Image analysis of catecholamine fluorescence.

Image analysis methods are being developed for measuring the density and distribution of perivascular noradrenergic nerves and their varicosities, demonstrated by fluorescence histochemistry. Image analysis is recommended in comparison with other methods for the quantitation of fluorescence, because image resolution is greater and larger areas of tissues can be scanned and measured more rapidly. Applications of image analysis have provided new and valuable information regarding sympathetic nerves: for example, we have shown rapid growth of perivascular nerves during perinatal development in the rabbit, and loss of nerves in different vessels in postnatal life and in old age; regional variations of nerve density and varicosity numbers in the central ear artery of the rabbit have also been demonstrated.