Miaomiao Mao, Aditya Nair and George J. Augustine Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Institute of Molecular and Cell Biology, Singapore, Singapore 3Life Sciences Programme, Faculty of Science, National University of Singapore, Singapore Bioimaging Consortium, Agency of Science, Technology and Research, Singapore
Abstract:
The striatum is predominantly composed of medium spiny projection neurons, with the remaining neurons consisting of several types of interneurons. Among the interneurons are a group of cells that express tyrosine hydroxylase (TH). Although the intrinsic electrical properties of these TH-expressing interneurons have been characterized, there is no agreement on the number of TH-expressing cell types and their electrical properties. Here, we have used transgenic mice in which YFP-tagged channelrhodopsin-2 (ChR2) was expressed in potential TH-expressing cells in a Cre-dependent manner. We found that the YFP+ neurons in the striatum were heterogeneous in their intrinsic electrical properties; unbiased clustering indicated that there are three main neuronal subtypes. One population of neurons had aspiny dendrites with high-frequency action potential (AP) firing and plateau potentials, resembling the TH interneurons (THIN) described previously. A second, very small population of labeled neurons resembled medium-sized spiny neurons (MSN). The third population of neurons had dendrites with an intermediate density of spines, showed substantial AP adaptation and generated prolonged spikes. This type of striatal neuron has not been previously identified in the adult mouse and we have named it the Frequency-Adapting Neuron with Spines (FANS). Because of their distinctive properties, FANS may play a unique role in striatal information processing.
License type:
http://creativecommons.org/licenses/by/4.0/
Funding Info:
This work was supported by research grants (MOE2015-T2-2-095 and MOE2017-T3-1-002) from the Singapore Ministry of Education and by a National Science Scholarship from the Agency of Science, Technology and Research, Singapore.