Zhuravin I A, Bures J
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Exp Brain Res. 1991;83(3):687-90. doi: 10.1007/BF00229849.
Spatial extent and duration of the functional blockade elicited by intracerebral injection of tetrodotoxin (TTX) was examined in rats anesthetized with pentobarbital. Pupillary diameter was measured under dissecting microscope before and up to 24 h after injection of TTX (10 ng/l microliters saline) into or 1.0, 1.5 and 2.0 mm lateral from the Edinger-Westphal nucleus. TTX administration elicited mydriasis the latency of which was directly and amplitude indirectly proportional to the target-injection distance. The maximum mydriasis attained 3.4 mm, lasted 2 h and slowly decayed over subsequent 20 h. Impulse transmission and conduction was blocked in a spherical volume of tissue about 3 mm in diameter the development of which could be approximated by diffusion from an instantaneous point source. Completeness and full reversibility make the TTX block a convenient research tool.
在戊巴比妥麻醉的大鼠中，研究了脑内注射河豚毒素（TTX）引起的功能阻断的空间范围和持续时间。在向动眼神经核内或其外侧1.0、1.5和2.0毫米处注射TTX（10纳克/微升生理盐水）之前及之后长达24小时内，在解剖显微镜下测量瞳孔直径。给予TTX引起瞳孔散大，其潜伏期与靶点注射距离成正比，幅度与靶点注射距离成反比。最大瞳孔散大达到3.4毫米，持续2小时，并在随后的20小时内缓慢消退。在直径约3毫米的球形组织体积中，冲动传递和传导被阻断，其发展过程可近似为从瞬时点源的扩散。TTX阻断的完全性和完全可逆性使其成为一种方便的研究工具。
