Gravity has also been recently involved since hyperstimulation of vestibular system by a chronic 2G centrifugation heavily disrupt circadian rhythmicity of Tb and ...
43rd annual meeting of the Society for Neuroscience, Nov 9-13, San-Diego , California
Transient modifications of circadian rhythms after vestibular lesion in rat Martin T1, Mauvieux B1, Bulla J2, Quarck G1, Davenne D1, Denise P1, Besnard S1 1U1075
COMETE UCBN/INSERM, Université de Caen Basse Normandie, 14032 – Caen, France 2 U6139 LMNO UCBN/CNRS, Université de Caen Basse Normandie, 14032 – Caen, France
1
BVL rat
39
Introduction
3 25
TEMPERATURE (°C)
38
regulate behavior and physiology. These biological rhythms such as core temperature (Tc) are controlled both by endogenous master clock and
20 37
Activity (count/min)
All living organisms have endogenous biological timing mechanisms that
15 36 10 35 5 34
synchronized by external factors, or “zeitgebers”, such as light/dark cycle,
0
1
39
vestibular system by a chronic 2G centrifugation heavily disrupt circadian
38
rhythmicity of Tb and locomotor activity in several species1,2. In order to precise vestibulo-hypothalamic links, we have studied how the loss of
TEMPERATURE (°C)
Gravity has also been recently involved since hyperstimulation of
3
4
5
6
7
8
9
1 0
DAYS
Sham rat
37
25 20
36
15 35 10 34
vestibular information via a chemical lesion influences circadian rhythm
5
Activity (count/min)
physical and social activities.
2
0
1
of temperature and activity in rat.
2
3
4
5
6
7
8
9
1 0
DAYS
Figure 1: Each plot represents a significant example for BVL group (at the top) and control group (in the bottom) for both core temperature (curves) and locomotor activity
Method
(histograms) rhythms. Before lesion, all rats exhibited a strong circadian rhythm of both Tc and activity (p < 0,01). Immediately after lesion, BVL rats had a large drop of Tc
4
followed by a progressive recovery. After this recovery, Periodogram and COSINOR analysis revealed that the Tc rhythm was abolished or presented a main ultradian period
Figure 3: In order to study the period corresponding to the drop and progressive recovery of Tc and locomotor activity after the transtympanic injection (period “B” on the figure 2), data
(τ) (τ
