Co‐induction of activity‐dependent genes in songbirds

Abstract

Song behavior in songbirds induces the expression of activity-dependent genes in brain areas involved in perceptual processing, production and learning of song. This genomic response is thought to represent a link between neuronal activation and long-term changes in song-processing circuits of the songbird brain. Here we demonstrate that Arc, an activity-regulated gene whose product has dendritic localization and is associated with synaptic plasticity, is rapidly induced by song in the brain of zebra finches. We show that, in the context of song auditory stimulation, Arc expression is induced in several telencephalic auditory areas, most prominently the caudomedial nidopallium and mesopallium, whereas in the context of singing, Arc is also induced in song control areas, namely nucleus HVC, used as a proper name, the robust nucleus of the arcopallium and the interface nucleus of the nidopallium. We also show that song-induced Arc expression co-localizes at the cellular level with those of the transcriptional regulators zenk and c-fos, and that the song induction of these three genes is dependent on activation of the mitogen-activated protein kinase signaling pathway. These findings provide evidence for an involvement of Arc in the brain's response to birdsong. They also demonstrate that genes representing distinct genomic and cellular regulatory programs, namely early effectors and transcription factors, are co-activated in the same neuronal cells by a naturally learned stimulus.

Estradiol Shapes Auditory Processing in the Adult Brain by Regulating Inhibitory Transmission and Plasticity-Associated Gene Expression

“…Sense strand riboprobes for all genes studied did not yield detectable signal. In addition, the expression of all three IEGs, as revealed by antisense riboprobe hybridization, were identical to expression patterns described previously (e.g., IEGs were induced by song, and their expression was absent in field L2a; these control data were obtained from separate animals not included in this study) (Mello et al, 1992;Pinaud et al, 2004;Velho et al, 2005).…”

“…As indicated previously, NCM exhibits selective responses to conspecific songs relative to heterospecific songs and artificial stimuli, as revealed by electrophysiological methods and activity-regulated gene expression (Mello et al, 1992;Chew et al, 1996;Velho et al, 2005). Based on this selectivity, we next asked whether the effects of E2 in the physiology of NCM are restricted to certain types of auditory stimuli, namely conspecific songs, or also generalize to nonsong auditory stimuli.…”

“…All birds (n ϭ 20) used for bilateral intracerebral injection experiments were fitted with head posts and an access skull chamber, as described above for electrophysiological experiments and detailed previously (Velho et al, 2005;Pinaud et al, 2008c). Birds were allowed to recover for a minimum of 48 h before experimentation.…”

“…Briefly, Qiagen miniprep kit was used to purify plasmids containing zebra finch homologs of the zenk, c-fos, and arc genes from bacteria. The zenk probes were derived from the cloned canary homolog (Mello et al, 1992), and the arc clone was originally obtained through PCR cloning (Velho et al, 2005). The c-fos clone was derived from the Songbird Transcriptome initiative (Duke University, Durham, NC; http://www.…”

Functional MRI of the zebra finch brain during song stimulation suggests a lateralized response topography

“…The latter activations, however, were spatially more variable and diffuse, and we were not able at this point to make clear assignments to specific regions. It is worth mentioning that methods of immediate early gene expression, which have a considerable higher resolution than the method used here, reveal activity after song playback in some of these areas (in particular, HVC shelf, RA cup, and nucleus mesencephalicus lateralis pars dorsalis in the midbrain) (30,36,37).…”