Single-Cell Electrophysiology and 2-Photon Imaging in Awake Mice with 2D-Locomotion Tracking

Single-Cell Electrophysiology and 2-Photon Imaging in Awake Mice with 2D-Locomotion Tracking

Scientists present methodology and research findings from neurophysiological studies in head-fixed, behaving mice.

Neuroscience research in freely behaving animals is inherently challenging for techniques that require a high degree of precision, such as 2-photon imaging, single-cell optogenetics and patch clamp recording. Scientists are forced to use general anesthesia to immobilize animals for single-cell recording and microscopy. Unfortunately, anesthetics have a profound physiological impact that compromises data quality and translational relevance.

In this webinar sponsored by Neurotar, experts present their research utilizing the Mobile HomeCage®, an experimental tool which ensures the stability required for high-precision neurophysiological techniques while allowing mice to navigate and explore their environment.

Case Study #1:
Dr. Sarah Stuart and Dr. Jon Palacios-Filardo of the University of Bristol present their studies combining analysis of goal-directed behavior with whole-cell recordings from the hippocampus of awake mice. The researchers share useful tips for the surgery protocol and for adjusting the head fixation angle in order to facilitate mouse motility and exploratory behavior.

Case Study #2:
Dr. Alexander Dityatev and Weilun Sun from the German Center for Neurodegenerative Diseases (DZNE) discuss 2-photon imaging of fluorescently labeled microglia in vivo in the context of neurodegenerative disease. They also present their recent data on the effects of different anesthetics on the microglial response to localized laser injury.

Case Study #3:
Dr. Norbert Hájos from the Hungarian Academy of Sciences presents his lab’s research into the amygdala’s role in reward-driven behavior. He shares the challenges of making single-unit recordings using silicon probes during mouse locomotion and subsequent morphological identification of active neurons in the amygdala.

Key topics covered during this webinar include…

  • Requirements for stable single-cell recordings and 2-photon imaging in behaving mice
  • Challenges of combining high-precision techniques with behavioral research
  • Methodological considerations for improving exploratory behavior in head-fixed mice
  • Quantitative analysis of microglial function using 2-photon microscopy in awake mice
  • Recording neuronal activity in the amygdala of awake mice followed by morphological identification of recorded neurons

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Jon Palacios-Filardo, PhD

Sarah Stuart, PhD

Jack Mellor Lab
School of Physiology, Pharmacology & Neuroscience,
University of Bristol, UK

Our ability to learn and remember information about our environment is underpinned by synaptic plasticity. This process is fundamental to shaping who we are as individuals and is also implicated in many neurological and psychiatric disorders. Memory is fundamentally dependent on the behavioural context of learnt information and we aim to investigate the contextual factors that are important for the encoding of memory by synaptic plasticity at a neuronal circuit level. 

At the Mellor Lab, we study this by considering the factors that regulate the induction of synaptic plasticity and the mechanisms underlying its expression. Current projects include:

  • The role of acetylcholine and other neuromodulators in synaptic circuit function.
  • The patterns of activity that induce synaptic plasticity.
  • The mechanisms underlying postsynaptic neurotransmitter receptor trafficking.

We use a combination of techniques including in vitro and in vivo electrophysiology, 2-photon imaging, optogenetics, behavioural assays and computational modelling.

Alexander Dityatev, PhD

Weilun Sun

Alexander Dityatev Lab
Molecular Neuroplasticity,
DZNE – German Center for Neurodegenerative Diseases,
Madgeburg, Germany

Our studies demonstrate that attenuation of the neural ECM, particularly in the form of hyaluronic acid and chondroitin sulfate-rich perineuronal nets, is found in the ketamine model of schizophrenia and may result in epileptiform activity. The mechanisms underlying ECM attenuation involve an upregulation of the activities of matrix metalloproteinases, such as ADAMTS4/5 and MMP-9. They appeared to be under the control of dopaminergic and serotoninergic systems, involving D1-like and 5-HT7 receptors, respectively.

Our pioneering works revealed the role of ECM in synaptic plasticity. For example, tenascin-C supports induction of long-term potentiation (LTP) at CA3-CA1 synapses and the extinction of fear memories by regulation of L-type voltage-gated Ca2+ channels. Similarly, hyaluronic acid regulates synaptic plasticity through these channels. Another mechanism involves a control of axonal excitability by heparan sulfates. In vivo, heparinase treatment impairs context discrimination in a fear conditioning paradigm and oscillatory network activity in the low theta frequency band.

Norbert Hajós, PhD, DSc

Norbert Hájos Lab
Institute of Experimental Medicine,
Hungarian Academy of Sciences,
Budapest, Hungary

Our research group is most interested in the cellular and synaptic mechanisms underlying the neural network operation in the cortical areas. 

The main goal of our research is to uncover the principles of information processing in cortical microcircuits at cellular and network levels. To this end, we examine the features of the connections among neurons using neuroanatomy, electrophysiology, imaging techniques combined with optogenetics.

At present, we study the circuit organization of amygdala networks with a specific focus on its basal nucleus. In addition, we examine how brain structures including the prefrontal cortex and basal forebrain modify information processing in the basal nucleus of the amygdala at the synaptic and circuit levels. Our results may help to understand how amygdalar neural circuits promote establishing fear memories both in normal and pathological circumstances.