Changes in Emotional Behavior of Mice in the Hole-Board Test After Olfactory Bulbectomy

Abstract

Abstract. The most consistent behavioral change caused by olfactory bulbectomy (OBX) is a hyperemotional response to novel environmental stimuli. The aim of this study was to characterize the emotional behavior of OBX mice using the hole-board test. After the olfactory bulbs were lesioned, sham and OBX mice were housed in single cages for 14 days. The number of head-dips in the hole-board test in single-housed OBX mice was significantly greater than that in single-housed sham mice. The head-dipping behaviors in single-housed sham and OBX mice were reversed by treatment with diazepam, a typical benzodiazepine anxiolytic. (±)-8-Hydroxy-2-(di-n-propylamino) tetraline hydrobromide (8-OH-DPAT), a selective 5-HT 1A -receptor agonist that has a non-benzodiazepine anxiolytic-like effect, and (+)-4-[(aR)-a-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethyl benzamide (SNC80), a δ-opioid-receptor agonist, also significantly reversed the number of head-dips in single-housed sham and OBX mice. In conclusion, we suggest that the single-housed OBX mice showed heightened emotional behavior (e.g., increase in head-dipping behavior) in the hole-board test. In addition, we suggest that the hyperemotional behavior characterized by head-dipping behavior in OBX mice was selectively reversed by benzodiazepine and non-benzodiazepine anxiolytics.

Antidepressant-like effect of quercetin in bulbectomized mice and involvement of the antioxidant defenses, and the glutamatergic and oxidonitrergic pathways

“…This evidence may be associated with reduced neurogenesis in depression (Atanasova et al, 2008;Negoias et al, 2010). Whereas temporary peripheral anosmia (inducible by zinc sulfate) does not cause behavioral changes (Cain, 1974;Calcagnetti et al, 1996), the destruction of the olfactory sensory receptors does not promote depressive symptoms, and only definitive structural injuries caused behavioral changes (Saitoh et al, 2006), authors argue that the OB model can also be used as a model of neurodegeneration Douma et al, 2012), since bulbectomy causes definitive interruption of neural connections present between the olfactory bulbs and other regions of the brain, particularly the olfactory-limbic circuit (Jesberger and Richardson, 1988).…”

Effects of milnacipran and fluvoxamine on hyperemotional behaviors and the loss of tryptophan hydroxylase-positive cells in olfactory bulbectomized rats

“…Similarly, OBX rats exhibited hyperemotional responses to given stimuli and a decrease in the time spent in the open arm of a plus-maze; these behavioral changes were reduced by subchronic treatment with the antidepressant desipramine for 7 days (Saitoh et al 2003). Thus, it was suggested that the evaluation of hyperemotional behaviors and the performance on a plus-maze in OBX rats may provide a suitable model for evaluating antidepressants (Yamaguchi et al 2002;Saitoh et al 2003Saitoh et al , 2006.…”

Bacopa monniera leaf extract up-regulates tryptophan hydroxylase (TPH2) and serotonin transporter (SERT) expression: Implications in memory formation

“…Hole-board apparatus was constructed and experiments conducted as described previously (Saitoh et al, 2006). Rat pups were randomly divided into two groups of 12 animals each.…”