Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

Figures

Discussion
Board

The periaqueductal gray of the midbrain (PAG) is assumed to play an essential role in vocal control. As the PAG projects to the nucl. retroambiguus, a structure known to be connected with the laryngeal and expiratory motoneurons, it has been proposed that the descending vocalization pathway consists of a PAG - nucl. retroambiguus - phonatory motoneuron chain. In order to find out whether, apart from the nucl. retroambiguus, there are additional relay stations within this pathway, the following experiment was carried out. Vocalization- eliciting stimulation electrodes were implanted into the PAG and injections of the glutamate antagonist kynurenic acid were made into different areas of the brainstem caudal to the PAG and rostral to the nucl. retroambiguus. It was found that some PAG-induced call types can be blocked not only by kynurenic acid injections into the nucl. retroambiguus but also by injections into the ventrolateral pontine reticular formation. It is concluded that the descending pathway from the PAG to the phonatory motoneurons responsible for the control of frequency-modulated calls synapses in the peri-olivary region.

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Presentation Number SAjürgens0207
Keywords: Central gray, PAG, Vocalization, Squirrel monkey, Pons