Patent ID: 8652438

Claim:
A method of labeling a central nervous system of a living body by dyeing from an olfactory epithelium by way of an olfactory bulb, the method comprising intranasally administering a central nervous system labeling composition comprising a compound of formula (1): where R 1 represents an alkyl group; each of R 3 through R 6 independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a carboxylic acid group, a sulfonic acid group, a heterocyclic group, an amino group, or a halogen atom, of which R 5 and R 6 may be bonded to each other to form a ring; X 1 − represents an anionic group; and A represents a formula (4): where Y represents an alkyl group; and * represents a binding site.