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The ontogeny of defensive reactions in the rat: Influence of the monoamine transmission systems
Author(s) -
HÅRD E.,
ENGEL J.,
MUSI B.
Publication year - 1982
Publication title -
scandinavian journal of psychology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.743
H-Index - 72
eISSN - 1467-9450
pISSN - 0036-5564
DOI - 10.1111/j.1467-9450.1982.tb00456.x
Subject(s) - dopamine , serotonin , ontogeny , apomorphine , monoamine neurotransmitter , stimulation , haloperidol , psychology , endocrinology , medicine , inhibitory postsynaptic potential , 5,7 dihydroxytryptamine , chemistry , neuroscience , receptor , dopaminergic , serotonergic , biology
The effects of neonatal treatment of rats with the neurotoxins 5,7‐dihydroxytryptamine and 6‐hydroxydopamine on the ontogeny of the ultra sound vocalization and the immobility response were studied. The 5,7‐dihydroxytryptamine treated rats showed reduced strength of both reactions indicating involvement of the serotonin system in their ontogeny. This hypothesis was supported by experiments with depletion of serotonin by para‐chlorophenylalanine followed by replenishment with 5‐hydroxytryptophan. The 6‐hydroxydopamine treated rats showed normal defensive reactions, but displayed hyperactivity from their second week of age. The role of the dopamine system in the defensive reactions was studied by variations of the dopamine activity level by traditional tools: depletion by α‐methyl‐tyrosin followed by replenishment by l ‐DOPA; stimulation or inhibition of the dopamine receptors by apomorphine or haloperidol. The results suggested an inhibitory function of the dopamine system in both defensive reactions, antagonistic to that of the serotonin system.