Lesion of the ventromedial nucleus of the thalamus blocks acute cocaine-induced changes in striatal glutamate.
A single injection of cocaine increases extracellular glutamate in the rat dorsolateral striatum 1 day after the acute cocaine was administered (McKee and Meshul, 2005). However, the nuclei that facilitate this increase in striatal glutamate remain unknown. We hypothesized that the cocaine-induced increase in striatal glutamate was produced by activation of the ventromedial (VM) nucleus of the thalamus via the thalamo-corticostriatal or thalamostriatal pathways. First, rats received an electrolytic lesion of the VM. One day after a single cocaine or vehicle injection, extracellular glutamate was measured in the dorsolateral striatum using in vivo microdialysis. The motor thalamus lesion blocked the cocaine-induced increase in striatal glutamate and reduced extracellular glutamate to the level of the vehicle-treated group. This study shows a critical role for the VM nucleus of the thalamus in mediating the effects of cocaine on extracellular glutamate levels in the rat dorsolateral striatum.
McKee
Brenda L
BL
Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, Oregon, USA. bmckee@wisc.edu
Keyghobadi
Modjgan
M
Tozier De La Poterie
Adrienne P
AP
Meshul
Charles K
CK
D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D003714:Denervation; D004195:Disease Models, Animal; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D019635:Neurosurgical Procedures; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D020651:Ventral Thalamic Nuclei / Q000187:drug effects* / Q000378:metabolism / Q000601:surgery
D018765:Dopamine Uptake Inhibitors; D018698:Glutamic Acid; D003042:Cocaine