Biomedical subjects

O Hornykiewicz

Publications and source records attributed to O Hornykiewicz.

At least 55 records · Page 3Linked to original sources

PubMed1991

Maturational and aging effects on guanine nucleotide binding protein immunoreactivity in human brain.

Age-related changes in transmembrane signal transduction have been reported for a number of hormonal receptors in human tissues. Guanine nucleotide binding proteins (G-proteins) are major regulatory components in the signal transduction processes for numerous receptors. Developmental changes in the abundance of specific G-protein alpha subunits, especially for Go, have already been shown in rat brain and in neuronal cell lines. In this study, immunoblotting analyses were performed with specific rabbit polyclonal antisera to Gs alpha, Gi alpha, Go alpha, and G beta subunits to estimate semi-quantitatively these G-protein subunits in samples of parietal cortex obtained postmortem from 18 subjects free of neurologic or psychiatric disease whose ages ranged from 3 days to 92 years. The Gs and Gi alpha subunit immunoreactivities were correlated significantly and inversely with age. The Gi alpha immunoreactivity declined markedly (46%) after the age of 40. As other G-protein subunit concentrations showed no age-dependent changes, the observed relationship between Gs and Gi alpha subunits and age is not likely due to cell loss occurring with advancing age. Of particular interest, the ratio of 52 to 45 kDa Gs alpha subunit immunoreactivities was significantly higher in infants than that found for adult parietal cortex. Given that changes in G-protein subunit abundance directly affect receptor-G-protein-effector functionality and response, these age-related alterations may be of importance in cerebral dysfunction and the development of neuropsychiatric disease in the later years of life.

Adolescent↗

PubMed1991

Quinolinic acid catabolism is increased in cerebellum of patients with dominantly inherited olivopontocerebellar atrophy.

We measured the activities of the enzymes responsible for the metabolism of the excitotoxin quinolinic acid, 3-hydroxyanthranilate oxygenase and quinolinic acid phosphoribosyltransferase, in autopsied brain of 11 patients with olivopontocerebellar atrophy. In cerebellar cortex, severe Purkinje cell loss was evident but with relative preservation of granule cells. As compared with the control subjects (n = 14), mean activity of 3-hydroxyanthranilate oxygenase was normal in cerebellar cortex from the patients with olivopontocerebellar atrophy, whereas quinolinic acid phosphoribosyltransferase activity was markedly increased (+92%, p less than 0.02). No significant changes in enzyme activities were found in samples from occipital cortex. Increased quinolinic acid phosphoribosyltransferase activity may represent a mechanism, in the degenerating cerebellum, to protect quinolinic acid-sensitive granule cells in patients with olivopontocerebellar atrophy.

Adult↗

PubMed1991

Cholinergic deficit induced by ethylcholine aziridinium (AF64A) in rat hippocampus: effect on glutamatergic systems.

The reaction of the glutamatergic systems in the rat hippocampus to the withdrawal of cholinergic function after cholinergic degeneration induced by ethylcholine aziridinium (AF64A) was investigated. Furthermore, the question whether blockade of N-methyl-D-aspartate (NMDA) receptors by MK-801 has an impact on the extent of the cholinergic lesion was addressed. After bilateral intracerebroventricular injection of AF64A (2 nmol/ventricle) the activity of choline acetyltransferase (ChAT) started to decline in the hippocampus within 24 h. The reduction of ChAT activity reached its maximum within 4 days (65%) and persisted during the observation period of 65 days. The loss of ChAT activity was accompanied by a transient decline in the level of glutamate, which was most pronounced 1 to 2 days after AF64A (25% reduction). Within 65 days the glutamate level returned to normal. A detailed subdissection of the hippocampus revealed that the cholinergic system was most affected in the ventral part of the hippocampus and the CA3 subfield. On the other hand, the transient reduction in glutamate was restricted to the CA1 and CA3 area. In the dentate gyrus the marked loss of cholinergic function was not accompanied by any reduction in glutamate level. Treatment of the AF64A-injected rats with the muscarinic agonist pilocarpine prevented the decline in glutamate levels. The transient nature of the decline in glutamate as well as its reversal by treatment with pilocarpine are suggestive of an increased release of glutamate in response to the withdrawal of cholinergic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine on the regional distribution of brain monoamines in the rhesus monkey.

