In this presentation, faculty cover some of the major caveats to optogenetics experiments, at the conceptual and technical level. Specifically:

• Stephan Lammel discusses the importance of careful methodological considerations for interpreting the results of optogenetic experiments.
• Karel Svoboda highlights some of the many potential unexpected effects of optogenetics perturbation in the context of neural circuit dynamics and behavior.
• David Kupferschmidt shares how diverse forms of synaptic plasticity and complex neurochemistry can complicate our ability to infer direct “causation” from optogenetics experiments.

After watching this presentation, you should be able to:

• Understand and control for potential confounds of optogenetics manipulations that involve non-cell-type-specific expression of opsins, toxicity, tissue heating, and scattered light delivery.
• Understand how to turn potential unexpected effects of optogenetics manipulation to your advantage using neurophysiological characterization of the system response optogenetics perturbation.
• Understand and minimize the potential confounds of synaptic plasticity and complex neurochemistry in the interpretation of optogenetics experiments.

Visit the Community forum for all eight modules to share your insights and best practices, ask questions, and engage with other training series’ participants.

Speakers

Stephan Lammel, PhD

Stephan Lammel is an assistant professor in the department of molecular and cell biology and the Helen Wills Neuroscience Institute at the University of California, Berkeley. His research focuses on understanding how brain circuits that use the neurotransmitter dopamine contribute to different aspects of motivated behavior. He earned his PhD in neuroscience from Philipps-University in Marburg (Germany) and completed his postdoctoral training at Stanford University.

Karel Svoboda, PhD

Karel Svoboda is a senior group leader at HHMI’s Janelia Research Campus. Svoboda’s work is at the intersection of neuronal biophysics and cognition. A current focus is to identify core principles underlying information processing in cortical circuits and related structures in the context of planning and execution of voluntary movements. He is also developing new methods to interrogate neural function in intact brains. Previously, he was a principal investigator at Cold Spring Harbor Laboratories. Svoboda earned a PhD in biophysics from Harvard University and was a postdoctoral fellow at Bell Laboratories.

David Kupferschmidt, PhD

David Kupferschmidt is the staff scientist for the Integrative Neuroscience Section at NIH National Institutes of Neurological Disorders and Stroke. In collaboration with principal investigator Joshua Gordon, Kupferschmidt guides research into the neural circuit basis of working memory and its dysfunction in mouse models of genetic susceptibility to neuropsychiatric disease, particularly schizophrenia. He earned his PhD in psychology from the University of Toronto, studying the neurochemistry of stress and relapse to drug seeking. During his postdoctoral training at NIH National Institute on Alcohol Abuse and Alcoholism, Kupferschmidt combined neurophysiology with optical, viral, and transgenic tools to assess synaptic and circuit mechanisms of skill and habit learning.

The articles below were selected by Stephan Lammel, Karel Svoboda, and David Kupferschmidt, faculty from Module 8 of SfN’s Optogenetics Training Series, to supplement their presentation, Caveats for Designing and Interpreting Optogenetics Approaches.

Use these resources to better understand and control for some of the major caveats related to designing, conducting, and interpreting the results from optogenetic experiments.

Resources Related to Stephan Lammel’s Presentation, Challenges of Designing Interpretable Optogenetics Experiments

Principles of Designing Interpretable Optogenetic Behavior Experiments

Allen, Singer and Boyden provide a conceptual review relevant to the topic of designing and interpreting optogenetics experiments.

Diversity of Transgenic Mouse Models for Selective Targeting of Midbrain Dopamine Neurons

In this 2015 paper, Lammel et al. show a prominent and supposedly dopamine-specific transgenic mouse line exhibits dramatic non-dopamine specific expression patterns in the ventral midbrain. This result corresponds to case study one discussed by Lammel.

Achieving High-Frequency Optical Control of Synaptic Transmission

Jackman et al. show optically-evoked responses can show abnormal synaptic depression when compared to electrical stimulation, and that these responses depend on the specific serotype of the adeno-associated virus expression vector used and the targeted brain region. This result corresponds to case study two outlined by Lammel.

