Martin Louis J, Sollars Suzanne I
Department of Psychology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE 68182, USA.
Department of Psychology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE 68182, USA
Chem Senses. 2015 Feb;40(2):97-108. doi: 10.1093/chemse/bju063. Epub 2014 Dec 23.
The peripheral taste system of the adult rodent is highly resilient against damage, with morphological, behavioral, and functional recovery evident after regeneration of a transected nerve. If chorda tympani transection (CTX) occurs at early postnatal ages however, the nerve fails to regenerate and effects on tongue morphology and behavior are more severe and longer-lasting compared to adult denervation. To examine whether neonatal CTX induces functional changes in intact nerves, whole-nerve electrophysiology was performed on the glossopharyngeal (GL) and chorda tympani (CT) nerves of adult rats that received CTX at P10. Attenuation of NaCl-elicited GL responses were observed in CTX rats 2 months after surgery, with bilateral denervation causing the largest decreases in responses. When assessed 1 year after neonatal CTX, amiloride-sensitive responses to NaCl in the contralateral CT increased while amiloride-insensitive responses decreased. Responses to other tastants were consistent with control animals. This is the first evidence of long-term functional changes to the peripheral taste system after injury in rats fed a normal diet. This study further characterizes the developing peripheral taste system as highly susceptible to change following neural injury.
成年啮齿动物的外周味觉系统对损伤具有高度的恢复能力，在横断神经再生后，形态、行为和功能的恢复都很明显。然而，如果在出生后早期进行鼓索横断（CTX），神经无法再生，与成年去神经支配相比，对舌形态和行为的影响更严重且持续时间更长。为了研究新生期CTX是否会在完整神经中引起功能变化，对出生后10天接受CTX的成年大鼠的舌咽神经（GL）和鼓索神经（CT）进行了全神经电生理检查。在手术后2个月，观察到CTX大鼠中NaCl诱发的GL反应减弱，双侧去神经支配导致反应下降幅度最大。在新生期CTX后1年进行评估时，对侧CT中对NaCl的氨氯地平敏感反应增加，而氨氯地平不敏感反应减少。对其他味觉物质的反应与对照动物一致。这是正常饮食喂养的大鼠受伤后外周味觉系统长期功能变化的首个证据。这项研究进一步表明，发育中的外周味觉系统在神经损伤后极易发生变化。
