PhD Scientific Days 2017

Oral Presentations: Neurosciences

Nanoscale distribution of voltage-gated Ca2+ channels and release-related proteins in presynaptic active zones

Előadó neve

Kirizs, Tekla

Előadó munkahelye

Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest

Előadó telefonszáma

06305150485

Előadó e-mail címe

kirizs.tekla@koki.mta.hu

Az előadás címe

Nanoscale distribution of voltage-gated Ca2+ channels and release-related proteins in presynaptic active zones

Szerző(k) neve és munkahelye

Tekla Kirizs1, Miklós Szoboszlay2, Zoltán Nusser3
1,2,3 Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest;
1,2 János Szentágothai School of Neurosciences, Semmelweis University, Budapest.

Szekció

Oral Presentations: Neurosciences

Data of the presenter

Doctoral School: János Szentágothai School of Neurosciences
Program: 01. Neuromorphology and Cell Biology
Supervisor: Zoltán Nusser
E-mail address: kirizs.tekla@koki.mta.hu

Text of the abstract

Communication between neurons relies on neurotransmitter release from presynaptic axon terminals upon the arrival of an action potential and the consequent influx of Ca2+ through voltage-gated Ca2+ channels (VGCCs). The density and spatial arrangement of VGCCs and other release-related proteins in the presynaptic active zone (AZ) are known to affect synaptic transmission. Here we combined the highly sensitive SDS-digested freeze-fracture replica immunogold labelling method with semi-automatic analysis of gold particle distributions to investigate the sub-AZ distribution of VGCCs (Cav2.1 and Cav2.2 subunits) and of the release-related proteins Rim1/2 and neurexin 1α in hippocampal and cerebellar excitatory synapses. We compared the experimental data to random distributions, which we generated by randomly placing the same number of gold particles in the same AZ areas. For all studied proteins, nearest neighbor distances (NNDs) of gold particles were significantly smaller than the NNDs of their random controls indicating that within-AZ distributions of these proteins are significantly different from random. In addition, we analysed the radii of largest empty circles capable to fill empty spaces within AZs, and found significantly higher values for the experimental data, than for simulated random distributions. Spatial auto-correlation function analysis also confirmed that all studied proteins show sub-AZ inhomogeneities. Our results demonstrate that presynaptic AZs are highly organized structures with non-random distribution of the constituent proteins, endowing highly specific Ca2+ influx-release coupling.

Kind

Szabad

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

1211

Authors (legacy)

Tekla Kirizs1, Miklós Szoboszlay2, Zoltán Nusser3
1,2,3 Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest;
1,2 János Szentágothai School of Neurosciences, Semmelweis University, Budapest.