An improved thioflavine S method for staining neurofibrillary tangles and senile plaques in Alzheimer's disease.

Large differences are usually observed when standard staining methods for a number of pathological lesions in neurodegenerative disorders are compared. With the modified thioflavine S method presented here (easy and cheap to perform), the morphological appearance of the stained neurofibrillary tangles (NFT) and senile plaques (SP) is greatly improved. Furthermore, the intense contrast between stained lesions and background obtained with this technique permits an accurate automatic quantification of NFT and SP using a computer-assisted image analysis system.

A comparative study of histological and immunohistochemical methods for neurofibrillary tangles and senile plaques in Alzheimer's disease.

Several studies have demonstrated that the accurate visualization and quantification of pathological lesions in neurodegenerative disorders depend on the reliability of staining methods. In an attempt to gain a better assessment of the density and distribution of the neuropathological markers of Alzheimer's disease, we compared the staining efficiency of a modified thioflavine S protocol for neurofibrillary tangles (NFT) and senile plaques (SP) to different argentic impregnation techniques (Bielchowsky, Gallyas, Globus, Campbell-Switzer-Martin) and to immunohistochemical stainings obtained with two different antibodies against the amyloid beta protein A4 and the microtubule-associated tau protein. The modified thioflavine S technique (MTST) detects up to 60% more SP and up to 50% more NFT than the Bielschowsky and Globus methods, respectively.

Tyrosine hydroxylase-immunoreactive neurons in paraventricular and supraoptic nuclei of the human brain demonstrated by a method adapted to prolonged formalin fixation.

We studied the distribution of tyrosine hydroxylase (TH) immunoreactive (IR) neurons in the adult human hypothalamus using a modification of the peroxidase-antiperoxidase immunohistochemical method which can be applied on autopsy brain material following prolonged formalin fixation. We observed that most of the TH-IR perikarya localized within the paraventricular (PVN) and supraoptic (SON) nuclei were large and showed homogeneous staining over the entire cytoplasm and processes. These results show that in the human brain a large population of neurons within the neurosecretory nuclei are able to synthesize a catecholamine.

Immunohistochemical mapping of delta sleep-inducing peptide in the cat brain and hypophysis. Relationships with the LHRH system and corticotropes.

Using the indirect immunofluorescence method, the distribution of the delta sleep-inducing peptide was studied in the cat brain and hypophysis. Delta sleep-inducing peptide-like-immunoreactive cell bodies mostly visualized in colchicine-pretreated animals were mainly found scattered throughout the diagonal band of Broca, the ventral septum and the anterior hypothalamic areas. A few immunoreactive cell somata were also seen in the ventrolateral hypothalamic area and more occasionally in the triangular septal nucleus.

An improved immunohistostaining procedure for peptides in human brain.

Floating sections from human brains immersed for more than forty years in formalin, or from brains freshly fixed for a short time are treated by KMnO4-Pal's modified solutions to suppress the endogenous peroxidase activity before using the peroxidase-antiperoxidase method (PAP), or to remove the autofluorescence of lipofuscin, which is very intense in brains from old patients, before using the immunofluorescence method. Following this, immersion of sections in NaOH and H2O2 allows for the demasking of antigenic sites. These treatments enhance the immunolabelling considerably, with results comparable to those obtained with freshly fixed tissues, and facilitate the discrimination between specifically and unspecifically stained structures.