SOME STUDIES ON DRUG-INDUCED BEHAVIOUR IN YOUNG CHICKS
SOME STUDIES ON DRUG-INDUCED BEHAVIOUR IN YOUNG CHICKS
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Date
1980-04
Authors
SOKOMBA, ELIJAH NDAJIYA
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Abstract
Some behavioural and electrophysiological
studies were undertaken in chicks and rats
using observational, EEG, EMG and evoked
potential techniques.
Some dopamine (DA) agonists (apomorphine,
d-amphetamine, amantadine, and piribedil)
induced stereotyped pecking activity and
aggressive behaviour of varying intensities in
chicks. On the other hand, DA, L-dopa and
ergometrine did not induce characteristic
stereotyped activity in the chicks.
D-amphetamine and ergometrine induced distinct
postural changes in chicks. Pretreatment of
chicks with ergometrine and piribedil antagonized
the behavioural effects of apomorphine and
d-amphetamine. The results show that apomorphine
d-amphetamine, amantadine and piribedil induce a
similar pattern of stereotyped activity in young
chicks. The results further suggest that
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ergometrine exerts a predominant inhibitory
influence on stereotyped behaviour , while
piribedil has both DA agonistic and antagonistic
effects in young chicks.
Pretreatment of chicks with reserpine
and 6-hydroxydoparaine (6-OHDA) potentiated
apomorphine and piribedil-induced stereotyped
behaviour while the effects of d-amphetamine and
amantadine were inhibited. The behavioural
effect of apomorphine were potentiated when chicks
were pretreated with dihydroxy-phenylserine,
while d-amphetamine and amantadine effects were
antagonised. FLA--63 potentiated d-amphetamine and
amantadine-induced stereotyped behaviour and
inhibited apomorphine effects. Propranolol
antagonized the behavioural effects of apomorphine
and d-amphetamine, while phenoxybenzamine slightly
potentiated the effects. Pimozide and haloperidol
antagonized apomorphine, d-amphetamine, amantadine
and piribedil-induced stereotyped behaviour.
These observations indicate a primary role for
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dopaminergic system in drug-induced stereotyped
behaviour in young chicks as in other species.
Serotonin and quipazine antagonized
apomorphine and d-amphetamine-induced stereotyped
behaviour. On the other hand, cyproheptadine
and parachloro-phenylalanine (PCPA) potentiated
the effects of apomorphine and d-amphetamine.
These results suggest that serotonergic system
plays an inhibitory role in drug-induced
stereotyped behaviour in chicks.
Desipraraine, imipramine and amitriptyline
induced biphasic locomotor effects in chicks.
Aporaorphine-induced locomotor activity was
potentiated when the chicKs were pretreated
30 rain, previously with amitriptyline and
imipramine. When the three antidepressants
were administered 1 h previously, apomorphineinduced
locomotor activity was inhibited.
The results suggest that tricyclic
antidepressants produce a time-dependent effect
on apomorphine-induced locomotor activity in
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chicks.
Repeated administration of j3,i$'-iminodipropionitrile(
IDPN) for five days induced
specific behavioural changes in chicks. These
behavioural changes were characterized by
excitation which was accompanied by loud
chirping, jerky head and neck movements, and
circling motion (i.e. ECC-syndrome). Amphetamine
potentiated the syndrome while apomorphine and
piribedil enhanced the head and neck movements
with minimal effect on the circling behaviour.
Pimozide antagonized the ECC-syndrome and also
inhibited amphetamine-induced potentiation of
the syndrome. Atropine and hyoscine enhanced
the ECC-syndrome and also potentiated the effects
of d-amphetamine, while physostigmine antagonised
the syndrome. Quipazine, in low doses, abolished
and in high doses enhanced the ECC-syndrome. The
latter effect was antagonised by both cyproheptadine
and pimozide. Such results suggest that DA and
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serotonergic mechanisms may be involved in
IDPN-induced effects in chicks. It is also
possible that cholinergic system may exert an
inhibitory influence on the ECC-syndroioe.
Evoked responses to photic stimulation
recorded under artificial light and dark
adaptation from three different brain areas in
conscious young chicks were compared. The
magnitude of the evoked responses varied from
one experiment to another, but for a particular
chick consistent responses were obtained under
the same behavioural state, stimulus intensity,
and recording conditions. The evoked responses
recorded under dark adaptation were larger in
magnitude and more reproducible when compared
with those recorded..under artificial light.
The photic-evoked responses under dark adaptation
were very sensitive to drug effects. These
observations suggest that photic-evoked
response (PER) could probably be utilized in
the elucidation of the actions of some
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Psychoactive drugs.
The influence of acute and chronic
administration of phenobarbitone and ethanol
on PER was studied in rats. Both phenobarbitone
and ethanol produced behavioural depression. EEG
synchronization and varying effects on the
averaged PER recorded from the frontal cortex
(FC) optic cortex (OC) and midbrain reticular
formation (MBRF). In phenobarbitone- and
ethanol- dependent animals, amplitude of the PER
recorded from the FC and OC were enhanced while
the recordings from the MBRF were reduced. On
the other hand, the amplitudes of the PER from
all the three brain areas were enhanced during
withdrawal. The results suggest that both
phenobarbitone and ethanol produce similar
effects on PER in rats and that the effects may
probably be characteristic of the sedative -
hypnotic group of drugs.
Description
A THESIS
Submitted to
Ahmadu Bello University, Zaria
In partial fulfilment for the degree of
DOCTOR OF PHILOSOPHY.
Department of Pharmacology
Faculty of Pharmaceutical Sciences.
APRIL, 1980.
Keywords
STUDIES,, DRUG-INDUCED,, BEHAVIOUR,, YOUNG CHICKS.