Behavioral actions of intranasal application of dopamine: effects on forced swimming, elevated plus-maze and open field parameters.
BACKGROUND
Recently, we found evidence that intra-nasally administered dopamine (DA), can enter the brain, leading to an immediate increase in extracellular DA levels in striatal subregions. This offers a potential alternative approach to target the brain with exogenous DA, which otherwise cannot cross the blood-brain barrier. Here, we examined whether intra-nasally applied DA also exerts behavioral activity on mesocortical and nigrostriatal dopaminergic functions.


METHODS
Male Wistar rats (3-4 months) were tested for potential behavioral effects of intra-nasally applied DA (0.03, 0.3 or 3.0 mg/kg) in the forced swimming test (FST) for antidepressant-like activity, elevated plus-maze for anxiety-related behavior, and on motor activity in a novel and familiar environment.


RESULTS
Intra-nasally administered dopamine in a dose of 0.3 mg/kg exerted antidepressant-like activity in the FST, but had neither anxiolytic-like nor anxiogenic-like effects in the elevated plus-maze. Furthermore, intra-nasal dopamine stimulated locomotor activity in a familiar, but not novel, open field.


CONCLUSIONS
These results support the view that intra-nasally applied DA can act on the central nervous system by entering the brain via the nose-brain pathway, making this kind of application procedure a promising alternative for targeting the brain, and thus treating disorders involving mesocortical and/or nigrostriatal dopaminergic disturbances.
Institute of Physiological Psychology, University of Dusseldorf, Dusseldorf, Germany.
Tim E
TE
Buddenberg
Bianca
B
Topic
E Demetris
ED
Mahlberg
Maria A
MA
de Souza Silva
Joseph P
JP
Huston
Claudia
C
Mattern
D000281:Administration, Intranasal; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003068:Coercion; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D008124:Locomotion / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D009832:Olfactory Nerve / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming
D004298:Dopamine