Abstract
Spontaneous respiratory patters are generated in the brain stem for metabolic, homeostatic purposes. However, the respiratory pattern comes from the complex interaction between metabolic requirements and the nonhomeostatic demands in an awake state. Over the last several years, we have been studying how respiratory patterns can be changed and which neural sources are activated by emotional stages in humans. During anticipatory anxiety produced by administering electrical stimulation to human subjects, positive potential changes were observed in EEGs approximately 350ms after the onset inspiration (RAP: Respiratory Anxiety Potential). The sources generating RAP were estimated in the limbic system by the dipole tracing method (BS-navi). Neural activities in the limbic or paralimbic systems were also examined using an optical recording system in a diencephalon-brainstem-spinal cord preparation from newborn rats. We optically detected spontaneous rhythmic burst activities that initially appeared in the piriform cortex and next migrated to the amygdala. The rhythmic activities tended to synchronize with spinal inspiratory activities. The results suggest that the spontaneous rhythmic activities in the limbic or paralimbic system correlate with respiratory rhythm and may be related to the olfactory sensory system and various emotional changes. [Jpn J Physiol 54 Suppl:S53 (2004)]
