Abstract
Seventeen rats received injections of 5,7-dihydroxytryptamine into the dorsal and median raphe nuclei: 12 rats received sham injections. The rats were trained in a series of discrete trials to press lever A following a 2-s presentation of a light stimulus and to press lever B following an 8-s presentation of the same stimulus. Both groups learnt the task rapidly and maintained >90% accuracy throughout the experiment. When stable performance had been attained, “probe” trials were introduced in which the light was presented for intermediate durations. Both groups showed sigmoid functions relating percent choice of lever B to log stimulus duration. The bisection point (duration corresponding to 50% choice of lever B) was significantly shorter in the lesioned group than in the control group. There was no significant difference between the slopes of the psychophysical functions or the Weber fractions derived for the two groups. The levels of 5-hydroxytryptamine (5HT) and 5-hydroxyindoleacetic acid in the parietal cortex, hippocampus, amygdala, nucleus accumbens and hypothalamus were markedly reduced in the lesioned group, but the levels of noradrenaline and dopamine were not significantly affected by the lesion. The results confirm the involvement of 5HTergic function in timing behaviour, but suggest that destruction of these pathways does not disrupt the capacity for temporal discrimination.
Similar content being viewed by others
References
Baumgarten HG, Jenner S, Bjorklund A, Klemm HP, Schlossberger HG (1982) Serotonin neurotoxins. In: Osborne NN (ed) Biology of serotonergic transmission. Wiley, Chichester
Bizot JC, Thiebot MH, LeBihan C, Soubrié P, Simon P (1988) Effects of imipramine-like drugs and serotonin uptake blockers on delay of reward in rats. Possible implication in the behavioral mechanism of action of antidepressants. J Pharmacol Exp Ther 246:1144–1151
Catania AC (1970) Reinforcement schedules and psychophysical judgements: A study of some temporal properties of behavior. In: Schoenfeld WN (ed) The theory of reinforcement schedules. Appleton-Century-Crofts, New York, pp 1–42
Church RM (1984) Properties of the internal clock. In: Gibbon J, Allan L (ed) Timing and time perception. Ann NY Acad Sci 423:566–582
Church RM, Deluty MZ (1977) Bisection of temporal intervals. J Exp Psychol [Anim Behav Proc] 3:216–228
Deakin JFW (1983) Roles of serotonergic systems in escape, avoidance and other behaviours. In: Cooper SJ (ed) Theory in psychopharmacology, vol 2. Academic Press, New York
Fetterman, JG, Killeen PR (1992) Time discrimination in Columbia livia and Homo sapiens. J Exp Psychol [Anim Behav Proc] 18:80–94
Gibbon J (1991) Origins of scalar timing. Learn Motiv 22:3–38
Heffner TG, Hartman JA, Seiden LS (1980) A method for the regional dissection of the rat brain. Pharmacol Biochem Behav 13:453–456
Killeen PR, Fetterman JC (1988) A behavioral theory of timing. Psychol Rev 95:274–295
Lewis D (1960) Quantitative methods in psychology. Springer, Berlin Heidelberg New York
Paxinos G, Watson C (1982) The rat brain in stereotaxic coordinates. Academic Press, New York
Platt JR (1984) Motivation and response factors in temporal differentiation. In: Gibbon J, Allan L (eds) Timing and time perception. Ann NY Acad Sci 423:200–210
Platt JR, Davis ER (1983) Bisection of temporal intervals by pigeons. J Exp Psychol [Anim Behav Proc] 9:160–170
Richardson WK, Loughead TE (1974) Behavior under large values of the differential-reinforcement-of-low-rate schedule. J Exp Anal Behav 22:121–129
Soubrié P (1986) Reconciling the role of central serotonin neurons in human and animal behavior. Behav Brain Sci 9:319–364
Stubbs DA (1976) Scaling of stimulus duration by pigeons. J Exp Anal Behav 26:15–25
Treisman M (1963) Temporal discrimination and the indifference interval: implications for a model of the “internal clock”. Psychol Monogr 77:1–31
Wearden JH (1990) Maximizing reinforcement rate on spaced responding schedules under conditions of temporal uncertaincy. Behav Proc 22:47–60
Wogar MA, Bradshaw CM, Szabadi E (1991) Evidence for an involvement of 5-hydroxytryptaminergic neurones in the maintenance of operant behaviour by positive reinforcement. Psychopharmacology 105:119–124
Wogar MA, Bradshaw CM, Szabadi E (1992) Impaired acquisition of temporal differentiation performance following lesions of the ascending 5-hydroxytryptaminergic pathways. Psychopharmacology 107:373–378
Wogar MA, Bradshaw CM, Szabadi E (1993) Effects of lesions of the ascending 5-hydroxytryptaminergic pathways on choice between delayed reinforcers. Psychopharmacology 111:239–243
Zeiler MD (1977) Schedules of reinforcement, the controlling variables. In: Honig WK, Staddon JER (eds) Handbook of operant behavior. Prentice Hall, Hillsdale NJ, pp 201–232
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Morrissey, G., Wogar, M.A., Bradshaw, C.M. et al. Effect of lesions of the ascending 5-hydroxytryptaminergic pathways on timing behaviour investigated with an interval bisection task. Psychopharmacology 112, 80–85 (1993). https://doi.org/10.1007/BF02247366
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02247366