title: Intra-medial prefrontal administration of SCH-23390 attenuates ERK phosphorylation and long-term memory for trace fear conditioning in rats.
abstract: The prefrontal cortex is known to be involved in the acquisition of trace conditioning, a higher-cognitive form of Pavlovian conditioning in which a conditioned stimulus and an unconditioned stimulus are separated by a time gap. We have recently reported that medial prefrontal (mPFC) extracellular-signal regulated kinase (Erk) phosphorylation is involved in the long-term memory storage of trace fear conditioning. Because of the important role dopamine D1 receptors play in prefrontal function, such as working memory, and due to evidence that dopamine D1 receptor activity can modulate plasticity, we investigated their role in prefrontal Erk phosphorylation following trace fear conditioning. We found that inhibition of dopamine D1 receptors through intra-mPFC infusion of SCH-23390 (1 microg/0.5 microL) 15 min prior to trace fear conditioning resulted in a decrease in training-related Erk phosphorylation. Additionally, pre-training intra-mPFC infusion of SCH-23390 also resulted in the impairment of long-term retention of CS-US association. These findings implicate mPFC dopamine D1 receptor activity in the storage of long-term memory for higher-cognitive associative tasks.
authors.affiliation: The Vivian L. Smith Center for Neurologic Research, Department of Neurobiology and Anatomy, The University of Texas Medical School, P.O. Box 20708, Houston, TX 77225, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Runyan
authors.forename: Pramod K
authors.initials: PK
authors.lastname: Dash
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001245:Association Learning / Q000187:drug effects / Q000502:physiology; D001552:Benzazepines / Q000008:administration & dosage*; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D018492:Dopamine Antagonists / Q000008:administration & dosage*; D005239:Fear; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D008845:Microinjections; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D020928:Mitogen-Activated Protein Kinases