An in vitro toolbox to study synaptic connectivity in health and disease
-
1
Laboratory of Cell Biology and Histology, University of Antwerp, Belgium
-
2
Janssen Pharmaceutica, Research and Development - CNS group, Belgium
During brain development, orchestrated activation of genetic programs, as well as spontaneous electrical activity guide the correct wiring of neuronal networks. Mature neuronal networks are characterized by the expression of synaptic markers, synchronized electrical activity and the presence of dendritic spines, tiny protrusions from the dendritic shaft that compartmentalize single synapses to ensure optimal regulation of synaptic strength. Neurodevelopmental disorders such as schizophrenia are thought to result from defective neuronal network formation, while neurodegenerative disorders like Alzheimer’s disease are characterized by progressive loss of synapses and associated mild cognitive impairment long before actual neurodegeneration occurs.
We established an in vitro model that recapitulates features of mature neuronal networks, based on primary hippocampal neurons isolated from mouse E18 embryos. In addition, we optimized a variety of microscopy workflows to quantitatively characterize both morphological (neurite outgrowth, synapse density, dendritic spine density) and functional (spontaneous electrical activity) aspects of the established neuronal networks (Cornelissen et al. 2013; Pani et al. 2014; Verstraelen et al. 2014).
Using calcium imaging as a proxy for electrical activity, we pinpointed a critical period in which stochastic activity of individual neurons turned into robust, synchronized network activity, indicative of the formation of functional synapses. This synchronization coincided with an increase in neurite outgrowth and synapse density, while dendritic spine density increased only after synchronization of the activity, suggesting that the latter enable fine-tuning of synaptic connections. We further showed that synchronized network activity is mediated by the NMDA receptor, and that interference with microtubule stability alters the bursting pattern.
In brief, we have established a robust platform for pharmacological and/or genetic interrogation of synaptic connectivity in in vitro neuronal networks. Our approach is easily amenable to upscaling, which makes it an attractive model for high content screening in the context of neurodevelopmental or neurodegenerative disorders.
References
Cornelissen F, Verstraelen P, Verbeke T, Pintelon I, Timmermans JP, Nuydens R, Meert T (2013) Quantitation of chronic and acute treatment effects on neuronal network activity using image and signal analysis: toward a high-content assay. Journal of biomolecular screening 18 (7):807-819. doi:10.1177/1087057113486518
Pani G, De Vos WH, Samari N, de Saint-Georges L, Baatout S, Van Oostveldt P, Benotmane MA (2014) MorphoNeuroNet: an automated method for dense neurite network analysis. Cytometry Part A : the journal of the International Society for Analytical Cytology 85 (2):188-199. doi:10.1002/cyto.a.22408
Verstraelen P, Pintelon I, Nuydens R, Cornelissen F, Meert T, Timmermans JP (2014) Pharmacological characterization of cultivated neuronal networks: relevance to synaptogenesis and synaptic connectivity. Cellular and molecular neurobiology 34 (5):757-776. doi:10.1007/s10571-014-0057-6
Keywords:
hippocampal neurons,
synaptogenesis,
Synaptic Transmission,
neuronal network,
Microscopy, Fluorescence,
Dendritic Spines,
high content imaging,
Neurodevelopmental disorders,
Neurodegenerative Diseases,
in vitro model
Conference:
11th National Congress of the Belgian Society for Neuroscience, Mons, Belgium, 22 May - 22 May, 2015.
Presentation Type:
Oral or Poster presentation
Topic:
Neuroscience
Citation:
Verstraelen
P,
Detrez
JR,
Pintelon
I,
Nuydens
R,
Meert
T,
De Vos
WH and
Timmermans
J
(2015). An in vitro toolbox to study synaptic connectivity in health and disease.
Front. Neurosci.
Conference Abstract:
11th National Congress of the Belgian Society for Neuroscience.
doi: 10.3389/conf.fnins.2015.89.00010
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
05 May 2015;
Published Online:
05 May 2015.
*
Correspondence:
Dr. Peter Verstraelen, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium, peter.verstraelen@uantwerpen.be