Psychopharmacology · Nov 3, 2026
Combination of IL-1β and IL-6 triggers parkinsonian-like tremor in rats: correlation of the effect with noradrenaline levels in the locus coeruleus and ventral anterior thalamic nucleus
By Ionov ID, Krasilova MD, Pushinskaya II et al.
Rationale One of parkinsonian signs is tremor; the mechanism of this dysfunction is unclear. There are indications that IL-1β, IL-6, and noradrenaline (NA) located in the locus coeruleus (LC) and thalamus participate in regulation of parkinsonian tremor (PT). Objectives We sought i) to determine the ability of IL-1β and IL-6 to induce tremulous jaw movements (TJMs), a rat model of PT; and ii) to characterize a link between TJMs development and NA metabolism in the LC and some thalamic nuclei. Methods Experiments were conducted in male Wistar rats of 530–570 days of age. IL-1β and IL-6 were injected intracerebroventricularly for 10 day at 1.0–25.0 pg and 10.0–250.0 pg, respectively; concentrations of NA and its metabolite 3,4-dihydroxyphenylglycol (DHPG) were determined by HPLC. TJMs were counted by standard method. Results Interleukins administered separately were ineffective; in contrast, IL-1β at 25.0 pg combined with IL-6 at 250.0 pg significantly stimulated TJM response and increased NA, DHPG, and DHPG/NA ratios in the LC and ventral anterior thalamic nucleus (VATN); NA metabolism in the paraventricular and posterior intralaminar thalamic nuclei did not change. The number of TJMs positively correlated with levels of NA in the LC and VATN. The effect of IL-1β–IL-6 combination was reversed by β-antagonist propranolol but not α₁- and α₂- antagonists terazosin and yohimbine. Conclusions The results advance our understanding of the mechanism underlying parkinsonian-like tremor in rats. The presented data suggests that IL-1β, IL-6, and β-receptors are a potential triple-target in therapy of PT.