Abstract
Chlordiazepoxide (CDP) at 20 mg/kg, i. p. reduced the rate of spontaneous alternation in hungry rats on 6 successive trials with no particular reward in a T-maze (Experiment I). The result could not be ascribed simply to the drug-produced changes in running speeds; although alternation is usually assumed to be higher in rate with shorter inter-choice intervals, CDP rats ran slightly faster than saline rats. The same dose of CDP depressed the hippocampal theta activity by decreasing its frequency and facilitating regular fast activity of about 30 Hz which was superimposed on the theta rhythm (Experiment II). The reduction of alternation after CDP was explained in terms of the drug's depressant action upon one of the hippocampal functions, characterized by the theta activity, which is assumed to have a significant role in internal inhibition underlying such behaviors as discrimination reversal, passive avoidance, extinction, frustration, habituation and spontaneous alternation.
Similar content being viewed by others
References
Adey, W. R.: Hippocampal states and functional relations with cortico-subcortical systems in attention and learning. In W. R. Adey, T. Tokizane (Eds.) Progress in brain research: Structure and function of the limbic system. Amsterdam: Elsevier 1967.
Bennet, T. L.: Hippocampal EEG correlates of behavior. Electroenceph. clin. Neurophysiol. 28, 17–23 (1970).
Bremner, F. J.: Hippocampal activity during avoidance behavior in the rat. J. comp. physiol. Psychol. 58, 16–22 (1964).
Bureš, J., Bohdanecký, Z., Weiss, T.: Physostigmine induced hippocampal theta activity and learning in rats. Psychopharmacologia (Berl.) 3, 254–263 (1962).
Carlton, P. L.: Cholinergic mechanisms in control of behavior by the brain. Psychol. Rev. 70, 19–39 (1963).
Dalland, T.: Response and stimulus perseveration in rats with septal and dorsal hippocampal lesions. J. comp. physiol. Psychol. 77, 114–118 (1970).
Douglas, R. J.: The hippocampus and behavior. Psychol. Bull. 67, 416–442 (1967).
—, Isaacson, R. L.: Hippocampal lesions and activity. Psychon. Sci. 1, 187–188 (1964).
Dember, W. N., Fowler, H.: Spontaneous alternation behavior. Psychol. Bull. 55, 412–428 (1958).
Grastyán, E., Lissák, K., Madarász, I., Donhoffer, H.: Hippocampal electrical activity during the development of conditioned reflexes. Electroenceph. clin. Neurophysiol. 11, 409–430 (1959).
Gray, J. A.: Sodium amobarbital, the hippocampal theta rhythm, and the partial reinforcement extinction effect. Psychol. Rev. 77, 465–480 (1970).
Hendrickson, C. W., Kimble, R. J., Kimble, D. P.: Hippocampal lesions and the orienting response. J. comp. physiol. Psychol. 67, 220–227 (1969).
Iwahara, S.: Response fixation of the shocked rat in the free-choice situation. Psychol. Rep. 7, 221–224 (1960).
—, Iwasaki, T.: Effect of chlordiazepoxide upon food intake and spontaneous motor activity of the rat as a function of hours of food deprivation. Jap. psychol. Res. 11, 117–128 (1969).
— —, Nagamura, N., Masuyama, E.: Effect of chlordiazepoxide upon partially-reinforced behavior of rats in the straight runway. Jap. psychol. Res. 8, 131–135 (1966).
—, Nagamura, N., Iwasaki, T.: Effect of chlordiazepoxide upon experimental extinction in the straight runway as a function of partial reinforcement in the rat. Jap. psychol. Res. 9, 128–134 (1967).
—, Sugimura, T.: Effects of chlordiazepoxide on black-white discrimination acquisition and reversal in white rats. (In Japanese with an English abstract.) Jap. J. Psychol. 41, 142–150 (1970).
Kimble, D. P.: Hippocampus and internal inhibition. Psychol. Bull. 70, 285–295 (1968).
König, J. F. R., Klippel, R. A.: The rat brain. A stereotaxic atlas of the brain stem. Baltimore: Williams & Wilkins 1963.
Nakagawa, S.: The influence of chlordiazepoxide upon EEG activities of cat's brain. (In Japanese.) Psychiat. Neurol. jap. 65, 963–973 (1963).
Numakura, K.: Effects of medial septal lesions upon the hippocampal electrical activity and orienting reflexes in the rat. (In Japanese.) Unpublished thesis (1971).
Oishi, H., Iwahara, S., Yang, K. M., Yogi, A.: Effects of drug-state changes upon passive avoidance responses in rats. Psychopharmacologia (Berl.) 23, 373–385 (1972).
Roberts, W. W., Dember, W. N., Brodwick, M.: Alternation and exploration in rats with hippocampal lesions. J. comp. physiol. Psychol. 55, 695–700 (1962).
Stumpf, C.: The fast component in the electrical activity of rabbit's hippocampus. Electroenceph. clin. Neurophysiol. 18, 477–486 (1965).
Torii, S.: Two types of pattern of hippocampal electrical activity induced by stimulation of hypothalamus and surrounding parts of rabbit's brain. Jap. J. Physiol. 11, 147–157 (1961).
—, Wikler, A.: Effects of atropine on electrical activity of hippocampus and cerebral cortex in cat. Psychopharmacologia (Berl.) 9, 189–204 (1966).
Vanderwolf, C. H.: Limbic-diencephalic mechanisms of voluntary movement. Psychol. Rev. 78, 83–113 (1971).
Wickelgren, W. O., Isaacson, R. L.: Effect of the introduction of an irrelevant stimulus on runway performance of the hippocampectomized rat. Nature (Lond.) 200, 48–50 (1963).
Yokota, T., Fujimori, B.: Effects of brain-stem stimulation upon hippocampal electrical activity, somatomotor reflexes and autonomic functions. Electroenceph. clin. Neurophysiol. 16, 375–382 (1964).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Iwahara, S., Oishi, H., Yamazaki, S. et al. Effects of chlordiazepoxide upon spontaneous alternation and the hippocampal electrical activity in white rats. Psychopharmacologia 24, 496–507 (1972). https://doi.org/10.1007/BF00423440
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00423440