A Subtype of Inhibitory Interneuron with Intrinsic Persistent Activity in Human and Monkey Neocortex

Abstract

A critical step in understanding the neural basis of human cognitive functions is to identify neuronal types in the neocortex. In this study, we performed whole-cell recording from human cortical slices and found a distinct subpopulation of neurons with intrinsic persistent activity that could be triggered by single action potentials (APs) but terminated by bursts of APs. This persistent activity was associated with a depolarizing plateau potential induced by the activation of a persistent Na current. Single-cell RT-PCR revealed that these neurons were inhibitory interneurons. This type of neuron was found in different cortical regions, including temporal, frontal, occipital, and parietal cortices in human and also in frontal and temporal lobes of nonhuman primate but not in rat cortical tissues, suggesting that it could be unique to primates. The characteristic persistent activity in these inhibitory interneurons may contribute to the regulation of pyramidal cell activity and participate in cortical processing.

Metabotropic glutamate receptor 5 responses dictate differentiation of neural progenitors to NMDA‐responsive cells in fragile X syndrome

“…The present data implicate mGluR5‐mediated mechanisms in the dysregulated developmental responses to NMDA in FXS (Pilpel et al, ). Recent studies revealed that higher order brain functions are linked with neuronal subpopulations present in primate but not in rat neocortex (Wang et al, ), and FXS iPS cell‐derived neuronal subpopulations remain to be investigated after extended differentiation. The present findings strongly support the potential use of human iPS‐derived progenitors for studies elucidating putative species‐specific differences of cellular plasticity and differential treatment responses to mGluR5 antagonist in humans with FXS than in Fmr1 ‐KO mice (Berry‐Kravis et al, ).…”

Between persistently active and activity‐silent frameworks: novel vistas on the cellular basis of working memory

“…What are the mechanisms that give rise to sustained neuronal activity? One possibility is cell autonomous mechanisms, which exist in certain specialized cells, including in humans . Another possibility is at the network level, facilitated by recurrent synaptic connections.…”

“…One possibility is cell autonomous mechanisms, which exist in certain specialized cells, 25,26 including in humans. 27 Another possibility is at the network level, facilitated by recurrent synaptic connections. By and large, current theories assume that the PA that gives rise to WM is due to network-level effects.…”

Whole cell patch clamp analysis of non-synaptic and synaptic signaling in rodent and human supragranular neocortex

“…Species-specific differences evidently exist in various anatomical features of the neocortex including the layering, some long-range connections and some intrinsic electrical and morphological properties of nerve cells (Boldog et al, 2017;Mohan et al, 2015;Wang et al, 2015). Yet,it has been thought that basic cellular elements and local synaptic circuits are fairly stereotyped among mammalian species and largely similar for instance between a rodent and a human.…”

“…In the past decade, increasing attention has been put on special features of the human neocortex microcircuits comparing them to those of other mammals such as non-human primates, carnivores, and rodents (Boldog et al, 2017;Komlósi et al, 2012;Mohan et al, 2015;Molnár et al, 2008;Oláh et al, 2007;Prince and Wong, 1981;Schwartzkroin and Knowles, 1984;Verhoog et al, 2013;Wang et al, 2015;Yáñez et al, 2005). Species-specific differences evidently exist in various anatomical features of the neocortex including the layering, some long-range connections and some intrinsic electrical and morphological properties of nerve cells (Boldog et al, 2017;Mohan et al, 2015;Wang et al, 2015).…”