In an attempt to define neurochemically the part played by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as a potential Parkinson's disease-inducing neurotoxin, we measured the tissue concentrations of the monoamines dopamine, noradrenaline and serotonin in 45 brain regions in nine rhesus monkeys (Macaca mulatta) receiving repeated intramuscular injections of a total amount of 2.1-7.5 mg/kg MPTP-HCl. Four monkeys treated with MPTP during a period of one to five weeks developed permanent Parkinsonism, and five animals receiving the neurotoxin during a period of two to seven months remained asymptomatic. We found that, compared with the distribution pattern established in the brain of seven normal (drug-free) rhesus monkeys, in the MPTP-treated monkeys none of the three major brain monoamine neuron systems was completely resistant to the neurotoxin. In addition, each brain monoamine had a characteristic regional pattern of MPTP-induced changes. As expected, the most significant alterations were found within the nigrostriatal dopamine system, i.e. profound dopamine loss in caudate nucleus, putamen and substantia nigra. However, many extrastriatal regions of the subcortex and brainstem also suffered significant loss of dopamine, with the noradrenaline loss in the regionally subdivided brainstem being less widespread, and the serotonin levels least affected. Thus, in subcortex/brainstem the ranking order of sensitivity to MPTP was: dopamine greater than noradrenaline much greater than serotonin. In the cerebral (neo- and limbic) cortex, all three monoamine neuron systems suffered widespread statistically significant losses. The ranking order of MPTP sensitivity of the cortical monoamines was: noradrenaline greater than serotonin greater than dopamine. In the cerebellar cortex, dopamine and noradrenaline concentrations were significantly reduced, whereas the serotonin level remained unchanged. A remarkable observation was that many of the subcortical and cortical changes found in the symptomatic monkeys were also found in the asymptomatic animals. Our data are compatible with several possible mechanisms by which MPTP may have produced the observed patterns of monoamine loss in the brain of the rhesus monkey. Our study demonstrates that in the rhesus monkey MPTP mimicked, in addition to the profound striatal dopamine loss, some of the extrastriatal dopamine, noradrenaline and serotonin changes often seen in the brain of patients with idiopathic Parkinson's disease. However, using our treatment regimen, we have not been able to reproduce in the rhesus monkey the inter-regional pattern of striatal dopamine loss typical of idiopathic Parkinson's disease, i.e. a significantly greater loss of dopamine in the putamen compared with the caudate nucleus.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1991

Reduced striatal [3H]inositol 1,4,5-trisphosphate binding in Huntington's disease.

Specific [3H]inositol 1,4,5-trisphosphate [( 3H]InsP3) binding was studied in regions of postmortem brain from 15 patients with Huntington's disease (HD) and 13 nonneurological controls. Single-point binding analyses, using 5.0 nM InsP3, showed statistically significant reductions in specific [3H]InsP3 binding in the caudate (-71%) and putamen (-75%) of HD patients compared with controls. Frontal and occipital cortical [3H]InsP3 binding was not significantly different between HD and controls, a finding suggesting that the reduced [3H]InsP3 binding parallels the brain regional specificity of the neuropathological changes in HD. Scatchard analyses of data from [3H]InsP3 competition binding assays performed on caudate nucleus revealed that the reductions found using single-point binding assays were due to a decrease in both binding density (-57%) and affinity (-50%) in HD brain compared with controls. The concomitant changes in InsP3 receptor density and affinity in HD brain suggest that these alterations may be produced by processes in addition to cell loss. These results suggest the possibility that disturbances in InsP3 receptor function, possibly resulting in altered intracellular calcium flux and homeostasis, occur in HD and may participate in the pathogenesis of this neurodegenerative disorder.

Brain↗

PubMed1991

Amyotrophic lateral sclerosis: glutamate dehydrogenase and transmitter amino acids in the spinal cord.

