Anatomofuctional evidences that retrotrapezoid nucleus regulates active expiration.

Author(s)

Josiane do Nascimento Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2014-10-10

Examining board members

Ana Carolina Thomaz Takakura; Sara Joyce Shammah Lagnado; Patricia Maria de Paula

• Advisor: Ana Carolina Thomaz Takakura

Abstract

The eupnoeic pattern of respiration consists of three phases: inspiration, post-inspiration and stage 2 of expiration (E2). The neural mechanisms for respiratory control are carefully organized by neuron system localized into the medulla oblongata and this system is highly sensitive to CO2. Evidences suggest the involvement of chemosensitive neurons of the retrotrapezoid nucleus (RTN) in the control of expiratory activity of the caudal ventral respiratory group (cVRG) (Janczewski e Feldman, 2006a). In this study, investigate the existence of a projection the RTN from cVRG, the phenotype of the neurons and the neurotransmitters involved in this projection. The experiments were performed in adult male Wistar rats, submitted to immunohistochemical and electrophysiological approaches. The results showed anatomofunctional evidences of excitatory projections from RTN to caudal ventral respiratory group region. This pathway is active during hypercapnia, has minimal involvement of Phox2b neurons of RTN and do not involve serotonergic neurons of raphe. (AU)