eprintid: 27330
rev_number: 16
eprint_status: archive
userid: 4750
dir: disk0/00/02/73/30
datestamp: 2019-11-12 12:00:16
lastmod: 2020-11-02 12:29:46
status_changed: 2019-11-12 12:00:16
type: doctoralThesis
metadata_visibility: show
creators_name: Albariri, Areej
title: Golgi apparatus and Golgi outposts in neurons
studied by correlative microscopy
subjects: 570
divisions: 140001
adv_faculty: af-14
cterms_swd: Golgi apparatus
cterms_swd: Golgi outposts
abstract: The Golgi apparatus is a highly dynamic organelle, which has many vital functions in
cellular mechanisms like lipid metabolism, protein secretion, intracellular signaling, and
regulation of cell division. First described in neurons, the ultrastructure and function of
this complex network is still not well delineated. Recent studies have shown this
secretory organelle also in dendrites of neurons, named Golgi outposts (GOs). To date,
these GOs have been analyzed mainly by light microscopy while their ultrastructural
appearance remained only poorly defined.
To study the morphology of GOs in dendrites and to examine if GOs show a
different ultrastructure to that of somatic Golgi apparatus, I established new applications
of correlative light and electron microscopy in cultured neurons and brain slices, which
combine fluorescence microscopy with the superior resolution of electron microscopy.
Photo-oxidation-based approaches allow for the direct ultra-structural visualization of
fluorescent markers in 3D, like genetically encoded green fluorescent proteins (GFPs).
However, this challenging methodology had to be adapted to detect Golgi enzymes in
neuronal cell cultures and brain tissue. Therefore, I first optimized the chemical fixation
conditions for cultured hippocampal neurons to approximate the morphologic quality of
high-pressure freeze fixation. Secondly, I enhanced sensitivity, reliability, and precision
of photo-oxidation procedures on neurons, which allowed to analyse the 3D
ultrastructure of GOs in dendrites of cultured neurons and mammalian brain slices.
Correlative 3D microscopy showed that GOs are smaller in volume and have
lower number of cisternae per stack compared to somatic Golgi apparatus of the same
cell. Further, the number of peri-Golgi vesicles around GOs appears to be less.
Additionally, while the stack polarity of somatic Golgi apparatus might switch along the
ribbon, GOs have strictly unidirectional polarity.
The technical achievements and enhanced sensitivity regarding correlative
microscopy of GFPs in cultured neurons and brain slices allow for further ultrastructural
investigations of GOs at different metabolic states to better understand their vital
functions.
date: 2020
id_scheme: DOI
id_number: 10.11588/heidok.00027330
ppn_swb: 1737552310
own_urn: urn:nbn:de:bsz:16-heidok-273309
date_accepted: 2019-10-08
advisor: HASH(0x5561209e7d50)
language: eng
bibsort: ALBARIRIARGOLGIAPPAR2020
full_text_status: public
place_of_pub: Heidelberg
citation:   Albariri, Areej  (2020) Golgi apparatus and Golgi outposts in neurons studied by correlative microscopy.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/27330/1/PhD_Areej%20Albariri_pdf_.pdf