Behavioral consequences of human methamphetamine (METH) abuse have been extensively documented. However, underlying neurobiological mechanisms for those behaviors remain unspecified. A more precise and thorough examination of those processes still requires the use of appropriate animal models that address the broad range of abuse patterns in humans. For the proposed studies, we will model aspects of human chronic METH exposure in nonhuman primates with an integrated evaluation of biological, psychological, and environmental determinants. A 6 month escalating METH dose protocol that reflects human METH abuse patterns will be administered to vervet monkeys (Cercopithecus aethiops sabaeus) housed in naturally composed social groups. Presynaptic striatal dopamine (DA) transporter binding decreases will be determined in vivo throughout the study with PET to establish its sensitivity as an in vivo index of behavioral reactivity to METH. Behavioral alterations of impulsivity, aggression, and social relationships will be evaluated throughout the METH exposure and then continued for 6 months post-METH abstinence period to assess potential recovery. Cognitive alterations will be assessed by a battery of neuropsychological tasks. Individual differences in behavioral reactivity to METH, which are often seen in humans, will be evaluated in our METH subjects by measurement of pre-METH CSF monoamine metabolite levels (HVA, 5-HIAA, MHPG) and the extent of their changes, post-METH. Neurotoxicity of METH as expressed in dopamine and serotonin pathways within cortical, nigrostriatal and limbic regions will be evaluated by post-mortem measures of substantia nigra cell loss, pre-synaptic transporter and post-synaptic receptor densities (DA 1, DA2, 5-HT 1 A, 5-HT2A). The results will show in socially-housed adult nonhuman primates, the vulnerability of regional brain systems to METH exposure in conjunction with specific behavioral and cognitive assessments. This paradigm will represent a validated primate model to evaluate the efficacy of pharmacotherapies designed for treatment of neurological and behavioral deficits associated with human METH abuse.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
2R01DA011237-04A1
Application #
6333260
Study Section
Integrative, Functional and Cognitive Neuroscience 8 (IFCN)
Program Officer
Frankenheim, Jerry
Project Start
1997-09-30
Project End
2005-03-31
Budget Start
2001-04-01
Budget End
2002-03-31
Support Year
4
Fiscal Year
2001
Total Cost
$341,097
Indirect Cost
Name
University of California Los Angeles
Department
Pharmacology
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Melega, William P; Jorgensen, Matthew J; Lacan, Goran et al. (2008) Long-term methamphetamine administration in the vervet monkey models aspects of a human exposure: brain neurotoxicity and behavioral profiles. Neuropsychopharmacology 33:1441-52
Melega, William P; Lacan, Goran; Harvey, Dennis C et al. (2007) Methamphetamine increases basal ganglia iron to levels observed in aging. Neuroreport 18:1741-5
Melega, William P; Cho, Arthur K; Harvey, Dennis et al. (2007) Methamphetamine blood concentrations in human abusers: application to pharmacokinetic modeling. Synapse 61:216-20
Cho, Arthur K; Melega, William P (2002) Patterns of methamphetamine abuse and their consequences. J Addict Dis 21:21-34
Harvey, D C; Lacan, G; Tanious, S P et al. (2000) Recovery from methamphetamine induced long-term nigrostriatal dopaminergic deficits without substantia nigra cell loss. Brain Res 871:259-70