title: Weak prepulses inhibit but do not elicit startle in rats and humans.
abstract: BACKGROUND
  Inhibition of startle by weak prestimuli is called prepulse inhibition (PPI). It has recently been reported that 10- to 20-dB prepulses trigger eye-blink motor activity and PPI in normal human subjects. Motor activity after prepulses correlated negatively with PPI in four of nine possible conditions. We now report the relationship between prepulse-elicited startle (PPES) and PPI using weak prepulses.
  
  
  METHODS
  We assessed PPI and PPES using 1- to 5-dB prepulses in humans and in rats after treatment with vehicle or apomorphine.
  
  
  RESULTS
  Prepulses inhibited startle in an intensity-dependent fashion but elicited no startle activity in humans or rats. Apomorphine eliminated PPI in rats and produced a well-documented increase in stimulus-independent motor activity but did not stimulate PPES.
  
  
  CONCLUSIONS
  In humans and rats, PPES is not a necessary condition for either the elicitation or the disruption of PPI.
authors.affiliation: Department of Psychiatry, University of California, San Diego School of Medicine, La Jolla 92093-0804, California, USA.
authors.forename: Neal R
authors.initials: NR
authors.lastname: Swerdlow
authors.forename: Jo
authors.initials: J
authors.lastname: Talledo
authors.forename: Jody M
authors.initials: JM
authors.lastname: Shoemaker
authors.forename: Katie
authors.initials: K
authors.lastname: Codon
authors.forename: Jana
authors.initials: J
authors.lastname: Goins
authors.forename: Pamela P
authors.initials: PP
authors.lastname: Auerbach
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*
chemical_list: D018491:Dopamine Agonists; D001058:Apomorphine