Measurements were taken of the activity of glutamate dehydrogenase (GDH) and the levels of transmitter amino acids in anatomically dissected regions of cervical and lumbar spinal cord in eight patients dying with amyotrophic lateral sclerosis (ALS) and in 11 neurologically normal controls. GDH activity was considerably increased in lateral and ventral white matter and in the dorsal horn of the ALS cervical spinal cord, but normal in the ventral horn and the dorsal columns. Similar, although less pronounced, GDH changes were found in the lumbar enlargement. The mean concentrations of aspartate and glutamate were reduced in all regions of ALS spinal cord investigated. Taurine concentrations were significantly increased in several subdivisions of cervical spinal cord, but normal in lumbar regions. Glycine levels were significantly reduced in lumbar ventral and dorsal horns. There was no striking change in spinal cord GABA levels in our ALS patients. It is suggested that the reduced levels of glutamate and aspartate as well as the elevated GDH activity in the spinal cord of ALS patients may reflect an overactivity of the neurons releasing these potentially excitotoxic amino acids and thus may be causally related to the spinal neuro-degenerative changes characteristic of ALS.

Amino Acids↗

PubMed1991

Technetium-99m-d,1-hexamethylpropyleneamine oxime (HMPAO) uptake and glutathione content in brain tumors.

Technetium-d, HMPAO SPECT was performed in 70 patients suffering from intracerebral tumors of various histologic types (glioma n = 30, meningioma n = 19, metastases n = 10, angioma n = 3, neuroma n = 2, lymphoma n = 2, neurocytoma n = 1, epidermoid n = 1, gliosis n = 1, cholesteatoma n = 1). Tumor classification was histologically verified in all subjects except in two cases with inoperable angiomas. SPECT was performed under resting state conditions with a dual-head rotating camera (SIEMENS ZLC 37) following intravenous injection of 18-25 mCi 99mTc-d, 1-HMPAO. Regional tracer deposit was expressed in terms of a cerebellar index (CBI). Significantly higher regional HMPAO uptake was found in meningiomas when compared with gliomas of different malignancy (ANOVA p less than 0.05). Within gliomas, regional uptake increased with malignancy (n.s.). In 23 patients, a total of 32 tumor specimens were obtained for histochemical analysis of glutathione (GSH) content using high-pressure liquid chromatography. A significant correlation (least square method, p less than 0.001) between CBIs and GSH values was found, supporting the hypothesis that GSH is the predominant factor for the conversion of the lipophilic complex to hydrophilic derivates.

Adult↗

PubMed1990

[3H]vesamicol binding in human brain cholinergic deficiency disorders.

We measured the binding of the vesicular acetylcholine transport blocker [3H]vesamicol (2-[4-phenylpiperidino] cyclohexanol; AH-5183) to autopsied frontal cortex and amygdala of patients from 4 disorders having a marked brain cholinergic reduction, namely Alzheimer's disease, Parkinson's disease with dementia, dominantly inherited olivopontocerebellar atrophy and Down's syndrome. Although mean activity of the specific cholinergic marker enzyme choline acetyltransferase (ChAT) was markedly reduced by about 60% in frontal cortex in the 4 patient groups and by 80% or greater in amygdala of the Alzheimer's and Down's syndrome patients, [3H]vesamicol binding density was, on average, either normal or only slightly reduced as compared with the controls. This discrepancy suggests that in human brain [3H]vesamicol binding is either not preferentially localized to cholinergic nerve endings or, in these cholinergic deficiency syndromes, a substantial proportion of the vesamicol binding sites persist on cholinergic nerve terminals despite loss of ChAT activity.

Acetylcholine↗

PubMed1990

Brain neurotransmitter changes in three patients who had a fatal hyperthermia syndrome.

The authors examined the autopsied brains from three patients who had a fatal hyperthermia syndrome. There was marked hypothalamic noradrenaline depletion in all three patients, severe brain choline acetyltransferase deficiency with nucleus basalis cell loss in two patients, and mild to moderate brain choline acetyltransferase loss in one patient. Striatal dopamine metabolite/dopamine ratio was below normal in two patients and not elevated, as would be expected after short-term neuroleptic administration, in the third. This suggests that reduced capability (aggravated by the cholinergic deficit) of the nigrostriatal dopamine system to respond adequately to stress and/or neuroleptic-induced receptor blockade may be important in the development and course of fatal hyperthermia syndrome.

Adolescent↗

PubMed1990

Cortical-basal ganglionic degeneration.

