ScanImage Enables Cutting Edge Visual Cortex Research
Complex imaging and experimental tasks must happen quickly in a smooth workflow so that experiments can be performed within the time constraints imposed by working with behaving animals. ScanImage is the software of choice for controlling your scanning microscopy experiments because it provides robust cutting edge imaging features coupled with the ability to automate and time workflows like no other application can. A key feature of ScanImage is the capability to synchronize with external data streams coming from other experimental apparatuses.
A recent paper by Wilson et. al (Nature Neuroscience, 2016) used elegant 2-photon imaging studies to shed new light on the complex mechanisms of visual cortex response to visual stimuli. The now classic studies by Hubel and Wiesel in the 1960s established that there are orientation selective neuronal responses arranged in columnar systems within the visual cortex of cats and monkeys. This work has been extended by other investigators into additional species and detailed neuronal maps have been created documenting the physical location of neurons that respond selectively to the orientation of edges. Over the decades several studies have attempted to elucidate the mechanism by which this type of selective neuronal activity can arise in response to visual stimuli. Like other studies, work by Wilson et. al at The Max Planck Florida Institute for Neuroscience confirmed that both neuronal soma and spines demonstrate orientation selective activity. As the authors noted, “The orientation preference of the summed spine inputs strongly predicted somatic orientation preference…” However, orientation selectivity was not completely explained by a simple summation of synaptic inputs. Through detailed imaging studies the authors demonstrated that the activity and clustering of co-tuned synaptic inputs within dendritic branches was a critical component of the mechanism that gives rise to selective somatic activity.
Dendritic spine imaging using ScanImage
The data that supports the conclusions in the Wilson et. al paper resulted from imaging more than 2,000 dendritic spines in eight animals using ScanImage on a Thorlabs b-scope.(add Figure here) The ScanImage, b-scope combination provides several technical advantages when performing this type of experiment. First, the 2 inch optical path of the b-scope provides exceptional light gathering and resolving capabilities allowing small synaptic structures to be nicely resolved. In addition, ScanImage provides the fast and sensitive data acquisition pipeline necessary not only for producing a crisp image but also for synchronizing with external data streams that are necessary for performing the overall experiment. In order to determine orientation selective somatic or spine activity, accurate time synchronization has to be maintained between imaging and the visual stimulus display. Wilson et. al. also described using ScanImage frame triggers to synchronize experimental workflow with the electrophysiology software Spike2. Vidrio engineers have invested 100’s of hours working directly with scientists to understand and optimize how ScanImage handles complex workflows like that described by Wilson et. al.