A Computational Analysis of the Function of Three Inhibitory Cell Types in Contextual Visual Processing

Abstract

Most cortical inhibitory cell types exclusively express one of three genes, parvalbumin, somatostatin and 5HT3a. We conjecture that these three inhibitory neuron types possess distinct roles in visual contextual processing based on two observations. First, they have distinctive synaptic sources and targets over different spatial extents and from different areas. Second, the visual responses of cortical neurons are affected not only by local cues, but also by visual context. We use modeling to relate structural information to function in primary visual cortex (V1) of the mouse, and investigate their role in contextual visual processing. Our findings are three-fold. First, the inhibition mediated by parvalbumin positive (PV) cells mediates local processing and could underlie their role in boundary detection. Second, the inhibition mediated by somatostatin-positive (SST) cells facilitates longer range spatial competition among receptive fields. Third, non-specific top-down modulation to interneurons expressing vasoactive intestinal polypeptide (VIP), a subclass of 5HT3a neurons, can selectively enhance V1 responses.

Brain-wide Maps Reveal Stereotyped Cell-Type-Based Cortical Architecture and Subcortical Sexual Dimorphism

“…Finally, since SST+ interneurons target the dendrites of excitatory neurons, it was suggested that SST+ neurons may gate the inputs onto excitatory neurons (Lee et al, 2017; Wang et al, 2004), and computational models suggest that SST+ interneurons can selectively gate inputs that originate from different areas or pathways (Yang et al, 2016). Therefore, higher SST+ interneuron density in the medial associational and lateral areas can also allow for a larger repertoire of selective neurons.…”

Cortical inhibitory interneurons control sensory processing

“…Recently, there have been attempts to make more realistic circuit models which include subtypes of interneurons [71,72]. Lee et al (2017) were able to replicate multiple experimental findings, including function of distinct interneuron subtypes in ‘attentional gating’ as well as an explanation for differential effects of VIP/SOM activity in visual cortex [19,41].…”

Extracellular spike waveform dissociates four functionally distinct cell classes in primate cortex

“…Neuronal cell types are central to brain function. The unique physiology, morphology and connectivity of different cortical interneurons and pyramidal cells shapes their functional role in local and large-scale circuit operations (Tremblay, Lee, and Rudy 2016;Lee, Koch, and Mihalas 2017;Zeng and Sanes 2017). Cell-type specific neuronal properties shape characteristic circuit oscillations associated with various computational and cognitive processes (Womelsdorf et al 2014;Veit et al 2017;Siegel, Donner, and Engel 2012) Thus, knowledge about cell types and their role in cortical circuits is key to understanding brain function.…”