Co‐release of glutamate and GABA from single, identified mossy fibre giant boutons

Abstract

Key points• The granule cells and their mossy fibres (MFs) can express, besides glutamate, all the markers of the GABAergic phenotype during development, suggesting that they can co-release glutamate and GABA.• Several groups have presented substantial electrophysiological evidence, albeit indirect, supporting this hypothesis.

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry

“…Recently, a growing number of studies using a combination of electrophysiological, immunohistochemical, and optogenetic techniques have shown that Glu and GABA may coexist and be coreleased from a single-neuron terminal (42)(43)(44). Our findings provided supporting evidence of the coexistence of Glu and GABA in the soma of all neuron types (both excitatory and inhibitory).…”

Characterizing the neuropeptide pathways between the forebrain and the pons.

“…These studies relied mostly on low resolution immunohistological techniques that focused only on GABA positive cell bodies. Importantly, GABA has been shown to be synthesized and released within axon terminals of the cerebellum (Beltran and Gutierrez, 2012). Our present data using cell type specific anterograde labeling combined with high-resolution electron microscopy suggest a similar scenario for CeA projections to the PBN.…”

“…CeA terminals innervating the lateral PBN have been reported to contain GABA (Jia et al, 2005). Alternatively, GABA synthesis might occur locally within axon terminals (Beltran and Gutierrez, 2012;Wu et al, 2007), and previous studies using retrograde tracer injections into the PBN combined with GABA staining in forebrain neurons would have been unable to detect co-localization.…”

The plastic neurotransmitter phenotype of the hippocampal granule cells and of the moss in their messy fibers

“…However, from P6 the glutamatergic phenotype is turned on in adddition to he GABAergic one enabling simultaneous glutamatergic and GABAergic transmission in a single pathway, which provides an efficient and rapid synergism on their target cells during development Kasyanov et al, 2004). It was also later proved that different fibers or boutons release either glutamate or GABA or both (Beltrán and Gutiérrez, 2012; Figure 4). The sequence of the development of the initially GABAergic-only, dual GABAergic-glutamatergic, and finally glutamatergic-only phenotype of the MFs is summarized in Figure 6.…”

“…This has been accomplished through a method that implies recording Page 7 of 42 A c c e p t e d M a n u s c r i p t 7 from a presynaptic giant MF bouton while recording the postsynaptic pyramidal cell in a hippocampal slice (Geiger and Jonas, 2000;Bischofberger et al, 2006). A second method that permits to record synaptic responses to selective stimulation of MF giant boutons implies labeling these boutons, then dissociating the pyramidal cells from their network with the MF boutons attached to their apical dendrites, which can then be identified and directly stimulated by means of a patch pipette while recording from the pyramidal cell Beltrán and Gutiérrez, 2012). Finally, pure granule cell-mediated synaptic responses can be obtained from cultured granule cells establishing autapses (Rost et al, 2010).…”