Localizing GABA Receptors and Glutamate Transporters Using Conjugated Quantum Dots in Rat Cerebellum Slices

2009 ◽  
Vol 1241 ◽  
Author(s):  
Abdel Illah El Abed ◽  
Anne Baudot ◽  
Mireille Chat ◽  
Sanaa Ben Khalifa ◽  
Gérard Louis
Keyword(s):  
Quantum Dots ◽  
Gaba Receptors ◽  
Granule Cells ◽  
Molecular Layer ◽  
Glutamate Transporters ◽  
Synaptic Proteins ◽  
Rat Cerebellum ◽  
Excitatory Neurotransmitters ◽  
Excitatory Action ◽  
Vertebrate Central Nervous System

AbstractGABA and glutamate are known as the principal inhibitory and excitatory neurotransmitters in the vertebrate central nervous system, respectively. However, recent electro-physiological and immunogold data reported by Stell et al. [1] indicate that GABA may undergo also an excitatory action on presynaptic varicosities of parallel fibers (PFs) in the molecular layer of the rat cerebellum. PFs are axonal extensions, with a cross section of about 0.1 m, of the glutamatergic granule cells. Such an unexpected excitatory action of GABA indicates clearly the presence of GABA receptors in the PFs of granule cells. We show in this study that quantum dots may be used specifically and efficiently to label two endogenous synaptic proteins, namely R-GABAA-1 receptors (GABAA Rs) and glutamate transporters (VGLUT1) in order to target their localization in very small structures such as the presynaptic varicosities of the PFs, in agreement with the results recently reported by Stell et al..

scholarly journals Distinctive alteration of presynaptic proteins in the outer molecular layer of the dentate gyrus in Alzheimer’s disease

2020 ◽  
Author(s):  
Hazal Haytural ◽  
Tomás Jordá-Siquer ◽  
Bengt Winblad ◽  
Christophe Mulle ◽  
Lars O. Tjernberg ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dentate Gyrus ◽  
Granule Cells ◽  
Molecular Layer ◽  
Relative Number ◽  
Synaptic Proteins ◽  
Amyloid Load ◽  
Immunofluorescence Labeling ◽  
Presynaptic Proteins

AbstractSynaptic degeneration has been reported as one of the best pathological correlate of cognitive deficit in Alzheimer’s Disease (AD). However, the location of these synaptic alterations within hippocampal sub-regions, the vulnerability of the presynaptic versus postsynaptic compartments, and the biological mechanisms for these impairments remain unknown. Here, we performed immunofluorescence labeling of different synaptic proteins in fixed and paraffin embedded human hippocampal sections and report reduced levels of several presynaptic proteins of the neurotransmitter release machinery (complexin-1, syntaxin-1A, synaptotagmin-1 and synaptogyrin-1) in AD cases. The deficit was restricted to the outer molecular layer (OML) of the dentate gyrus whereas other hippocampal sub-fields were preserved. Interestingly, standard markers of postsynaptic densities (SHANK2) and dendrites (MAP2) were unaltered, as well as the relative number of granule cells in the dentate gyrus, indicating that the deficit is preferentially presynaptic. Notably, staining for the axonal components, myelin basic protein, SMI-312 and Tau, was unaffected, suggesting that the local presynaptic impairment does not result from axonal loss or alterations of structural proteins of axons. There was no correlation between the reduction in presynaptic proteins in OML and the extent of the amyloid load or of the dystrophic neurites expressing phosphorylated forms of Tau. Altogether, this study highlights the distinctive vulnerability of the OML of dentate gyrus and supports the notion of presynaptic failure in AD.

scholarly journals Inward rectifier potassium channel Kir2.2 is associated with synapse-associated protein SAP97

2001 ◽  
Vol 114 (5) ◽  
pp. 987-998
Author(s):  
D. Leonoudakis ◽  
W. Mailliard ◽  
K. Wingerd ◽  
D. Clegg ◽  
C. Vandenberg
Keyword(s):  
Fusion Proteins ◽  
Granule Cells ◽  
Ventricular Myocytes ◽  
Molecular Layer ◽  
Pdz Domain ◽  
Granule Cell Layer ◽  
Signaling Complex ◽  
Rat Cerebellum ◽  
Maguk Protein ◽  
Gst Fusion Proteins

The strong inwardly rectifying potassium channels Kir2.x are involved in maintenance and control of cell excitability. Recent studies reveal that the function and localization of ion channels are regulated by interactions with members of the membrane-associated guanylate kinase (MAGUK) protein family. To identify novel interacting MAGUK family members, we constructed GST-fusion proteins with the C termini of Kir2.1, Kir2.2 and Kir2.3. GST affinity-pulldown assays from solubilized rat cerebellum and heart membrane proteins revealed an interaction between all three Kir2.x C-terminal fusion proteins and the MAGUK protein synapse-associated protein 97 (SAP97). A truncated form of the C-terminal GST-Kir2.2 fusion protein indicated that the last three amino acids (S-E-I) are essential for association with SAP97. Affinity interactions using GST-fusion proteins containing the modular domains of SAP97 demonstrate that the second PSD-95/Dlg/ZO-1 (PDZ) domain is sufficient for interaction with Kir2.2. Coimmunoprecipitations demonstrated that endogenous Kir2.2 associates with SAP97 in rat cerebellum and heart. Additionally, phosphorylation of the Kir2.2 C terminus by protein kinase A inhibited the association with SAP97. In rat cardiac ventricular myocytes, Kir2.2 and SAP97 colocalized in striated bands corresponding to T-tubules. In rat cerebellum, Kir2.2 was present in a punctate pattern along SAP97-positive processes of Bergmann glia in the molecular layer, and colocalized with astrocytes and granule cells in the granule cell layer. These results identify a direct association of Kir2.1, Kir2.2 and Kir2.3 with the MAGUK family member SAP97 that may form part of a macromolecular signaling complex in many different tissues.

