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5 Cerebro-spinal fluid

MORPHOLOGICAL AND FINE STRUCTURAL STUDIES ON CEREBROSPINAL FLUID CIRCULATION

PAULO HITONARI t IAStt lMOTO, TAKAO ICHIMURA*, NOBUO TAKASU* and TOSHIO NAKATANI*, Department of Anatomy, Osaka University Medical School Nakaneshima 4, Kitaku, Osaka 530, Japan.

A r a c h n o i d g r a n u l a t i o n s a r e no t a lways p r e s e n t in lower mammals and p r i m a t e n e w b o r n s . In o r d e r to v i sua l i ze t h e r o u t e fo r t h e c e r e b r o s p i n a l f lu id (CSF) to d ra in in to t he v e n o u s s y s t e m , h o r s e r a d i s h p e r o x i d a s e (HRP) was i n j e c t e d in to t h e l a t e ra l v e n t r i c l e o r c i s t e r n a c e r e b e l l o m e d u l l a r i s of t he mouse a n d r a t . 30-60 rain a f t e r t h e o n s e t o f a s tow in f u s i o n fo r 15-30 mln of 0 .05 -0 .1 mI so lu t ion c o n t a i n i n g 10-20 mg HRP, t he mouse , whose skul l had b e e n e x p o s e d , was d r o p p e d in to cold a c e t o n e at d r y ice t e m p e r a t u r e ; o r animals , t o g e t h e r wi th n o n - t r e a t e d ca t s and m o n k e y s , were f i x e d b y p e r f u s i o n wi th a l d e h y d e so lu t ion . The f r o z e n h e a d was d i s s e c t e d in a c r y o s t a t k e p t a t -18°C to r e m o v e t h e skul l b u t not t h e d u r a ma te r n o r t he fa lx c e r e b r i . The b r a i n wi th m e n i n g e s was cut in to 30-45 ~m sa g i t t a l s e c t i o n s in t he c r y o s t a t , a n d p r o c e s s e d fo r p e r o x i d a s e r e a c t i o n . The perfusion f i x e d b r a i n s w e r e u s e d fo r s c a n n i n g e l e c t r o n m i c r o s c o p y , h i g h v o l t a g e e l e c t r o n m i c r o s c o p y , a n d fo r e l e c t r o n mic roscope o b s e r v a t i o n of the t r a c e r . The c o v e r i n g e n d o t h e l i u m of t he monkey a r a c h n o i d g r a n u l a t i o n was s imply c o n t i n u o u s , w h e r e a s , t he t r a c e r was found with in f e n e s t r a t e d v e n o u s cap i l l a r i e s of t h e r a t c h o r o i d p l e x u s , s u b f o r n i c a l o r g a n , p inea l b o d y , h y p o p h y s i s , and a r e a p o s t r e m a . The r o u t e fo r t he HRP in GSF to d r a i n in to t he s i n u s r e c t u s v ia t he v e n a e h o r i o i d e a and v e n a c e r e b r i magna was d i r e c t l y v i sua l i zed in the mo u s e .

THE CHANGE OF GUANIDINO COMPOUND LEVELS IN THE CEREBROSPINAL FLUID OF RABBIT WITH PENTYLENETETRAZOL-INDUCED CONVULSIONS

AKITANE MORI, MIDORI HIRAMATSU*, SHIGEYUKI SUZUKI*, AKIYOSHI SHIRASU*, MASASHI YAF~MOTO* AND REI EDAMATSU*, Department of Neurochemistry, Institute for Neuro- biology, Okayama University Medical School, 2-5-I Shikata-cho, Okayama 700, Japan

A method for repeated sampling of cerebrospinal f luid {CSF) from the freely moving rabbit was developed. Guanidino compound levels were estimated in the rabbit CSF with pentylenetetrazol (PTZ) induced convulsions. A catheter was implanted via the skull into the cisterna magna and was fixed by screws. One week after the operation, I00 pl of CSF was collected by a microsyringe. PTZ solution (3.3%) was injected ~ntraveneously and CSF was collected at the same time, at which time clonic-convulsions suddenly appeared. Clonic-tonic con- vulsions continued for about 20 seconds. After that, no convulsions were in- duced until I hour after the injection. CSF collections were also performed 20 min and 60 min after the injection. As for the control, CSF was collected 5 min before the PTZ injection. Guanidino compound levels in lO0 pl of CSF were determined by high pressure liquid chromatography. Guanidinoacetic acid (GAA), creatinine {CRN) and arginine (Arg) were found in the rabbit CSF. The GAA level was significantly increased at the onset of convulsions. This in- creased level continued after the convulsions ( t i l l 60 min after PTZ injection ). The CRN ]eve] was sl ightly increased at the onset of convu]sions (p<O.05). This level returned to the control level after the convulsions. The Arg level was not changed by PTZ-induced convulsions. These results suggest that GAA may be related to a PTZ-induced convulsive mechanism.