Minear M M, Hammack S E, Lundy R F, Contreras R J
Florida State University, Department of Psychology, Tallahassee 32306-1051, USA.
Physiol Behav. 1996 Aug;60(2):507-16. doi: 10.1016/s0031-9384(96)80026-6.
In a two-bottle test, Sprague-Dawley rats preferentially consume a greater amount of hypotonic and isotonic NaCl solutions relative to water, whereas inbred Fischer 344 (F344) rats fail to prefer NaCl solutions at any concentration relative to water. To determine whether taste contributes to this strain difference, we measured the integrated neural responses of the chorda tympani nerve to a concentration range of NaCl and KCl solutions. The amiloride-sensitive component of the taste nerve response was assessed by adding amiloride during salt stimulation in Experiment 1, and by pretreating the taste receptors with amiloride prior to salt stimulation in Experiment 2. Adding amiloride to NaCl during sustained neural activity suppressed chorda tympani nerve responses more than pretreating the tongue with amiloride. Adding amiloride during salt stimulation also partially suppressed chorda tympani neuron responses to KCl, a presumed control stimulus. The neural responses of the chorda tympani nerve to NaCl and KCl were similar for salt-avoiding F344 and salt-preferring Sprague-Dawley rats. However, amiloride pretreatment suppressed the taste nerve responses to NaCl significantly less in F344 rats than in Sprague-Dawley rats. The strain difference in the amiloride-sensitive component of the taste response may contribute to the difference in NaCl preference.
在双瓶测试中，与水相比，斯普拉格-道利大鼠优先消耗更多的低渗和等渗氯化钠溶液，而近交系费希尔344（F344）大鼠相对于水而言，在任何浓度下都不偏好氯化钠溶液。为了确定味觉是否导致了这种品系差异，我们测量了鼓索神经对一系列氯化钠和氯化钾溶液浓度的综合神经反应。在实验1中，通过在盐刺激期间添加氨氯吡脒来评估味觉神经反应中对氨氯吡脒敏感的成分，在实验2中，通过在盐刺激之前用氨氯吡脒预处理味觉感受器来评估。在持续神经活动期间向氯化钠中添加氨氯吡脒比用氨氯吡脒预处理舌头更能抑制鼓索神经反应。在盐刺激期间添加氨氯吡脒也部分抑制了鼓索神经元对氯化钾（一种假定的对照刺激物）的反应。对于回避盐的F344大鼠和偏好盐的斯普拉格-道利大鼠，鼓索神经对氯化钠和氯化钾的神经反应相似。然而，氨氯吡脒预处理对F344大鼠味觉神经对氯化钠反应的抑制作用明显小于对斯普拉格-道利大鼠的抑制作用。味觉反应中对氨氯吡脒敏感成分的品系差异可能导致了对氯化钠偏好的差异。
