Journal article icon

Journal article

Synaptic organisation and behaviour-dependent activity of mGluR8a-innervated GABAergic trilaminar cells projecting from the hippocampus to the subiculum

Abstract:
In the hippocampal CA1 area, the GABAergic trilaminar cells have their axon distributed locally in three layers and also innervate the subiculum. Trilaminar cells have a high level of somato-dendritic muscarinic M2 acetylcholine receptor, lack somatostatin expression and their presynaptic inputs are enriched in mGluR8a. But the origin of their inputs and their behaviour-dependent activity remain to be characterised. Here we demonstrate that (1) GABAergic neurons with the molecular features of trilaminar cells are present in CA1 and CA3 in both rats and mice. (2) Trilaminar cells receive mGluR8a-enriched GABAergic inputs, e.g. from the medial septum, which are probably susceptible to hetero-synaptic modulation of neurotransmitter release by group III mGluRs. (3) An electron microscopic analysis identifies trilaminar cell output synapses with specialised postsynaptic densities and a strong bias towards interneurons as targets, including parvalbumin-expressing cells in the CA1 area. (4) Recordings in freely moving rats revealed the network state-dependent segregation of trilaminar cell activity, with reduced firing during movement, but substantial increase in activity with prolonged burst firing (> 200 Hz) during slow wave sleep. We predict that the behaviour-dependent temporal dynamics of trilaminar cell firing are regulated by their specialised inhibitory inputs. Trilaminar cells might support glutamatergic principal cells by disinhibition and mediate the binding of neuronal assemblies between the hippocampus and the subiculum via the transient inhibition of local interneurons.
Publication status:
Published
Peer review status:
Peer reviewed

Actions


Access Document


Files:
Publisher copy:
10.1007/s00429-020-02029-2

Authors


More by this author
Institution:
University of Oxford
Division:
MSD
Department:
Pharmacology
Oxford college:
Brasenose College
Role:
Author
ORCID:
0000-0002-9942-4502
More by this author
Institution:
University of Oxford
Division:
MSD
Department:
Pharmacology
Role:
Author
More by this author
Role:
Author
ORCID:
0000-0001-7569-4121
More by this author
Institution:
University of Oxford
Division:
MSD
Department:
Pharmacology
Role:
Author
More by this author
Institution:
University of Oxford
Division:
MSD
Department:
RDM
Sub department:
RDM Clinical Laboratory Sciences
Role:
Author


Publisher:
Springer
Journal:
Brain Structure and Function More from this journal
Volume:
225
Pages:
705–734
Publication date:
2020-02-03
Acceptance date:
2020-01-16
DOI:
EISSN:
1863-2661
ISSN:
1863-2653
Pmid:
32016558


Language:
English
Keywords:
Pubs id:
1085529
Local pid:
pubs:1085529
Deposit date:
2020-02-24

Terms of use



Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP