A songbird forebrain area potentially involved in auditory discrimination and memory formation

Raphael Pinaud, Thomas A. Terleph
2008 Journal of Biosciences  
Songbirds rely on auditory processing of natural communication signals for a number of social behaviors, including mate selection, individual recognition and the rare behavior of vocal learning -the ability to learn vocalizations through imitation of an adult model, rather than by instinct. Like mammals, songbirds possess a set of interconnected ascending and descending auditory brain pathways that process acoustic information and that are presumably involved in the perceptual processing of
more » ... l communication signals. Most auditory areas studied to date are located in the caudomedial forebrain of the songbird and include the thalamo-recipient fi eld L (subfi elds L1, L2 and L3), the caudomedial and caudolateral mesopallium (CMM and CLM, respectively) and the caudomedial nidopallium (NCM). This review focuses on NCM, an auditory area previously proposed to be analogous to parts of the primary auditory cortex in mammals. Stimulation of songbirds with auditory stimuli drives vigorous electrophysiological responses and the expression of several activity-regulated genes in NCM. Interestingly, NCM neurons are tuned to species-specifi c songs and undergo some forms of experience-dependent plasticity in-vivo. These activity-dependent changes may underlie long-term modifi cations in the functional performance of NCM and constitute a potential neural substrate for auditory discrimination. We end this review by discussing evidence that suggests that NCM may be a site of auditory memory formation and/or storage. [Pinaud R and Terleph T A 2008 A songbird forebrain area potentially involved in auditory discrimination and memory formation; J. Biosci. 33 [145][146][147][148][149][150][151][152][153][154][155] Abbreviations used: AFP, Anterior forebrain pathway; BOS, bird's own song; CMM, caudomedial mesopallium; DLM, dorsolateral thalamic nucleus; IEG, immediate early gene; LMAN, lateral magnocellular nucleus of the anterior nidopallium; NCM, caudomedial nidopallium; PFP, posterior forebrain pathway; RA, robust nucleus of the intercollicular complex; ZENK, zif268, egr-1, NGFI-A, Krox24 J. Biosci. 33(1) , March 2008 Res. Mol. Brain Res. 116 147-154 Bailey D J and Wade J 2005 FOS and ZENK responses in 45-dayold zebra fi nches vary with auditory stimulus and brain region, but not sex; Behav. Brain Res. 162 108-115 Bolhuis J J and Gahr M 2006 Neural mechanisms of birdsong memory; Nat. Rev. Neurosci . 7 learning: vocal behavior in songbirds; J. Neurobiol. 33 602-618 Bottjer S W, Miesner E A and Arnold A P 1984 Forebrain lesions disrupt development but not maintenance of song in passerine birds; Science 224 901-903 Bottjer S W, Brady J D and Cribbs B 2000 Connections of a motor cortical region in zebra fi nches: relation to pathways for vocal learning; J. Comp. Neurol. 420 244-260 Bottjer S W, Halsema K A, Brown S A and Miesner E A 1989 Axonal connections of a forebrain nucleus involved with vocal learning in zebra fi nches; J. Comp. Neurol. 279 312-326 Brainard M S 2004 Contributions of the anterior forebrain pathway to vocal plasticity; Ann. N. Y. Acad. Sci. 1016 377-394 Brainard M S and Doupe A J 2000 Auditory feedback in learning and maintenance of vocal behaviour; Nat. Rev. Neurosci. 1 31-40 Brauth S E, McHale C M, Brasher C A and Dooling R J 1987 Auditory pathways in the budgerigar. I. Thalamo-telencephalic projections; Brain Behav. Evol. 30 174-199 Brenowitz E A and Kroodsma D E 1996 The neuroethology of birdsong; in Ecology and evolution of acoustic communication in birds (eds) D E Kroodsma and E H Miller (Ithaca, NY: Cornell University Press) pp 285-304 Cardin J A and Schmidt M F 2003 Song system auditory responses are stable and highly tuned during sedation, rapidly modulated and unselective during wakefulness, and suppressed by arousal; J. Neurophysiol. 90 2884-2899
doi:10.1007/s12038-008-0030-y pmid:18376079 fatcat:52jficapgray5jbdd4kxch6l4e