A comparative study of teriflunomide and dimethyl fumarate within the Swedish MS Registry.

BACKGROUND: Teriflunomide and dimethyl fumarate (DMF) are first-line disease-modifying treatments for multiple sclerosis with similar labels that are used in comparable populations. OBJECTIVES: The objective of this study was to compare the effectiveness and persistence of teriflunomide and DMF in a Swedish real-world setting. METHODS: All relapsing-remitting multiple sclerosis (RRMS) patients in the Swedish MS registry initiating teriflunomide or DMF were included in the analysis. The primary endpoint was treatment persistence. Propensity score matching was used to adjust comparisons for baseline confounders. RESULTS: A total of 353 teriflunomide patients were successfully matched to 353 DMF. There was no difference in the rate of overall treatment discontinuation by treatment group across the entire observation period (hazard ratio (HR) = 1.12; 95% confidence interval (CI) = 0.91-1.39; p = 0.277; reference = teriflunomide). Annualised relapse rate (ARR) was comparable (p = 0.237) between DMF (0.07; 95% CI = 0.05-0.10) and teriflunomide (0.09; 95% CI = 0.07-0.12). There was no difference in time to first on-treatment relapse (HR = 0.78; 95% CI = 0.50-1.21), disability progression (HR = 0.55; 95% CI = 0.27-1.12) or confirmed improvement (HR = 1.17; 95% CI = 0.57-2.36). CONCLUSION: This population-based real-world study reports similarities in treatment persistence, clinical effectiveness and quality of life outcomes between teriflunomide and dimethyl fumarate.

High frequency stimulation induces LTD of AMPA receptor-mediated postsynaptic responses and LTP of synaptically-evoked firing in the dorsolateral striatum.

In the striatum, long term potentiation (LTP) and long-term depression (LTD) of glutamatergic transmission are believed to underlie motor learning and are impaired in animal models of Parkinson's disease. High frequency stimulation (HFS) is often used to induce synaptic plasticity in the brain. In the striatum, the polarity of HFS-induced plasticity is influenced by the recording conditions, which can differ between various studies. Here, we examined the ability of HFS to induce synaptic plasticity in the dorsolateral striatum in the presence of extracellular Mg2+ ions, with no GABAA receptor blocker, and without membrane depolarization during HFS. We found that HFS induced a LTD of excitatory postsynaptic currents (EPSCs) mediated by AMPA receptors (AMPARs) in medium spiny neurons (MSNs) recorded with whole-cell voltage-clamp. However, HFS induced a LTP of field excitatory postsynaptic potentials/population spikes (fEPSP/PSs), which was dependent on the stimulation intensity applied. The rate of synaptically-evoked spiking in MSNs, measured with cell-attached recordings, showed LTP following HFS. LTD and LTP were impaired in the dopamine-depleted striatum of 6-hydroxydopamine (6-OHDA) lesioned mice, a model of Parkinson's disease. This study shows that HFS induces opposing forms of dopamine-dependent synaptic plasticity in the striatum, i.e. LTD of AMPAR-EPSCs and LTP of both fEPSP/PS and synaptically-evoked firing in MSNs.

CIQ, a positive allosteric modulator of GluN2C/D-containing N-methyl-d-aspartate receptors, rescues striatal synaptic plasticity deficit in a mouse model of Parkinson's disease.

AIMS: To investigate if CIQ, a positive allosteric modulator of N-methyl-d-aspartate receptors (NMDARs) containing GluN2C/D subunits, rescues the loss of long-term potentiation (LTP) and forelimb-use asymmetry in a mouse model of Parkinson's disease (PD). METHODS: We have used electrophysiology in brain slices and the cylinder test to examine the effect of CIQ on glutamatergic synaptic transmission, synaptic plasticity, and forelimb-use in the unilateral 6-hydroxydopamine-lesion mouse model of PD. RESULTS: CIQ, applied in the perfusion solution, reversibly reduced glutamatergic synaptic transmission in the dopamine-depleted striatum and had no effect in the dopamine-intact striatum. LTP, a dopamine- and NMDAR-dependent form of synaptic plasticity, was induced in the dopamine-intact striatum but was lost in the dopamine-depleted striatum. This impaired LTP was restored in the presence of CIQ applied in the perfusion solution. This treatment, however, prevented LTP induction in control slices. In brain slices from mice which received single and chronic intraperitoneal injections of CIQ, LTP was restored in the dopamine-depleted striatum and unaffected in the dopamine-intact striatum. Forelimb-use asymmetry, a test which assesses deficits in paw usage in the unilateral lesion model of PD, was reversed by systemic chronic treatment with CIQ. CONCLUSION: A positive allosteric modulator of GluN2C/D-containing NMDARs rescues LTP and forelimb-use asymmetry in a mouse model of PD. This study proposes GluN2D as a potential candidate for therapeutic intervention in PD.