Differences between adolescents and adults in the acute effects of PCP and ketamine and in sensitization following intermittent administration.
Angelica Rocha, Nigel Hart, Keith A Trujillo
Pharmacology, biochemistry, and behavior June 1, 2017 DOI: 10.1016/j.pbb.2017.04.007 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Periadolescent and adult Sprague-Dawley rats |
| Interventions | PCP ketamine |
| Dose | 6 mg/kg IP for PCP, 20 mg/kg IP for ketamine |
| Duration | Five injections once every three days |
| Topics | Addiction Ketamine Esketamine |
| Keywords | Locomotor Phencyclidine Sensitization |
| Key findings | Adolescent rats show a greater acute stimulant response to PCP and ketamine than adults, but adults develop stronger sensitization with repeated doses. |
Abstract
Adolescence is a phase of development during which many physiological and behavioral changes occur, including increased novelty seeking and risk taking. In humans, this is reflected in experimentation with drugs. Research demonstrates that drug use that begins during adolescence is more likely to lead to addiction than drug use that begins later in life. Despite this, relatively little is known of the effects of drugs in adolescence, and differences in response between adolescents and adults. PCP and ketamine are popular club drugs, both possessing rewarding properties that could lead to escalating use. Drug sensitization (or reverse tolerance), which refers to an increase in an effect of a drug following repeated use, has been linked with the development of drug cravings that is a hallmark of addiction. The current work investigated the acute response and the development of sensitization to PCP and ketamine in adolescent and adult rats. Periadolescent Sprague-Dawley rats (30days or 38days of age), and young adults (60days of age) received PCP (6mg/kg IP) or ketamine (20mg/kg IP) once every three days, for a total of five drug injections. Adolescents and adults showed a stimulant response to the first injection of either drug, however the response was considerably greater in the youngest adolescents and lowest in the adults. With repeated administration, adults showed a robust escalation in activity that was indicative of the development of sensitization. Adolescents showed a flatter trajectory, with similar high levels of activity following an acute treatment and after five drug treatments. The results demonstrate important distinctions between adolescents and adults in the acute and repeated effects of PCP and ketamine.