Deborah J Clarke

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Light microscopic autoradiography was used to identify cells in the neostriatum that became labelled after the local injection of [3H]gamma-aminobutyrate (GABA). The GABA-accumulating cells comprised up to 15% of the total population of neurons. Thirty-seven of these cells were examined in the electron microscope and it was found that they all had similar(More)
Unilateral ibotenic acid lesions of the rat nucleus basalis magnocellularis produce approximately 60% depletion of choline acetyltransferase activity in ipsilateral frontal and frontoparietal neocortex. This depletion, which represents the loss of most of the extrinsic neocortical cholinergic input, is stable for at least 6 months. Embryonic ventral(More)
Epidermal Growth Factor (EGF)-responsive stem cells isolated from the developing central nervous system (CNS) can be expanded exponentially in culture while retaining the ability to differentiate into neurons and glia. As such, they represent a possible source of tissue for neural transplantation, providing they can survive and mature following grafting(More)
We have used a rat model of Parkinson's disease (PD) to address issues of importance for a future clinical application of dopamine (DA) neuron grafting in patients with PD. Human mesencephalic DA neurons, obtained from 6.5–8 week old fetuses, were found to survive intracerebral cell suspension xenografting to the striatum of rats immunosup-pressed with(More)
GABA release was recorded in vivo by push-pull perfusion from the globus pallidus and substantia nigra of control rats, rats with unilateral ibotenic acid lesions of the neostriatum, and rats with embryonic striatal tissue grafts implanted in the lesioned striatum. The lesions reduced baseline levels of GABA release to 5% of control levels in the globus(More)
The physical process of cell suspension preparation from embryonic ventral mesencephala (VM) may be responsible for the low numbers of dopaminergic (DA) neurons that survive following neural transplantation or in vitro culture. In particular, the disruption of cell to extracellular matrix attachment may result in cell death through deactivation of a(More)
Injection of [3H]taurine into the neostriatum of the rat led to accumulation of radioactivity in a distinct population of neurons. Taurine-accumulating neurons had a medium-size cell body, a smooth nucleus and relatively little cytoplasm. Other neuron types, e.g. large neurons with indented nuclei, did not accumulate taurine. Striatonigral neurons,(More)
Human fetal mesencephalic dopamine (DA) neurons, obtained from 6.5–9 week old aborted fetuses, were grafted to the striatum of immunosuppressed rats with 6-hydroxydopamine lesions of the ascending mesostriatal DA pathway. The effects on amphetamine-induced motor asymmetry were studied at various timepoints after grafting. At eight weeks, functional graft(More)
Synaptic relationships between gamma-aminobutyric acid-ergic systems intrinsic to intrastriatal striatal grafts and inputs from host adult rat neocortex and substantia nigra were investigated using a variety of neuroanatomical techniques. The input from host frontal cortex was demonstrated using an anterograde degeneration technique, whilst a double(More)