Original Research ARTICLE

Front. Integr. Neurosci., 23 September 2010 | http://dx.doi.org/10.3389/fnint.2010.00123

Activation of frontal neocortical areas by vocal production in marmosets

  • 1 Edmond and Lily Safra - International Institute of Neuroscience of Natal, Natal, Rio Grande do Norte, Brazil
  • 2 Department of Physiology, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
  • 3 Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
  • 4 Department of Physiology, University of Brasília, Brasília, Distrito Federal, Brazil
  • 5 Laboratory of Brain Studies, Juquery Hospital, Franco da Rocha, São Paulo, Brazil
  • 6 Department of Physiology, Federal University of São Paulo, São Paulo, São Paulo, Brazil
  • 7 Cesar Timo-Iaria Laboratory, Instituto de Ensino e Pesquisa, Hospital Sírio-Libanês, São Paulo, São Paulo, Brazil
  • 8 Department of Radiology, University of São Paulo, São Paulo, São Paulo, Brazil
  • 9 Center for Neuroengineering, Department of Neurobiology, Duke University Medical Center, Durham, NC, USA
  • 10 Department of Biomedical Engineering, Duke University, Durham, NC, USA
  • 11 Department of Psychological and Brain Sciences, Duke University, Durham, NC, USA

Primates often rely on vocal communication to mediate social interactions. Although much is known about the acoustic structure of primate vocalizations and the social context in which they are usually uttered, our knowledge about the neocortical control of audio–vocal interactions in primates is still incipient, being mostly derived from lesion studies in squirrel monkeys and macaques. To map the neocortical areas related to vocal control in a New World primate species, the common marmoset, we employed a method previously used with success in other vertebrate species: Analysis of the expression of the immediate early gene Egr-1 in freely behaving animals. The neocortical distribution of Egr-1 immunoreactive cells in three marmosets that were exposed to the playback of conspecific vocalizations and vocalized spontaneously (H/V group) was compared to data from three other marmosets that also heard the playback but did not vocalize (H/n group). The anterior cingulate cortex, the dorsomedial prefrontal cortex and the ventrolateral prefrontal cortex presented a higher number of Egr-1 immunoreactive cells in the H/V group than in H/n animals. Our results provide direct evidence that the ventrolateral prefrontal cortex, the region that comprises Broca’s area in humans and has been associated with auditory processing of species-specific vocalizations and orofacial control in macaques, is engaged during vocal output in marmosets. Altogether, our results support the notion that the network of neocortical areas related to vocal communication in marmosets is quite similar to that of Old world primates. The vocal production role played by these areas and their importance for the evolution of speech in primates are discussed.

Keywords: vocalization, speech, auditory, neocortex, immediate early gene, Egr-1, broca, primate

Citation: Simões CS, Vianney PVR, de Moura MM, Freire MAM, Mello LE, Sameshima K, Araújo JF, Nicolelis MAL, Mello CV and Ribeiro S (2010) Activation of frontal neocortical areas by vocal production in marmosets. Front. Integr. Neurosci. 4:123 doi:10.3389/fnint.2010.00123

Received: 13 August 2010; Paper pending published: 31 August 2010;
Accepted: 06 September 2010; Published online: 23 September 2010.

Edited by:

John J. Foxe, Nathan S. Kline Institute for Psychiatric Research, USA

Reviewed by:

Asif A. Ghazanfar, Princeton University, USA
Gary Donohoe, Trinity College Dublin, Ireland

Copyright: © 2010 Simões, Vianney, de Moura, Freire, Mello, Sameshima, Araújo, Nicolelis, Mello and Ribeiro. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.

*Correspondence: Sidarta Ribeiro, Edmond and Lily Safra - International Institute of Neuroscience of Natal (ELS IINN), Rua Professor Francisco Luciano de Oliveira, 2460, Natal, Rio Grande do Norte, 59066-060, Brazil. e-mail: ribeiro@natalneuro.org.br