title: Effects of context-drug learning on synaptic connectivity in the basolateral nucleus of the amygdala in rats.
abstract: Context-drug learning produces structural and functional synaptic changes in the circuitry of the basolateral nucleus of the amygdala (BLA). However, how the synaptic changes translated to the neuronal targets was not established. Thus, in the present study, immunohistochemistry with a cell-specific marker and the stereological quantification of synapses was used to determine if context-drug learning increases the number of excitatory and inhibitory/modulatory synapses contacting the gamma-aminobutyric acid (GABA) interneurons and/or the pyramidal neurons in the BLA circuitry. Amphetamine-conditioned place preference increased the number of asymmetric (excitatory) synapses contacting the spines and dendrites of pyramidal neurons and the number of multisynaptic boutons contacting pyramidal neurons and GABA interneurons. Context-drug learning increased asymmetric (excitatory) synapses onto dendrites of GABA interneurons and increased symmetric (inhibitory or modulatory) synapses onto dendrites but not perikarya of these same interneurons. The formation of context-drug associations alters the synaptic connectivity in the BLA circuitry, findings that have important implications for drug-seeking behavior.
authors.affiliation: Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA; Department of Psychology, Lake Forest College, Lake Forest, IL, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Rademacher
authors.forename: Nasya
authors.initials: N
authors.lastname: Mendoza-Elias
authors.forename: Gloria E
authors.initials: GE
authors.lastname: Meredith
mesh_terms: D000818:Animals; D066272:Basolateral Nuclear Complex / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D049229:Dendritic Spines / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D003913:Dextroamphetamine / Q000494:pharmacology; D058999:Drug-Seeking Behavior / Q000502:physiology; D007150:Immunohistochemistry; D007395:Interneurons / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D017207:Rats, Sprague-Dawley; D065853:Spatial Learning / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000697:Central Nervous System Stimulants; D005680:gamma-Aminobutyric Acid; D003913:Dextroamphetamine
keywords: addiction; associative learning; basolateral amygdala; electron microscopy; glutamic acid decarboxylase; physical disector