News & Events






General informations
21/11/2019
Cyril Herry, an influential researcher!

Thanks to the 5200 citations of his work, Cyril Herry appears in the ranking Clarivate Analytics of the most influential researchers in the last 10 years. This ranking is based on data and analysis through ralises bibliomtriques experts from the Institute for Scientific Information Web of Science Group. The Web of Science Group recognizes 6 216 scientists who have demonstrated significant influence your product using their peers by publishing numerous articles that rank among the 1% most cits per domain per year. The analysis covers the period 2008-2018. Only 10 other researchers from Inserm and 4 others from the University of Bordeaux are included in this ranking. Congratulations Cyril!




PhD/HDR defense
21/11/2019 14h00
Olivier DUBANET Dynamics of interactions between excitation and perisomatic inhibition in the normal and epileptic hippocampal circuit in vivo.

Dynamics of interactions between excitation and perisomatic inhibition in the normal and epileptic hippocampal circuit in vivo.
Directeur de thèse : Xavier Leinekugel
Date de la soutenance: 21/11/2019 - 14h00
Lieu: Magendie Salle de conference


PhD/HDR defense
14/11/2019 14h00
de Thèse – Ashley Castellanos Jankiewicz Bile acids signaling as a novel mechanism in the hypothalamic control of energy balance

Bile acids signaling as a novel mechanism in the hypothalamic control of energy balance

Thesis supervisor:
Daniela Cota, MD, HDR

Summary: Bile acids (BA) are cholesterol-derived molecules mostly known for participating in the digestion of lipids. By activating the Takeda G protein coupled receptor 5 (TGR5) in peripheral organs, BA can also act as signaling molecules to reduce body weight, increase energy expenditure and improve glycaemia. These outcomes imply an anti-obesity function for TGR5. Since the major center of convergence of nutrient, hormonal, and environmental cues is the brain, particularly the hypothalamus, we hypothesized a role for TGR5 in this brain structure, specifically under diet-induced obesity.

Our results show that TGR5 and BAs transporters are expressed in the mediobasal hypothalamus (MBH), and that obese mice have decreased circulating and hypothalamic BA levels. Acute intracerebroventricular (ICV) or intra-MBH administration of TGR5 agonists reduced food intake and body weight in obese mice only, and improved insulin sensitivity. Accordingly, chronic ICV administration of the TGR5 agonist in obese mice reduced their body weight and adiposity, while increasing energy expenditure and markers of sympathetic activity in the adipose tissue. Indeed, experiments conducted at thermoneutrality (30°C) or chemical sympathectomy blunted these effects, demonstrating that central TGR5 effects require the engagement of the sympathetic nervous system. Conversely, by using genetic animal models, we observed that the deletion of TGR5 in the MBH rapidly increased food intake, body weight and adiposity, while blunting the sympathetic response to a cold challenge (4h at 4°C), hence worsening obesity.

Our work proves the existence of a functional hypothalamic BA – TGR5 receptor system. We show for the first time that the activation of TGR5 in the MBH decreases body weight and adiposity, while increasing energy expenditure through recruitment of the sympathetic nervous system. These results expose a new mechanism of action for potential anti-obesity therapies.

Keywords: Bile acids, TGR5, diet-induced obesity, mediobasal hypothalamus, energy balance, sympathetic activity, thermogenesis.
Date de la soutenance: 14/11/2019 - 14h00
Lieu: Neurocentre Magendie Seminar room



A commentary to "Are animal models of addiction useful?"





Hottopic
30/10/2019 10h00
Antonio PAGANO-ZOTTOLA from Marsicano's lab will give a presentation entitled ' Melatonin Receptor 1, a new partner for CB1 receptor in mitochondria.'

Hottopic
30/10/2019 10h30
Ashley CASTELLANOS JANKIEWICZ from Cota's lab will give a presentation entitled ' Bile acids signaling as a novel mechanism for the hypothalamic control of energy balance.'



mTORC1 and CB1 receptor signaling regulate excitatory glutamatergic inputs onto the hypothalamic paraventricular nucleus in response to energy availability

Wilfrid Mazier, Nicolas Saucisse, Vincent Simon, Astrid Cannich, Giovanni Marsicano, Federico Massa & Daniela Cota