Ultrasturcture of cerebellar cells and neuropil in rats subjected to partial global cerebral ischemia

1986 ◽  
Vol 44 ◽  
pp. 126-127
Author(s):  
R.V.W. Dimlich ◽  
M.H. Biros
Keyword(s):  
Purkinje Cells ◽  
Glial Cells ◽  
Granule Cells ◽  
Molecular Layer ◽  
Cell Types ◽  
Primary Objective ◽  
Global Cerebral Ischemia ◽  
Forebrain Ischemia ◽  
Substantial Evidence ◽  
Cerebellar Cells

Although a previous study in this laboratory determined that Purkinje cells of the rat cerebellum did not appear to be damaged following 30 min of forebrain ischemia followed by 30 min of reperfusion, it was suggested that an increase in rough endoplasmic reticulum (RER) and/or polysomes had occurred in these cells. The primary objective of the present study was to morphometrically determine whether or not this increase had occurred. In addition, since there is substantial evidence that glial cells may be affected by ischemia earlier than other cell types, glial cells also were examined. To ascertain possible effects on other cerebellar components, granule cells and neuropil near Purkinje cells as well as neuropil in the molecular layer also were evaluated in this investigation.

Effects of aging on axon terminals in the dentate molecular layer

1987 ◽  
Vol 45 ◽  
pp. 928-929
Author(s):  
K. Cullen-Dockstader ◽  
E. Fifkova
Keyword(s):  
Granule Cells ◽  
Molecular Layer ◽  
Age Groups ◽  
Long Term Potentiation ◽  
Male Rats ◽  
Perforant Path ◽  
Axon Terminals ◽  
Fischer 344 ◽  
Spatial Memory Deficit ◽  
Effects Of Aging

Normal aging results in a pronounced spatial memory deficit associated with a rapid decay of long-term potentiation at the synapses between the perforant path and spines in the medial and distal thirds of the dentate molecular layer (DML), suggesting the alteration of synaptic transmission in the dentate fascia. While the number of dentate granule cells remains unchanged, and there are no obvious pathological changes in these cells associated with increasing age, the density of their axospinous contacts has been shown to decrease. There are indications that the presynaptic element is affected by senescence before the postsynaptic element, yet little attention has been given to the fine structure of the remaining axon terminals. Therefore, we studied the axon terminals of the perforant path in the DML across three age groups.5 Male rats (Fischer 344) of each age group (3, 24 and 30 months), were perfused through the aorta.

scholarly journals Topography and Response Timing of Intact Cerebellum Stained With Absorbance Voltage-Sensitive Dye

2009 ◽  
Vol 101 (1) ◽  
pp. 474-490 ◽  
Author(s):  
Michael E. Brown ◽  
Michael Ariel
Keyword(s):  
Time Course ◽  
Granule Cells ◽  
Physiological Activity ◽  
Timing Analysis ◽  
Molecular Layer ◽  
Stimulus Position ◽  
Voltage Sensitive Dye ◽  
Limited Region ◽  
Response Timing

Physiological activity of the turtle cerebellar cortex (Cb), maintained in vitro, was recorded during microstimulation of inferior olive (IO). Previous single-electrode responses to such stimulation showed similar latencies across a limited region of Cb, yet those recordings lacked spatial and temporal resolution and the recording depth was variable. The topography and timing of those responses were reexamined using photodiode optical recordings. Because turtle Cb is thin and unfoliated, its entire surface can be stained by a voltage-sensitive dye and transilluminated to measure changes in its local absorbance. Microstimulation of the IO evoked widespread depolarization from the rostral to the caudal edge of the contralateral Cb. The time course of responses measured at a single photodiode matched that of single-microelectrode responses in the corresponding Cb locus. The largest and most readily evoked response was a sagittal band centered about 0.7 mm from the midline. Focal white-matter (WM) microstimulation on the ventricular surface also activated sagittal bands, whereas stimulation of adjacent granule cells evoked a radial patch of activation. In contrast, molecular-layer (ML) microstimulation evoked transverse beams of activation, centered on the rostrocaudal stimulus position, which traveled bidirectionally across the midline to the lateral edges of the Cb. A timing analysis demonstrated that both IO and WM microstimulation evoked responses with a nearly simultaneous onset along a sagittal band, whereas ML microstimulation evoked a slowly propagating wave traveling about 25 cm/s. The response similarity to IO and WM microstimulation suggests that the responses to WM microstimulation are dominated by activation of its climbing fibers. The Cb's role in the generation of precise motor control may result from these temporal and topographic differences in orthogonally oriented pathways. Optical recordings of the turtle's thin flat Cb can provide insights into that role.

Effects of Selected Neuroactive Chemicals on Calcium Transporting Systems in Rat Cerebellum and on Survival of Cerebellar Granule Cells

1993 ◽  
Vol 21 (3) ◽  
pp. 308-316
Author(s):  
PRASADA RAO S. KODAVANTI ◽  
WILLIAM R. MUNDY ◽  
HUGH A. TILSON ◽  
G. JEAN HARRY
Keyword(s):  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Cerebellar Granule ◽  
Rat Cerebellum
Sign in / Sign up

Export Citation Format

Share Document