Cocaine alters glutamic acid decarboxylase differentially in the nucleus accumbens core and shell.
The effects of acute and repeated daily cocaine on the levels of mRNA coding for glutamic acid decarboxylase (GAD), preproenkephalin (PPE), preprotachykinin (PPT), and the dopamine D2 receptor were determined in the striatum, nucleus accumbens core and shell areas (NAcore, NAshell), and medial prefrontal cortex. Rats were given repeated saline or cocaine for 6 days. A cocaine challenge administered 24 h later resulted in an augmented locomotor response in daily cocaine-pretreated rats. Six h after the challenge, rats were sacrificed and Northern blot analysis revealed that acute cocaine increased GAD mRNA levels by 44% in the NAshell, while repeated cocaine prevented the acute cocaine-induced increase. These data suggest that cocaine may differentially regulate GABA release at NA core and shell projection fields.
Sorg
B A
BA
Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman 99164-6520, USA.
Guminski
B J
BJ
Hooks
M S
MS
Kalivas
P W
PW
D000704:Analysis of Variance; D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004745:Enkephalins / Q000235:genetics; D005815:Genetic Code; D005968:Glutamate Decarboxylase / Q000235:genetics*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009714:Nucleus Accumbens / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D015320:Tachykinins / Q000235:genetics; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis
D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D015320:Tachykinins; C044206:preprotachykinin; C029992:proenkephalin; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; D003042:Cocaine