Session Information
Date: Wednesday, September 25, 2019
Session Title: Physiology and Pathophysiology
Session Time: 1:15pm-2:45pm
Location: Les Muses, Level 3
Objective: This study aimed to investigate the firing properties of fast spiking interneurons (FSIs) and medium spiny neurons (MSNs) of the dorsomedial striatum (DLStr) and motor cortical burst activity in a rat model of PD and with levodopa induced dyskinesias (LID).
Background: Striatal inhibitory interneurons are important modulatory components for the direct and indirect pathways of basal ganglia (BG). However, their role in PD and with LID remains unclear.
Method: Single neuron activity and local field potentials (LFPs) were recorded from the DLStr together with electrocorticogram (ECoG) from the motor cortex (MCtx) area in 6-hydroxydopamine lesioned hemiparkinsonian (HP) and levodopa-primed dyskinetic (HP-LID) rats as compared to controls. Putative GABAergic interneurons (fast-spiking interneurons, FSIs) and medium spiny neurons (MSNs) were identified based on peak to trough analyses of the signals. For the calculation of beta (13-30Hz) and gamma (30-100Hz) bursts the signals were filtered using Blackman bandpass filter and further down sampled to 100 Hz. Hilbert transformation was used to get the envelope, and the threshold value for burst was set at the 75th percentile of signal amplitude.
Results: The firing rate of MSNs was increased in HP and HP-LID rats, while the firing rate of FSIs wase only enhanced in HP-LID rats which was associated with reduced burst activity. The coefficient of variation (measure of firing irregularity) was higher in HP rats in both MSNs and FSIs, with no difference in HP-LID rats. In HP-LID MSNs spike-triggered averaging of LFP were phase locked to beta (12-30 Hz) and gamma (30-100 Hz). Further, ECoG oscillatory activity in the beta and gamma burst count was increased in both HP and HP-LID rats, however, theta burst was higher only in HP-LID rats.
Conclusion: Our study suggests that there may be distinct MSNs and FSNs firing patterns and irregular MCtx burst activity in a rat model of PD with LID, which may depend on the functional state after dopamine depletion and treatment indicating maladaptive neuroplasticity.
To cite this abstract in AMA style:
X. Jin, D. Milakara, K. Schwabe, J. Krauss, M. Alam. Dorsolateral striatal neuronal activity in a rat model of Parkinson`s disease with levodopa-induced dyskinesias [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/dorsolateral-striatal-neuronal-activity-in-a-rat-model-of-parkinsons-disease-with-levodopa-induced-dyskinesias/. Accessed June 15, 2025.« Back to 2019 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/dorsolateral-striatal-neuronal-activity-in-a-rat-model-of-parkinsons-disease-with-levodopa-induced-dyskinesias/