ABC Seminar: In Vivo Magnetic Recording of Neuronal Activity, and Functions of Brain Rhythms

Welcome to our ABC Seminars! This seminar series is open for everyone. The talk will take place in Otakaari 3, F239a Auditorio. After the talks, coffee and pulla will be served.

The event will be also streamed via Zoom at: https://aalto.zoom.us/j/67444945844

Title: In Vivo Magnetic Recording of Neuronal Activity, and Functions of Brain Rhythms

Abstract:This talk will have two parts, one on magnetic recordings and one on brain rhythms and their functions. I will first show that giant magnetoresistance (GMR) sensors can be miniaturized to micron size, and then introduced into the brain to record both event-related fields from groups of neurons and action potentials of isolated single neurons. I will then show that brain rhythms likely subserve functions. For example, when visual stimuli are repeated, they induce reduced firing rates yet enhanced gamma-band synchronization, likely to maintain postsynaptic impact. This impact is indeed optimal for gamma-rhythmic inputs, as I will show by controlling inputs with optogenetics. Optogenetics can also be used to control top-down inputs. I will show that this Opto-Top-Down induces strong, up to several fold, changes in gamma-band synchronization together with much smaller changes in firing rate and no correlation between the two effects.