A Quantitative Comparison of Inhibitory Interneuron Size and Distribution between Mouse and Macaque V1, Using Calcium-Binding Proteins

Abstract

The mouse is a useful and popular model for studying of visual cortical function. To facilitate the translation of results from mice to primates, it is important to establish the extent of cortical organization equivalence between species and to identify possible differences. We focused on the different types of interneurons as defined by calcium binding protein (CBP) expression in the layers of primary visual cortex (V1) in mouse and rhesus macaque. CBPs parvalbumin (PV), calbindin (CB), and calretinin (CR) provide a standard, largely non-overlapping, labelling scheme in macaque, with preserved corresponding morphologies in mouse, despite a slightly higher overlap. Other protein markers, that are relevant in mouse, are not preserved in macaque. We fluorescently tagged CBPs in V1 of both species, using antibodies raised against preserved aminoacid sequences. Our data demonstrate important similarities between the expression patterns of interneuron classes in the different layers between rodents and primates. However, in macaque, expression of parvalbumin and calbindin is more abundant, calretinin expression is lower, and the laminar distribution of interneuron populations is more differentiated. Our results reveal an integrated view of interneuron types that provides a basis for translating results from rodents to primates, and suggest a reconciliation of previous results.

HCN channels at the cell soma ensure the rapid electrical reactivity of fast-spiking interneurons in human neocortex

“…This, in turn, increases the delay between EPSP input and spike output [22,35,36]. This slower EPSP-spike coupling compared with that of rodent basket cells results, at least partly, from a lower density of persistently open membrane ion channels at the resting potential and concomitantly higher resting input resistance, which leads to slower membrane potential kinetics [40,54,69,[79][80][81]. Our experiments and simulations revealed that robust expression of voltage-sensitive HCN channels at the human basket cell soma membrane can increase membrane ion leak at the resting potential and thus accelerate EPSP-spike transformation.…”

A dopamine gradient controls access to distributed working memory in the large-scale monkey cortex

“…CR is expressed in most VIP neurons in primate cortex (Gabbott and Bacon, 1997;Lake et al, 2016), and both VIP and CR show a similar expression across layers and cortical areas in the macaque (Dienel et al, 2020). However, the investigation of cross-species interneuron type similarities and differences is ongoing and not resolved (Hodge et al, 2019;Kooijmans et al, 2020;Krienen et al, 2020). In our model, the three interneuron types should be more appropriately interpreted according to their synaptic targets, rather than other cellular markers.…”

Comparative Features of Calretinin, Calbindin and Parvalbumin Expressing Interneurons in Mouse and Monkey Primary Visual and Frontal Cortices

“…Different interneuron subtypes exhibit distinctive distributions across the six neocortical layers- CR+ and CB+ interneurons neurons are primarily located superficially in layers 1-3 while PV+ neurons are localized principally in layers 2-4. (Conde et al, 1994; DeFelipe; Disney & Aoki, 2008; Dombrowski et al, 2001; Kooijmans et al, 2014; Kooijmans et al, 2020; Tremblay et al, 2016; van Brederode et al, 1990; Zaitsev et al, 2005; Zaitsev et al, 2009). How these neurochemically distinct subpopulations of interneurons compare across species and cortical areas is poorly understood.…”