The effects of ventromedial tegmental lesions on the biosynthesis of catecholamines in the striatum

The Effects of DL Dopa on Harmaline Induced Tremor and on Resting Tremor in Monkeys with Tegmental Lesions

“…Such lesions are associated with a low endogenous dopamine [10] and a low uptake of dopamine in the ipsilateral striatum [5,6]. These findings are similar to the reports of low striatal amines found in Parkinson pa tients [3,7].…”

Physiopathology of Experimental Parkinsonism in the Monkey

“…Such a relationship has been greatly facilitated by the identification of the monoaminergic neurons and the distribution of their efferent fibers with the help of the histofluorescence method (Dahlstrom and Fuxe, 1964;Anden et al, 1965) and the combined use of biochemical and histopathological approaches (Poirier andSourkes, 1965, 1972;Sourkes and Poirier, 1966;Goldstein et al, 1966Goldstein et al, , 1969a. On the one hand, these various data have determined the importance of the histopathological changes at the level of the substantia nigra and the associated dopamine decrease in the neostriatum (caudate nucleus and putamen) in the production of the most characteristic signs of Parkinsonism.…”

“…On the other hand these findings have also contributed in elucidating drug-induced Parkinsonism as these drugs have been shown to interfere with brain monoamine metabolism. Thus the interruption of the nigrostriatal pathway leads to a cell loss (retrograde degeneration) in the corresponding substantia nigra and an associated decrease of dopamine (DA) in the ipsilateral neostriatum (Poirier and Sourkes, 1965;Poirier et al, 1966), the latter effect most likely resulting from the loss of important enzymes involved in monoamine metabolism, namely, tyrosine hydroxylase (Goldstein et al, 1966;Poirier et al, 1969c) and DOPA (5-HTP) decarboxylase (Anden et al, 1966;Goldstein et al, 1969a;Lancaster et al, 1970). Sftnilar enzymic defects have also been disclosed in the brains from Parkinsonian patients (Lloyd and Hornykiewicz, 1970).…”

Drug Induced Changes of Abnormal Movements in Monkeys with Central Nervous System Lesions

“…The results of these experiments have indicated that the storage of intraventricularly injected radioactive labelled dopamine (exogenous dopamine) is impaired in the striatum ipsilateral to the teg mental lesion [5,6]. This reduction of striatal dopamine is accompanied by a decrease in tyrosine hydroxylase activity [5]. The ventromedial teg mental lesion thus affects the biosynthesis and storage of dopamine in the ipsilateral striatum.…”