Circadian cellular spatiotemporal organization conducted by simple Ca2+ oscillation

s212

17. Biological Rhythms and Sleep

CIRCADIAN CELLULAR OSCILLATION.

432

KENJI HASEGAWA’,

SPATIOTEMPORAL

HIROTO KIKUCHI’,

ORGANIZATION

CONDUCTED

SHIGEO ISHIZAK13, YASUO TSUKAHARA3,

BY SIMPLE Ca”

AND EIICHI IWAI’

‘Div. of Brain Sci., Graduate School of Medicine, Kitasato Univ., Kitasato I-15-1, Sagamihara 228-8111, 2Dept Phys. Nihon Med. Univ., Kawasaki 211-0063, 3Div. of Biol. Information Sci., Graduate School of Information Sciences, Tohoku Univ., Katahira I-2-1, Sendai 980-0185 Adenylate (AC) and guanylate (GC) cyclases of Paramecium nick-named swimming neuron, are known to be inherited with different Ca*’ dependence. From mathematical simulation using mathematical functions which were determined to well mimic the Ca*’ dependence of AC and GC, experimental results of fluctuating concentrations of intracellular cAMP and cGMP which appeared to clearly support the conclusion of the simulation, and measured circadian fluctuations of activities of CAMP-dependent protein kinases (PKA), a spatiotempral organization in the Paramecium cell can be described as follows. (1) A sinusoidal fluctuation of intracellular Ca2’ concentration with a period of 24-h administrates activities of AC and GC to cause circadian fluctuations of concentrations of CAMP and cGMP. (2) The fluctuating CAMP concentrations conduct circadian phosphorylation of two types of CAMP-dependent protein kinases (PKA), which distribute in different compartments within the cell. (3) Then, multiple physiological phenomena, such as ciliary activity and resting membrane potential (and seemingly gene expressions and glucose metabolism as well), are eventually conducted to occur with circadian periods at varying circadian phases. EFFECT

433 SADAKO

OOKA-SOUDA’,

‘Atomi Junior College, Medicine,

THE

SPINAL

TETSUO KADOTA,

l-5-2 Otsuka, Bunkyo-ku,

Yokohama 236-0004, Dept.

We examined observation

OE‘ CUTTING

CORD

ON

CIRCADIAN

Tokyo 112-0012. ‘Dept. of Anatomy,

of Biology, Fat. of Science, Shizuoka

the effect of cutting the hagfish spinal cord on the swimming and then by analyzing the results together with recordings

HAGFISH,

12D (LD) and in constant darkness

(DD).

swim to the surface and exhibit nocturnal of the body, the animals systems connected

Yokohama

City Univ. School of

Univ., Shizuoka 422-8017 pattern and the activity rhythm first by general

of activity of the operated by i&a-red

the caudai part behind the cut was high, the animals would move randomly

descending

OF THE

HIRO-AJU TAKEUCHI’

were made at the surface and at the bottom the tank simultaneously

middle

RHYTHM

EPTATRETiJS BURGERI (CYCLOSTOMATA)

photocell

animals.

systems.

The recordings

(I) When the ratio of

at the bottom with no rhythm both under 12L-

(II) When the ratio of the frontal part before the cut was high, the animal would rhythm in LD and circadian

rhythm in DD

would show both (1) and (II) types of swimming.

to the circadian

pacemaker directed the locomotor

(RI) When the cut was neaa the ‘These findings

activity of the hagfish.

suggest

that the