Neurokinin-1 receptor in the basolateral nuclear group of the canine amygdala--comparative study in normal and aggressive dogs.
Substance P and its NK-1 receptor are involved in the modulation of aggressive behavior. Because of the role of the basolateral nuclear group (BNG) of the amygdala in canine aggression, neurokinin-1 receptor (NK-1) immunoreactivity in this brain region was assessed stereologically in 7 normally behaving and 6 pathologically aggressive dogs. The first aim of this study was to obtain information about the absolute number of neurons expressing the NK-1 receptor in the canine BNG because absolute numbers of neurons expressing the NK-1 receptor are not documented in literature. Additionally, an exploratory comparison was made between NK-1 expressing neurons in the BNGs of normally behaving and aggressive dogs. Results showed a very low amount (1-2%) of BNG neurons containing the NK-1 receptor in both groups. Aggressive dogs had significantly more NK-1-receptor-positive BNG neurons than normal dogs, but the numerical densities and fractions of receptor-positive neurons did not differ significantly between both groups. Combined with the fact that aggressive dogs have 27% more neurons in their BNGs than normal dogs, as reported in a previous study, these findings suggest a limited role for the NK-1-receptor-positive neurons within the BNG in the modulation of canine aggression. The present report of absolute numbers of neurons expressing the NK-1 receptor in the canine BNG could however be useful for further quantitative studies.
Jacobs
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C
Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Christel.Jacobs@UGent.be
Van Den Broeck
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Simoens
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D000374:Aggression / Q000502:physiology*; D000679:Amygdala / Q000033:anatomy & histology / Q000378:metabolism*; D000818:Animals; D002452:Cell Count; D004285:Dogs; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000096:biosynthesis; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D013702:Temporal Lobe / Q000033:anatomy & histology; D016707:Tissue Fixation
D012333:RNA, Messenger; D018040:Receptors, Neurokinin-1