We report our experience with 15 patients believed to have cortical-basal ganglionic degeneration. The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Characteristic manifestations include cortical sensory loss, focal reflex myoclonus, "alien limb" phenomena, apraxia, rigidity and akinesia, a postural-action tremor, limb dystonia, hyperreflexia, and postural instability. The asymmetry of symptoms and signs is often striking. Brain imaging may demonstrate greater abnormalities contralateral to the more affected side. Postmortem studies in 2 patients revealed the characteristic pathologic features of swollen, poorly staining (achromatic) neurons and degeneration of cerebral cortex and substantia nigra. Biochemical analysis of 1 brain showed a severe, diffuse loss of dopamine in the striatum. This condition is more frequent than previously believed, and the diagnosis can be predicted during life on the basis of clinical findings. However, as with other "degenerative" diseases of the nervous system, a definitive diagnosis of cortical-basal ganglionic degeneration requires confirmation by autopsy.

Aged↗

PubMed1990

Some mechanisms of brain edema studied in a kainic acid model.

Kainic acid (KA) is a potent neuroexcitatory drug widely used in the experimental study of seizure activity. Subcutaneous injection of KA into rats (10 mg/kg in saline 10 mg/ml; pH 7.0) induced longlasting status epilepticus followed by damage of CNS tissue in the entorhinal/pyriform cortex and in the hippocampus. The studies covered by this report demonstrated the formation of cytotoxic brain edema characterized by massive swelling of perineuronal and perivascular astroglia with microcirculation disturbance after KA injection, resulting in parenchymal necrosis of the affected region; furthermore perivenous hemorrhages and necroses corresponding to herniation lesions of the brain appear. Tracer studies with Na-fluorescein, Evans blue, albumin, and horseradish peroxidase revealed only a mild increase in the permeability of cerebral vessels, topographically unrelated to areas of brain edema. Treatment of brain edema with dexamethasone did not influence the incidence and severity of edematous brain damage. Treatment with mannitol, however, completely prevented the lesion in 54% of animals injected with KA. The present results indicate that brain edema plays an important role in the pathogenesis of epileptic brain damage following systemic KA intoxication. It is suggested that in this model brain edema develops due to massive ionic imbalance caused by KA induced persistent neuronal excitation. In addition the model demonstrates the possible pathogenetic role of selective astrocytic swelling in the production of local hippocampal ischemia followed by herniation and its sequels. Such pathology originating from astrocytes probably may occur also in closed brain injury.

Animals↗

PubMed1989

Kainic acid-induced seizures: potentiation by alpha-methyl-p-tyrosine.

We have investigated the influence of central noradrenergic and dopaminergic systems on the susceptibility of rats to seizures in the kainic acid (KA)-model of epilepsy. In the dose range of 0.75 to 10 mg/kg s.c., KA dose-dependently induced characteristic behavioural changes. Partial depletion of noradrenaline (NA) and dopamine (DA) in the brain by pretreatment with the tyrosine hydroxylase inhibitor alpha-methyl-p-tyrosine (AMPT; 250 mg/kg, i.p.) markedly potentiated KA-induced epileptic symptoms. A low dose of KA (1.5 mg/kg s.c.), which was ineffective in normal rats, triggered in AMPT-pretreated rats a high incidence of wet dog shakes (WDS) and a seizure activity (seizure rating: 3.17 +/- 0.31) which was comparable in degree to that resulting from 10 mg/kg KA in rats with normal catecholamine synthesis (seizure rating: 3.33 +/- 0.28). In AMPT-pretreated rats a higher dose of KA (10 mg/kg) further enhanced seizure activity and was associated with a mortality rate of up to 80%. Within 6.5 h after AMPT-pretreatment the levels of NA and DA in amygdala/pyriform cortex declined from 0.56 +/- 0.02 (control) to 0.23 +/- 0.01 ng/mg tissue and from 0.21 +/- 0.03 to 0.05 +/- 0.01 ng/mg tissue, respectively. At a dose of 1.5 mg/kg KA was ineffective on the levels of NA and DA in normal rats, but further reduced these levels in AMPT-pretreated rats to 0.08 +/- 0.02 and 0.020 +/- 0.004 ng/mg tissue, respectively. Induction of seizure activity and decline in NA and DA levels in amygdala/pyriform cortex after AMPT/KA (1.5 mg/kg) treatment was antagonized by the alpha-adrenoceptor agonist clonidine (0.1 mg/kg, i.p.).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Limbic seizures without brain damage after injection of low doses of kainic acid into the amygdala of freely moving rats.

