Chapter 52 Differential regulation of dopamine metabolism in solid fetal substantia nigra transplants and their terminals in the host striatum

This chapter examines the differential regulation of dopamine metabolism in solid fetal substantia nigra transplants and their terminals in the host striatum. Male Sprague–Dawley rats, weightng 300 g at the start of the experiment, were used in an experiment described in the chapter. They were group housed in standard laboratory cages with unlimited access to water and standard laboratory food. Room temperature was maintained at 21°C and a 12:12 light/dark cycle was in effect. The rats received a micro-injection of 6-hydroxydopamine (6-OHDA) into the left medial forebrain bundle to destroy the ascending dopamine (DA) projections. The rats were evaluated for their turning behavior after a challenge both with apomorphine (APO) (0.5 mg/kg s.c.) and, separately, with amphetamine (AMPH) (5 mg/kg i.p.) This behavioral testing was performed before transplantation and again at least 3 months following transplantation. All the rats successfully lesioned with 6-OHDA showed strong ipsilateral and contralateral turning behavior after challenge, respectively, with AMPH and APO. The DA content in the transplant itself was higher than that of the adjacent 6-OHDA lesioned striatum, with a significant difference between the transplants of the compensated as compared to that of the noncompensated rats.