Effect of gymnemic acid on single taste hairs of the housefly, Musca domestica.
The effect of a gymnemate salt extract (KGE) on the behavioral and neurophysiological taste responses of Musca domestica to sugar and salt were studied. After exposure of single taste hairs to KGE, the behavioral positive response to a just-suprathreshold sugar stimulus was abolished,  and the neuronal firing pattern was modified in a form that ranged from a waxing and waning of impulse frequently to an abolishment of impulses. The neurophysiological response to a salt stimulus was similarly modified, although the waxing and waning of spike frequency was more rapid and firing returned to a near-control pattern sooner. Neurophysiological studies were replicated with two other fly genera. The results uniformly suggest a narcotic effect on the dendrites of taste neurons.
D000818:Animals; D005947:Glucose; D006793:Houseflies / Q000502:physiology*; D012503:Saponins / Q000494:pharmacology*; D011984:Sensory Receptor Cells / Q000187:drug effects / Q000502:physiology; D012965:Sodium Chloride; D013649:Taste / Q000187:drug effects* / Q000502:physiology; D014315:Triterpenes / Q000494:pharmacology*
D012503:Saponins; D014315:Triterpenes; D012965:Sodium Chloride; D005947:Glucose