Studying Epilepsy in Awake Head-Fixed Mice Using Microscopy, Electrophysiology, and Optogenetics

Studying Epilepsy in Awake Head-Fixed Mice Using Microscopy, Electrophysiology, and Optogenetics

DATE: THU, OCTOBER 8, 2020

TIME: 11:00 AM EDT (UTC -4)

Experts discuss how microscopy, electrophysiology, and optogenetics are used to study microglial calcium signaling and epileptic networks in awake head-fixed mice.

Epilepsy research employs sophisticated research methods such as fluorescence optical imaging and optogenetics, as well as novel electrophysiological techniques, to address unresolved questions about seizure generation and propagation on the cellular and circuitry levels. Since epilepsy research is most relevant when performed in non-anesthetized mice, it requires specialized tools that ensure stable head fixation during high-precision imaging and recordings.

In this webinar, Dr. Anthony Umpierre (Prof. LongJun Wu group, Mayo Clinic, USA) and Prof. Rob Wykes (UCL, UK) present their research on microglial calcium signaling and epileptic networks carried out in awake head-fixed mice. In addition to sharing exciting new findings, the presenters address the challenges of working with awake mice.

Key topics will include…

  • Mesoscopic investigations of seizure dynamics and propagation using widefield calcium imaging
  • Generating full-bandwidth electrophysiological recordings enabled by graphene micro-transistors to detect spreading depolarizations and seizures
  • On-demand optogenetic induction of spreading depolarizations to investigate pharmacological suppression in the awake brain
  • The impact of acute versus chronic window preparations on microglial calcium activity
  • The use of genetically encoded calcium indicators to study calcium dynamics in microglia
  • The effects of bi-directional shifts in neuronal activity caused by kainate-triggered status epilepticus and isoflurane anesthesia on microglial calcium
 Neuronal calcium traces recorded in awake, head-fixed mice

Neuronal calcium traces recorded in awake, head-fixed mice

About the Presenters:

Robert Wykes, PhD
Senior Research Fellow at UCL Queen Square Institute of Neurology,
Senior Lecturer at The University of Manchester, Dept.of Nanomedicine

Dr. Wykes is a Senior Research Fellow at the UCL Queen Square Institute of Neurology and a Senior Lecturer in the Nanomedicine Lab at the University of Manchester. He is well regarded for development of novel technology and therapies to investigate and treat seizures. He was amongst the first to adapt in vivo optogenetic and calcium imaging approaches to epilepsy research, and established the efficacy of a potassium channel gene therapy approach in preclinical models. More recently as a partner on the European Commission Graphene Flagship Project he has been characterising in vivo graphene micro-transistors capable of full bandwidth electrographic recordings. These devices promise to facilitate detection and therefore improved understanding of the role spreading depolarisations play in several neurological disorders including epilepsy.

Anthony Umpierre, PhD
Postdoctoral Researcher at Mayo Clinic, Dept. of Neurology

Dr. Umpierre is interested in how glial cells shape neuronal circuits in the basal state and during the pathological progression towards epilepsy. In his graduate work, he studied how astrocytes heighten their sensitivity to neuronal glutamate release after status epilepticus—a prolonged seizure condition that may precipitate epilepsy development. In response, astrocytes increase their glutamate uptake in the latent period preceding epilepsy, representing a potentially neuroprotective mechanism. In his postdoctoral work, he studies the role of purinergic signaling in shaping microglial responses to shifts in neuronal activity across a physiological and pathophysiological range. His work focuses on calcium signaling in brain slice and awake mice using two-photon microscopy to study glial function, combined with pharmacology, single-cell recording, EEG, and chemogenetic approaches.