Structural-functional properties of direct-pathway striatal neurons at early and chronic stages of dopamine denervation

© 2023 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd..

The dendritic arbour of striatal projection neurons (SPNs) is the primary anatomical site where dopamine and glutamate inputs to the basal ganglia functionally interact to control movement. These dendritic arbourisations undergo atrophic changes in Parkinson's disease. A reduction in the dendritic complexity of SPNs is found also in animal models with severe striatal dopamine denervation. Using 6-hydroxydopamine (6-OHDA) lesions of the medial forebrain bundle as a model, we set out to compare morphological and electrophysiological properties of SPNs at an early versus a chronic stage of dopaminergic degeneration. Ex vivo recordings were performed in transgenic mice where SPNs forming the direct pathway (dSPNs) express a fluorescent reporter protein. At both the time points studied (5 and 28 days following 6-OHDA lesion), there was a complete loss of dopaminergic fibres through the dorsolateral striatum. A reduction in dSPN dendritic complexity and spine density was manifest at 28, but not 5 days post-lesion. At the late time point, dSPN also exhibited a marked increase in intrinsic excitability (reduced rheobase current, increased input resistance, more evoked action potentials in response to depolarising currents), which was not present at 5 days. The increase in neuronal excitability was accompanied by a marked reduction in inward-rectifying potassium (Kir) currents (which dampen the SPN response to depolarising stimuli). Our results show that dSPNs undergo delayed coordinate changes in dendritic morphology, intrinsic excitability and Kir conductance following dopamine denervation. These changes are predicted to interfere with the dSPN capacity to produce a normal movement-related output.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:59

Enthalten in:

The European journal of neuroscience - 59(2024), 6 vom: 20. März, Seite 1227-1241

Sprache:

Englisch

Beteiligte Personen:

Li, Chang [VerfasserIn]
Elabi, Osama F [VerfasserIn]
Fieblinger, Tim [VerfasserIn]
Cenci, M Angela [VerfasserIn]

Links:

Volltext

Themen:

8HW4YBZ748
Animal models
Basal ganglia
Dopamine
Journal Article
Medium spiny neurons
Movement disorders
Oxidopamine
Parkinsonism
Plasticity
VTD58H1Z2X

Anmerkungen:

Date Completed 22.03.2024

Date Revised 22.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/ejn.16166

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM363685758