF) cholinergic neurons are not well explained by this hypothesis. Specifically, it is not clear why cognitive decline appears early when the loss of BF cholinergic neurons and plaque deposition are manifested late in AD. Soluble oligomeric forms of Aβ are proposed to appear early in the pathology and to be better predictors of synaptic loss and cognitive deficits. The present study was designed to examine the impact of Aβ oligomers on attentional functions and presynaptic cholinergic transmission in young and aged rats. Chronic intracranial infusions of Aβ oligomers produced subtle decrements in the ability of rats to sustain attentional performance with time on task, irrespective of the age of the animals. However, Aβ oligomers produced robust detrimental effects on performance under conditions of enhanced attentional load in aged animals. In vivo electrochemical recordings show reduced depolarization-evoked cholinergic signals in Aβ-infused aged rats. Moreover, soluble Aβ disrupted the capacity of cholinergic synapses to clear exogenous choline from the extracellular space in both young and aged rats, reflecting impairments in the choline transport process that is critical for acetylcholine (ACh) synthesis and release. Although aging per se reduced the cross-sectional area of BF cholinergic neurons and presynaptic cholinergic proteins in the cortex, attentional performance and ACh release remained unaffected in aged rats infused with the control peptide. Taken together, these data suggest that soluble Aβ may marginally influence attentional functions at young ages primarily by interfering with the choline uptake processes. However, age-related weakening of the cholinergic system may synergistically interact with these disruptive presynaptic mechanisms to make this neurotransmitter system vulnerable to the toxic effects of oligomeric Aβ in robustly impeding attentional capacities.

journal_name

Behav Brain Res

journal_title

Behavioural brain research

authors

Parikh V,Bernard CS,Naughton SX,Yegla B

doi

10.1016/j.bbr.2014.07.046

subject

Has Abstract

pub_date

2014-11-01 00:00:00

pages

30-42

eissn

0166-4328

issn

1872-7549

pii

S0166-4328(14)00495-1

journal_volume

274

pub_type

杂志文章

在线工具

Interactions between Aβ oligomers and presynaptic cholinergic signaling: age-dependent effects on attentional capacities.