Effect of monosialoganglioside internal ester (agf2) in monocular deprived kitten

434

SELECTED

COMMUNICATIONS

METABOLIC

48

ASPECTS

EFFECT OF MONOSIALOGANGLIOSIDEINTERNAL ESTER (AGFZ) IN MONOCULAR DEPRIVED KITTENS. G. Carmignoto, C. Comelli, R. Canella, A. Gorio and S. Bisti*. Fidia Research Laboratories, Dept. of Cytopharmacology,Abano Terme, Italy. *Ist. di Neurofisiologia, C.N.R. di Pisa, Pisa, Italy. We have investigated the possible effect of the monosialoganglioside internal ester (AGFZ) treatment in the functional and anatomical modifications of the visual cortex and Lateral Geniculate Nucleus (LGN) after monocular deprivation. AGF2 treatment (30 mg/kg i.p.) covers all the time of deprivation. Kittens were monocularly deprived at the age of 17 and 35 days. Ocular dominance distribution is assessed by recording from single units In area centralis of area 17. Our experiments shows that in AGF2 treated kittens the ocular dominance shift is reduced compared to untreated control kittens. In kittens deprived at 35th day AGF2 trested animals maintain 41.1% of cortical neurons with a binocular input (group 2-6) compared to only 21% in untreated kittens. In animals deprived at 17th day the effect of the treatment seems even more evident: 21% are binocular units in the AGF2 group compared to only 4% in the control group. Moreover, a morphometrical study on Golgi-impregnated relay neurons in the LGN suggests that in the LGN deprived laminae of the untreated kittens Guillery's class 1 and 2 neurons undergo a significant alteration of the dendritic tree and soma size while the treatment seems to ensure, at least for class 2 cells, an almost normal development of the dendritic arbor and soma size. A diminished cortical plasticity could account for these effects. Anyway some tentative different explanations are hypothesized.

49

LOCALIZATION

OF EMBRYONIC

CHOLINESTERASES

IN CHICKEN

BRAINS

PHOGENETIC FUNCTIONS FOR NEUROGENESIS Paul G. LAYER - Max-Planck-Institut fir Entwicklungsbiologie, 74 TUBINGEN, Cells e.g.

of a developing nerve

connections In

The main

both enzymes of

localization. trying

to

for

fibers

system require

finding

for

described

acetylcholinesterase

nature

nervous

cells

their

finding

(e.g. retina-tectal

(1) I have

head.

POSSIBLE

Spemannstrasse

MOR-

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FRG

migrating

growing

AND THEIR

some

data concerning

final positions

their

ways

to

achieve

specific

information; laminae,

topologically

or

ordered

system). general

principles

of

(AChE) and of pseudocholinesterase

observations

positional

within

included:

early

appearance

the

localization

of

embryonic

(BuChE) in the entire chicken and partial

disappearance

of

long before synaptogenesis occurs, their local exclusiveness, the graded of their extra-neuronal as some aspects their appearance, as well In this report

explain

how

I would like to discuss information might

positional

some alternative model schemes be generated by the observed

In addition I will describe our experimental principles of enzyme localizations. attempts aiming at the verification of these proposed morphogenetic functions. Ref.: Layer, P.G.,

(1983) Proc. Natl. Acad. Sci. USA 80, 6413-6417.