Altered activity-based sleep measures in rhesus monkeys following cocaine self-administration and abstinence.
Impairments in sleep and cognitive function have been observed in patients with substance abuse disorders and may be potential factors contributing to drug relapse. In addition, sleep disruption may itself contribute to cognitive deficits. In the present study we examined the impact of prolonged cocaine self-administration and abstinence on actigraphy-based measures of night-time activity in rhesus macaques as an inferential measure of sleep, and determined whether sleep-efficiency correlated with cognitive impairments in the same subjects on drug free days.



Actigraphy data was obtained from a group of rhesus macaques intravenously self-administering cocaine (n=6) and a control group (n=5). Periods were evaluated during which the mean cumulative doses of cocaine were 3.0+0.0 and 4.5+0.2mg/kg/day for 4days (Tuesday-Thursday) each week.



Actigraphy-based sleep efficiency decreased during days of cocaine self-administration in a dose-dependent manner. Consistent with this observation, sleep became more fragmented. Activity-based sleep efficiency normalized during the weekend without cocaine prior to cognitive assessment on Monday. The magnitude of activity-based sleep disruption during self-administration did not correlate with the level of cognitive impairment on drug free days. With continued self-administration, the impact of cocaine on activity-based sleep efficiency declined indicating the development of tolerance.



Cocaine self-administration disrupted sleep efficiency in rhesus macaques as measured by actigraphy, but normalized quickly in the absence of cocaine. The cognitive impairment observed on drug free days was unlikely to be related to disruption of the nightly activity patterns on days of cocaine self-administration.
Departments of Bioengineering, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Jennifer A
JA
Cortes
Departments of Neuroscience, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Gustavo
G
Gomez
Departments of Psychiatry, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Carol
C
Ehnerd
Departments of Psychiatry, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Kate
K
Gurnsey
Departments of Psychiatry, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Jessica
J
Nicolazzo
Departments of Neuroscience, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA; Departments of Psychiatry, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA; VA Pittsburgh Healthcare System, University Drive, Pittsburgh, PA 15240, USA.
Charles W
CW
Bradberry
Departments of Psychiatry, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA. Electronic address: Jedema@pitt.edu.
Hank P
HP
Jedema
D056044:Actigraphy / Q000379:methods; D000818:Animals; D003042:Cocaine / Q000008:administration & dosage* / Q000009:adverse effects*; D019970:Cocaine-Related Disorders / Q000503:physiopathology* / Q000523:psychology; D003071:Cognition / Q000187:drug effects / Q000502:physiology; D003072:Cognition Disorders / Q000139:chemically induced / Q000503:physiopathology* / Q000523:psychology; D008253:Macaca mulatta; D008297:Male; D012646:Self Administration; D012893:Sleep Wake Disorders / Q000139:chemically induced / Q000503:physiopathology* / Q000523:psychology; D012895:Sleep, REM / Q000187:drug effects / Q000502:physiology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000523:psychology
D003042:Cocaine
Actigraphy; Cocaine; Cognition; Rhesus macaque; Sleep efficiency; Stimulant