Amyloid-b1-42 treatment does not have a specific effect on cholinergic neurons in in vitro basal forebrain neuronal cultures of rat

The neurotoxic effect of amyloid-beta peptide (1-42) was investigated in cultures of neuronal tissue derived from the basal forebrain of embryonic rat. The axonal varicosities of the cholinergic cells were revealed by vesicular acetylcholine transporter staining, and the axonal varicosities in general by synaptophysin immunohistochemistry. The results demonstrate that the treatment of in vitro neuronal cultures with 20 mM amyloid-beta peptide (1-42) for 2 days on day 5, 12 or 15 exerted a neurotoxic effect on both the cholinergic and the non-cholinergic neurons. In the same cultures, the absolute number of synaptophysin-positive axon varicosities was reduced to greater extent (control: 203 ± 37/field vs treated: 101 ± 16/field) than the number of vesicular acetylcholine transporter-immunoreactive (control: 48 ± 4/field vs treated: 0/field) structures. It is concluded that amyloid-beta peptide (1-42) does not have a specific effect only on the cholinergic neurons, but affects non-cholinergic neurons as well

A modification of Pr equation for Measurement of Tablet’s Compactibility

One of several different ways to quantify the compactibility of pharmaceutical powders is the calculation of Pr [1], [...

Expression and distribution of carboxypeptidase B in the hippocampal subregions of normal and Alzheimer's disease brain

Earlier neurochemical studies suggested that human brain carboxypeptidase B may play a significant role in the degradation of amyloid-β1-42 in the brain. Using an immunohistochemical technique we report here on the neuronal expression and distribution of this enzyme in the segments (CA1a, CA1b and CA1c) of the CA1 subfield and in area CA4 of the hippocampus in normal and Alzheimer's disease brain samples. Its distribution was compared with the appearance of neurofibrillary tangles in the same brain sample. For immunohistochemical localization of carboxypeptidase B, a specific C14-module antibody was applied, together with the Gallyas silver impregnation technique for the demonstration of neurofibrillary tangles. The results revealed that, in the control samples, most of the immunoreactivity appeared in segment CA1a in the pyramidal cells, less in segment CA1b and least in segment CA1c. In the Alzheimer's disease samples, there was no particular immunostaining in the neurons, but, a large number of silver-impregnated degenerated neurons appeared. The results support the suggestion that carboxypeptidase B may play a significant role in elimination of the intracellular accumulation and toxicity of amyloid-β in the human brain and thereby protect the neurons from degeneration