The histochemical study of the catecholamine Part I. Glyoxylic acid-formaldehyde methods with chloral-hydrate

The formaldehyde-induced fluorescence technique (Falck et al'62) allows for the microscopic visualization of intraneural monoamines. The recently introduced glyoxylic acid techique (Lindvall and Bjorklund'74) appears to offer a most advantageous approach to monoamine tract tracing. The technique allows the important finding that a marked degree of mixing of the various adrenergic components occurs in the central tract in the rat brain. However, the technique in its present form is difficult to apply to large mammals. Because, the catecholamine diffuse in the neural tissue during perfusion. In this report, the author shows that it is able to prevent this defect by adding chloralhydrate to the glyoxylic acid-formaldehyde solution. In this modified method, the fluorescence of catecholamine is enhanced and is easily classified in its color. For this reason, chloralhydrate-glyoxylic acid-formaldehyde method can apply to large mammals.