Constitutive tumor necrosis factor (TNF)-deficiency causes a reduction in spine density in mouse dentate granule cells accompanied by homeostatic adaptations of spine head size

© 2021 The Authors. The Journal of Comparative Neurology published by Wiley Periodicals LLC..

The majority of excitatory synapses terminating on cortical neurons are found on dendritic spines. The geometry of spines, in particular the size of the spine head, tightly correlates with the strength of the excitatory synapse formed with the spine. Under conditions of synaptic plasticity, spine geometry may change, reflecting functional adaptations. Since the cytokine tumor necrosis factor (TNF) has been shown to influence synaptic transmission as well as Hebbian and homeostatic forms of synaptic plasticity, we speculated that TNF-deficiency may cause concomitant structural changes at the level of dendritic spines. To address this question, we analyzed spine density and spine head area of Alexa568-filled granule cells in the dentate gyrus of adult C57BL/6J and TNF-deficient (TNF-KO) mice. Tissue sections were double-stained for the actin-modulating and plasticity-related protein synaptopodin (SP), a molecular marker for strong and stable spines. Dendritic segments of TNF-deficient granule cells exhibited ∼20% fewer spines in the outer molecular layer of the dentate gyrus compared to controls, indicating a reduced afferent innervation. Of note, these segments also had larger spines containing larger SP-clusters. This pattern of changes is strikingly similar to the one seen after denervation-associated spine loss following experimental entorhinal denervation of granule cells: Denervated granule cells increase the SP-content and strength of their remaining spines to homeostatically compensate for those that were lost. Our data suggest a similar compensatory mechanism in TNF-deficient granule cells in response to a reduction in their afferent innervation.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:530

Enthalten in:

The Journal of comparative neurology - 530(2022), 3 vom: 15. Feb., Seite 656-669

Sprache:

Englisch

Beteiligte Personen:

Smilovic, Dinko [VerfasserIn]
Rietsche, Michael [VerfasserIn]
Drakew, Alexander [VerfasserIn]
Vuksic, Mario [VerfasserIn]
Deller, Thomas [VerfasserIn]

Links:

Volltext

Themen:

Dentate gyrus
Homeostatic plasticity
Journal Article
Research Support, Non-U.S. Gov't
Spine head
Synaptic plasticity
Synaptopodin
Tnf protein, mouse
Tumor Necrosis Factor-alpha
Tumor Necrosis Factors
Tumor necrosis factor

Anmerkungen:

Date Completed 04.04.2022

Date Revised 31.05.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/cne.25237

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM330409999