Effects of acute systemic 3-nitropropionic acid administration on rat activity and acoustic startle

Spontaneous activity, acoustic startle, and prepulse inhibition (PPI) of acoustic startle were measured in male Sprague-Dawley rats 3-5 h after 0, 10, 15, or 20 mg/kg i.p. 3-nitropropionic acid (3-NP), a mitochondrial toxin. Mean activity was significantly influenced by the 3-NP dose due to decreased activity for 20 mg/kg. Mean startle amplitude was not significantly affected by the 3-NP dose. Means of PPI for prepulses 6 and 12 dBA above background were smaller than means for respective 0 mg/kg doses, but the main effect of 3-NP dose did not reach statistical significance in ANOVA. The changes in measured exploratory-type activity and, possibly, in startle PPI parallel the occurrence of clinical signs exhibited at 3-5 h after 3-NP injection. Neural processing involved in these quantitative behavioral endpoints seems to be affected as energy stores are depleted and degenerative processes are beginning. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.