1146
RESEARCH NOTES
in passerine birds. Such work in geese could proceed from knowledge of their minimal obligatory photorefractory period. ACKNOWLEDGEMENTS The records for this study were kindly provided by Marlin Schiltz, Bancroft, Iowa. REFERENCES
STRYCHNINE CONVULSIONS IN COCKERELS TAKANORI
OOKAWA
Department of Physiology, Gifu University School of Medicine, Gifu, Japan (Received for publication December 16, 1975)
ABSTRACT An intravenous injection of 0.85 mg./kg. strychnine nitrate produced typical convulsions in all cockerels, aged 4 to 12 weeks, as well as adult hens. Convulsions consisted of an initial excitement, tonic stage associated with opisthotonos, transient clonic movement, and finally vigorous tonic convulsions. Strychnine spikes in the Wulst EEG were not induced by the same intravenous dose of strychnine in both cockerels and adult hens. POULTRY SCIENCE 55: 1146-1148,
R
ECENTLY, Osuide (1968) reported that 0.85 mg./kg. strychnine was not convulsant in most cockerels, aged 9 to 12 weeks, and no death occurred. In contrast, Ookawa (1973a, b) previously observed that 0.5 mg./kg. strychnine, administered intravenously, produced typical convulsions in the adult chicken. To confirm Osuide's observation, further investigations, using 0.85 mg./kg. body weight strychnine, were made on cockerels, aged from 3 to 12 weeks. Thirty-six male White Leghorn chickens and 11 adult White Leghorn hens were used for this experiment. Twenty-five out of 36 young chickens and 7 out of 11 hens were used for behavioral effects of strychnine. The influence of the convulsant on polygraphic recordings was investigated in the remaining 11 young chickens and 4 adult hens. The bird was fixed in a stereotaxic apparatus. Then,
1976
the beak and both external meati of the chicken were fixed in a holder. The skin of the head was cut under local anesthesia. A platinum-ball electrode insulated with a vinyl tube was used for the electroencephalogram (EEG) of 4-week-old young chickens. The electrodes covered with electrode paste used for recording human electrocardiogram (ECG) were placed symmetrically on the frontal bones, and finally fastened with dental cement over the Wulst, the accessory hyperstriatum (van Tienhoven and Juhasz, 1962; Pearson, 1972). The insect-pin electrodes were inserted into the fine holes on each side, and fixed to the skull with dental cement. The EEG recording electrode was fixed into the skull, so as not to damage the brain. The site of recording EEG was located on the Wulst. The EEG, the neck movement (NM) and
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis S on May 4, 2015
Balko, L., A. Grom and L. Landau. 1967. On the study of some productive characters in geese under
the conditions of large scale production. Vedecke Prace Vyskumny Ustav Pre Chov Hydiny, 4: 223239. Bielinski, K., and K. Bielinska, 1970. Investigation of the egg laying curve of geese in relation to annual egg production. Postepy Droviarstura, 12: 89-92. Farner, D. S., 1967. The control of avian reproductive cycles, pp. 107-133. In: Proceedings XIV International Ornithological Congress, Oxford, 1966. Blackwells, Oxford. Wolf son, A., 1954. Production of repeated gonadal, fat, and molt cycles within one year in the Junco and White-crowned Sparrow by manipulation of day length. J. Exp. Zool. 125: 353-376.
1147
RESEARCH NOTES
the E C G were simultaneously recorded. For the E E G recording, a monopolar lead was used with the reference electrode on the c o m b . For recording the neck m o v e m e n t , a needle electrode was inserted into the neck muscle (with the reference used in the E E G
TABLE 1.—Effect
of 0.85 mg./kg.
