Mature hippocampal astrocytes exhibit functional metabotropic and ionotropic glutamate receptors in situ

Glia ◽  
1999 ◽  
Vol 26 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Marilee K. Shelton ◽  
Ken D. McCarthy
2002 ◽  
Vol 87 (1) ◽  
pp. 528-537 ◽  
Author(s):  
Wolfgang J. Nett ◽  
Scott H. Oloff ◽  
Ken D. McCarthy

Results presented in this study indicate that a large subpopulation (∼65%) of hippocampal astrocytes in situ exhibit calcium oscillations in the absence of neuronal activity. Further, the spontaneous oscillations observed within individual hippocampal astrocytes generally developed asynchronously throughout the astrocyte's fine processes and occasionally spread through a portion of that astrocyte as a calcium wave but do not appear to spread among astrocytes as an intercellular calcium wave. Bath application of cyclopiazonic acid and injection of individual astrocytes with heparin blocked astrocytic calcium oscillations. Application of tetrodotoxin or incubation of slices with bafilomycin A1 had no effect on astrocytic calcium oscillations but did block evoked and spontaneous postsynaptic currents measured in CA1 pyramidal neurons. Application of a cocktail of antagonists for metabotropic glutamate receptors and purinergic receptors had no effect on the astrocytic calcium oscillations but blocked the ability of purinergic and metabotropic glutamatergic agonists to increase astrocytic calcium levels. These results indicate that the spontaneous calcium oscillations observed in hippocampal astrocytes in situ are mediated by IP3 receptor activation, are not dependent on neuronal activity, and do not depend on activation of metabotropic glutamate receptors or purinergic receptors. To our knowledge, this is the first demonstration that astrocytes in situ exhibit intrinsic signaling. This finding supports the hypothesis that astrocytes, independent of neuronal input, may act as pacemakers to modulate neuronal activity in situ.


2021 ◽  
pp. 108631
Author(s):  
David Stroebel ◽  
Laetitia Mony ◽  
Pierre Paoletti

Author(s):  
Yukari Maeno ◽  
Yuichi Kotaki ◽  
Ryuta Terada ◽  
Masafumi Hidaka ◽  
Yuko Cho ◽  
...  

Domoic acid (1, DA), a member of the natural kainoid family, is a potent agonist of ionotropic glutamate receptors in the central nervous system. The chemical synthesis of DA and...


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 77
Author(s):  
Fabrizio Gardoni ◽  
Jennifer Stanic ◽  
Diego Scheggia ◽  
Alberto Benussi ◽  
Barbara Borroni ◽  
...  

The role of autoimmunity in central nervous system (CNS) disorders is rapidly expanding. In the last twenty years, different types of autoantibodies targeting subunits of ionotropic glutamate receptors have been found in a variety of patients affected by brain disorders. Several of these antibodies are directed against NMDA receptors (NMDAR), mostly in autoimmune encephalitis, whereas a growing field of research has identified antibodies against AMPA receptor (AMPAR) subunits in patients with different types of epilepsy or frontotemporal dementia. Several in vitro and in vivo studies performed in the last decade have dramatically improved our understanding of the molecular and functional effects induced by both NMDAR and AMPAR autoantibodies at the excitatory glutamatergic synapse and, consequently, their possible role in the onset of clinical symptoms. In particular, the method by which autoantibodies can modulate the localization at synapses of specific target subunits leading to functional impairments and behavioral alterations has been well addressed in animal studies. Overall, these preclinical studies have opened new avenues for the development of novel pharmacological treatments specifically targeting the synaptic activation of ionotropic glutamate receptors.


2013 ◽  
Vol 104 (2) ◽  
pp. 272a
Author(s):  
Christel B. Jensen ◽  
Niels G. Nørager ◽  
Anders S. Kristensen ◽  
Kristian Strømgaard

2014 ◽  
Vol 75 ◽  
pp. 151-158 ◽  
Author(s):  
Andrea Pinto ◽  
Lucia Tamborini ◽  
Federica Mastronardi ◽  
Roberta Ettari ◽  
Yeliz Safoz ◽  
...  

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