Electrophysiological characteristic of the ventromedial hypothalamic nucleus and lateral hypothalamic area in normally fed and 24 hour food deprived conscious sheep.
We registered telemetrically the spontaneous electrical activity of the hypothalamic ventromedial nucleus (VMH) and the lateral hypothalamic area (LH) in conscious adult sheep-male, with implanted electrodes,-in a state of normal feeding or after 24 hour food deprivation. The frequency of electrical activity, the amplitude of electrical activity and the frequency by Fourier analysis were evaluated. The frequency of electrical activity was found to be approximately the same in the VMH and LH with mean values +/- S.E.M. 11.5 +/- 0.5 Hz in feed sheep. The amplitude of electrical activity in the VMH was higher compared with the LH, with mean absolute values +/- S.E.M. 41.5 +/- 2.7 microV in the VMH and 35.5 +/- 3.2 microV in the LH. The Fourier analysis showed that from the total amount of harmonic frequencies-the first one i.e. the basic frequency represented 48-56%, the rest are higher frequencies. In sheep after 24 hour food deprivation the frequency of electrical activity decreased on 9.4-9.6 Hz in average in both regions under study and the absolute values of the amplitude of electrical activity increased. The mean absolute value +/- S.E.M. was 115 +/- 5.2 microV in the VMH and 101.2 +/- 3.0 microV in the LH. Along with theses changes we found by Fourier analysis that in the total amount of harmonic frequencies the basic frequency decreased by 6% due to the greater amount of higher harmonic frequencies.
Institute of Animal Physiology, Slovak Academy of Sciences, Kosice, Czechoslovakia.
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Kosta
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Kostová
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Rehák
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Boda
D000818:Animals; D004435:Eating; D004594:Electrophysiology; D005508:Food Deprivation / Q000502:physiology*; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D012756:Sheep / Q000502:physiology*