Kainic acid (KA, 8-15 ng) was injected into the amygdala of conscious freely moving rats via chronically implanted fused silica cannulas. At 15-25 min after the injection, most rats suffered a limbic seizure attack of short duration, consisting of mastication, forelimb clonus, and raising on hind limbs, behaviorally indistinguishable from kindled seizures. Typically, the attack was followed by stereotypies, intense exploration, and by 1 or 2 more attacks. About 60 min after the injection, most rats appeared normal again and histopathological changes in their brains did not exceed those seen in vehicle-injected rats. In 3 cases, however, recurrent seizures culminated in behavioral status epilepticus 60-90 min after the injection. The status epilepticus was stopped by i.p. injection of diazepam (10 mg/kg) after a duration of 10 min (1 case) and 30 min (2 cases), respectively. After 10 min status epilepticus, we observed marginal neuronal damage with slight gliosis in both hippocampi (CA3 and CA1); after 30 min, hippocampal histopathology was more pronounced, with additional necrosis of the ipsilateral piriform cortex. After 0.8 microgram KA, a hundredfold higher dose, the incidence of limbic seizures during the first 40 min was not significantly higher (9/12) than after the lower KA doses (13/19). However, a significantly higher proportion of rats exhibited long-lasting seizure activity, associated with confluent destruction of CA3 pyramidal cells and additional seizure-related brain damage. Our results show that limbic motor seizures do not inevitably lead to histopathological changes in the brain, provided they do not culminate in a state of permanent seizure activity.

Amygdala↗

PubMed1989

Ageing and neurotoxins as causative factors in idiopathic Parkinson's disease--a critical analysis of the neurochemical evidence.

1. Idiopathic Parkinson's disease (PD) is set apart from other Parkinsonian conditions by a specific interregional (caudate-putamen) as well as a subregional (rostral-caudal) pattern of striatal dopamine (DA) loss. 2. Using the characteristic patterns of striatal DA loss as neurochemical criteria, a critical evaluation of the "ageing/neurotoxin" hypothesis of idiopathic PD is presented. 3. Although both ageing of the brain DA neurones and MPTP (as an example of a DA-specific neurotoxin) reproduce some aspects of the subregional striatal DA loss found in idiopathic PD, neither of these two mechanisms mimicks the large caudate-putamen difference in DA loss (with the putamen much more affected than the caudate nucleus) which is typical of idiopathic PD. 4. From the discussed observations the conclusion is drawn that the pathoetiological factor, or factors, operative in idiopathic PD must involve a mechanism preferentially damaging the nigral DA neurones which project to the putamen.

Aging↗

PubMed1989

Down's syndrome individuals begin life with normal levels of brain cholinergic markers.

We measured the activities of the cholinergic marker enzymes choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in autopsied brains of seven infants (age range 3 months to 1 year) with Down's syndrome (DS), a disorder in which virtually all individuals will develop by middle age the neuropathological changes of Alzheimer's disease accompanied by a marked brain cholinergic reduction. When compared with age-matched controls cholinergic enzyme activity was normal in all brain regions of the individuals with infant DS with the exception of above-normal activity in the putamen (ChAT) and the occipital cortex (AChE). Our neurochemical observations suggest that DS individuals begin life with a normal complement of brain cholinergic neurons. This opens the possibility of early therapeutic intervention to prevent the development of brain cholinergic changes in patients with DS.

Acetylcholinesterase↗

PubMed1988

The neurotoxin MPTP does not reproduce in the rhesus monkey the interregional pattern of striatal dopamine loss typical of human idiopathic Parkinson's disease.

