Fig. 8. Responses of single facial taste fibers. (A) A single fiber responding only to the bile salt (BS) mixture (10^–5 mol l^–1 TCDC, TCA, GCDC and CDC); (B) a single fiber responding only to the amino acid (AA) mixture (10^–6 mol l^–1 Ala, Arg and Pro); (C) a single fiber responding to both stimulus mixtures. A and B were recorded simultaneously from different fibers in the same preparation, whereas unit no. 3 was recorded from a different animal. Clusters of individual spike trains are shown in insets I and II to indicate that the action potentials recorded in A–C were evoked by single fibers. Ct, CFTW. Horizontal bars indicate 2 s stimulus applications.