Effects of autoshaping procedures on 3H-8-OH-DPAT-labeled 5-HT1a binding and 125I-LSD-labeled 5-HT2a binding in rat brain.
Effects of experience with Pavlovian autoshaping procedures on lever-press autoshaping conditioned response (CR) performance and 3H-8-OH-DPAT-labeled binding of 5-HT(1a) receptors as well as 125I-LSD-labeled binding of 5-HT(2a) receptors were evaluated in four groups of male Long-Evans hooded rats. Two groups of rats (Group Paired High CR and Group Paired Low CR) received Pavlovian autoshaping procedures wherein the presentation of a lever (conditioned stimulus, CS) was followed by the response-independent presentation of food (unconditioned stimulus, US). Rats in Group Paired High CR (n=12) showed more rapid CR acquisition and higher asymptotic levels of lever-press autoshaping CR performance relative to rats in Group Low CR (n=12). Group Omission (n=9) received autoshaping with an omission contingency, such that performing the lever-press autoshaping CR resulted in the cancellation the food US, while Group Random (n=9) received presentations of lever CS and food US randomly with respect to one another. Though Groups Omission and Random did not differ in lever-press autoshaping CR performance, Group Omission showed significantly lower levels of 3H-8-OH-DPAT-labeled 5-HT(1a) binding in post-synaptic areas (frontal cortex, septum, caudate putamen), as well as significantly higher plasma corticosterone levels than Group Random. In addition, Group Random showed higher levels of 3H-8-OH-DPAT-labeled 5-HT(1a) binding in pre-synaptic somatodendritic autoreceptors on dorsal raphe nucleus relative to each of the other three groups. Autoradiographic analysis of 125I-LSD-labeled 5-HT(2a) receptor binding revealed no significant differences between Groups Paired High CR and Paired Low CR or between Groups Omission and Random in any brain regions.
Tomie
Arthur
A
Department of Psychology/Center of Alcohol Studies, Rutgers University, New Brunswick, NJ 08903, USA. tomie@rci.rutgers.edu
Di Poce
Jason
J
Aguado
Allison
A
Janes
Amy
A
Benjamin
Daniel
D
Pohorecky
Larissa
L
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001345:Autoradiography; D001923:Brain Chemistry / Q000187:drug effects*; D002065:Buspirone / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects*; D003345:Corticosterone / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology; D007457:Iodine Radioisotopes; D008238:Lysergic Acid Diethylamide; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D020318:Rats, Long-Evans; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000187:drug effects*; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D015031:Zimeldine / Q000494:pharmacology
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D014151:Anti-Anxiety Agents; D002065:Buspirone; D002492:Central Nervous System Depressants; D003345:Corticosterone; D000431:Ethanol; D007457:Iodine Radioisotopes; D008238:Lysergic Acid Diethylamide; D010880:Piperidines; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors; D015031:Zimeldine; C018181:indalpine