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Temporal and spatial rhythmicity of jejunal wall motion in rats
Author(s) -
Bouchoucha,
Michael F. Benard,
Dupres
Publication year - 1999
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1046/j.1365-2982.1999.00162.x
Subject(s) - rhythm , jejunum , amplitude , spatial frequency , physics , phase (matter) , wavelength , anatomy , nuclear magnetic resonance , chemistry , optics , biology , endocrinology , acoustics , quantum mechanics
Isolated segments of jejunum of fasted rats exhibit regular rhythmic contractions at the same frequency as slow‐waves. The aim of the present study was to search for a possible spatial rhythmicity of this activity. Using a video imaging technique, jejunal segments of 50 rats were studied. Only experiments (n=76) with no propagated contractions at visual inspection were included in the study. After the measurement, a spectral analysis of the diameter variations was performed. The bands were characterized by four parameters: level, main frequency, amplitude and phase. At each level, the phase varied, suggesting that the same rhythmic phenomenon occurred, but with a delay as a function of the spatial position. In 58 measurements, the rhythmic activity had a frequency near 0.50 Hz and in 18, near 0.25 Hz. Phase difference was found in 32 segments (42%). The variation with distance was linear as a function of time and its length was greater for the low‐frequency group than for the high‐frequency group (25.6 ± 9.4 vs. 33.3 ± 5.2 mm, P=0.015). By contrast, the speed of propagation was not significantly different. The wavelength λ of the spatial rhythmicity was 27.7 ± 23.2 and 9.8 ± 4.2 mm (P=NS) in the high‐ and low‐frequency groups, respectively. This corresponds to a speed of propagation of v=λ*f, where f is the frequency of the wall motion (7.0 ± 5.2 vs. 5.2 ± 2.2 mm sec −1 , P=NS).