Transposon-mediated genetic manipulation of OPCs to study their role in synapse formation

Oligodendrocyte precursor cells (OPCs) are best known as precursor cells that generate myelinating oligodendrocytes. In demyelinating disorders such as multiple sclerosis, OPCs are an important source of remyelinating cells. OPCs exist abundantly not only during development when myelinating cells are generated but also in the mature brain in the gray matter as well as white matter. This suggests that OPCs may be involved in cellular functions other than generating myelinating oligodendrocytes. Unlike other non-neuronal cell types, they receive synapses from neurons and depolarize upon stimulation. While past studies have focused on the role of neuron-to- OPC synapses in activity-dependent myelin plasticity, emerging evidence suggests that OPCs play an active role in the neural network, possibly through a mechanism that is independent of myelin. A fundamental question that has not been resolved is how OPCs modulate neuronal network function. Accumulating reports that many of the synaptic proteins previously considered to be unique to neurons are also expressed by OPCs and supports their role in synapse formation or reorganization. As a first step toward elucidating the role of OPCs in neuronal synapses, this project will develop improved techniques and test the hypothesis that OPCs in an activity-dependent manner dynamically modulate nearby neuron-neuron synapses. This will be examined after chemogenetic OPC activation (Aim 1) and in which the gene encoding the synaptic organizer protein C1QL1 is selectively deleted from OPCs (Aim 2). A current challenge in studying neuron-OPC synapses is an inability to quantify them free of confounding signals from nearby neuron-neuron synapses. To solve this problem, while simultaneously monitoring neuron-neuron synapses, we will develop a transposon-mediated conditional in utero electroporation approach optimized to deliver nanobodies that specifically mark excitatory and inhibitory postsynaptic proteins in OPCs. The outcome of the proposed study will likely lead to novel principles regarding the role of OPCs in regulating neuronal excitation or inhibition and have profound impact on the regulatory mechanism and development of therapeutic strategies to ameliorate pathological conditions of altered excitation/inhibition imbalance such as epilepsy, schizophrenia, and autism spectrum disorders. Project Number: 1R21NS142499-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Neurological Disorders and Stroke (NINDS) | Principal Investigator: David Martinelli (+1 co-PI) | Institution: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT, FARMINGTON, CT | Award Amount: $471,861 | Activity Code: R21 | Study Section: Neuronal Communications Study Section[NC] View on NIH RePORTER: https://reporter.nih.gov/project-details/11299628