Role of the thalamic reuniens nucleus in spatial memory in rats

Description

Spatial memory involves different brain regions, primarily the hippocampus (HPC) and the medial prefrontal cortex (mPFC), which synchronize during acquisition and sleep to encode and consolidate information. The thalamic reuniens nucleus (NR) is an anatomical relay between the HPC and mPFC. Our main aim is to determine whether it is also a functional relay that could modulate HPC-mPFC synchronization underlying the memorization of a spatial memory.
Within this framework, one of our objectives is to evaluate the impact of chronic chemogenetic inhibition of the NR on memory performance whilst recording electrophysiological activity in the three regions.
During this internship, adult rats will initially be injected with a virus allowing the expression of a DREADD in the NR, then implanted with multi-site electrodes (silicon probes) to collect activity from the mPFC, HPC and NR before and after taking DCZ (a selective inhibitory DREADD ligand provided in drinking water). Activity (aka field potentials and action potentials) will be collected during different vigilance states (wakefulness, sleep, activity) and during an object displacement task.
Surgeries will be performed by members of the host team. The student will learn and experience animal handling, collection of electrophysiological and behavioural data, their analysis (toolboxes in Matlab) and post-hoc histological verifications.

Profil recherché

Student enrolled in the NCC programme, with solid knowledge in neurophysiology, and interest in the study of animal behaviour and in data science (basic knowledge of data processing, statistics, & Matlab programming is a plus).

Établissement d'accueil

The M2 internship will take place at the Institut de Neurosciences des Systèmes, on the Campus Santé of La Timone.
The intern will be supervised by Pascale Quilichini (PhysioNet team). The PhysioNet team is an international team of researchers from diverse backgrounds, pooling expertise in biology, physics, and mathematics. Our work aims at understanding how neuronal network dynamics allow the exchange of information between brain areas in physiological and pathological conditions. We investigate how the information encoded in one neural structure can modulate the encoding in another area (and the other way around), how these interactions orchestrate perception, learning, and behaviour, and how these processes are affected in epilepsy. We use high-density recordings of individual neurons simultaneously in multiple brain sites of freely behaving rats (healthy or epileptic) performing memory tests and then use data mining and analysis to study neural population dynamics.