Targeting Neurons and Photons for Optogenetics

In this conceptual review from 2013, Packer, Roska, and Häusser describe technical considerations and potential confounds of optogenetic experiments.

Optogenetics in Neural Systems

Yizhar et al. provide an extensive review on the application of optogenetics in neuroscience and highlight important challenges and technical considerations.

Resources Related to Karel Svoboda’s Presentation, Interpreting Optogenetics Experiments: It’s Tricky… and Requires Neurophysiology

Genetic Dissection of Neural Circuits: A Decade of Progress

Luo, Callaway, and Svoboda provide an extensive review of methods for analysis of neural circuits, with a substantial focus on optogenetics. This resource is written for beginning graduate students or researchers new to the field.

Cell Type-Specific and Time-Dependent Light Exposure Contribute to Silencing in Neurons Expressing Channelrhodopsin-2

Herman et al. show photostimulation of ChR2-expressing neurons in certain types of neurons can cause depolarization block and inactivate these neurons in a cell autonomous manner. This result corresponds to case study 1 described by Svoboda.

Gain Control by Layer Six in Cortical Circuits of Vision

Oleson et al. demonstrate how photostimulation of ChR2-expressing L6 neurons silences neurons in other cortical layers. This result corresponds to case study two shared by Svoboda.

Flow of Cortical Activity Underlying a Tactile Decision in Mice

Guo et al. report how photostimulation of ChR2-expressing fast-spiking neurons can be used to inactivate one millimeter brain volumes with approximately 10 millisecond temporal resolution (photoinhibition). This paper identifies a frontal cortical area (anterior lateral motor cortex) using an unbiased photoinhibition screen. This result corresponds to case study three highlighted by Svoboda.

Robust Neuronal Dynamics in Premotor Cortex During Motor Planning

Li, Daie, Svoboda, and Druckmann show memory traces in the context of motor planning are distributed across multiple brain regions. The distributed nature of this representation produces robustness to perturbation. This result corresponds to case study three explained by Svoboda.

Navigating the Neural Space in Search of the Neural Code

Jazayeri and Afraz provide a conceptual review relevant to the topic of interpreting optogenetic experiments.

Resources that support David Kupferschmidt’s presentation, Synaptic Plasticity and Complex Neurochemistry

Engineering a Memory with LTD and LTP

Nabavi et al. provide clear examples of how optical stimulation can drive bidirectional synaptic plasticity with stark consequences for the expression of conditioned fear responses.

Bidirectional and Long-Lasting Control of Alcohol-Seeking Behavior by Corticostriatal LTP and LTD

Ma et al. demonstrate how optically-induced potentiation and depression of corticostriatal inputs can bidirectionally alter ethanol self-administration behavior.

Dopaminergic Terminals in the Nucleus Accumbens but Not the Dorsal Striatum Corelease Glutamate

Stuber et al. provide direct evidence of the co-release of glutamate and dopamine from genetically defined dopamine neurons in the mammalian ventral midbrain.

Dopaminergic Neurons Inhibit Striatal Output Through Non-Canonical Release of GABA

Tritsch, Ding, and Sabatini provide evidence supporting the co-release of GABA and dopamine from genetically defined dopamine neurons in the mammalian ventral midbrain.

Visit the Community forum for all eight modules to share your insights and best practices, ask questions, and engage with other training series’ participants.

Complete this short survey to provide valuable feedback about Module 8 to SfN and the series faculty.

Optogenetics is an incredibly powerful technique for investigating neural circuits and brain function. However, there are numerous caveats to consider when designing, conducting, and interpreting results from optogenetic experiments.

SfN members have the opportunity to submit questions about these caveats August 1–30 to Stephan Lammel, Karel Svoboda, and David Kupferschmidt in a Neuronline Community discussion thread.

If you are unable to log in to the forum, please email your questions to digitallearning@sfn.org.

It is encouraged you first watch their video presentation, Module 8A Caveats for Designing and Interpreting Optogenetics Approaches.