Using high-pressure liquid chromatography with electrochemical detection, we measured dopamine (DA) and homovanillic acid (HVA) in caudate nucleus, putamen and substantia nigra in 4 untreated rhesus monkeys and 4 monkeys with permanent parkinsonism produced by repeated injections of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; total dose: 2.1-6.45 mg/kg, i.m.). MPTP consistently produced a severe striatal and nigral loss of DA and HVA and an increase in the ratio 'HVA/DA'. In this respect, MPTP mimicked the changes found in human Parkinson's disease (PD). However, MPTP lowered the DA in caudate (-99.6%) to the same degree as in putamen (-99.5%). This is in contrast to idiopathic PD where the caudate is significantly less affected by DA loss (-84%) than the putamen (-98%). Thus, in our rhesus monkeys MPTP failed to reproduce the interregional caudate-putamen gradient characteristic of idiopathic PD. The DA pattern produced by MPTP was similar to the DA loss in caudate (-98%) and putamen (-99%) observed in patients with postencephalitic parkinsonism.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1988

The dopamine autoreceptor agonist, B-HT 920, preferentially reduces brain dopamine release in vivo: biochemical indices of brain dopamine, noradrenaline and serotonin in ventriculocisternal perfusates in the cat.

B-HT 920 (6-allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]azepine), a candidate for selective dopamine (DA) autoreceptor agonist activity, was tested for its interactions with biochemical parameters of brain dopaminergic, noradrenergic and serotoninergic systems as measured in ventriculocisternal perfusates of chloralose-anaesthetized cats. DA, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), noradrenaline (NA) and 5-hydroxyindolic acid (5-HIAA) were measured in samples of 30 min collection periods by high-pressure liquid chromatography with electrochemical detection. B-HT 920, in the dose range of 0.03-1 mg/kg i.v., promptly inhibited the efflux of DA and DOPAC in a dose-dependent manner. The 1 mg/kg dose of B-HT 920 reduced the DA levels below 25% of control levels for the whole length of the experiments. The HVA levels were reduced less and in a protracted manner. Only the highest dose of B-HT 920 tested (1 mg/kg) had a significant effect on the level of NA (marked, prompt reduction) and 5-HIAA (delayed, moderate reduction), reflecting its well known alpha 2-adrenoceptor agonist property. The effects of B-HT 920 on the dopaminergic indices were DA receptor-mediated as they were reversed by a low dose (0.05 mg/kg i.v.) of haloperidol. In contrast, the alpha 2-adrenoceptor blocking drug, idazoxan, 4 mg/kg i.v., while it reversed the NA and 5-HIAA reductions did not modify the effect of B-HT 920 on DA, DOPAC and HVA. Thus B-HT 920, in the dose range between 0.03-0.1 mg/kg, selectively affected brain dopaminergic parameters. Our experiments demonstrated that B-HT 920 causes an effective, long lasting and selective suppression of extracellular brain DA levels in vivo. B-HT 920 represents a promising compound for clinical use in pathological conditions known to be ameliorated by a reduction of brain DA activity, such as Huntington's disease, mania and schizophrenia.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1988

Uneven pattern of dopamine loss in the striatum of patients with idiopathic Parkinson's disease. Pathophysiologic and clinical implications.

Autografting of dopamine-producing adrenal medullary tissue to the striatal region of the brain is now being attempted in patients with Parkinson's disease. Since the success of this neurosurgical approach to dopamine-replacement therapy may depend on the selection of the most appropriate subregion of the striatum for implantation, we examined the pattern and degree of dopamine loss in striatum obtained at autopsy from eight patients with idiopathic Parkinson's disease. We found that in the putamen there was a nearly complete depletion of dopamine in all subdivisions, with the greatest reduction in the caudal portions (less than 1 percent of the dopamine remaining). In the caudate nucleus, the only subdivision with severe dopamine reduction was the most dorsal rostral part (4 percent of the dopamine remaining); the other subdivisions still had substantial levels of dopamine (up to approximately 40 percent of control levels). We propose that the motor deficits that are a constant and characteristic feature of idiopathic Parkinson's disease are for the most part a consequence of dopamine loss in the putamen, and that the dopamine-related caudate deficits (in "higher" cognitive functions) are, if present, less marked or restricted to discrete functions only. We conclude that the putamen--particularly its caudal portions--may be the most appropriate site for intrastriatal application of dopamine-producing autografts in patients with idiopathic Parkinson's disease.

Adrenal Medulla↗