Bilateral lesions involving the nucleus locus coeruleus produced a substantial decrease in the forebrain noradrenaline concentrations. Lesioned animals showed an increased susceptibility to audiogenic seizures. It is supposed that noradrenergic neurons, belonging to the locus coeruleus, play an inhibitory role in the seizure mechanism.

Animals↗

PubMedDate not supplied

[Neurotransplantation. III. Intracerebral grafting of fetal substantia nigra in Parkinson's disease].

The paper reports the results of fetal substantia nigra transplantations into the brain of patients suffering from Parkinson's disease, performed in different neurosurgical centers in the world. Commonly accepted Ethical Guidelines for Fetal Tissue Transplantations are presented. The criteria regarding patients selection for therapeutic transplantation are also discussed. The results of studies concerning the problem of optimal fetal age for transplantations are presented. The optimal age seems to cover the period between the 7th gestational week when dopamine synthesis begins and the 11th week when protoplasmic processes start to grow intensively. The damage of these processes during transplantation procedure is thought to make the fetal cells survival difficult. The discussion concerning controversial problem of immunosuppression treatment after the neurotransplantation is also reported. The paper presents the principles of signs and symptoms assessment before and after operation including CAPIT system which emphasises the role of movement ability tests, PET-scanning with [18F]-6-L-fluorodopa and magnetic resonance imaging. The PET-scanning allows to follow up the changes in patient's brain resulting from the graft survival and its dopamine synthesis ability. The methods of donor woman examination to avoid the transmission of infections into the patient's brain are reviewed. The analysis of yet published results of about 100 operated on parkinsonian patients show marked improvement due to human fetal substantia nigra transplantation. The improvement lasts, at least 46 months postoperatively (the longest period of observation). Many of the grafted patients returned to normal self-dependent living activities and some of them resumed even their professional jobs. Most authors present the opinion that the therapeutic effects of fetal substantia nigra transplantations are more valuable and longer lasting than those after adrenal medulla autografts. However it should be borne in mind that both methods are yet only the experimental approach in Parkinson's disease therapy.

Fetal Tissue Transplantation↗

PubMedDate not supplied

[Neurotransplantations: experimental studies].

Before the intracerebral transplantations of adrenal medulla and fetal substantia nigra in parkinsonian patients were introduced to restore the dopamine deficit, many intensive experimental studies were performed during the last decades. The history of these experiments was presented including the animal models of Parkinson's disease, different implantation techniques and the effects of neurotransplantations of adrenal medulla and fetal substantia nigra obtained in experimental animals. Different mechanisms underlying the transplant-induced functional effects as well as the methods of its stimulation to extend the graft survival and function were described. The ability of intracerebral transplantations to ameliorate the symptoms in animal models of disorders other than Parkinson's disease is also discussed.

Adrenal Medulla↗

PubMedDate not supplied

[Neurotransplantation Part II. Autografts of adrenal medulla in Parkinson's disease].

The paper reports the results of adrenal medulla autotransplantations into the brain of parkinsonian patients performed up to now in many neurosurgical centers in the world. Different surgical techniques and methods of tissue preparation for transplantation are also reviewed. Core Assessment Program for Intracerebral Transplantation (CAPIT) is presented. This program was developed as an unified system for patients' diagnosis and evaluation of clinical signs and symptoms before and after transplantation. It enables direct comparison of the results obtained in different centers. Surgical risk depending on the method of operation is discussed. The mechanisms involved in functioning of adrenal medulla grafts are considered as well as the trials to improve graft survival and its activity in the host brain. The results of neuropathological studies from autopsy cases are also reported. The analysis of about 400 published cases shows moderate or marked clinical improvement due to adrenal medulla autotransplantation which was observed until 20 months postoperatively. The results indicate that the progress of Parkinson's disease becomes slower and the clinical symptoms are less severe. L-dopa doses might be decreased which is followed by the reduction of its side effects. The opinions from different neurosurgical centers evaluating adrenal medulla autografts vary depending on the results noticed after those neurotransplantations.

Adrenal Medulla↗