A B S T R A C T
The purposes of this study were: (a) to compare the effect of
gastric vagal stimulation on phrenic nerve activity during respiration
and fictive vomiting, (b) to evaluate the modulatory effect of the
central pattern generators (CPGs) for respiration and vomiting
following peripheral inputs from gastric vagus.
Decerebrate, paralyzed, and ventilated cats were used in this
study. Vomiting was induced by electric stimulation of the gastric
vagus or injection of emetic drugs (e.g. apomorphine). Fictive
vomiting was identified by a characteristic series of synchronous
bursts of phrenic nerves and abdominal nerves.
During respiratory phase, the average duration of the phrenic
nerve activity was 0.79 ¡Ó 0.07 second. The average duration of the
phrenic cycles was 2.55 ¡Ó 0.13 second. Spectral analysis indicated
that the phrenic activation had high frequency oscillation of 85~95 Hz.
Gastric vagus stimulation (100 Hz, 300 mA) during respiratory phase
lead to a deviation of the phrenic duration of -0.04 seconds. The
duration of phrenic cycles was also decreased (reduced 0.25 seconds).
The spectral distribution of the phrenic neurogram was also shifted
during gastric vagal stimulation (dextral to 100~110 Hz).
During vomiting phase, the average duration of the phrenic
activity was 0.22 ¡Ó 0.03 seconds which was shorter than that during
respiratory phase. The duration of the phrenic cycle during vomiting
was 0.54 ¡Ó0.08 second. The major distribution of the power
spectrum of the phrenic neurogram during vomiting was 100~120 Hz
which is apparently higher than that during the respiratory phase.
Gastric vagus stimulation during vomiting showed an averagely
increased phrenic cycle (0.74 ¡Ó 0.05 seconds), and a shift of its
spectral distribution (dextral to 120~150 Hz).
These results suggest that vomiting and respiration were
controlled by separate CPGs. Since the output of these two CPGs
can be modified by a common peripheral signal such as stimulatary
input signal from the gastric vagus, it is postulated that these two
CPGs might be highly overlaped. Alternatively, they might be
equipped with a single neural network while possessing two separate
functions. Normally, this naural network will presume respiratory
function, once properly stimulated, such as by injecting apomorphine
or by chronic electric stimulation of gastric vagus, functions of this
neural network, driving same set of motor fibers (diaphragm and
abdominal muscles), will be shifted from respiratory control to
vomiting phase control.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0715103-171441 |
| Date | 15 July 2003 |
| Creators | Chou, Shun-Hsiang |
| Contributors | none, none, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0715103-171441 |
| Rights | unrestricted, Copyright information available at source archive |
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