We have studied effects of TRH analogue, TA-0910 
(3-methyl-(s)-5,6-dihydroorotyl-L-histidyl-L-prolinamide) (from Tanabe, Osaka, 
Japan) on explanted ventral and dorsal spinal cord cultures from 13- and 
14-day-old rat embryos. TA-0910-treated cultures had significantly increased 
neurite outgrowth with cultures of ventral spinal cord, but not with cultures of 
dorsal spinal cord. The effect was dose-dependent. A possible role for TRH in 
amyotrophic lateral sclerosis remains to be defined.