Development of cortical interneurons

Abstract

Inhibitory local circuit neurons (LCNs), often called interneurons, have vital roles in the development and function of cortical networks. Their inhibitory influences regulate both the excitability of cortical projection neurons on the level of individual cells, and the synchronous activity of projection neuron ensembles that appear to be a neural basis for major aspects of cognitive processing. Dysfunction of LCNs has been associated with neurological and psychiatric diseases, such as epilepsy, schizophrenia, and autism. Here we review progress in understanding LCN fate determination, their nonradial migration to the cortex, their maturation within the cortex, and the contribution of LCN dysfunction to neuropsychiatric disorders.

Figure 1

Development of cortical LCNs in humans in relation to proposed LCN-related disruptions that contribute to neuropsychiatric disorders. This schema shows a human coronal-plane hemisection at roughly 12 weeks of gestation. Basic stages of cortical LCN development are highlighted, including proliferation and fate determination, nonradial migration, and then initial integration into cortical circuitry. References link these stages with studies, mainly in rodents, that examine the functions disease-related genes in relation to these developmental stages. (1)—Maynard et al, 2013; (2)—Toritsuka et al, 2013; (3)—Meechan et al, 2012a; (4)—Steinecke et al, 2012; (5)—Del Pino et al, 2013; (6)—Yang et al, 2013; (7) —Tai et al, 2014; (8)—Karayannis et al, 2014; (9)—Arguello et al, 2013. Ncx, neocortex; MGE, medial ganglionic eminence.