Synaptic Receptors Sampler Kit

Calcium signaling plays a fundamental role in normal brain physiology, and is essential for many processes including synaptic activity, cell-cell communications, activity-dependent synaptic remodeling, and memory formation. Activation of synaptic receptors such as NMDA receptors (NMDAR) result in the influx of calcium, activating signaling pathways that regulate various cellular functions. Calcium homeostasis must be tightly regulated due to its involvement in a multitude of pre- and post-synaptic processes. Increased excitatory stimulation and sustained calcium overload can lead to the dysregulation of cytosolic calcium homeostasis, and is detrimental for cellular health. Perturbations in cytosolic calcium levels have been observed in neurodegenerative diseases such as Alzheimer’s (AD), Parkinson’s (PD) and amyotrophic lateral sclerosis (ALS). In AD, deregulation of calcium levels has been linked to excitotoxicity mediated by Aβ-induced increase in NMDAR activity. In ALS, motor neurons become vulnerable to AMPA receptor (AMPAR)-mediated excitotoxicity in part due to the absence of the GluA2 subunit rendering AMPA receptors permeable to calcium.

To complement our Presynaptic Vesicle and Postsynaptic Antibody Sampler kits, we offer sampler kits for AMPA and NMDA receptors. The GluA1/2 Receptor Antibody Sampler Kit allows detection of AMPAR subunits GluA1 and GluA2, and proteins involved in the regulation of AMPA receptor content: PICK1 and SynDYG1. PSD95 was included as a control for postsynapse identification.
 

GluA1/2 Receptor Antibody Sampler Kit contents:

Clone N355/1 is specific for GluR1, which belongs to the family of Glutamate Receptors (GluRs) essential for regulating excitatory synaptic transmission by L-glutamate in the CNS. These are mostly expressed in granule and pyramidal cells in the hippocampus. 

Clone L21/32 recognizes Glutamate Receptor 2 (GluR2), a subunit of AMPA receptors (AMPARs) involved in fast excitatory synaptic transmission. GluR2 regulates the permeability of an AMPAR to sodium, potassium, and calcium.

Clone L20/8 detects PICK1, an adaptor protein that interacts with and organizes multiple glutamate receptors, sodium channels, and membrane proteins.

Clone K28/74 detects PSD95, a member of the MAGUK family that forms a complex with DLG2 to act as a scaffold for receptors, ion channels, and signaling proteins.

An interferon-inducible type II transmembrane protein, SynDIG1 co-localizes with AMPA receptors at both postsynaptic terminals and extra-synaptic regions. Clone L42/17 can be used to detect SynDIG1 by WB.

The NMDA (GluN) Receptor Antibody Sampler Kit contains antibodies specific for NMDA receptor subunits GluN1, GluN2A, and GluN2B. The kit also includes antibodies for PSD95 and Shank to allow protein localization assessment.

NMDA (GluN) Receptor Antibody Sampler Kit :

Clone N308/48 detects NMDAR1, a subunit of glutamate-activated ion channels sensitive to N-methyl-D-aspartate (NMDA). These receptor channels are heterotetramer complexes involved in synapse plasticity, and may play a role in memory and learning.

Clone N327/95 recognizes another subunit of NMDA receptors, NMDAR2A. Dysfunction of NMDAR2A can be associated with neurological disorders.

Clone N59/36 is specific for subunit NMDAR2B of NMDA receptors. NMDAR2B is expressed early in development, and mutations in NMDAR2B are associated with neurodevelopmental disorders.

Clone N23B/49 is a pan-reactive antibody against SHANK proteins, adapter proteins that interact with other postsynaptic density proteins such as PSD-95 and Homer. These proteins form a structure that anchors glutamate receptors to the postsynaptic membrane.

Perturbation of calcium homeostasis in neurodegenerative disorders. Glutamate-mediated excitotoxicity through sustained NMDAR and AMPAR activity affects cytosolic calcium levels in AD, ALS and Huntington’s disease (HD). Aβ oligomers and mutant huntingtin protein were shown to increase NDMAR activity leading to the vulnerability of neurons to excitotoxicity. In ALS, neurons become vulnerable to glutamate toxicity mediated by AMPARs due to the absence of the GluA2 subunit, which interferes with the calcium permeability of AMPAR. Calcium overload and neurotoxicity can also be caused by the formation of calcium permeable channels by α-Synuclein and Aβ oligomers. Mitochondria are important regulators of calcium, and take up and reduce cytosolic levels of this ion. However, high mitochondrial calcium levels can trigger depolarization, opening of the mitochondrial permeability transition pore, and the release of apoptotic factors leading to cell death.