Kainate receptor activation potentiates GABAergic synaptic transmission in the nucleus accumbens core.
Inhibitory synaptic transmission plays an important role in regulating the activity of medium spiny neurons (MSNs) in the nucleus accumbens (NAcc). The kainate (KA) subtype of ionotropic glutamate receptor has been shown to potently modulate GABAergic synaptic transmission in several brain regions. Although KA receptor subunits are expressed in the NAcc, KA receptor modulation of GABAergic synaptic transmission in this brain region has not been previously examined. In the current study, we sought to determine if KA receptor activation could alter inhibitory synaptic transmission in the NAcc as it has been shown to do in other brain regions. Using the whole cell patch-clamp technique, we demonstrate that KA receptor activation potentiates evoked GABAergic synaptic transmission and increases the frequency of spontaneous, but not miniature, GABA(A)-receptor-mediated IPSCs in the NAcc. In contrast, KA has no effect on currents evoked by exogenous application of GABA onto MSNs. Taken together, these data suggest that activation of KA receptors in the NAcc core potently facilitates action-potential-dependent GABAergic synaptic transmission, likely via an excitation of presynaptic GABAergic interneurons.
Crowder
Tara L
TL
Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-34932, USA.
Ariwodola
Olusegun J
OJ
Weiner
Jeff L
JL
D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009714:Nucleus Accumbens / Q000166:cytology*; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D018092:Kainic Acid Receptors / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D005680:gamma-Aminobutyric Acid / Q000378:metabolism* / Q000494:pharmacology
D001640:Bicuculline; D002118:Calcium; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D007608:Kainic Acid; D018092:Kainic Acid Receptors; D005680:gamma-Aminobutyric Acid