Morphology and Distribution of Chandelier Cell Axon Terminals in the Mouse Cerebral Cortex and Claustroamygdaloid Complex

Abstract

Chandelier cells represent a unique type of cortical gamma-aminobutityric acidergic interneuron whose axon terminals (Ch-terminals) only form synapses with the axon initial segments of some pyramidal cells. Here, we have used immunocytochemistry for the high-affinity plasma membrane transporter GAT-1 and the calcium-binding protein parvalbumin to analyze the morphology and distribution of Ch-terminals in the mouse cerebral cortex and claustroamygdaloid complex. In general, 2 types of Ch-terminals were distinguished on the basis of their size and the density of the axonal boutons that made up the terminal. Simple Ch-terminals were made up of 1 or 2 rows of labeled boutons, each row consisting of only 3-5 boutons. In contrast, complex Ch-terminals were tight cylinder-like structures made up of multiple rows of boutons. Simple Ch-terminals were detected throughout the cerebral cortex and claustroamygdaloid complex, the complex type was only occasionally found in certain regions, whereas in others they were very abundant. These results indicate that there are substantial differences in the morphology and distribution of Ch-terminals between different areas and layers of the mouse cerebral cortex. Furthermore, we suggest that the distribution of complex Ch-terminals may be related to the developmental origin of the different brain regions analyzed.

Genetic disruption of ankyrin-G in adult mouse forebrain causes cortical synapse alteration and behavior reminiscent of bipolar disorder

“…Decreased inhibitory connections have also been reported for bipolar disorder (19). When quantifying cartridges, we chose piriform and cingulate cortex because unlike humans, who have clear cartridge synapses throughout the cortex, mice have the clearest and most distinctive cartridge synapses in piriform cortex, and to a lesser extent in cingulate cortex (26). Our findings are consistent with the concept of alterations of inhibitory synapses in bipolar disorder.…”

“…In cortex, chandelier inhibitory neurons normally form synapses in cartridge-like structures innervating pyramidal neuron AISs (16). Cartridgelike structures in mouse are most evident in the piriform cortex, as shown by labeling with anti-GAD67 and anti-GAT-1 antibodies (25); the GAT-1 cartridges are also present in cingulate cortex (26). We examined GAT-1-labeled cartridges in piriform and cingulate cortex, and GAD67-labeled cartridges in piriform cortex.…”

Molecular identity of axonal sodium channels in human cortical pyramidal cells

“…Previous studies in rodents demonstrated that axo-axonic cells innervated the distal regions of the AIS of PCs (Inda et al, 2009; Wang and Sun, 2012; Inan et al, 2013; Taniguchi et al, 2013). In the human cortex, chandelier cells selectively target the distal AIS regions where K + channel subtype K V 1.2 accumulates, suggesting important roles of chandelier cells in controlling the activity of PCs (Inda et al, 2006).…”

Differential Pharmacological Regulation of Sensorimotor Gating Deficit in CB1 Knockout Mice and Associated Neurochemical and Histological Alterations

“…Another type of GABAergic neurons are the PV-ir chandelier cells that synapse the axon initial segment of the pyramidal neurons (Inda et al, 2009). Recent data show that migrating neurons express CB1r during neocorticogenesis and that the endocannabinoid signaling control not only pyramidal positioning but also long-range axon patterning (Berghuis et al, 2007;Mulder et al, 2008;Oudin et al, 2011).…”

“…The study of the distribution of parvalbumin (PV; basket and chandelier) and cholecystokinin-8 (CCK; basket) interneurons is relevant because both are fast-spiking GABAergic interneurons involved in the synchronization of pyramidal cell discharges (Cardin et al, 2009;Inda et al, 2009;LovettBarron and Losonczy, 2014;Somogyi and Klausberger, 2005). Cortical disinhibition is associated to preattentional deficits that are core symptoms of schizophrenia (Glausier et al, 2014;Lewis, 2014;Pezze et al, 2014;Volk and Lewis, 2014).…”