Visit the Community forum for all eight modules to share your insights and best practices, ask questions, and engage with other training series’ participants.

Complete this short survey to provide valuable feedback about Module 8 to SfN and the series faculty.

Speakers

Stephan Lammel, PhD

Stephan Lammel is an assistant professor in the department of molecular and cell biology and the Helen Wills Neuroscience Institute at the University of California, Berkeley. His research focuses on understanding how brain circuits that use the neurotransmitter dopamine contribute to different aspects of motivated behavior. He earned his PhD in neuroscience from Philipps-University in Marburg (Germany) and completed his postdoctoral training at Stanford University.

Karel Svoboda, PhD

Karel Svoboda is a senior group leader at HHMI’s Janelia Research Campus. Svoboda’s work is at the intersection of neuronal biophysics and cognition. A current focus is to identify core principles underlying information processing in cortical circuits and related structures in the context of planning and execution of voluntary movements. He is also developing new methods to interrogate neural function in intact brains. Previously, he was a principal investigator at Cold Spring Harbor Laboratories. Svoboda earned a PhD in biophysics from Harvard University and was a postdoctoral fellow at Bell Laboratories.

David Kupferschmidt, PhD

David Kupferschmidt is the staff scientist for the Integrative Neuroscience Section at NIH National Institutes of Neurological Disorders and Stroke. In collaboration with principal investigator Joshua Gordon, Kupferschmidt guides research into the neural circuit basis of working memory and its dysfunction in mouse models of genetic susceptibility to neuropsychiatric disease, particularly schizophrenia. He earned his PhD in psychology from the University of Toronto, studying the neurochemistry of stress and relapse to drug seeking. During his postdoctoral training at NIH National Institute on Alcohol Abuse and Alcoholism, Kupferschmidt combined neurophysiology with optical, viral, and transgenic tools to assess synaptic and circuit mechanisms of skill and habit learning.

In this video panel discussion, Stephan Lammel, Karel Svoboda, and David Kupferschmidt answer questions related to their Module 8 presentations. Topics include assessing potential channelrhodopsin induced toxicity, determining direct versus circuit effects of optogenetic manipulation, reliability of wireless optogenetic hardware, and others.

Visit the Community forum for all eight modules to share your insights and best practices, ask questions, and engage with other training series’ participants.

Speakers

Stephan Lammel, PhD

Stephan Lammel is an assistant professor in the department of molecular and cell biology and the Helen Wills Neuroscience Institute at the University of California, Berkeley. His research focuses on understanding how brain circuits that use the neurotransmitter dopamine contribute to different aspects of motivated behavior. He earned his PhD in neuroscience from Philipps-University in Marburg (Germany) and completed his postdoctoral training at Stanford University.

Karel Svoboda, PhD

Karel Svoboda is a senior group leader at HHMI’s Janelia Research Campus. Svoboda’s work is at the intersection of neuronal biophysics and cognition. A current focus is to identify core principles underlying information processing in cortical circuits and related structures in the context of planning and execution of voluntary movements. He is also developing new methods to interrogate neural function in intact brains. Previously, he was a principal investigator at Cold Spring Harbor Laboratories. Svoboda earned a PhD in biophysics from Harvard University and was a postdoctoral fellow at Bell Laboratories.

David Kupferschmidt, PhD

David Kupferschmidt is the staff scientist for the Integrative Neuroscience Section at NIH National Institutes of Neurological Disorders and Stroke. In collaboration with principal investigator Joshua Gordon, Kupferschmidt guides research into the neural circuit basis of working memory and its dysfunction in mouse models of genetic susceptibility to neuropsychiatric disease, particularly schizophrenia. He earned his PhD in psychology from the University of Toronto, studying the neurochemistry of stress and relapse to drug seeking. During his postdoctoral training at NIH National Institute on Alcohol Abuse and Alcoholism, Kupferschmidt combined neurophysiology with optical, viral, and transgenic tools to assess synaptic and circuit mechanisms of skill and habit learning.