title: Latent inhibition of a conditioned taste aversion in fetal rats.
abstract: The etiology of schizophrenia's cognitive symptoms may have its basis in prenatal alterations of glutamate N-methyl-D-aspartate (NMDA) receptor functioning. Therefore, the current study investigated the effects of ketamine (an NMDA receptor blocking drug) on both a conditioned taste aversion (CTA) and latent inhibition (LI; a model of attentional capacity) in rat fetuses. We first sought to determine if a CTA could be diminished by nonreinforced preexposure to a CS in fetal rats (i.e., LI). We injected E18 pregnant Sprague-Dawley rats with 100% allicin (garlic taste) or an equal volume of saline. Some of the pregnant dams also received ketamine (100 mg/kg, i.p.). One day later (E19), the dams received a second injection of the CS, followed by either lithium chloride (the US) or saline. Finally, on E21 pups received oral lavage with allicin and observations of ingestive orofacial motor responses were recorded. When allicin had been paired with LiCl in utero, E21 fetuses exhibited a conditioned suppression of orofacial movements, indicative of an aversion to this taste. Preexposure to the garlic taste on E18 produced a LI of this CTA. Ketamine significantly disrupted the formation of the CTA and had some impact on LI. However, the direct effect of ketamine on LI is less certain since the drug also blocked the original CTA.
authors.affiliation: The Neuroscience Program, Baldwin Wallace University, 275 Eastland Rd., Berea, OH, 44017. amickley@bw.edu.
authors.forename: G Andrew
authors.initials: GA
authors.lastname: Mickley
authors.forename: Zana
authors.initials: Z
authors.lastname: Hoxha
authors.forename: Anthony
authors.initials: A
authors.lastname: DiSorbo
authors.forename: Gina N
authors.initials: GN
authors.lastname: Wilson
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Remus
authors.forename: Orion
authors.initials: O
authors.lastname: Biesan
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Ketchesin
authors.forename: Linnet
authors.initials: L
authors.lastname: Ramos
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Luchsinger
authors.forename: Suzanna
authors.initials: S
authors.lastname: Prodan
authors.forename: Morgan
authors.initials: M
authors.lastname: Rogers
authors.forename: Nathanael R
authors.initials: NR
authors.lastname: Wiles
authors.forename: Nita
authors.initials: N
authors.lastname: Hoxha
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D004220:Disulfides; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D007266:Inhibition, Psychological; D007649:Ketamine / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013441:Sulfinic Acids / Q000494:pharmacology*
chemical_list: D004220:Disulfides; D018691:Excitatory Amino Acid Antagonists; D013441:Sulfinic Acids; C006452:allicin; D007649:Ketamine
keywords: CTA; N-methyl-D-aspartate; NMDA; conditioned taste aversion; fetal; ketamine; latent inhibition; learning; memory