title: Neurochemical organization and experience-dependent activation of estrogen-associated circuits in the songbird auditory forebrain.
abstract: The classic steroid hormone estradiol is rapidly produced by central auditory neurons in the songbird brain and instantaneously modulates auditory coding to enhance the neural and behavioral discrimination of acoustic signals. Although recent advances highlight novel roles for estradiol in the regulation of central auditory processing, current knowledge on the functional and neurochemical organization of estrogen-associated circuits, as well as the impact of sensory experience in these auditory forebrain networks, remains very limited. Here we show that both estrogen-producing and -sensitive neurons are highly expressed in the caudomedial nidopallium (NCM), the zebra finch analog of the mammalian auditory association cortex, but not other auditory forebrain areas. We further demonstrate that auditory experience primarily engages estrogen-producing, and to a lesser extent, estrogen-responsive neurons in NCM, that these neuronal populations moderately overlap and that acute episodes of sensory experience do not quantitatively affect these circuits. Finally, we show that whereas estrogen-producing cells are neurochemically heterogeneous, estrogen-sensitive neurons are primarily glutamatergic. These findings reveal the neurochemical and functional organization of estrogen-associated circuits in the auditory forebrain, demonstrate their activation and stability in response to sensory experience in behaving animals, and highlight estrogenic circuits as fundamental components of central networks supporting sensory processing.
authors.affiliation: Departments of Physiology and Geriatric Medicine, and Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
authors.forename: Jin Kwon
authors.initials: JK
authors.lastname: Jeong
authors.forename: Kaiping
authors.initials: K
authors.lastname: Burrows
authors.forename: Liisa A
authors.initials: LA
authors.lastname: Tremere
authors.forename: Raphael
authors.initials: R
authors.lastname: Pinaud
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D001303:Auditory Cortex / Q000033:anatomy & histology / Q000502:physiology*; D001306:Auditory Pathways / Q000033:anatomy & histology / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D046369:Finches / Q000033:anatomy & histology* / Q000502:physiology*; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009474:Neurons / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D018377:Neurotransmitter Agents; D014157:Transcription Factors; D001141:Aromatase