Tags

Type your tag names separated by a space and hit enter

Sparing of behavior and basal extracellular dopamine after 6-hydroxydopamine lesions of the nigrostriatal pathway in rats exposed to a prelesion sensitizing regimen of amphetamine.
Exp Neurol 2004; 189(1):78-93EN

Abstract

Repeated administration of amphetamine leads to enduring augmentation of its behavioral-activating effects, enhanced dopamine (DA) release in striatal regions, and morphological changes in DA target neurons. Here we show that exposure to a 2-week escalating-dose regimen of amphetamine prevents behavioral asymmetries of forelimb use and spontaneous (drug-independent) turning behavior following unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal pathway made 7-14 days after termination of amphetamine treatment (Experiments 1-3). Exposure to three nonescalating injections of amphetamine 7 days before 6-OHDA lesions had no effect (Experiment 2). Prelesion amphetamine treatment led to normalization of basal extracellular levels of striatal DA as measured by microdialysis on days 11-14 and 25-28 after lesioning (Experiment 3). However, there were no significant differences between treatment groups in postmortem tissue levels of DA and its metabolites, indicating a dissociation between the DA depletion and the extracellular levels of DA as measured by microdialysis. Finally, rats exposed to the escalating amphetamine regimen had reduced lesion-induced loss of TH-IR cells in the ipsilateral DA cell body regions (Experiment 3). Thus, prelesion exposure to the escalating doses of amphetamine may render the cells resistant to the consequences of damage after subsequent 6-OHDA lesions, possibly by accelerating the development of compensatory changes in the DA neurons that typically accompany behavioral recovery. The potential role of amphetamine-induced endogenous neurotrophic factors in the behavioral sparing and normalization of basal extracellular DA levels observed after subsequent 6-OHDA lesions is discussed.

Authors+Show Affiliations

Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, PQ, Canada.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15296838

Citation

Moroz, Isabella Anna, et al. "Sparing of Behavior and Basal Extracellular Dopamine After 6-hydroxydopamine Lesions of the Nigrostriatal Pathway in Rats Exposed to a Prelesion Sensitizing Regimen of Amphetamine." Experimental Neurology, vol. 189, no. 1, 2004, pp. 78-93.
Moroz IA, Peciña S, Schallert T, et al. Sparing of behavior and basal extracellular dopamine after 6-hydroxydopamine lesions of the nigrostriatal pathway in rats exposed to a prelesion sensitizing regimen of amphetamine. Exp Neurol. 2004;189(1):78-93.
Moroz, I. A., Peciña, S., Schallert, T., & Stewart, J. (2004). Sparing of behavior and basal extracellular dopamine after 6-hydroxydopamine lesions of the nigrostriatal pathway in rats exposed to a prelesion sensitizing regimen of amphetamine. Experimental Neurology, 189(1), pp. 78-93.
Moroz IA, et al. Sparing of Behavior and Basal Extracellular Dopamine After 6-hydroxydopamine Lesions of the Nigrostriatal Pathway in Rats Exposed to a Prelesion Sensitizing Regimen of Amphetamine. Exp Neurol. 2004;189(1):78-93. PubMed PMID: 15296838.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Sparing of behavior and basal extracellular dopamine after 6-hydroxydopamine lesions of the nigrostriatal pathway in rats exposed to a prelesion sensitizing regimen of amphetamine. AU - Moroz,Isabella Anna, AU - Peciña,Susana, AU - Schallert,Timothy, AU - Stewart,Jane, PY - 2003/12/06/received PY - 2004/05/01/revised PY - 2004/05/07/accepted PY - 2004/8/7/pubmed PY - 2004/10/28/medline PY - 2004/8/7/entrez SP - 78 EP - 93 JF - Experimental neurology JO - Exp. Neurol. VL - 189 IS - 1 N2 - Repeated administration of amphetamine leads to enduring augmentation of its behavioral-activating effects, enhanced dopamine (DA) release in striatal regions, and morphological changes in DA target neurons. Here we show that exposure to a 2-week escalating-dose regimen of amphetamine prevents behavioral asymmetries of forelimb use and spontaneous (drug-independent) turning behavior following unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal pathway made 7-14 days after termination of amphetamine treatment (Experiments 1-3). Exposure to three nonescalating injections of amphetamine 7 days before 6-OHDA lesions had no effect (Experiment 2). Prelesion amphetamine treatment led to normalization of basal extracellular levels of striatal DA as measured by microdialysis on days 11-14 and 25-28 after lesioning (Experiment 3). However, there were no significant differences between treatment groups in postmortem tissue levels of DA and its metabolites, indicating a dissociation between the DA depletion and the extracellular levels of DA as measured by microdialysis. Finally, rats exposed to the escalating amphetamine regimen had reduced lesion-induced loss of TH-IR cells in the ipsilateral DA cell body regions (Experiment 3). Thus, prelesion exposure to the escalating doses of amphetamine may render the cells resistant to the consequences of damage after subsequent 6-OHDA lesions, possibly by accelerating the development of compensatory changes in the DA neurons that typically accompany behavioral recovery. The potential role of amphetamine-induced endogenous neurotrophic factors in the behavioral sparing and normalization of basal extracellular DA levels observed after subsequent 6-OHDA lesions is discussed. SN - 0014-4886 UR - https://www.unboundmedicine.com/medline/citation/15296838/Sparing_of_behavior_and_basal_extracellular_dopamine_after_6_hydroxydopamine_lesions_of_the_nigrostriatal_pathway_in_rats_exposed_to_a_prelesion_sensitizing_regimen_of_amphetamine_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014488604001864 DB - PRIME DP - Unbound Medicine ER -