title: Parvalbumin-containing neurons in the rat basolateral amygdala: morphology and co-localization of Calbindin-D(28k).
abstract: Parvalbumin is a calcium-binding protein that is contained in certain neuronal populations in the brain. Although the exact function of parvalbumin is not clear, it has been found to be a useful marker for studying the connections of specific cell types in immunohistochemical studies. In the present investigation immunohistochemical techniques were used to study the morphology of parvalbumin-containing neurons in the rat basolateral amygdala. These neurons were found to be a morphologically heterogeneous subpopulation of non-pyramidal interneurons. Parvalbumin-positive axons in the basolateral amygdala were observed to form "pericellular baskets" that enveloped the perikarya of pyramidal neurons. In addition, some parvalbumin-immunoreactive axons formed "cartridges" that appeared to surround non-immunoreactive processes. The morphology of parvalbumin-positive neurons closely resembled that of neurons containing calbindin, a related calcium-binding protein. Analysis of adjacent sections stained for each protein using the mirror technique revealed that approximately 80% of parvalbumin neurons also contained calbindin, and that approximately 60% of calbindin neurons also contained parvalbumin. This study demonstrates that parvalbumin-containing neurons constitute an important subpopulation of non-pyramidal interneurons in the rat basolateral amygdala. The axonal configurations of these cells indicate that they may exert a potent inhibitory influence over pyramidal projection neurons. We suggest that parvalbumin-containing neurons can control emotional responses mediated by the basolateral amygdala by controlling the output from this important brain region.
authors.affiliation: Department of Cell Biology and Neuroscience, University of South Carolina School of Medicine, Columbia SC 29208, USA. McDonald@dcmserver.med.sc.edu
authors.forename: A J
authors.initials: AJ
authors.lastname: McDonald
authors.forename: R L
authors.initials: RL
authors.lastname: Betette
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D064026:Calbindins; D002452:Cell Count; D048429:Cell Size; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*
chemical_list: D064026:Calbindins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G