Neuronal integration and the depolarizing effects of axonal GABAA receptors

2011 ◽  
Vol 106 (5) ◽  
pp. 2105-2107
Author(s):  
Thomas J. Younts ◽  
Sachin Makani
Keyword(s):  
Gabaa Receptors ◽  
Neurotransmitter Release ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Gamma Amino Butyric Acid ◽  
Cerebellar Granule ◽  
Amino Butyric Acid ◽  
Acid Type ◽  
The Central Nervous System ◽  
The Impact

Despite their presence throughout the central nervous system, the impact of axonally expressed gamma-amino-butyric acid type-A receptors (GABAARs) on neuronal signaling is just beginning to be understood. A recently published article (Pugh JR and Jahr CE, J Neurosci 31: 565–574, 2011) tackled this important issue by investigating GABAAR-mediated function in axons of cerebellar granule cells. The results of Pugh and Jahr indicate parallel fiber GABAARs enhance neurotransmitter release probability and boost axonal and somatic excitability.

The effects of zolpidem treatment on GABAA receptors in cultured cerebellar granule cells: Changes in functional coupling

Life Sciences ◽  
2012 ◽  
Vol 90 (23-24) ◽  
pp. 889-894 ◽  
Author(s):  
Josipa Vlainić ◽  
Dubravka Švob Štrac ◽  
Maja Jazvinšćak Jembrek ◽  
Toni Vlainić ◽  
Danka Peričić
Keyword(s):  
Gabaa Receptors ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Functional Coupling ◽  
Cerebellar Granule

scholarly journals Synaptically Released Neurotransmitter Fails to Desensitize Postsynaptic GABAA Receptors in Cerebellar Cultures

2001 ◽  
Vol 85 (5) ◽  
pp. 1847-1857 ◽  
Author(s):  
J. R. Mellor ◽  
A. D. Randall
Keyword(s):  
Gabaa Receptors ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
High Concentration ◽  
Concentration Jump ◽  
Cerebellar Granule ◽  
Resistant Population ◽  
S Application ◽  
Stimulation Technique ◽  
Cerebellar Cultures

GABA concentration jump experiments performed on membrane patches predict that postsynaptic GABAAreceptors will become desensitized following the release of the contents of a single GABA-containing synaptic vesicle. To examine this we used a single synaptic bouton stimulation technique to directly examine whether postsynaptic GABAA receptors in cultured cerebellar granule cells exhibit transmitter-induced desensitization. In a large number of recordings, no evidence was found for desensitization of postsynaptic GABAAreceptors by vesicularly released transmitter. This was the case even when as many as 40 vesicles were released from a single bouton within 1.5 s. In addition, postsynaptic depolarization and application of the benzodiazepine flunitrazepam, manipulations previously shown to enhance desensitization of GABAA receptors, failed to unmask transmitter-induced desensitization. In contrast, a single 2- to 3-s application of a high concentration of exogenous GABA was able to depress synaptic responsiveness for up to 70 s. Furthermore, pharmacological depletion of GABA eliminated inhibitory synaptic communication, suggesting that GABA is the transmitter and the desensitization-resistant inhibitory postsynaptic currents are not mediated by a “nondesensitizing” ligand such as β-alanine. Overall our data indicate that a specific desensitization-resistant population of GABAA receptors are present at postsynaptic sites on cultured cerebellar granule cells.

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