Perceived location specificity in perceptual separation-induced but not fear conditioning-induced enhancement of prepulse inhibition in rats.
Prepulse inhibition (PPI) is the suppression of the startle reflex when the startling stimulus is shortly preceded by a non-startling stimulus (the prepulse). Previous studies have shown that both fear conditioning of a prepulse and precedence-effect-induced perceptual separation between the conditioned prepulse and a noise masker facilitate selective attention to the prepulse and consequently enhance PPI with a remarkable prepulse-feature specificity. This study investigated whether the two types of attentional enhancements of PPI in rats also exhibit a prepulse-location specificity. The results showed that when a prepulse was delivered by each of the two spatially separated loudspeakers, fear conditioning of the prepulse at a particularly perceived location (left or right to the tested rat) enhanced PPI without exhibiting any perceived-location specificity. However, when a noise masker was presented, the precedence-effect-induced perceptual separation between the conditioned prepulse and the noise masker further enhanced PPI when the prepulse was perceived as coming from the location that was conditioned but not the location without being conditioned. Moreover, both conditioning-induced and perceptual separation-induced PPI enhancements were eliminated by extinction learning, whose effect could be blocked by systemic injection of the selective antagonist of metabotropic glutamate receptor subtype 5 (mGluR5), 2-methyl-6-(phenylethynyl)-pyridine (MPEP). Thus, fear conditioning of a prepulse perceived at a particular location not only facilitates selective attention to the conditioned prepulse but also induces a learning-based spatial gating effect on the spatial unmasking of the conditioned prepulse, leading to that the perceptual separation-induced PPI enhancement becomes perceived-location specific.
Department of Psychology, McGovern Institute for Brain Research, Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing 100871, China.
Ming
M
Lei
Department of Psychology, McGovern Institute for Brain Research, Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing 100871, China.
Lu
L
Luo
Department of Machine Intelligence, Speech and Hearing Research Center, Peking University, Beijing 100871, China.
Tianshu
T
Qu
Beijing An Ding Hospital, Capital Medical University, Beijing 100088, China.
Hongxiao
H
Jia
Department of Psychology, McGovern Institute for Brain Research, Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing 100871, China. Electronic address: liangli@pku.edu.cn.
Liang
L
Li
D000161:Acoustic Stimulation; D000818:Animals; D001288:Attention / Q000187:drug effects / Q000502:physiology*; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D004597:Electroshock; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D008297:Male; D065808:Prepulse Inhibition / Q000187:drug effects / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D064529:Receptor, Metabotropic Glutamate 5 / Q000037:antagonists & inhibitors / Q000378:metabolism; D013017:Sound Localization / Q000187:drug effects / Q000502:physiology; D013028:Space Perception / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; C578937:Grm5 protein, rat; D011725:Pyridines; D064529:Receptor, Metabotropic Glutamate 5; C121465:6-methyl-2-(phenylethynyl)pyridine
Fear conditioning; Metabotropic glutamate receptor; Perceived location specificity; Perceptual spatial separation; Precedence effect; Prepulse inhibition