Different inhibitory inputs onto neostriatal projection neurons as revealed by field stimulation

Fatuel Tecuapetla, Luis Carrillo-Reid, Jaime N. Guzmán, Elvira Galarraga, José Bargas*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


This work investigated if diverse properties could be ascribed to evoked inhibitory postsynaptic currents (IPSCs) recorded on rat neostriatal neurons when field stimulation was delivered at two different locations: the globus pallidus (GP) and the neostriatum (NS). Previous work stated that stimulation in the GP could antidromically excite projection axons from medium spiny neurons. This maneuver would predominantly activate the inhibitory synapses that interconnect spiny cells. In contrast, intrastriatal stimulation would preferentially activate inhibitory synapses provided by interneurons. This study shows that, in fact, intensity-amplitude experiments are able to reveal different properties for IPSCs evoked from these two locations (GP and NS). In addition, while all IPSCs evoked from the GP were always sensitive to ω-conotoxin GVIA (CaV2.22.2 or N-channel blocker), one-half of the inhibition evoked from the NS exhibited little sensitivity to ω-conotoxin GVIA. Characteristically, all ω-conotoxin GVIA-insensitive IPSCs exhibited strong paired pulse depression, whereas ω-conotoxin GVIA-sensitive IPSCs evoked from either the GP or the NS could exhibit short-time depression or facilitation. ω-Agatoxin TK (Ca V2.12.1 or P/Q-channel blocker) blocked IPSCs evoked from both locations. Therefore 1) distinct inhibitory inputs onto projection neostriatal cells can be differentially stimulated with field electrodes; 2) N-type Ca2+ channels are not equally expressed in inhibitory terminals activated in the NS; and 3) synapses that interconnect spiny neurons use both N- and P/Q-type Ca2+ channels.

Original languageEnglish (US)
Pages (from-to)1119-1126
Number of pages8
JournalJournal of neurophysiology
Issue number2
StatePublished - Feb 2005

ASJC Scopus subject areas

  • General Neuroscience
  • Physiology


Dive into the research topics of 'Different inhibitory inputs onto neostriatal projection neurons as revealed by field stimulation'. Together they form a unique fingerprint.

Cite this