Transecting the gustatory branches of the facial nerve impairs NH(4)Cl vs. KCl discrimination in rats.
Ammonium and potassium chloride share a common taste quality and an amiloride-insensitive route of transduction. An amiloride-sensitive pathway might also be partially activated by these salts, although very few studies have reported effects of amiloride on nonsodium salt perception. This experiment was designed to determine 1) whether rats could discriminate KCl from NH(4)Cl and, if discrimination was evident, whether performance was impaired with 2) amiloride or 3) gustatory nerve transection. Rats were trained to discriminate KCl from NH(4)Cl (n = 8) and NaCl from NH(4)Cl (n = 8). Amiloride (100 microM) impaired NaCl vs. NH(4)Cl but not KCl vs. NH(4)Cl performance, whereas both groups showed significant impairments after transection of the chorda tympani (CT) and greater superficial petrosal (GSP) branches of the facial nerve. This suggests that rats can discriminate between KCl and NH(4)Cl and that this discrimination does not rely on an amiloride-sensitive mechanism but does depend on the CT and/or GSP nerves. This experiment supports the hypothesis that the facial nerve is important for salt taste recognition and discrimination.
Department of Psychology and Center for Smell and Taste, University of Florida, Gainesville, Florida 32611-2250, USA.
Laura C
LC
Geran
Mircea
M
Garcea
Alan C
AC
Spector
D000584:Amiloride / Q000494:pharmacology; D000643:Ammonium Chloride; D000818:Animals; D002814:Chorda Tympani Nerve / Q000502:physiology* / Q000601:surgery; D003714:Denervation; D004192:Discrimination, Psychological / Q000187:drug effects / Q000502:physiology*; D004232:Diuretics / Q000494:pharmacology; D008297:Male; D011189:Potassium Chloride; D051381:Rats; D017207:Rats, Sprague-Dawley; D013649:Taste / Q000187:drug effects / Q000502:physiology*; D014867:Water
D004232:Diuretics; D000643:Ammonium Chloride; D014867:Water; D011189:Potassium Chloride; D000584:Amiloride