Brain Research Bulletin 69 (2006) 174–181 Disruption of the development of cholinergic-induced translocation/activation of PKC isoforms after prenatal heroin exposure Rabab Huleihel a , Joseph Yanai a,b,∗ a The Ross Laboratory for Studies in Neural Birth Defects, Department of Anatomy and Cell Biology, The Hebrew University-Hadassah Medical School, Box 12272, 91120 Jerusalem, Israel b Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA Received 7 September 2005; received in revised form 13 November 2005; accepted 30 November 2005 Available online 27 December 2005 Abstract Prenatal exposure of mice to heroin resulted in behavioral deficits present at adulthood, and related to septohippocampal cholinergic innervation accompanied by both pre- and postsynaptic cholinergic hyperactivity; including an increase in membrane PKC activity, and a desensitization of PKC to cholinergic input, which correlated highly with the behavioral performance, and was reversed by cholinergic grafting. The effect was shown in the behaviorally relevant PKC and  whereas the less behaviorally relevant PKC isoform was not affected. The present study was designed to establish the effect of heroin exposure on the expression of the PKC isoforms level and on the more functionally relevant cholinergic translocation/activation of the isoforms throughout postnatal development. The hippocampi of mice pups, exposed to heroin transplacentally, were assayed after incubation with carbachol for PKC isoforms on postnatal days (PN) 1, 7, 14, 21, 30 and 50. Prenatal heroin exposure increased basal PKC,  and  levels. PKC and  levels returned to control levels on PN50. While in PKC, this increase lasted until PN50. Translocation/activation of the PKC isoforms  and  by cholinergic receptor stimulation was present from PN1, concurrent with the presence of the isoforms. Prenatal exposure to heroin completely abolished the translocation/activation throughout the entire postnatal development. This defect was shown from the very beginning, PN1, the day when the PKC isoforms appear. The results suggest that the PKC and  isoforms are functional concurrent with their developmental appearance. Unlike findings on some other teratogens, the prenatal heroin effect on the isoforms function is similar throughout postnatal development. © 2006 Elsevier Inc. All rights reserved. Keywords: Heroin; Hippocampal cholinergic innervation; Mice; PKC; Prenatal exposure 1. Introduction Heroin is one of the major drugs abused by women of child- bearing age throughout the world. The 2003 National Survey on Drug Use and Health found that the peak age for drug use is 18–20 years, which corresponds with female childbearing age. The neurobehavioral teratogenicity of heroin and other opiates has been widely reported in both humans and laboratory animals [32,49,51]. Abbreviations: cPKC, cellular protein kinase C; DTT, dithiothreitol; ECL, enhanced chemiluminescence; GD, gestation day; HS/Ibg, heterogeneous stock mice; PBS, phosphate-buffered saline; PKC, protein kinase C; PN, postnatal day; pPKC, phosphorylated protein kinase C ∗ Corresponding author. Tel.: +972 2 675 8439; fax: +972 2 675 8443. E-mail address: yanai@md.huji.ac.il (J. Yanai). In order to reverse, or at least alleviate, heroin-induced neurobehavioral birth defects it is necessary to establish their mechanism. In our mouse model of neurobehavioral terato- genicity, heroin-exposed offspring exhibited behavioral deficits, related to the septohippocampal cholinergic innervation bio- chemistry and its signaling protein, PKC [42,43]. Specifically, the offspring displayed pre- and postsynaptic hyperactivity of the hippocampal cholinergic innervation resultant in desensiti- zation to cholinergic-induced translocation/activation of PKC isoforms [39,50]. Taken together with our models of other neuroteratogens, it appears that changes in cholinergic translo- cation/activation of PKC represent a central component of the mechanism by which many teratogens exert their delete- rious actions on behavior [7,21,50]. Understanding the mech- anisms of the deficits enabled their reversal by various means [7,36,44]. 0361-9230/$ – see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.brainresbull.2005.11.023