strychnine administered intravenously to cockerels and adult hens*
5
5
10-29 2
9-15 1
6-8
12
Adult*
10-23 2
3-6 2
STRYCHNINE (I.V) 0S5 MG/KG
4-WEEK-OLD
085 MG/KG
12-WEEK-OLD
MIN
I mV
ECG
ADULT
085 MG/KG **
I — W M W II
H"«l I l l |
i
(I I
I |i I ||ll||H|Hll |l"ill»M
1H
RESEARCH NOTES
in passerine birds. Such work in geese could proceed from knowledge of their minimal obligatory photorefractory period. ACKNOWLEDGEMENTS The records for this study were kindly provided by Marlin Schiltz, Bancroft, Iowa. REFERENCES
STRYCHNINE CONVULSIONS IN COCKERELS TAKANORI
OOKAWA
Department of Physiology, Gifu University School of Medicine, Gifu, Japan (Received for publication December 16, 1975)
ABSTRACT An intravenous injection of 0.85 mg./kg. strychnine nitrate produced typical convulsions in all cockerels, aged 4 to 12 weeks, as well as adult hens. Convulsions consisted of an initial excitement, tonic stage associated with opisthotonos, transient clonic movement, and finally vigorous tonic convulsions. Strychnine spikes in the Wulst EEG were not induced by the same intravenous dose of strychnine in both cockerels and adult hens. POULTRY SCIENCE 55: 1146-1148,
R
ECENTLY, Osuide (1968) reported that 0.85 mg./kg. strychnine was not convulsant in most cockerels, aged 9 to 12 weeks, and no death occurred. In contrast, Ookawa (1973a, b) previously observed that 0.5 mg./kg. strychnine, administered intravenously, produced typical convulsions in the adult chicken. To confirm Osuide's observation, further investigations, using 0.85 mg./kg. body weight strychnine, were made on cockerels, aged from 3 to 12 weeks. Thirty-six male White Leghorn chickens and 11 adult White Leghorn hens were used for this experiment. Twenty-five out of 36 young chickens and 7 out of 11 hens were used for behavioral effects of strychnine. The influence of the convulsant on polygraphic recordings was investigated in the remaining 11 young chickens and 4 adult hens. The bird was fixed in a stereotaxic apparatus. Then,
1976
the beak and both external meati of the chicken were fixed in a holder. The skin of the head was cut under local anesthesia. A platinum-ball electrode insulated with a vinyl tube was used for the electroencephalogram (EEG) of 4-week-old young chickens. The electrodes covered with electrode paste used for recording human electrocardiogram (ECG) were placed symmetrically on the frontal bones, and finally fastened with dental cement over the Wulst, the accessory hyperstriatum (van Tienhoven and Juhasz, 1962; Pearson, 1972). The insect-pin electrodes were inserted into the fine holes on each side, and fixed to the skull with dental cement. The EEG recording electrode was fixed into the skull, so as not to damage the brain. The site of recording EEG was located on the Wulst. The EEG, the neck movement (NM) and
Downloaded from http://ps.oxfordjournals.org/ at D H Hill Library - Acquis S on May 4, 2015
Balko, L., A. Grom and L. Landau. 1967. On the study of some productive characters in geese under
the conditions of large scale production. Vedecke Prace Vyskumny Ustav Pre Chov Hydiny, 4: 223239. Bielinski, K., and K. Bielinska, 1970. Investigation of the egg laying curve of geese in relation to annual egg production. Postepy Droviarstura, 12: 89-92. Farner, D. S., 1967. The control of avian reproductive cycles, pp. 107-133. In: Proceedings XIV International Ornithological Congress, Oxford, 1966. Blackwells, Oxford. Wolf son, A., 1954. Production of repeated gonadal, fat, and molt cycles within one year in the Junco and White-crowned Sparrow by manipulation of day length. J. Exp. Zool. 125: 353-376.
1147
RESEARCH NOTES
the E C G were simultaneously recorded. For the E E G recording, a monopolar lead was used with the reference electrode on the c o m b . For recording the neck m o v e m e n t , a needle electrode was inserted into the neck muscle (with the reference used in the E E G
TABLE 1.—Effect
of 0.85 mg./kg.
strychnine administered intravenously to cockerels and adult hens*
5
5
10-29 2
9-15 1
6-8
12
Adult*
10-23 2
3-6 2
STRYCHNINE (I.V) 0S5 MG/KG
4-WEEK-OLD
085 MG/KG
12-WEEK-OLD
MIN
I mV
ECG
ADULT
085 MG/KG **
I — W M W II
H"«l I l l |
i
(I I
I |i I ||ll||H|Hll |l"ill»M
1H
