Human cerebrospinal fluid increases the excitability of pyramidal neurons in the in vitro brain slice.

The cerebrospinal fluid contains numerous neuromodulators at ambient levels but whether, and how, they affect the activity of central neurons is unknown. This study provides experimental evidence that human cerebrospinal fluid (hCSF) increases the excitability of hippocampal and neocortical pyramidal neurons. Hippocampal CA1 pyramidal neurons in hCSF displayed lowered firing thresholds, depolarized resting membrane potentials and reduced input resistance, mimicking properties of pyramidal neurons recorded in vivo.

Altered cognitive performance and synaptic function in the hippocampus of mice lacking C3.

Previous work implicated the complement system in adult neurogenesis as well as elimination of synapses in the developing and injured CNS. In the present study, we used mice lacking the third complement component (C3) to elucidate the role the complement system plays in hippocampus-dependent learning and synaptic function. We found that the constitutive absence of C3 is associated with enhanced place and reversal learning in adult mice.

Complement gene single nucleotide polymorphisms and biomarker endophenotypes of Alzheimer's disease.

The complement system has been implicated in both physiological synapse elimination and Alzheimer's disease (AD). Here, we investigated associations between four single nucleotide polymorphisms (SNPs) in complement genes and cerebrospinal fluid (CSF) biomarkers for AD in 452 neurochemically or neuropathologically verified AD cases and 678 cognitively normal controls. None of the SNPs associated with risk of AD but there were potential associations of rs9332739 in the C2 gene and rs4151667 in the complement factor B gene with CSF tau levels (p = 0.

Cerebrospinal fluid levels of complement proteins C3, C4 and CR1 in Alzheimer's disease.

Alzheimer's disease (AD) is strongly associated with loss of synapses. The complement system has been shown to be involved in synaptic elimination. Several studies point to an association between AD and the complement system.

Association of the RAGE G82S polymorphism with Alzheimer's disease.

The receptor for advanced glycation end-products (RAGE) has been implicated in several pathophysiological processes relevant to Alzheimer's disease (AD), including transport and synaptotoxicity of AD-associated amyloid beta (Abeta) peptides. A recent Chinese study (Li et al. in J Neural Transm 117:97-104, 2010) suggested an association between the 82S allele of the functional single nucleotide polymorphism (SNP) G82S (rs2070600) in the RAGE-encoding gene AGER and risk of AD.

Distinct cerebrospinal fluid amyloid beta peptide signatures in sporadic and PSEN1 A431E-associated familial Alzheimer's disease.

Background: Alzheimer's disease (AD) is associated with deposition of amyloid beta (Abeta) in the brain, which is reflected by low concentration of the Abeta1-42 peptide in the cerebrospinal fluid (CSF). There are at least 15 additional Abeta peptides in human CSF and their relative abundance pattern is thought to reflect the production and degradation of Abeta. Here, we test the hypothesis that AD is characterized by a specific CSF Abeta isoform pattern that is distinct when comparing sporadic AD (SAD) and familial AD (FAD) due to different mechanisms underlying brain amyloid pathology in the two disease groups.

Synaptic retrogenesis and amyloid-beta in Alzheimer's disease.

Pathological hallmarks of Alzheimer's disease (AD) include synaptic and neuronal degeneration and the presence of extracellular deposits of amyloid-beta (Abeta) in senile plaques in the cerebral cortex. Although these brain lesions may be seen also in aged non-demented individuals, the increase in brain Abeta is believed by many to represent the earliest event in the disease process. Accumulating evidence suggests that Abeta, which is highly conserved by evolution, may have an important physiological role in synapse elimination during brain development.