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CURRENT SCIENCE REVIEWS by Joe Bruman December 1996 p. 1 of Lancet; 26 October 1996:1159 (news item): Fetal neurons are used in graft therapy because they can diversify in response to external cues, whereas adult ones generally cannot. Now adult (rat) neurons have been found and cultured which can do that. The use of autologous cells for transplants could eliminate the present requirement for fetal ones, as well as the need for immunosuppression. Further, if the desired cues for self-repair could be found, surgical transplantation might become unnecessary. Zhou F et al; J Neurosci 1996;6966-6974: To succeed, a fetal transplant must not only survive, it must replace the neural pathway that has failed in PD. In a rat model, authors supplemented a transplant to the substantia nigra, with a track of kainic acid that guided growth toward the corpus striatum, restoring the lost motor function. Winkler C et al; J Neurosci 1996;7206-7215: In a rat model of PD, injection of glial-derived neurotrophic factor (GDNF) near the substantia nigra gave long-term protection to the damaged neurons, but they didn't reinnervate the corpus striatum, nor was striatal dopamine function restored. Mendez I et al; J Neurosci 1996;7216-7227: In current practice, fetal substantia nigra cells are implanted, not in the host substantia nigra but in the corpus striatum, because the cells can't grow along the desired pathway. In a rat model, authors found that simultaneous grafts in both the corpus striatum and the substantia nigra resulted in rapid restoration of the destroyed pathway and some recovery of function, by growing toward each other. Basso M et al; J Neurosci 1996;7308-7317: and Basso M et al; J Neurosci 1996;7318-7330: Hyperexcitable reflex blinks are a cardinal sign of PD. In two related papers, authors describe a series of elegant experiments (on rats) showing how the loss of dopamine from the substantia nigra leads to this symptom. In the normal brain, reflex blink is inhibited by a series of reactions passing through several centers; from the substantia nigra via the superior colliculus to the nucleus raphe magnus, and thence to the spinal trigeminal neurons involved in the reflex blink circuit. This discovery should lead to better understanding of PD cause and treatment. Science News, 16 November 1996:316 (news item): Apoptosis, a common natural mechanism by which organisms get rid of damaged, aged, or unneeded cells, may become abnormal and cause a number of disorders, including neurodegenerative diseases such as ALS, AD, and Huntington's disease. While not mentioned, PD is an obvious candidate for inclusion. Polymeropoulos M et al; Science, 15 Nov 1996:1197-1199: Tedious analysis of DNA from a 592-member family, including 60 with PD, suggests that a single mutant gene, located in a short region of chromosome 4, confers susceptibility to the disease. They haven't found it yet, and in similar cases the final search has taken from a few months to as long as 8 years. Success should help to clarify the cause of PD, as well as a valuable diagnostic aid.