ANALYSIS OF THE PROPAGATION OF SPIKE BURST POTENTIALS IN THE CALF

HAL Id: hal-00901224

https://hal.archives-ouvertes.fr/hal-00901224

Submitted on 1 Jan 1979

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of

sci-entific research documents, whether they are

pub-lished or not. The documents may come from

teaching and research institutions in France or

abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est

destinée au dépôt et à la diffusion de documents

scientifiques de niveau recherche, publiés ou non,

émanant des établissements d’enseignement et de

recherche français ou étrangers, des laboratoires

publics ou privés.

ANALYSIS OF THE PROPAGATION OF SPIKE

BURST POTENTIALS IN THE CALF

C. Dardillat, Lionel Bueno

To cite this version:

ANALYSIS OF

THE

PROPAGATION OF SPIKE BURST POTENTIALS

IN

THE CALF

C. DARDILLAT

L. BUENO*

L

Laboratoire de la Digestion des _{Ruminants ;} INRA Centre de Recherches Zootechnique et Vétérinaire de Theix 63110 Beaumont - France

**

Eco% Nationale Vétérinaire, 31076 Toulouse - France

The

_{long-term techniques}

used to

_study

intestinal electrical

activity require

the location

of either at least two electrodes at each

recor-ding

site

(Ruckebusch,

1970) or one or two electrodes fixed to a support sewn onto the intestine (Allen

et al.,

19641. These

_techniques

are well

adapted

for

_describing

different

pha-ses of

activity,

but a

_{precise study}

of the

pro-pagation

of each burst of

spike potential

requi-res numerous electrode sites more

_closely

situated.

However,

a

_large

number of

electro-des on a short segment of

_intestine,

_especially

when attached to supports, could be the

ori-gin

of an irritation of the

bowel,

thus

disrup-ting

gut

activity.

To avoid such

_problems,

we

propsoe

using

a

_single

electrode at each

recor-ding

site and

_designing

a suitable

anchorage

technique.

Methods of

_studying

the

direc-tion,

velocity

and distance of

propagation

of

spike

bursts will be described in this paper.

Electrode

preparation

Enamelled nickel chrome wire 0.12 mm in dia. was used

(Ruckebusch,

1973). A curved

surgical

needle,

20 mm

_long

with 0.35 mm

round diameter and a 0.25 mm groove, was

attached to the end of the wire

by inserting

the wire in the groove and

squeezing.

Five cm

from the

_end,

a 2 mm

_length

of wire was

squeezed

in a

special pair

of

_{pincers, causing}

the enamel to come off and the electrode

sur-face to increase to 0.4 mm wide. The wire was

bent in the middle of the flattened surface.

Electrode

_Anchorage

The needle eased the

_anchorage

of the

elec-trode into the intestinal muscular

_layers

and

care was taken to ensure that the

_stripped

part

of the wire was

_completely

inserted into the

wall. The electrod was held in

_{place by}

twisting

the wire and the end attached to the needle was cut off at the base of the twist. Ten electrodes were anchored in this way at intervals of 1.5 cm in the

_jejunum

or 0.7 cm in

the ileum. A second group of 10 electrodes

was

_placed

40 cm _{away from} the first.

During

the

_sewing-up

of the

peritoneum,

the electrodes were

_{arranged regularly}

bet-ween each stitch. The

_length

of the electrode inside the abdominal

_cavity

was restricted to

no more than 3-4 cm. This

precaution

was to avoid intestinal

occlusion,

which is

_particularly

frequent

in the calf. The electrodes were made to

_protrude

from the wound in a

_single

bunch

and were held

_{together by}

adhesive

_plaster

for

approx. 40 cm and left free for the last 10 cm.

Connection and

_recording

The animal was

_placed

in a _{wooden pen.}

The

_tips

of the

_{electrodes, exposed, by}

bur-ning.

were attached to the connection board

of the recorder which was fixed to the animal

and followed all its movements. The

electro-des,

10 cm above the bunch had to be

movement

by

the

animal,

which is an

impor-tant cause of

artefacts,

could be avoided

_by

the presence of straps. An earth electrode was

anchored in the skin near the ilium.

Monopolar

recordings

were made with a

time constant of 0.1 sec. on an

electroence-phalograph (Reega

X

Alvar),

the reference

potential

being automatically

obtained

by

con-necting

all the electrodes across resistances.

Bipolar recordings

between two

_adjacent

elec-trodes could be used to obtain

high amplitude

slow waves.

Record

analysis

Seven

surgical

interventions were made on

4 calves at 15-30

day

intervals without any

pathological

consequences.

Only

4 of the 140

implanted

electrodes did not function and the usual inconvenience of

monopolar

recording

which is the presence of artefacts of muscular

origin especially

from the heart and

_diaphragm

was in fact reduced

by

the

_proximity

of the

electrodes to each

other,

far away from the

heart.

The bursts of

spike potentials

from

mono-polar

recordings

were shorter than those from

bipolar recordings,

and

they

were

_always

dis-tinct. On the other

hand,

the slow waves were

less

pronounced

and sometimes

disappeared.

The

_{propagation of.spike}

burst can be

follo-wed without

difficulty

using

this

technique

and the direction of

_propagation,

usually

abo-ral,

is

easily

identified

(fig.

1 The

velocity

of

propagation

(several cm/s) is

_easily

measured

by using

a transparent scale. The distance of

propagation

can be

appreciated

from the bursts of

_spike

which appear and

disappear

within the recorded segment. With other bursts of

_spike,

the

_propagation

distance can

only

be assumed

by

statistical

methods,

depending

on the

frequency

of

interruptions

in

propagation.

These _parameters were measured to

com-pare the

propagation

of slow waves and bursts of

_{spike potential,}

the

_{propagation during}

dif-ferent

phases

of

_{activity, during feeding}

or

fas-ting

or when disturbances occur.

This

_technique

enabled us to

_complete

pre-vious work on the

description

of motor

pheno-mena in the small intestine of the calf. A

study

on burst

_propagation

similar to that

_performed

earlier in isolated organs or under anesthesia

(Bortoff and

Sacco,

1973) has been carried out

References

ALLEN G.L., POOLE E.W., CODE C.F., 1964. Relationships between electrical activities of antrum and duo-denum. Am J. _{Physiol., 207,} 906-910.

BORTOFF A., SACCO J., 1973. Myogenic control of intestinal peristalsis. Proc. of the 41hInternational

Symposium on Gastrointestinal Motility, 53-60. Mitchell Press, Vancouver.

RUCKEBUSCH Y., 1970. The electrical activity of the _digestive tract of the _sheep as an indication of the mechanical events in various _regions. J. Physiot G.B., 210, 857-882.