Immunocytochemical demonstration of induction of tyrosine hydroxylase in catecholamine neurons in reserpine-treated rats

$117 A STUDY ON THE AREAS RELATED TO THE CONDITIONED EMOTIONAL RESPONSE BY MEANS OF THE --[14C] 2-DEOXYGLUCOSE METHOD. V. EFFECTS OF INCREASED NUMBER OF PAIRED AND RANDOM CS-US PRESENTATIONS. KOZO SUGIOKA, TOKIKO NAKAMURA* and TAKASHI YAMADORI, F i r s t Department of Anatomy, Kobe U n i v e r s i t y School of Medicine, 7 - 5 - I , Kusunoki-cho, Chuo-ku, Kobe, 650 This study was performed to determine the a c t i v a t e d areas in the r a t brain at the time of a conditioned emotional response t e s t (CER t e s t ) a f t e r Pavlovian aversive c o n d i t i o n i n g . Male a l b i n o rats of the Wistar s t r a i n were d i v i d e d i n t o 2 experimental (CSE-25, CSE-50) groups and 2 random control (CSR-25, CSR-50) groups. The CSE-25 and CSE-50 animals were conditioned with paired CS (25-second f l i c k e r ) and US (l-second 150 Vac e l e c t r i c shock) t r i a l s presented 25 and 50 times, r e s p e c t i v e l y . The CSR-25 and CSR-50 animals were given unpaired CS and US of 25 and 50 times, r e s p e c t i v e l y . Two days a f t e r the c o n d i t i o n i n g the r a t was exposed to 3 times the CS f o r the CER t e s t . At the s t a r t of the t e s t , 50 uCi of [14C] 2-Deoxy-d-glucose in 0.5 ml s a l i n e was i n j e c t e d i n t r a v e n o u s l y through an implanted cannula. The r a t was s a c r i f i c e d immediately and the brain was removed and frozen to prepare s e r i a l sections f o r the autoradiography. Average o p t i c a l d e n s i t i e s (OD) of the u n i t area of 57 structures in the l e f t hemisphere were obtained from the autoradiogram and t h e i r o p t i c a l d e n s i t y r a t i o s (ODR) were s t a t i s t i c a l l y compared by F- and t - t e s t . The r e s u l t s of 2(Group) by 2 ( T r i a l ) ANOVAs(F-test) were as f o l l o w s : the main e f f e c t of Group was s i g n i f i c a n t in the zona i n c e r t a (ZI) and substantia nigra (SNR), implying increased 2-DG uptake in the group of paired CS-US p r e s e n t a t i o n s ; the main e f f e c t of T r i a l was s i g n i f i c a n t in the ZI, habenula (Hb), c o l l i c u l u s i n f e r i o r (CI), gyrus dentatus (GD) and areas 7 and 40 of the cerebral c o r t e x , implying decreased 2-DG uptake in the group of 50 CS-US p r e s e n t a t i o n s ; and Group by T r i a l I n t e r a c t i o n was s i g n i f i c a n t in areas 24, I0, 6, 4, 3, 17, 18 and 18a, implying d i f f e r e n t patterns of 2-DG uptake in the groups of paired CS-US and random CS-US as a function of numbers of CS-US p r e s e n t a t i o n .

A MECHANISbl OF TIlE LONG-TERM POTENTIATION OF TRANSMITTER RELEASE INDUCED BY THE PRESYNAPTIC ACTIVITIES IN BULLFROG SYMPATHETIC GANGLIA StlOIChI MINOTA, EIICItI KUMAHOTO* AND KENJI KUBA D e p a r t m e n t o f P h y s i o l o g y , Saga M e d i c a l S c h o o l , Nabeshima, Saga 840-01, J a p a n The h y p o t h e s i s t h a t tetanus

a sustained rise

in the intracellular

i s a mechanism o f t h e l o n g - t e r m p o t e n t i a t i o n

c a l c i u m c a u s e d by a p r e s y n a p t i c

of transmitter

bullfrog

In normal R i n g e r , t h e f r e q u e n c y o f t h e m i n i a t u r e e . p . s . p ,

f o r more t h a n one hour a f t e r effect

depended on t e t a n u s

short-term

facilitation

stimulation

duration.

of the fast

of the preganglionic

e.p.s.p,

i s p r e s u m a b l y c a u s e d by t h e r e s i d u a l

e.p.s.p,

and i t s

Ca 2+, i n i t i a l l y

the amplitude of the fast c o n t e n t and s i z e . effects

suggest that

of a

the first

that

i m p u l s e , was was i n c r e a s e d a s

reduced the facilitation. be h y d r o l y z e d and c h e l a t e

A Ca 2+the

( a b o u t 5 min) and t h e n g r a d u a l l y r e d u c e d

T h i s d e c r e a s e was due t o t h e r e d u c t i o n o f b o t h t h e q u a n t a l

condition,

the magnitude of facilitation

o f Quin2/AM were o b s e r v e d a t l e a s t

These r e s u l t s

the magnitude

A c a l c i u m i o n o p h o r e , A-23187 (10 uM), i n c r e a s e d t h e

increased for a short period

the pre.-1.t.p,

l e v e l o f f r e e Ca 2+ i n t h e p r e s y n a p t i c

in

increased

(50-100 ms i n t e r v a l s )

The r e d u c t i o n o f f a c i l i t a t i o n

quantal content while it

e.p.s.p..

Under t h i s

was

intracellularly

n e r v e (33 Hz, 20-30 s e c ) and t h i s

i n d u c e d by a p a i r e d s t i m u i i

b i n d i n g a g e n t , Quin2/AM (3 uM), which would e n t e r t h e c e l l , intracellular

e,p.s.p.)

Ca 2+ r e m a i n i n g i n t h e t e r m i n a l a f t e r

of the magnitude of pre.-1.t.p..

amplitude of fast

(fast

In a low Ca 2+ and h i g h Mg2+ s o l u t i o n ,

decreased during the generation of the pre-l.t.p.. an i n c r e a s e

potential

(pre.-1.t.p.)

excitatory

sympathetic ganglia.

postsynaptic

release

examined by r e c o r d i n g t h e f a s t

40 min a f t e r

its

was a l s o r e d u c e d .

These

withdrqwal.

i s i n d u c e d i n p a r t by a s u s t a i n e d r i s e

t e r m i n a l and by o t h e r unknown p r o c e s s e s .

in the basal