CENTRAL DSP-4 TREATMENT DECREASES NOREPINEPHRINE LEVELS AND COURTSHIPBEHAVIOR IN MALE ZEBRA FINCHES

In zebra finches, gonadal steroids activate male courtship, including singing, and also strongly modulate norepinephrine (NE) levels and tur nover in brain areas regulating courtship behavior. In a previous stud y, systemic administration of DSP-4 caused significant decreases in co urtship singing. These behavioral decrements were correlated with the degree of NE depletion in several vocal control nuclei. In the present study, we attempted to further decrease brain NE levels while minimiz ing systemic effects by infusing DSP-4 directly into the third ventric le. DSP-4 treatment significantly reduced NE levels in three of six vo cal control nuclei and both hypothalamic nuclei sampled without signif icantly altering dopamine or serotonin levels in any areas. DSP-4-trea ted males took longer to begin singing and performed fewer song bouts and courtship displays. Interestingly, behavioral deficits were limite d to courtship song displays, other behavior patterns, including femal e-directed behaviors like approach and follow, were unaffected by DSP- 4 treatment. DSP-4 treatment appeared to affect singing behavior by ca using deficits in initial attentiveness to females and initiation of s inging rather than by affecting song structure.