Cystic fibrosis transmembrane conductance regulator (CFTR) mRNA expression has been found in the medial preoptic area using in situ hybridization, addressing the possibility of CFTR regulation of sexual maturation and reproductive behaviour. CFTR mRNA has also been found in the cortical deep pyramidal layer V implying possible involvement of CFTR in 'motor' function and output control over bodily movements and secretion. CFTR production in the brain regions observed in this study implicate involvement of CFTR in cerebral control over motor/visceral and endocrine systems.