-The role of astrocytes in social transmission of stress-
In threating situations, stress mechanisms override most other functions, including cognitive abilities not directly related to the danger itself. Stress-associated information can be transmitted from stressed to naïve individuals through olfactory signals, but the impact of this socially-transmitted stress on higher order cognitive processes is currently unknown. The olfactory bulb, the first relay of olfactory information in the main nervous system, controls information processing related to specific odors and sends information to other brain regions to translate sensory odor inputs into complex behaviors. The present thesis explores the role of astrocytes, and particularly of mitochondrial cannabinoid-type 1 receptors in these cells, in the olfactory transmission of stress information and the cognitive consequences this has in mice, using a combination of in vivo approaches including genetic manipulations and calcium recordings. This thesis work is co-supervised by Giovanni Marsicano and Jaideep Bains.
Date de la soutenance: 26/01/2024 - 14h00
Lieu: Broca Auditorium

Meeting room: Auditorium Broca-Nouvelle Aquitaine

IMAGINATION DAY
Please find the program of a one-day symposium attempting to put together human psychologist and psychiatrist and neuroscience and to find common ground around higher order associations.

PROGRAM
09:00-10:00 Welcome / coffee
10:00-10:10 Introduction
10:10-10:55 Thorsten Kahnt (NIDA, Baltimore, USA)
Orbitofrontal contributions to the flexible use of associative information
10:55-11:30 Arnau Busquets Garcia (IMIM, Barcelona, Spain)
Understanding higher-order conditioning in mice
11:30-11:50 Mélie Talaron (UNSW, Sidney, Australia/Cnrs, Bordeaux, France)
Role of the hippocampus in sensory preconditioning
11:50-12:25 Anne Giersch (Inserm, Strasbourg, France)
Being in contact with reality, or not: the time perspective in schizophrenia
12:25-14:30 Lunch break (restaurant for speakers)
14:30-15:05 Mihaela Iordanova (Concordia University, Montreal, Canada)
Amygdalo-cortical regulation of higher-order fear.
15:05-15:25 Unai Blanco (Inserm/Inrae, Bordeaux, France)
Role of the endocannabinoid system in incidental learning and reality testing
15:25-16:00 Jerome Brunelin (Inserm, Lyon, France)
Unraveling the Brain Mechanisms of Reality Monitoring with Non-invasive Brain Stimulation
in healthy and pathological conditions
16:00-16:30 Coffee break
16:30-17:05 Renaud Jardri (Inserm, Lille, France)
Advances in fMRI capture of hallucinatory experiences: from biomarker validation to clinical
applications
17:05-17:40 Katharina Schmack (Crick Institute, London, UK)
Computational psychiatry across species to study the biology of hallucinations

from Abrous's lab will defend his thesis entitled 'Role of adult-born dentate neurons in the resilience to cognitive aging'


Thursday 14 December / 09:30
Venue: Centre Broca

Defense in english

Nicolas Blin
Inserm
Team: Neurogenesis and pathophysiology (Magendie)
Thesis supervisor: Nora Abrous

Title
Role of adult-born dentate neurons in the resilience to cognitive aging

Jury
Pf. René Hen – Columbia University – New York City
Pf. Sandrine Thuret – King’s College – London
Dr. Luisa V. Lopez – Lisbon University – Lisbon
Dr. Luisa Pinto – Minho University – Minho
Dr. Nora Abrous – Université de Bordeaux – Bordeaux (Directrice de thèse)
Dr. Vanessa Charrier – Université de Bordeaux – Bordeaux (Membre invité – Co-superviseure)

Publications
1. The temporal origin of dentate granule neurons dictates their role in spatial memory – Molecular Psychiatry 2021 (26, 7130–7140, 2021) Masachs N*, Charrier V*, Farrugia F, Lemaire V, Blin N, Mazier W, Tronel S, Montaron MF, Ge S, Marsicano G, Cota D, Deroche-Gamonet V, Herry C, Abrous DN.

2. Responsiveness of dentate neurons generated throughout adult life is associated with resilience to cognitive aging – Aging Cell 2020 (Aug;19(8):e13161) Montaron MF*, Charrier V*, Blin N, Garcia P, Abrous DN.
Date de la soutenance: 14/12/2023 - 09h30
Lieu: Centre Broca

Pièces jointes

Meeting room: Neurocentre Magendie Seminar room

from Tokyo University, will give a presentation entitled 'LACCO series: Genetically encoded fluorescent L-lactate biosensors for neuroscience'

Invited by Giovanni Marsicano

Yusuke Nasu
https://www.s.u-tokyo.ac.jp/en/people/nasu_yusuke/
https://orcid.org/0000-0002-3193-9104

Abstract
Organisms on Earth produce biologically-useful energy by catabolizing glucose to pyruvate which, in the absence of oxygen, is normally converted into L-lactate. Traditionally, L-lactate has been considered “waste” by-products of glucose metabolism. However, growing evidence suggests that L-lactate is better considered a biological “fuel currency”, that can be shuttled from cell-to-cell and plays a central role in the energy supply for organisms. For example, the astrocyte-to-neuron lactate shuttle (ANLS) hypothesis proposes that astrocytes metabolize glucose to produce L-lactate which is then released to the extracellular environment and taken up by neurons. In neurons, L-lactate is converted to pyruvate which is fed into the tricarboxylic acid cycle (TCA) for production of adenosine triphosphate (ATP) which provides energy necessary to sustain heightened neural activity. The ANLS hypothesis remains a controversial mystery, with recent reports of evidence both for and against it.
Fluorescent proteins (FPs) have been proven to be versatile scaffolds for development of biosensors (protein constructs that change their fluorescence intensity in response to changes in the environment). Specifically, GCaMP, a calcium ion (Ca2+) sensor based on green FP (GFP) and Ca2+ sensing domains, has been widely employed to monitor neural activities in live model organisms. In addition to GCaMP, various FP-based biosensors for non-Ca2+ target have been developed. However, few sensors have sensitivity as high as GCaMP, hampering their wide application in vivo.
Herein, we show that directed protein evolution can enable the engineering of FP-based biosensors for an important metabolite L-lactate with high sensitivity comparable to GCaMP. This study provides a powerful new optical toolbox, LACCO series, for the investigation of extracellular and intracellular L-lactate in neurons and astrocytes. We anticipate that the LACCO series will play a central role in investigations of L-lactate shuttles, including the controversial ANLS hypothesis.