Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease

<p>Dopamine (DA) is a key striatal neuromodulator which is central to processes including action selection and reward-related learning. DA dysfunction is associated with a number of psychomotor disorders, most notably of which is Parkinson's disease (PD). This thesis uses fast-scan cycl...

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Main Authors: Brimblecombe, K, Katherine Brimblecombe
Other Authors: Cragg, S
Format: Thesis
Language:English
Published: 2014
Subjects:
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author Brimblecombe, K
Katherine Brimblecombe
author2 Cragg, S
author_facet Cragg, S
Brimblecombe, K
Katherine Brimblecombe
author_sort Brimblecombe, K
collection OXFORD
description <p>Dopamine (DA) is a key striatal neuromodulator which is central to processes including action selection and reward-related learning. DA dysfunction is associated with a number of psychomotor disorders, most notably of which is Parkinson's disease (PD). This thesis uses fast-scan cyclic voltammetry in acute mouse striatal slices to detect DA release at carbon fibre microelectrodes with subsecond temporal resolution, to investigate factors affecting the presynaptic control of DA release.</p> <p>In this thesis, I have investigated the roles of voltage dependent calcium channels (VDCCs) and the neuromodulator, substance P (SP), in the presynaptic control of DA, in the presence of nicotinic acetylcholine receptor (nAChR) blockade. This is because ACh has profound modulatory and driving effects on DA release, via activation of nAChRs on DA terminals.</p> <p>In CPu, blockers for N-, P/Q-, T- or L-type VDCCs (ω-Conotoxin GVIA, ω-Agatoxin IVA, NNC 55-0396, isradipine) reduced DA release to varying degrees (N&gt;P/Q&gt;T&gt;L). Furthermore, L-type function was eliminated by α-synuclein knockout. In NAc, only N and P/Q-blockers modified DA release (N&gt;P/Q) and more weakly than in CPu. Frequency-specific effects of some VGCCs were reproduced by changes to extracellular Ca2+ or release probability, consistent with Ca2+ entry governing the relationship between DA release probability and its short-term plasticity. Finally I have shown that SP can directly modulate striatal DA release in a manner that depends on striosome-matrix location. To date there is much conflict in the literature on the role of SP in a number of striatal processes, this finding may help to resolve these conflicts and shed light on the little understood role of the striosome-matrix division of the striatum.</p>
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spelling oxford-uuid:31384235-dbbc-4055-8e3b-a1d292b376d52024-12-07T11:52:54ZInvestigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's diseaseThesishttp://purl.org/coar/resource_type/c_db06uuid:31384235-dbbc-4055-8e3b-a1d292b376d5Physiology and anatomyEnglish2014Brimblecombe, KKatherine BrimblecombeCragg, S<p>Dopamine (DA) is a key striatal neuromodulator which is central to processes including action selection and reward-related learning. DA dysfunction is associated with a number of psychomotor disorders, most notably of which is Parkinson's disease (PD). This thesis uses fast-scan cyclic voltammetry in acute mouse striatal slices to detect DA release at carbon fibre microelectrodes with subsecond temporal resolution, to investigate factors affecting the presynaptic control of DA release.</p> <p>In this thesis, I have investigated the roles of voltage dependent calcium channels (VDCCs) and the neuromodulator, substance P (SP), in the presynaptic control of DA, in the presence of nicotinic acetylcholine receptor (nAChR) blockade. This is because ACh has profound modulatory and driving effects on DA release, via activation of nAChRs on DA terminals.</p> <p>In CPu, blockers for N-, P/Q-, T- or L-type VDCCs (ω-Conotoxin GVIA, ω-Agatoxin IVA, NNC 55-0396, isradipine) reduced DA release to varying degrees (N&gt;P/Q&gt;T&gt;L). Furthermore, L-type function was eliminated by α-synuclein knockout. In NAc, only N and P/Q-blockers modified DA release (N&gt;P/Q) and more weakly than in CPu. Frequency-specific effects of some VGCCs were reproduced by changes to extracellular Ca2+ or release probability, consistent with Ca2+ entry governing the relationship between DA release probability and its short-term plasticity. Finally I have shown that SP can directly modulate striatal DA release in a manner that depends on striosome-matrix location. To date there is much conflict in the literature on the role of SP in a number of striatal processes, this finding may help to resolve these conflicts and shed light on the little understood role of the striosome-matrix division of the striatum.</p>
spellingShingle Physiology and anatomy
Brimblecombe, K
Katherine Brimblecombe
Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title_full Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title_fullStr Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title_full_unstemmed Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title_short Investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators: Insights for Parkinson's disease
title_sort investigating the control of striatal dopamine neurotransmission by axonal calcium channels and by striatal neuromodulators insights for parkinson s disease
topic Physiology and anatomy
work_keys_str_mv AT brimblecombek investigatingthecontrolofstriataldopamineneurotransmissionbyaxonalcalciumchannelsandbystriatalneuromodulatorsinsightsforparkinsonsdisease
AT katherinebrimblecombe investigatingthecontrolofstriataldopamineneurotransmissionbyaxonalcalciumchannelsandbystriatalneuromodulatorsinsightsforparkinsonsdisease