Abstract
Previous studies have shown that cortico-striatal pathways link auditory signals to action-selection and reward-learning behavior through excitatory projections. Only recently it has been demonstrated that long-range GABAergic cortico-striatal somatostatin-expressing neurons in the auditory cortex project to the dorsal striatum, and functionally inhibit the main projecting neuronal population, the spiny projecting neuron. Here we tested the hypothesis that parvalbumin-expressing neurons of the auditory cortex can also send long-range projections to the auditory striatum. To address this fundamental question, we took advantage of viral and non-viral anatomical tracing approaches to identify cortico-striatal parvalbumin neurons (CS-Parv inhibitory projections → auditory striatum). Here, we describe their anatomical distribution in the auditory cortex and determine the anatomical and electrophysiological properties of layer 5 CS-Parv neurons. We also analyzed their characteristic voltage-dependent membrane potential gamma oscillation, showing that intrinsic membrane mechanisms generate them. The inherent membrane mechanisms can also trigger intermittent and irregular bursts (stuttering) of the action potential in response to steps of depolarizing current pulses.
Highlights
Since the late 19th century, the Spanish neuroanatomist Santiago Ramon y Cajal postulated the importance of interneurons in the neocortex (Ramon y Cajal et al, 1988; Benavides-Piccione and DeFelipe, 2007)
The present study focused on three main goals: (1) determine the laminar and areal distribution of cortico-striatal parvalbumin-expressing (CS-Parv neurons) neurons in the auditory cortex; (2) describe the anatomical and electrophysiological properties of these neurons; and (3) determine the impact that the voltage-dependent membrane potential resonance has on the spiking pattern of layer 5 CS-Parv neurons
To visualize long-range GABAergic projection originating in the auditory cortex (AC) and terminating in the ipsilateral striatum, we conditionally expressed GFP in parvalbumin-expressing neurons by injecting AAV1-Flex-GFP into the right striatum of ParvCre/tdTomato transgenic mice
Summary
Since the late 19th century, the Spanish neuroanatomist Santiago Ramon y Cajal postulated the importance of interneurons in the neocortex (Ramon y Cajal et al, 1988; Benavides-Piccione and DeFelipe, 2007). The local connectivity and neuronal computations of GABAergic ‘‘interneurons’’ in the cerebral cortex, which comprise 15–20% of the whole neuronal population (Xu et al, 2010; Rudy et al, 2011), has been extensively studied. This leading to the overall principle that excitation is both local and long-range, while inhibition is described as being exclusively local (for review see: Isaacson and Scanziani, 2011; Tremblay et al, 2016).
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call