Koce A, Valentincic T
Department of Biology, University of Ljubljana, Slovenia.
Pflugers Arch. 2000;439(3 Suppl):R171-2.
We recorded simultaneously the electrophysiological responses of the olfactory organ [the electroolfactogram (EOG)] and action potential activity of single olfactory receptor neurons (ORNs) to amino acid stimuli in the brown bullhead catfish, Ameiurus nebulosus. To determine whether the amplitude of the EOG depends upon the number of responding ORNs, we tested two highly stimulatory (based on EOG recordings) amino acids [L-norvaline (L-nVal) and L-cysteine (L-Cys)], two amino acids of intermediate potency [L-arginine (L-Arg) and L-isoleucine (L-Ile)], and a poorly stimulatory amino acid [L-proline (L-Pro)]. Forty-nine percent of the spontaneously active, single ORNs tested (n=142) were either suppressed or excited by amino acid stimuli. Of the ORNs tested with specific amino acids, 61% responded to 1 mM L-nVal (n=49), 57% responded to 1 mM L-Cys (n=30), 45% responded to L-Arg (n=31) and 36% responded to L-Ile (n=22) with either suppression or excitation. Only one ORN responded with suppression to 10(-2) M L-Pro (n=10). These data suggest that the amplitude of the EOG in the brown bullhead catfish is correlated with the number of responsive ORNs (Spearman corr. coef. = 0.9; P<0.05).
我们同时记录了褐首鲶（Ameiurus nebulosus）嗅觉器官的电生理反应[嗅觉电图（EOG）]以及单个嗅觉受体神经元（ORN）对氨基酸刺激的动作电位活动。为了确定EOG的幅度是否取决于响应ORN的数量，我们测试了两种高刺激性（基于EOG记录）的氨基酸[L-正缬氨酸（L-nVal）和L-半胱氨酸（L-Cys）]、两种中等效力的氨基酸[L-精氨酸（L-Arg）和L-异亮氨酸（L-Ile）]以及一种低刺激性氨基酸[L-脯氨酸（L-Pro）]。在测试的142个自发活动的单个ORN中，49%受到氨基酸刺激的抑制或兴奋。在用特定氨基酸测试的ORN中，61%对1 mM L-nVal有反应（n = 49），57%对1 mM L-Cys有反应（n = 30），45%对L-Arg有反应（n = 31），36%对L-Ile有反应（n = 22），表现为抑制或兴奋。只有一个ORN对10^(-2) M L-Pro有抑制反应（n = 10）。这些数据表明，褐首鲶中EOG的幅度与响应ORN的数量相关（斯皮尔曼相关系数 = 0.9；P < 0.05）。
