MilliporeSigma
  • Home
  • Search Results
  • Novel GABAergic circuits mediating excitation/inhibition of Cajal-Retzius cells in the developing hippocampus.

Novel GABAergic circuits mediating excitation/inhibition of Cajal-Retzius cells in the developing hippocampus.

The Journal of neuroscience : the official journal of the Society for Neuroscience (2013-03-29)
Giulia Quattrocolo, Gianmaria Maccaferri
ABSTRACT

Cajal-Retzius cells are a class of neurons believed to play critical roles during cortical development. However, their network computational functions remain poorly understood. Although work in the neocortex and hippocampus has shown that Cajal-Retzius cells receive predominantly, if not exclusively, spontaneous GABA(A) receptor-mediated input, the cellular sources originating these events remain unclear. However, a precise definition of the presynaptic GABAergic interneurons contacting Cajal-Retzius cells is important to understand the microcircuits and network patterns controlling their activation. Here, we have taken advantage of electrophysiological and anatomical techniques applied to mouse hippocampal slices in vitro to directly address this question. Our paired recording experiments indicate that Cajal-Retzius cells receive small-amplitude, kinetically slow synaptic input from stratum lacunosum-moleculare interneurons, anatomically identified as neurogliaform cells. In addition, a convergence of optogenetic, electrophysiological, and pharmacological experiments shows that Cajal-Retzius cells receive GABAergic input from oriens lacunosum-moleculare cells and that this input has different physiological properties (i.e., larger amplitude and faster kinetics) from the one provided by neurogliaform cells. Last, we show that GABAergic evoked synaptic input onto Cajal-Retzius cells may either increase their excitability and trigger action potentials or inhibit spontaneous firing by depolarization block. We propose that the specific type of response depends on both the membrane potential of Cajal-Retzius cells and the kinetics of the received GABAergic input. In conclusion, we have unraveled a novel hippocampal microcircuit with complex GABAergic synaptic signaling, which we suggest may play a role in the refinement of the hippocampal network and connections during development.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
NBQX hydrate, powder, ≥98% (HPLC)
Sigma-Aldrich
L-Valine, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 98.5-101.0%
Sigma-Aldrich
L-Valine, reagent grade, ≥98% (HPLC)
Supelco
L-Valine, certified reference material, TraceCERT®
Supelco
L-Valine, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
L-Valine, BioUltra, ≥99.5% (NT)
Sigma-Aldrich
DL-2-Amino-5-phosphonopentanoic acid, solid
SAFC
L-Valine
Sigma-Aldrich
NBQX disodium salt hydrate, ≥98% (HPLC)
Sigma-Aldrich
SR-95531, ≥98% (HPLC), powder
Sigma-Aldrich
DL-3,4-Dihydroxyphenyl glycol