Topography of estradiol-modulated genomic responses in the songbird auditory forebrain.
Dev Neurobiol
; 70(2): 73-86, 2010 Feb.
Article
in En
| MEDLINE
| ID: mdl-19885833
ABSTRACT
Sex steroids facilitate dramatic changes in behavioral responses to sociosexual signals and are increasingly implicated in the sensory processing of those signals. Our previous work demonstrated that in female white-throated sparrows, which are seasonal breeders, genomic responses in the auditory forebrain are selective for conspecific song over frequency-matched tones only when plasma estradiol (E2) reaches breeding levels. Here, we sought to map this E2-dependent selectivity in the best-studied area of the auditory forebrain, the caudomedial nidopallium (NCM). Nonbreeding females with low endogenous levels of E2 were treated with E2 or a placebo and exposed to conspecific song, tones, or no sound playback. Immunoreactive protein product of the immediate early gene zenk (egr-1) was then quantified within seven distinct subregions, or domains, of NCM. We report three main findings:
(1) regardless of hormone treatment, the zenk response is significantly higher in dorsal than in ventral NCM, and higher in medial than in lateral NCM; (2) E2-dependent selectivity of the response is limited to the rostral and medial domains of NCM; in the more caudal domains, song induces more zenk expression than tones regardless of hormone treatment; (3) even when no sound stimuli were presented, E2 treatment significantly increased zenk expression in the rostral, but not the caudal, domains of NCM. Together, the latter two findings suggest that E2-dependent plasticity in NCM is concentrated in rostral NCM, which is hodologically and neurochemically distinct from caudal NCM. Activity in rostral NCM may therefore be seasonally regulated in this species.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Auditory Perception
/
Vocalization, Animal
/
Prosencephalon
/
Avian Proteins
/
Estradiol
/
Early Growth Response Protein 1
Limits:
Animals
Language:
En
Journal:
Dev Neurobiol
Journal subject:
BIOLOGIA
/
NEUROLOGIA
Year:
2010
Type:
Article
Affiliation country:
United States