α 2 ar agonist uk14304  (Bio-Techne corporation)

Journal: bioRxiv

Article Title: A neuronal circuit driven by GLP-1 in the olfactory bulb regulates insulin secretion

doi: 10.1101/2023.08.28.555086

Figure Lengend Snippet: (A) Pancreatic NA levels of RD and WD mice after Ex4 injection in the OB (n=2-3/group). (B) Schematic illustration of bilateral OB injections of Ex4 combined with IP administration of UK14304 followed by an OGTT in OB-cannulated WD and OB-cannulated RD mice. (C) OGTT tests preceded by an IP injection of UK14304 and an OB injection of Ex4 in OB-cannulated WD after 20 weeks under WD (n=8) (left). AUC of glycaemia (right). OGTT data are analyzed using RM two-way ANOVA followed by Bonferroni post-hoc test and AUCs by using paired Student’s t-test. (D) Plasma insulin levels of OB-cannulated WD during OGTT tests preceded with OB-injected Ex4 and IP injected UK14304 (RM two-way ANOVA followed by Bonferroni post-hoc test; n=8). (E) Strategy to deliver Ex4 in the OB of OB-cannulated C57BL6 mice. (F) Representative photomicrographs of cFos immunoreactivity and automated cell counting in the MCL using CellProfiler software (left). cFos density in the MCL after Ex4 or saline injection in the OB in WD mice (right). Data are expressed as cFos+ nuclei/mean MCL area of all mice. Data are analyzed using an unpaired Student’s t-test (n=5). (G) cFos density in the LH after Ex4 or saline injection in the OB in WD mice. Data are expressed as cFos+ nuclei/mean LH area of all mice. Data are analyzed using an unpaired Student’s t-test (n=4). (H) Schematic illustration of unilateral Alexa 488-conjugated cholera toxin B subunit (CTB green ) delivery in the LH for retrograde tracing of the primary olfactory cortex. (I) Coronal sections of the LH after unilateral injection of CTB green (left). CTB staining in the primary olfactory cortex (right). LH, lateral hypothalamus; AHP, anterior hypothalamus; VMH, ventromedial hypothalamus; 3V, third ventricle; AON, anterior olfactory nucleus; VTT, ventral tenia tecta; VON, ventral olfactory nucleus; PC, piriform cortex; OT, olfactory tubercle. Structure boundaries were drawn based on Franklin and Paxinos mouse brain atlas. (J) Schematic illustration of viral delivery in the OB and bilateral cannula placement in the PVN of Glp1r -Cre WD mice followed by OGTTs. (K) OGTT tests preceded with an IP injection of CNO in Glp1r OBhM3Dq WD PVN-cannulated mice after 20 weeks under WD (26-week old; n=10) (left). The black square and the green line indicate Bicuculline and CNO delivery, respectively, before the glucose gavage (T0). AUC of glycaemia (right). OGTT data are analyzed using RM two-way ANOVA followed by Bonferroni post-hoc test and AUCs by using RM one-way ANOVA followed by Bonferroni post-hoc test. (L) Plasma insulin levels of Glp1r OBhM3Dq WD PVN-cannulated mice after CNO IP injection (RM two-way ANOVA followed by Bonferroni post-hoc test, n=10). Data are given as mean ± SEM. *p <0.05; **p < 0.01; ***p < 0.001; ns, not significant.

Article Snippet: Three experimental groups underwent OGTTs: i) WD and RD cannulated mice OB-infused with GLP-1, Ex4 or Ex9 [combined with IP injections of either Ex4 (3 µg/kg) or the α 2 -AR agonist UK14304 (Bio-Techne; 1μg/kg) when stated]; ii) Vagotomized WD mice OB-infused with Ex4; iii) Glp1r OBKORD RD and Glp1r OBhM3Dq WD mice in which OB Glp1r -expressing neurons were chemogenetically activated by IP injections of Salvinorin B (SALB; Sigma-Aldrich; 10mg/kg) or Clozapine N-oxide (CNO; Sigma-Aldrich; 3 mg/kg) respectively (combined with acute PVN injections of Bicuculline Methiodide 3 min prior to CNO administration when stated).

Techniques: Injection, Cell Counting, Software, Saline, Retrograde Tracing, Staining