Motor neurone disease serum and beta-N-methylamino-L-alanine stimulate thyrotrophin-releasing hormone production by cultured brain cells. 
We have investigated the effects of serum from patients with motor neurone disease (MND) and of the plant-derived excitotoxin beta-N-methylamino-L-alanine (L-BMAA) on thyrotrophin-releasing hormone (TRH) and somatostatin (SS) production by fetal rat brainstem cell cultures.  Compared to age- and sex-matched normal and neurological disease control sera, MND sera produce a 2- to 3-fold increase in TRH content of the cultures with no change in SS levels.  L-BMAA produced similar dose-related and stereospecific effects on the cultures increasing TRH levels to 2-fold with no effect on SS levels.  These findings may be relevant to the understanding of the aetiology of MND.