Septal transplant reinnervation of the hippocampus: Cholinergic enhancement of radial maze performance

258 Selective

chemical

lesions by 6 - O H D A in the s u b s t a n t i a

nigra

also a b o l i s h e d

the i n f l u e n c e of i n t r a v e n t r i c u l a r l y

administered

PRL.

injections

failed

Bilateral

induce

excessive

grooming,

tide i n t o the s u b s t a n t i a behavioral

whereas

nigra

that PRL may

It is p r o b a b l y

tal d o p a m i n e r g i c

transmission

in p r e s y n a p t i c

rather

than

system.

SEPTAL

REINNERVATION

TRANSPLANT

ENHANCEMENT

OF R A D I A L

S.B.,

P.R.,

Psychology

LOW,

MAZE

W.,

Septal

transplant

implanted

1977

the lesion.

to r e s t o r e

month

later

1980

1978

to l e s i o n s

experiment

in the

the o r i g i -

( Bjorklund

and

the a b i l i t y

function disrupted ( Thomas

et al

of

by

) detail:

a sham operation,

of e m b r y o n i c

Behavioural

of the

in

of the t r a n s p l a n t .

task w h i c h

trial,

conducted

has been

( Eckerman

each

5

shown (Often

et al,

arm of the m a z e

The n u m b e r

8 c h o i c e s was

fim-

s e p t u m to the

t e s t i n g was

f i m b r i a or h i p p o c a m p u s

food pellet.

first

innervation

explores

presentation

). At the start of the daily

arms v i s i t e d

lesion

), and to c h o l i n e r g i c b l o c k a d e

is b a i t e d w i t h a single

S.D.,

C a m b r i d g e , (England)

that c l o s e l y m i m i c s

in an 8 - a r m r a d i a l maze

to be s e n s i t i v e et al,

IVERSEN,

U.

received either

cavity.

S.R.,

cholinergic

or t r a n s p l a n t a t i o n

fimbrial

CHOLINERGIC

in the c a v i t y of a f i m b r i a l

properties

groups of rats

in the g r o o m i n g the n i g r o s t r i a -

or at the p o s t s y n a p -

University,

behavioural

accompanying

the e l e c t r o p h y s i o l o g i c a l

brial ablation,

a role

THOMAS,

r e m o v e d by the

). The p r e s e n t

The

S.T.,

to r e s t o r e

pattern

such t r a n s p l a n t s

lesioned

the

OF T H E H I P P O C A M P U S :

A. AND STENEVI,

the d e n e r v a t e d h o s t h i p p o c a m p u s nal i n n e r v a t i o n

Three

of pep-

) elicited

an a c t i o n on the cell bo-

terminals

Cambridge

lesion have been shown

Stenevi,

injections

PERFORMANCE

BUNCH,

BJORKLUND,

Department,

also play

through

tic level of this

LEWIS,

ul

that PRL i n t e r a c t s w i t h

dies

DUNNETT,

bilateral

( 1 ug/0.5

to

response.

It is c o n c l u d e d behavior.

of PRL in the n e o s t r a t u m

recorded

of d i f f e r e n t for each rat.

259 Control formance

animals

after

no i m p r o v e m e n t transplant

above

initial

9 <

group in o v e r a l l After

fimbrial

group

scores w i t h

repeated

testing.

of per-

showed The

0.05

) , a l t h o u g h not

physostigmine, to e n h a n c e

trials,

they w e r e

all a n i m a l s w e r e injected

a cholinesterase

and t r a n s p l a n t groups ( p < 0.05

the f i m b r i a l g r o u p The p r e s e n t

fimbrial

results

for a f u r t h e r 0.05 m g / k g

i n h i b i t o r w h i c h has b e e n shown or w i t h

saline.

Both

showed e n h a n c e d maze p e r f o r m a n c e

and<0.001,

respectively

demonstrate restore

) , whereas

that

enhance

septal

transplants

complex behavioural

d i a t e d by the d e n e r v a t e d h i p p o c a m p u s , further

tested

s h o w e d no i m p r o v e m e n t .

can at least p a r t i a l l y

can

from the

alternately with

discrimination performance,

under the drug

as g r e a t as c o n t r o l

significantly

performance.

30 d a i l y

8 days on w h i c h

agents

level

the

and they did not d i f f e r

control

at a r e l a t i v e l y h i g h

By contrast,

g r o u p did show i m p r o v e m e n t over r e p e a t e d t r i a l s

( linear trend, rats,

stabilized

15 days.

f u n c t i o n me n

and that p h a r m a c o l o g i c a l

this process.

P R I N C I P L E S OF L E S I O N - I N D U C E D F U N C T I O N A L R E O R G A N I Z A T I O N

IN THE

A D U L T CAT L A T E R A L G E N I C U L A T E N U C L E U S

EYSEL,

U.Th.

of Essen,

AND ~ Y E R ,

Essen,

U.,

Visual deafferentation cat lateral reactivation

I n s t i t u t e of P h y s i o l o g y ,

geniculate

of r e s t r i c t e d

nucleus

of o r i g i n a l l y

( LGN

regions

in the adult

) is f o l l o w e d by p a r t i a l

non-responsive

cells:

about

after p h o t o c o a g u l a t i o n

of parts of the retina,

citation

i n n e r v a t e d into d e a f f e r e n t e d

observed With

University

F.R.G.

from normally

30 days

a s p r e a d of exr e g i o n s was

in the LGN. retinal

vibal-times

lesions

it was

lesion-induced

of d i f f e r e n t

possible

to d e d u c e

reorganization

sizes

and d i f f e r e n t

some p r i n c i p l e s

in the LGN.

sur-

governing