We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Differential surface density and modulatory effects of presynaptic GABA receptors in hippocampal cholecystokinin and parvalbumin basket cells.
- Authors
Booker, Sam; Althof, Daniel; Degro, Claudius; Watanabe, Masahiko; Kulik, Ákos; Vida, Imre
- Abstract
The perisomatic domain of cortical neurons is under the control of two major GABAergic inhibitory interneuron types: regular-spiking cholecystokinin (CCK) basket cells (BCs) and fast-spiking parvalbumin (PV) BCs. CCK and PV BCs are different not only in their intrinsic physiological, anatomical and molecular characteristics, but also in their presynaptic modulation of their synaptic output. Most GABAergic terminals are known to contain GABA receptors (GABAR), but their role in presynaptic inhibition and surface expression have not been comparatively characterized in the two BC types. To address this, we performed whole-cell recordings from CCK and PV BCs and postsynaptic pyramidal cells (PCs), as well as freeze-fracture replica-based quantitative immunogold electron microscopy of their synapses in the rat hippocampal CA1 area. Our results demonstrate that while both CCK and PV BCs contain functional presynaptic GABARs, their modulatory effects and relative abundance are markedly different at these two synapses: GABA release is dramatically inhibited by the agonist baclofen at CCK BC synapses, whereas a moderate reduction in inhibitory transmission is observed at PV BC synapses. Furthermore, GABAR activation has divergent effects on synaptic dynamics: paired-pulse depression (PPD) is enhanced at CCK BC synapses, but abolished at PV BC synapses. Consistent with the quantitative differences in presynaptic inhibition, virtually all CCK BC terminals were found to contain GABARs at high densities, but only 40% of PV BC axon terminals contain GABARs at detectable levels. These findings add to an increasing list of differences between these two interneuron types, with implications for their network functions.
- Subjects
NEURONS; GABAERGIC neurons; CHOLECYSTOKININ; SYNAPSES; GABA receptors
- Publication
Brain Structure & Function, 2017, Vol 222, Issue 8, p3677
- ISSN
1863-2653
- Publication type
Article
- DOI
10.1007/s00429-017-1427-x