Instituição: ICVS – Escola de Medicina, Universidade do Minho
Responsável: João Filipe Oliveira
Contacto: joaooliveira@med.uminho.pt
Tema da Dissertação: The other brain: astrocytes, the stars of the brain, are modulators of neuronal function and behavior computation. Dissecting electrophysiological fingerprints of astrocytes in brain circuits in cognition and depression.

Descrição da Dissertação:

Summary: An exciting body of evidence in the past years challenged the classical paradigm that brain information processing is exclusively neuronal. Indeed, the importance of astrocytes (star-shaped, about 20% of all brain cells) is rising due to emerging data describing dynamic neuron-glia interactions. Nevertheless, little is known about the involvement of astrocytes in the circuit computation of complex behavior outputs. Our laboratory has been working on this topic (e.g., Lima et al. 2014 Molecular Psychiatry IF=14.5), and we showed recently that the blockade of neurotransmitter release by astrocytes in vivo to induces loss of neuronal oscillations theta synchrony, affecting learning and memory (work of Vanessa Sardinha, former Biomedical Engineering MSc student: Sardinha et al., 2017 Glia IF=8.1). We recently produced a worldwide consensus statement on the role of astrocytes in health and disease contexts (Escartin et al. 2021 Nature Neuroscience IF=24.9).  Our lab uses rodent models to allow the recording and manipulation of neuronal networks in freely behaving animals. The use of this technique for the study of astrocyte function is unique in this field of neuroscience worldwide. We also use behavioral, optogenetic, and chemogenetic manipulation of brain circuits.

The project will be supervised by: João Filipe Oliveira, PhD (ICVS, School of Medicine, U. Minho; neurophysiology, electrophysiology); Marcelo Dias, PhD (ICVS – Escola de Medicina, electrophysiology, microelectronics, signal analysis).

Aims: This project aims to address the electrophysiological correlates of this astrocyte modulation by using an innovative recording and analysis of neuronal signals in anesthetized and behaving (freely behaving) mice. This project proposal seeks 1 or 2 students to carry out these tasks individually or in combination:

• focus on microelectronics and signal recording in behaving animals;
• focus on data analysis and implementation of available algorithms/electrophysiological measures. The final structure of the project will be discussed with the student(s) to meet the expectations for the dissertation.

Work plan: Transgenic mouse lines will be employed: e.g., IP3R2KO mice that display silent astrocytes, i.e., unable to process neuronal signals. By assessing its neural signatures during learning and memory tasks, we expect to dissect the net role of astrocytes in these functions. These results will ultimately provide insights into the roles of astrocytes in the human brain in health and disease contexts. Our laboratory has all equipment, technical requirements, and reagents available for the project to take place. This project is part of our recently funded laCaixa Foundation Grant to study the physiology of cortico-limbic circuits involved in cognition and depression. The overall budget is 0.5 million Euro and includes support to carry out these MSc dissertations, and fellowships to pursue PhD. More information under: https://fundacionlacaixa.org/en/caixaresearch-health-call-2021-project-depression-therapies.

Skills and techniques: The student will learn to record and analyze neural signals such as local field potentials (LFP) and single-unit activity (spikes) on the temporal and frequency domains to correlate with specific behavior outputs, using/adapting existing routines. Students can enroll in the project in one or both following tasks:

   – construct/implant wire electrodes (stereodes or tetrodes) or commercially available probes and collect electrophysiological data from anesthetized or freely-moving/behaving mice;

   – handle and analyze data obtained using Matlab/Python scripts to correlate the performances obtained in the tests with the electrophysiological activity recorded from the hippocampus and prefrontal cortex, regions involved in these tasks.

Período durante o qual o estudante poderá realizar a Dissertação: A discutir
Data a partir da qual a oportunidade poderá ser divulgada: Logo que possível.