15 Fakultätsübergreifend / Sonstige Einrichtung
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Item Open Access Spontaneous short-term fluctuations in the daily pattern of heart rate, body temperature and locomotor activity in the laboratory rat(1982) Büttner, Dietmar; Wollnik, FranziskaHeart rate (HR), body temperature (BT) and locomotor activity (LA) were measured continuously over 5 days in freely moving rats. In addition to the well-known circadian rhythms, all variables exhibited considerable fluctuations in amplitude mainly during the dark, but also in the light periods. The values of HR varied from 286 ± 12 to 470 ± 26 b.p.m. and BT from 36·15 ± 0·15°C to 38·45 ± 0·25°C. The large variability of HR, BT and LA within a single day was due more to large short-term fluctuations within periods of about 3-5 hours duration, than to differences between the light and the dark period. Good consistency of daily patterns and similarity of the 3 variables was found within the animals. Usually there were 3 or 4 regular peaks during the dark and often another peak 3-4 hours after the onset of light. Correlation coefficients, calculated on the basis of 5-min mean values, were highly significant (P<0·001) for LA vs HR (0·61-0·73), LA vs BT (0·40-0·53), and HR vs BT (0·61-0·68). Between-hour correlations were higher than these common correlations of 5-min values. HR vs BT (0·76-0·83) and LA vs BT (0·63-0·79) correlated as well as LA vs HR (0·72-0·83). The short-term fluctuations (within-hours) gave lower correlation coefficients for LA vs BT (0·23-0·32) and HR vs BT (0·29-0·41) than LA vs HR (0·40-0·70). This seems to result from a physiological delay of BT relative to HR and LA.Item Open Access Genetic analysis of circadian and ultradian locomotor activity rhythms in laboratory rats(1987) Wollnik, Franziska; Gärtner, Klaus; Büttner, DietmarObvious differences exist in the daily activity patterns of the LEW/Ztm and ACI/Ztm inbred strains of laboratory rats. The inbred strain ACI/Ztm shows a clear 24-h rhythm of locomotor activity. The activity pattern of the LEW/Ztm strain, however, is characterized by ultradian rhythms of 4- and 4.8-h periods. Genetic analysis of crosses between the two strains was used to examine the relative amounts of additive genetic and dominance effects for traits associated with circadian and ultradian rhythms of locomotor activity. The measured variables of the timing mechanism (amplitude c; acrophase φ; 24, 4.8-, and 4-h spectral estimates) exhibited substantial heritability, with general dominant-recessive modes of inheritance and the associated dominance variance.Item Open Access Strain-differentiated circadian and ultradian rhythms in locomotor activity of the laboratory rat(1984) Büttner, Dietmar; Wollnik, FranziskaSpontaneous locomotor activity (LA) was recorded in five inbred strains of laboratory rats (ACI/Ztm, AS/Ztm, BH/Ztm, BS/Ztm, LEW/Ztm) under light-dark (LD 12∶12), continuous-dark (DD), and continuous-light (LL) conditions. Strain-dependent differences in LA were observed under each light condition. Under LD conditions, 24-h rhythms were found in the LA pattern of each strain studied. In addition, the BH strain showed a clear bimodal, and the LEW strain a trimodal, activity pattern. Spectral analysis of the activity patterns revealed distinct 4- and 4.8-h ultradian rhythms in the LEW strain and 12-, 6-, 4.8-, and 4-h rhythms in the BH strain. These strain-characteristic patterns persisted under continuous-dark conditions, therefore demonstrating their endogenous character. Under continuous-bright-light conditions the circadian rhythms decreased to a non-significant level in the AS and BS strains. This was not the case, however, in all animals of the LEW and BH strains. Despite the rapid decrease in the 24-h rhythm under LL, the LEW and BH strains showed significant ultradian rhythms.Item Open Access Blood pressure in rats : a comparison of a multifactorial experimental design to measurements in an outbred stock(1984) Büttner, Dietmar; Hackbarth, Hansjoachim; Wollnik, Franziska; Borggreve, H.Systolic blood pressure was measured in males of 8 inbred strains and 1 outbred stock of rats 5 times over a period of 20 min on 5 consecutive days. The strain means ranged between 107·9 mmHg and 149·3 mmHg. The estimated variance between strains (V = 248·7 mmHg) was about 5 times higher than the variance within strains (V = 54·3 mmHg). The intraindividual variance within strains was relatively constant (V = 24·0-37·6 mmHg), while the interindividual variance varied to a great extent (V = 4·5-44·5 mmHg) from strain to strain. The outbred stock showed values of blood pressure and components of variance similar to those of a single inbred strain. Thus, by investigation of a battery of 8 inbred strains in a multifactorial experimental design a greater phenotypic variability due to genetic strain differences is achieved than by measurements in a single outbred stock.Item Open Access Untersuchungen zur Kurzzeitperiodik beim Meerschweinchen (Cavia aperea f. porcellus). 1, Bewegungsaktivität unter Licht-Dunkelwechsel, Dauerdunkel und Dauerlicht(1982) Büttner, Dietmar; Wollnik, FranziskaStudied locomotor activity of the male guinea pig (Cavia aperea f. porcellus), exposed to different light conditions. Under a light-dark cycle (LD 12:12) the guinea pig was found to be dark-active. The main maximum of activity occurs at the beginning of the dark period and a ancillary maximum follows 8 h later. The pattern of locomotor activity is characterized by the alternation of short activity bursts and short resting periods, mainly during the dark period. The total time of rest within 24 h summed up on an average of 6 h 11 min (± 1 h 27 min) under LD, whereby 4 h 06 min (± 1 h 14 min) of rest were spent in the light period. After exposure to continuous dark or light the circadian rhythms were markly reduced and the short activity bursts manifested themselves during the whole 24-h-period. The total time of rest within 24 h decreases to 4 h 45 min (± 1 h 42 min) (DD) respectively 2 h 58 min (± 1 h 50 min) (LL). Now the time of rest is evenly divided between the previous dark and light period. Analysis of power spectra confirm the reduction of the 24-h-rhythms and the manifestation of ultradian rhythms of 1-2 h period length after exposure to continuous dark or light. Furthermore the power spectra show a 8-h-rhythm which is nearly constant under different light conditions.