Detection of input sites in scanning photostimulation data based on spatial correlations

Journal of Neuroscience Methods 192(2), pp. 286-295

Authors: Bendels, M.H.K., Beed, P., Schmitz, D., Johenning, F.W., Leibold, C.
Year: 2010
Source: Journal of Neuroscience Methods 192(2), pp. 286-295
Link: http://linkinghub.elsevier.com/retrieve/pii/S0165027010004474

Abstract:
Scanning photostimulation is a well-established method for studying the functional microcircuitry in brain slices. Light-evoked responses are thereby taken as an indicator for a connected presynaptic partner. Such an approach thus requires a clear distinction between the photo-evoked and the spontaneous responses. Here we show that, for a data set from entorhinal cortex layer II with high spontaneous synaptic rates of up to 10 Hz, it is possible to identify presynaptic sites. The underlying detection algorithm is based on the finding that a presynaptic cell has several neighboring activation sites, resulting in the clustered appearance of specific photo-evoked inputs. The main idea behind this approach is to identify “hit” locations at which the number of intracellularly recorded synaptic events is significantly larger as expected from the hypothesis of statistical independence. The algorithm works without making use of EPSC amplitude information and for single trials, i.e., each site is stimulated only once. The hit maps are tested upon reliability by repeated stimulations and by blocking synaptically mediated responses via TTX. Furthermore, based on the hit density of surrogate data, we devise a Bayesian formalism to estimate the number of presynaptic partners. In these simulations we find good agreement between estimated and real number of input cells, which shows that the hit density can be used as a reliable measure for afferent connectivity.

Affiliations: Division of Neurobiology, Ludwig-Maximilians-Universität München, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany; Bernstein Center for Computational Neuroscience Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany; NeuroScience Research Center, Charite Berlin, Chariteplatz 1, 10557 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, Philippstr. 13, 10115 Berlin, Germany

Keywords: Laser scanning photostimulation; Optical uncaging; Functional anatomy; Entorhinal cortex
Document Type: Research article
DOI: 10.1016/j.jneumeth.2010.08.006

Morgentau M1 microscope software

Our software application, the microscope software Morgentau M1, allows comfortable controlling high-end microscope systems with an ordinary computer: controlling XYZ-stages, autofocus, time lapse, photostimulation capabilities and many other features.

More: Control software for Luigs and Neumann shifting tables and micromanipulators

Navigation Module

Scanning Module

References: research institutes

See which leading research institutes rely on the microscope software Morgentau M1.

References: research projects

See the publications that employ the microscope software Morgentau M1.