Journal: bioRxiv
Article Title: Chronic stress impairs autoinhibition in neurons of the locus coeruleus to increase asparagine endopeptidase activity
doi: 10.1101/2025.03.10.642335
Figure Lengend Snippet: ( A-E ) Representative traces of NA-induced GIRK-I obtained from LC neurons in non-stress and 1-day, 2-day, 3-day, and 5-day RS mice. ( F, G ) Amplitudes of inward and outward components of NA-induced GIRK-I obtained from LC neurons in non-stress and 1-day, 2-day, 3-day, and 5-day RS mice ( n = 8, 7, 5, 6 and 8, respectively) decreased with the increase in the period of RS, in a way that can be described by a saturation function (red interrupted lines). The saturation level ( a + b ) and the half saturation constant ( c ) were determined by fitting the saturation function, defined as y = a + ( b * x) / ( c + x), to the data points. The values of a , b and c for the inward component of GIRK-I were −151.1, 108, and 0.9, respectively, and those for the outward component of GIRK-I were 81.1, –67, and 1.6, respectively. Inward component: one-way ANOVA, p < 0.001, post hoc fisher’s PLSD, 1-day; # p < 0.001 vs Non-stress and * p < 0.05 vs 3-day and 5-day, 2-day; # p < 0.001 vs Non-stress, 3-day; # p < 0.001 vs Non-stress, 5-day; # p < 0.001 vs Non-stress. Outward component: one-way ANOVA, p < 0.001, post hoc fisher’s PLSD, 1-day; p = 0.004 vs Non-stress and * p < 0.05 vs 3-day and 5-day, 2-day; p = 0.015 vs Non-stress, 3-day; p < 0.001 vs Non-stress, 5-day; p < 0.001 vs Non-stress. ( H ) Relative expressions of α2A and α2C mRNAs, normalized to GAPDH in LC neurons ( n = 5). Paired t -test, ‡ p = 0.014. ( I ) Relative expressions of GIRK1, GIRK2, and GIRK3 mRNAs, normalized to GAPDH in LC neurons ( n = 5). One-way RM ANOVA, p < 0.001, post hoc fisher’s PLSD; * p = 0.008 for GIRK1 vs GIRK2, * p < 0.001 for GIRK1 vs GIRK3, * p = 0.008 for GIRK2 vs GIRK3. ( J, K ) Relative expressions of α2A and GIRK1 mRNAs, respectively, normalized to GAPDH in LC neurons in non-stress mice ( n = 8), and 3-day RS mice ( n = 6). α2A-AR: unpaired t -test, † p = 0.020; GIRK1: unpaired t -test, † p = 0.013. (L) Normalized relative expressions of GIRK2 mRNA in LC neurons in non-stress mice ( n = 8) and 3-day RS mice ( n = 6), normalized to the ratio of the mean value of the relative expressions of GIRK1 mRNA to that of GIRK2 mRNA in LC neurons in non-stress mice ( I ). Unpaired t -test, † p = 0.037.
Article Snippet: To examine the distribution of α2A-AR in LC neurons, mouse anti-TH (1:500; sc-25269, Santa Cruz Biotechnology, Santa Cruz, CA, USA), rabbit anti-sodium potassium ATPase (1:1000; ab76020, Abcam, Cambridge, MA, USA) and goat anti-α2A-AR (1:200; ab45871, Abcam) or rabbit anti-α2A-AR (1:500; RA14110, Neuromics, Northfield, MN, USA) were used as primary antibodies, while cy5 donkey anti-mouse IgG (1:500; cy-2500, Vector Laboratories, Burlingame, CA, USA), FITC donkey anti-rabbit IgG (1:500; 711-095-152, Jackson ImmunoResearch, West Grove, PA, USA) and Cy3 donkey anti-goat IgG (1:500; 706-165-147, Jackson ImmunoResearch) were used as secondary antibodies.
Techniques: