ELECTROCONVULSIVE TREATMENT EVOKES RELEASE OF PREPROTACHYKININ-A MESSENGER-RNA INTO THE CEREBROSPINAL-FLUID AND OCULAR AQUEOUS-HUMOR OF RABBITS

Following electroconvulsive treatment (ECT) of rabbits, preprotachykin in-A (PPT-A) mRNA was detected by Southern blot analysis of polymerase chain reaction (PCR)-amplified products in the cerebrospinal fluid (C SF) and aqueous humor of the eye. In contrast, no PPT-A mRNA could be detected in samples from untreated animals. In addition, several neuro peptides (substance P, neuropeptide Y, cholecystokinin, calcitonin gen e-related peptide and pituitary adenylate cyclase activating peptide) were released into the CSF (and aqueous humor) following ECT. The resu lts suggest that PPT-A mRNA was released together with neuropeptides i nto the CSF and aqueous humor in response to ECT. Indeed, previous stu dies have suggested that neurons can release neuropeptide mRNAs and th at neurons are capable of taking up and expressing foreign mRNA. If ne uropeptide mRNA can be taken up and utilized by another neuronal popul ation, it might explain instances when neurons display 'phenotypic swi tch', i.e. the transient expression of novel neuropeptides. (C) 1997 E lsevier Science Ireland Ltd.