Academic Journal

Unambiguous identification of asymmetric and symmetric synapses using volume electron microscopy

التفاصيل البيبلوغرافية
العنوان: Unambiguous identification of asymmetric and symmetric synapses using volume electron microscopy
المؤلفون: Nicolás Cano-Astorga, Sergio Plaza-Alonso, Marta Turegano-Lopez, José Rodrigo-Rodríguez, Angel Merchan-Perez, Javier DeFelipe
المصدر: Frontiers in Neuroanatomy, Vol 18 (2024)
بيانات النشر: Frontiers Media S.A., 2024.
سنة النشر: 2024
المجموعة: LCC:Neurosciences. Biological psychiatry. Neuropsychiatry
LCC:Human anatomy
مصطلحات موضوعية: cerebral cortex, 3D-electron microscopy, FIB-SEM, excitatory and inhibitory synapses, potassium ferrocyanide, ultrastructure, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571, Human anatomy, QM1-695
الوصف: The brain contains thousands of millions of synapses, exhibiting diverse structural, molecular, and functional characteristics. However, synapses can be classified into two primary morphological types: Gray’s type I and type II, corresponding to Colonnier’s asymmetric (AS) and symmetric (SS) synapses, respectively. AS and SS have a thick and thin postsynaptic density, respectively. In the cerebral cortex, since most AS are excitatory (glutamatergic), and SS are inhibitory (GABAergic), determining the distribution, size, density, and proportion of the two major cortical types of synapses is critical, not only to better understand synaptic organization in terms of connectivity, but also from a functional perspective. However, several technical challenges complicate the study of synapses. Potassium ferrocyanide has been utilized in recent volume electron microscope studies to enhance electron density in cellular membranes. However, identifying synaptic junctions, especially SS, becomes more challenging as the postsynaptic densities become thinner with increasing concentrations of potassium ferrocyanide. Here we describe a protocol employing Focused Ion Beam Milling and Scanning Electron Microscopy for studying brain tissue. The focus is on the unequivocal identification of AS and SS types. To validate SS observed using this protocol as GABAergic, experiments with immunocytochemistry for the vesicular GABA transporter were conducted on fixed mouse brain tissue sections. This material was processed with different concentrations of potassium ferrocyanide, aiming to determine its optimal concentration. We demonstrate that using a low concentration of potassium ferrocyanide (0.1%) improves membrane visualization while allowing unequivocal identification of synapses as AS or SS.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1662-5129
Relation: https://www.frontiersin.org/articles/10.3389/fnana.2024.1348032/full; https://doaj.org/toc/1662-5129
DOI: 10.3389/fnana.2024.1348032
URL الوصول: https://doaj.org/article/0f35f3a82ffa4d14b08165301db86cc7
رقم الانضمام: edsdoj.0f35f3a82ffa4d14b08165301db86cc7
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:16625129
DOI:10.3389/fnana.2024.1348032