Long-lasting sensitization induced by repeated risperidone treatment in adolescent Sprague-Dawley rats: A possible D2 receptor mediated phenomenon?

Jing Qiao, Jun Gao, Qing Shu, Qinglin Zhang, Gang Hu, Ming Li

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Rationale: Risperidone use in children and adolescents for the treatment of various neuropsychiatric disorders (e.g., schizophrenia, autism, disruptive behavior, etc.) has increased substantially in recent decades. However, its long-term effect on the brain and behavioral functions is not well understood. Objective: The present study investigated how a short-term risperidone treatment in adolescence impacts antipsychotic response in adulthood in the conditioned avoidance response and phencyclidine (PCP)-induced hyperlocomotion tests. Methods: Male adolescent Sprague-Dawley rats (postnatal days [P] 40-44 or 43-48) were first treated with risperidone (0.3, 0.5, or 1.0 mg/kg, subcutaneously (sc)) and tested in the conditioned avoidance or PCP (3.2 mg/kg, sc)-induced hyperlocomotion model daily for five consecutive days. After they became adults (~P 76-80), they were challenged with risperidone (0.3 mg/kg, sc) to assess their sensitivity to risperidone reexposure. A quinpirole (a D2/3 receptor agonist, 1.0 mg/kg, sc)-induced hyperlocomotion test was later conducted to assess the risperidone-induced functional changes in D2 receptor. Results: In the risperidone challenge test in adulthood, adult rats previously treated with risperidone in adolescence made significantly fewer avoidance responses and exhibited significantly lower PCP-induced hyperlocomotion than those previously treated with vehicle. They also appeared to be more hyperactive than the vehicle-pretreated ones in the quinpirole-induced hyperlocomotion test. Prepulse inhibition of acoustic startle or fear-induced 22 kHz ultrasonic vocalizations in adulthood was not altered by adolescence risperidone treatment. Conclusions: Adolescent risperidone exposure induces a long-term increase in behavioral sensitivity to risperidone that persists into adulthood. This long-lasting change might be due to functional upregulation of D2-mediated neurotransmission.

Original languageEnglish (US)
Pages (from-to)1649-1659
Number of pages11
JournalPsychopharmacology
Volume231
Issue number8
DOIs
StatePublished - Apr 2014

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Keywords

  • 22 kHz ultrasonic vocalization
  • Adolescence
  • Conditioned avoidance response
  • Motor activity
  • Phencyclidine
  • Prepulse inhibition
  • Quinpirole
  • Risperidone
  • Sensitization

ASJC Scopus subject areas

  • Pharmacology

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