Increased risk of developing schizophrenia in animals exposed to cigarette smoke during the gestational period

Prog Neuropsychopharmacol Biol Psychiatry. 2017 Apr 3:75:199-206. doi: 10.1016/j.pnpbp.2017.02.010. Epub 2017 Feb 14.

Abstract

Cigarette smoking during the prenatal period has been investigated as a causative factor of obstetric abnormalities, which lead to cognitive and behavioural changes associated with schizophrenia. The aim of this study was to investigate behaviour and AChE activity in brain structures in adult rats exposed to cigarette smoke during the prenatal period. Pregnant rats were divided into non-PCSE (non-prenatal cigarette smoke exposure) and PCSE (prenatal cigarette smoke exposure) groups. On post-natal day 60, the rats received saline or ketamine for 7days and were subjected to behavioural tasks. In the locomotor activity task, the non-PCSE+ketamine and PCSE+ketamine groups exhibited increased locomotor activity compared with the saline group. In the social interaction task, the non-PCSE+ketamine and PCSE+ketamine groups exhibited an increased latency compared with the control groups. However, the PCSE+ketamine group exhibited a decreased latency compared with the non-PCSE+ketamine group, which indicates that the cigarette exposure appeared to decrease, the social deficits generated by ketamine. In the inhibitory avoidance task, the non-PCSE+ketamine, PCSE, and PCSE+ketamine groups exhibited impairments in working memory, short-term memory, and long-term memory. In the pre-pulse inhibition (PPI) test, cigarette smoke associated with ketamine resulted in impaired PPI in 3 pre-pulse (PP) intensity groups compared with the control groups. In the biochemical analysis, the AChE activity in brain structures increased in the ketamine groups; however, the PCSE+ketamine group exhibited an exacerbated effect in all brain structures. The present study indicates that exposure to cigarette smoke during the prenatal period may affect behaviour and cerebral cholinergic structures during adulthood.

Keywords: Acetylcholinesterase; Inhibitory avoidance; Locomotor activity; Maternal smoking; Schizophrenia; Social interaction.

MeSH terms

  • Acetylcholinesterase / metabolism
  • Analysis of Variance
  • Animals
  • Animals, Newborn
  • Avoidance Learning / drug effects
  • Choline O-Acetyltransferase / metabolism
  • Disease Models, Animal
  • Excitatory Amino Acid Antagonists / pharmacology
  • Excitatory Amino Acid Antagonists / therapeutic use
  • Exploratory Behavior / drug effects
  • Female
  • Inhibition, Psychological
  • Interpersonal Relations
  • Ketamine / pharmacology
  • Ketamine / therapeutic use
  • Male
  • Pregnancy
  • Prenatal Exposure Delayed Effects / physiopathology*
  • Prepulse Inhibition / drug effects
  • Rats, Wistar
  • Schizophrenia / drug therapy
  • Schizophrenia / etiology*
  • Smoking / adverse effects*

Substances

  • Excitatory Amino Acid Antagonists
  • Ketamine
  • Choline O-Acetyltransferase
  • Acetylcholinesterase