Interaction of chronic food restriction and methylphenidate in sensation seeking of rats.
Psychopharmacology. 2017-04-08; 234(14): 2197-2206
DOI: 10.1007/s00213-017-4625-6
Lire sur PubMed
Talishinsky AD(1), Nicolas C(1), Ikemoto S(2).
Author information:
(1)Behavioral Neuroscience Research Branch, National Institute on Drug Abuse,
National Institutes of Health, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA.
(2)Behavioral Neuroscience Research Branch, National Institute on Drug Abuse,
National Institutes of Health, 251 Bayview Blvd., Suite 200, Baltimore, MD, USA.
.
RATIONALE: It is necessary to understand better how chronic food restriction
(CFR) and psychostimulant drugs interact in motivated behavior unrelated to food
or energy homeostasis.
OBJECTIVES: We examined whether CFR augments methylphenidate (MPH)-potentiated
responding reinforced by visual sensation (VS) and whether repeated MPH
injections or prolonged CFR further augments such responses.
METHODS: Before starting the following experiments, rats on a CFR diet received
a limited daily ration in such a way that their body weights decreased to 85-90%
of their original weights over 2 weeks. In experiment 1, rats on CFR and ad
libitum diet received four injections of varying MPH doses (0, 2.5, 5, and
10 mg/kg). In experiment 2, CFR and ad libitum groups received repeated
injections of MPH (2.5 mg/kg). In experiment 3, half of CFR rats received
repeated injections of MPH (2.5 mg/kg), and the other half received saline, and
following a 7-day abstinence, they all received the 2.5-mg/kg dose of MPH.
RESULTS: CFR rats increased VS-reinforced responding more than ad libitum rats
when they received MPH. Repeated injections of MPH with prolonged CFR further
increased VS-reinforced responding. We found a double dissociation where
prolonged CFR (3 vs. 6 weeks) made VS-reinforced responding, but not locomotor
activity, more responsive to MPH, whereas repeated MPH injections made locomotor
activity, but not VS-reinforced responding, more responsive to MPH.
CONCLUSIONS: CFR markedly potentiates effects of MPH on VS-reinforced
responding. The present study demonstrates that the longer CFR continues, the
greater psychostimulant drugs augment behavioral interaction with salient
stimuli.
DOI: 10.1007/s00213-017-4625-6
PMCID: PMC5482769
PMID: 28391507 [Indexed for MEDLINE]