In:
European Journal of Neuroscience, Wiley, Vol. 23, No. 4 ( 2006-02), p. 1015-1027
Abstract:
In an excised Wistar rat medulla‐spinal cord block preparation we previously found that dopamine slows respiratory rhythm by activation of dopamine D 4 receptors [ Fujii et al ., (2004) Neurosci. Res. , 50, 355–359.] In the present paper, we investigated the effect of dopamine on pre‐inspiratory (Pre‐I) and inspiratory (I) neurons using the combination of an optical recording technique with a voltage‐sensitive dye, unit recording and patch‐clamp recording. Optical imaging of the ventral surface of the block preparation disclosed different locations and activity patterns of Pre‐I and I neurons. In addition to slowing the rhythm, dopamine depressed respiratory activity of Pre‐I neurons collectively but not that of I neurons. The dopaminergic suppression of Pre‐I neurons was mimicked by a dopamine D 4 receptor agonist, PD168077. Unit recording and patch‐clamp recording demonstrated that dopamine depolarizes Pre‐I neurons, disperses Pre‐I firing and depresses Pre‐I phase postsynaptic potentials (PSPs) of I neurons. Immunohistological investigation revealed that Pre‐I neurons express dopamine D 4 receptors. We found that approximately 60% of Pre‐I neurons express dopamine D 4 receptors. These results show that dopaminergic respiratory rhythm depression is due to dispersion of synchronized Pre‐I driving of I neurons caused by dopamine D 4 receptor stimulation of Pre‐I neurons.
Type of Medium:
Online Resource
ISSN:
0953-816X
,
1460-9568
DOI:
10.1111/ejn.2006.23.issue-4
DOI:
10.1111/j.1460-9568.2006.04622.x
Language:
English
Publisher:
Wiley
Publication Date:
2006
detail.hit.zdb_id:
2005178-5
SSG:
12
Bookmarklink
