Enhancement of prepulse inhibition after blockade of GABA activity within the superior colliculus.
The present study examined the effects of local microinjections of the GABA chloride channel blocker Picrotoxin into the superior colliculus (SC) on prepulse inhibition (PPI) of the acoustic startle response (ASR) in rats. PPI is a useful model for the investigation of the neuronal basis of sensorimotor gating which is deficient in some psychiatric disorders, such as schizophrenia. Blockade of GABA activity within the SC by Picrotoxin injections (leading to a moderate stimulation of the SC) significantly enhanced PPI without affecting the ASR baseline amplitude or the spontaneous motor activity. Based on these results we discuss the role of the SC in a hypothetical neuronal circuit mediating PPI of the ASR.
Fendt
M
M
Tierphysiologie, Universität Tübingen, Auf der Morgenstelle 28, D-72076, Tübingen, Germany. markus.fendt@uni-tuebingen.de
D000161:Acoustic Stimulation; D000818:Animals; D018756:GABA Antagonists / Q000494:pharmacology*; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects* / Q000502:physiology*; D010852:Picrotoxin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology; D013477:Superior Colliculi / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*
D018756:GABA Antagonists; D010852:Picrotoxin