Facilitation or inhibition of learning by morphine: A question of dosage and intensity of foot shock

251 FACILITATION OF DOSAGE

CLASSEN, Biology

OR I N H I B I T I O N

AND I N T E N S I T Y

CIBA-GEIGY

phine,

learning

rences shock

in the p a r a m e t e r s

the

the

could be o b s e r v e d

30 mg d i s t i n c t l y level

slightly

facilitated

retention

improved

At a shock

level

( 0,

was

impaired

by 3 m g / k g

0.5,

literaThere-

systemi-

1.0,

2.0 mA,

30 m g / k g

avoidance

i.p.

situation

immediately of s t e p - d o w n At a shock

impaired

retention

strain,

in the

were

3.0,

no learning.

slightly

of effects

of the results.

0.3,

no p r o l o n g a t i o n

doses

species,

two p a r a m e t e r s

0,

In

by mor-

The d i f f e r e -

) as d e s c r i b e d

intensity

published

to be facilitated.

( animal

to a p a s s i v e

indicating

of 0.5 mA the lower

been

processing.

related.

intraperitoneally

level

have

the d i r e c t i o n

comparison

of m o r p h i n e exposed

shown

that

etc.

experiment,

substance

At zero shock

shock

Division,

to be i n h i b i t e d

) is dose

task

food shock

900 male mice were received

suggest

any direct

) and the dose

on m e m o r y

found

employed

dosage,

in the p r e s e n t

reports

it has been

or i n h i b i t i o n

intensity,

cally varies: isec

of o p i a t e s

findings

ture do not p e r m i t fore,

, Pharmaceutical

has been

in others

The c o n t r a d i c t o r y ( facilitation

C.

contradictory

on the effects

whereas

A QUESTION

Basle, (Switzerland)

of h i g h l y

studies,

BY MORPHINE:

SHOCK

Laboratories

Ltd.,

A number

some

OF FOOT

W., AND M O N D A D O R I , Research

recently

OF L E A R N I N G

posttrial. latencies intensity

retention,

performance.

At

whereas 1 mA

by a dose of 0.3 m g / k g

and d i s t i n c t l y

of 2 mA all doses

impaired

improved

).

and

but

by 30 mg/kg.

performance

in

retest. The p r e s e n t aictions ever,

found

opiate

of receptor nist,

in the

they do not

is p r o b a b l y neous

results

due

to the

( mu,

a simple

effects.

How-

relationship.

This

complexicity at least

). Morphine,

presumably

that the c o n t r a -

are due to dose

involves sigma

suggestion

dose-effect

functional

kappa,

doses

our

literature

system which

at higher

ceptors.

show

confirm

also

of the e n d o g e -

three

different

a specific

interacts

with

types

mu-ago-

other

re-

252 The f u n c t i o n a l s t a t e of the b r a i n w h i c h of m o r p h i n e m a y t h e r e f o r e be d i s t i n c t l y duced

by high

ced by nal

doses.

the v a r i o u s

state

processing.

VISUAL

INFORMATION

chemin

To

ment was

Joseph

analyse

on the g r o u n d

tangular

). T h e

CONTROL

influen.

functio-

OF U P R I G H T

central

used:

random

with

hips

ankles.

We have

Cedex

and

of u p r i g h t adults

( 3 and

wall

POS-

( 6 cm wide light,

6 Hz The

reported

each

lateral

three

i,

2)

is c r u c i a l

for

the

In the p r e s e n t

experiment

there

vertically

was 1,2

a reccm wide

control

levels:

vision, of

with

illumination

accelerations

anatomical

)

of i l l u m i n a -

illumination

that motion

one,

was

cylinder

types

stroboscopic

at

support

cylinder

). F o u r

subject's

accelerometers

of d i s p l a c e -

either

stroboscopic

), and

(France)

the e x p e r i m e n t

a vertical

the

4,

two visual

rubber

stripes,

INP

test position

presented

of

and white

bar

posture,

of

9,

analyse

). A f o a m

center

inner

of the

the

in M a n n ' s

pattern

permanent

already

ly p e r i p h e r a l

Marseille

at the

frequency.

measured

C.N.R.S.,

contribution

the o t h e r

( black

frequency

and

are

or inhibits

G~n~rale,

visual

on the

grating

a broad

tion were

with

facilitates

AND

vision

12 h u m a n

just before

cm wide

fixed

control

with

or h o r i z o n t a l l y

with

hand,

ILLUMINATION

13277

the m o t i o n

in the

foot

( 115

Aiguier,

the r e l a t i v e

, namely

cues,

placed

STROBOSCOPIC

the o t h e r

It is the r e s u l t i n g

either

de P s y c h o p h y s i o l o g i e

conducted

( one

levels.

which

on

J., AMBLARD, B., CARBLANC, A.

Laboratoire

systems

states,

ON SELF-MOTION

IN MAN UNDER

CREMIEUX,

31,

shock

of the b r a i n

memory

TURE

Both

is i n d u c e d by low d o s e s d i f f e r e n t f r o m that i n -

rapid

were

head,

especiallateral

oscillations.

ficant

difference

between This

horizontal

stroboscopic

light.

result

contribution

of d i s p l a c e m e n t

are a v a i l a b l e in s t r o b o s c o p i c upright posture.

is a s t a t i s t i c a l l y and vertical

indicates

visual

cues

lighting)

that ( the

in the

signi-

patterns

there only

in

is a c l e a r one which

control

of

the