Transplantation of melanocytes obtained from the skin ameliorates apomorphine-induced abnormal behavior in rodent hemi-parkinsonian models

Tyrosinase, which catalyzes both the hydroxylation of tyrosine and consequent oxidation of L-DOPA to form melanin in melanocytes, is also expressed in the brain, and oxidizes L-DOPA and dopamine. Replacement of dopamine synthesis by tyrosinase was reported in tyrosine hydroxylase null mice. To examine the potential benefits of autograft cell transplantation for patients with Parkinson's disease, tyrosinase-producing cells including melanocytes, were transplanted into the striatum of hemi-parkinsonian model rats or mice lesioned with 6-hydroxydopamine. Marked improvement in apomorphine-induced rotation was noted at day 40 after intrastriatal melanoma cell transplantation. Transplantation of tyrosinase cDNA-transfected hepatoma cells, which constitutively produce L-DOPA, resulted in marked amelioration of the asymmetric apomorphine-induced rotation in hemi-parkinsonian mice and the effect was present up to 2 months. Moreover, parkinsonian mice transplanted with melanocytes from the back skin of black newborn mice, but not from albino mice, showed marked improvement in the apomorphine-induced rotation behavior up to 3 months after the transplantation. Dopamine-positive signals were seen around the surviving transplants in these experiments. Taken together with previous studies showing dopamine synthesis and metabolism by tyrosinase, these results highlight therapeutic potential of intrastriatal autograft cell transplantation of melanocytes in patients with Parkinson's disease

Costly Subjective Learning

Information acquisition is an important aspect of decision making. Acquiring information is costly, but the cost of information acquisition is not typically observable and hence it is not obvious how it can be measured. Using preference over menus, de Oliveira, Denti, Mihm, and Ozbek [15] provide an axiomatic foundation for the additive costs model of information acquisition. If obtaining signals from experiments is time-consuming, such as in the case of a long-run investment decision, however, costs may be measured as a discount factor or waiting time for acquiring information. We propose a general class of representations which allows for non-additive costs for information acquisition and provide its axiomatic foundation. Furthermore, the discounting costs model is characterized as a special case

Transplantation of Melanocytes Obtained from the Skin Ameliorates Apomorphine-Induced Abnormal Behavior in Rodent Hemi-Parkinsonian Models

Tyrosinase, which catalyzes both the hydroxylation of tyrosine and consequent oxidation of L-DOPA to form melanin in melanocytes, is also expressed in the brain, and oxidizes L-DOPA and dopamine. Replacement of dopamine synthesis by tyrosinase was reported in tyrosine hydroxylase null mice. To examine the potential benefits of autograft cell transplantation for patients with Parkinson's disease, tyrosinase-producing cells including melanocytes, were transplanted into the striatum of hemi-parkinsonian model rats or mice lesioned with 6-hydroxydopamine. Marked improvement in apomorphine-induced rotation was noted at day 40 after intrastriatal melanoma cell transplantation. Transplantation of tyrosinase cDNA-transfected hepatoma cells, which constitutively produce L-DOPA, resulted in marked amelioration of the asymmetric apomorphine-induced rotation in hemi-parkinsonian mice and the effect was present up to 2 months. Moreover, parkinsonian mice transplanted with melanocytes from the back skin of black newborn mice, but not from albino mice, showed marked improvement in the apomorphine-induced rotation behavior up to 3 months after the transplantation. Dopamine-positive signals were seen around the surviving transplants in these experiments. Taken together with previous studies showing dopamine synthesis and metabolism by tyrosinase, these results highlight therapeutic potential of intrastriatal autograft cell transplantation of melanocytes in patients with Parkinson's disease. © 2013 Asanuma et al.This work was supported, in part, by Grants-in-aid for Scientific Research on Innovative Areas ‘‘Brain Environment’’ (M.A.), for Scientific Research (C) (M.A. and I.M.) and for the Encouragement of Young Scientists ( ) (I.M.) from the Japanese Ministry of Education, Culture, Sports, Science and Technology, and by Health and Labour Sciences Research Grants for Research on Measures for Intractable Diseases (M.A.), for Research on Psychiatric and Neurological Diseases and Mental Health (M.A. and N.O.), and for Comprehensive Research on Aging and Health (M.A. and N.O.) from the Japanese Ministry of Health, Labour and Welfare.Peer Reviewe

Comment on "Ellsberg's two-color experiment, portfolio inertia and ambiguity"

International audienceThe final step in the proof of Proposition 1 (p.311) of Mukerji and Tallon (2003) may not hold in generalbecause $\varepsilon>0$ in the proof cannot be chosen independently of $w,z$. We point out by a counterexample that the axioms they impose are too weak for Proposition 1. We introduce a modified set of axioms and re-establish the propositio