TY - JOUR
T1 - The Effect of Methylphenidate on the Microstructure of Schedule-Induced Polydipsia in an animal model of ADHD
AU - Íbias, Javier
AU - Daniels, Carter W.
AU - Miguéns, Miguel
AU - Pellón, Ricardo
AU - Sanabria, Federico
PY - 2017/8/30
Y1 - 2017/8/30
N2 - Schedule-induced polydipsia (SIP) was established in spontaneously hypertensive rats (SHR), Wistar Kyoto rats (WKY), and Wistar rats, using a multiple fixed-time (FT) schedule of food delivery, with 30- and 90-s components. Thereafter, animals were exposed to methylphenidate (MPH; 2.5 mg/kg/d) for six consecutive SIP sessions. A test to assess possible sensitization effects was also conducted four days after termination of the drug treatment. At baseline, FT 90-s produced longer and more frequent drinking episodes in SHR than in WKY. An analysis of the distribution of inter-lick intervals revealed that drinking was organized in bouts, which were shorter in SHR than in WKY. Across strains and schedules, MPH shifted drinking episodes towards the beginning of inter-food intervals, which may reflect a stimulant effect on SIP. MPH transiently reduced the frequency of drinking episodes in WKY in FT 30-s, and more permanently reduced the frequency of licking bouts in Wistar rats. MPH also increased the length of licking bouts in Wistar rats. Overall, SHR displayed a hyperactive-like pattern of drinking (frequent but short bouts), which 2.5 mg/kg MPH appears to reduce in WKY and Wistar but not in SHR rats. It appears that therapeutic effects of MPH on hyperactive-like SIP require higher doses in SHR relative to control strains.
AB - Schedule-induced polydipsia (SIP) was established in spontaneously hypertensive rats (SHR), Wistar Kyoto rats (WKY), and Wistar rats, using a multiple fixed-time (FT) schedule of food delivery, with 30- and 90-s components. Thereafter, animals were exposed to methylphenidate (MPH; 2.5 mg/kg/d) for six consecutive SIP sessions. A test to assess possible sensitization effects was also conducted four days after termination of the drug treatment. At baseline, FT 90-s produced longer and more frequent drinking episodes in SHR than in WKY. An analysis of the distribution of inter-lick intervals revealed that drinking was organized in bouts, which were shorter in SHR than in WKY. Across strains and schedules, MPH shifted drinking episodes towards the beginning of inter-food intervals, which may reflect a stimulant effect on SIP. MPH transiently reduced the frequency of drinking episodes in WKY in FT 30-s, and more permanently reduced the frequency of licking bouts in Wistar rats. MPH also increased the length of licking bouts in Wistar rats. Overall, SHR displayed a hyperactive-like pattern of drinking (frequent but short bouts), which 2.5 mg/kg MPH appears to reduce in WKY and Wistar but not in SHR rats. It appears that therapeutic effects of MPH on hyperactive-like SIP require higher doses in SHR relative to control strains.
KW - Attention-deficit hyperactivity disorder
KW - Bouts
KW - Methylphenidate
KW - Schedule-induced polydipsia
KW - Spontaneously hypertensive rat
KW - Wistar Kyoto rats
UR - http://www.scopus.com/inward/record.url?scp=85022202457&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85022202457&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2017.06.048
DO - 10.1016/j.bbr.2017.06.048
M3 - Article
C2 - 28669538
AN - SCOPUS:85022202457
SN - 0166-4328
VL - 333
SP - 211
EP - 217
JO - Behavioural Brain Research
JF - Behavioural Brain Research
ER -