No spatial memory deficit exists in Kunming mice that recently recovered from motor defects following 3-nitropropionic acid intoxication / 神经科学通报·英文版

<p><b>OBJECTIVE</b>Numerous studies have described both motor defects and cognitive impairments in several strains of rodents following 3-nitropropionic acid (3-NP) intoxication. In the present study, we investigated spatial recognition memory in Kunming mice that just recovered from motor defects induced by 3-NP.</p><p><b>METHODS</b>Mouse model was made by systemic subacute 3-NP treatment, and spatial recognition memory was measured through the Y-maze Test, a simple two-trial recognition test.</p><p><b>RESULTS</b>(1) On day 15 following 3-NP treatment, affected Kunming mice did not show motor defects in the Rotarod test and presented normal gait again. (2) In the following Y-maze test after 1h interval, the percentage (90.0%) of mice showing novel arm preference in 3-NP treatment group was significantly higher than the random chance level (50%), although it was only slightly higher than that (83.3%) in control group. On day 45 after 3-NP treatment, mice failed to choose unfamiliar novel arm as first choice, and the same occured in the control group. (3) For both post-intoxicated (on day 15 and day 45 following 3-NP treatment) and control groups, the duration in the novel arm and the frequency of entering it, were longer and higher compared with familiar start and other arms. For these mice that recently recovered from motor defects following 3-NP intoxication, no spatial memory deficits were observed through Y-maze Test.</p><p><b>CONCLUSION</b>Kunming mice used in our assays might possess resistance to cognitive impairment induced by 3-NP, which is consistent with previous findings in Swiss EPM-M1 mice.</p>

Depressive-like behavior in mice recently recovered from motor disorders after 3-nitropropionic acid intoxication / 神经科学通报·英文版

<p><b>OBJECTIVE</b>Striatum may be involved in depressive disorders according to the neuroimaging analysis and clinical data. However, no animal model at present supported the possible role of striatum in the pathogenesis of depression. In the present study, we have investigated the depressive-like behavior in mice recently intoxicated with 3-nitropropionic acid (3-NP), a widely known toxin that selectively damages the striatum in the brain.</p><p><b>METHODS</b>Mouse model was made with subacute systemic 3-NP treatment, and the depressive-like behavior was measured using the duration of immobility during forced swimming test (FST).</p><p><b>RESULTS</b>When the mice at day 15 post-intoxication just totally recovered from motor deficits, the duration of immobility in FST was significantly longer than that in controls. The depressive-like behavior was not due to the fatigue or general sickness following 3-NP intoxication and could be reversed by the antidepressant, desipramine hydrochloride. In two successive FST in 24 h interval, the depressive-like behavior could be observed again in subsequent FST (at day 16 post-intoxication), and the mice presented a normal "learned helplessness".</p><p><b>CONCLUSION</b>A novel depression animal model could be established in mice during the initial period of recovery from 3-NP intoxication. The depression-like behavior might occur independently without involvement of cognitive defects, and the striatal lesions may underlie the depression-like behavior attributable to 3-NP intoxication.</p>