Changes in locomotor activity and passive avoidance task performance induced by cerebral ischemia in Mongolian gerbils.

Abstract

We investigated changes in locomotor activity, passive avoidance task performance, and hippocampal CA1 neurons induced by cerebral ischemia in Mongolian gerbils to examine the relation between these behavioral changes and CA1 neuronal damage. Spontaneous locomotor activity was measured using the open field method before and 1, 3, 7, 14, or 28 days after 1- to 5-minute occlusion of the bilateral common carotid arteries. Locomotor activity after the second episode of 5-minute ischemia was also measured at 1-month intervals. The passive avoidance task was performed 7 or 28 days after induced ischemia. Histopathological changes in CA1 neurons after ischemia were assessed. Locomotor activity was increased 1 and 3 days after induced ischemia but not 14 and 28 days later. When the gerbils were again subjected to 5-minute ischemia 1 month after the initial 5-minute induced ischemia, locomotor activity even 1 day later was significantly increased. In contrast, passive avoidance impairment depended on the duration of ischemia, as determined 7 and 28 days after induced ischemia. Hippocampal CA1 neuronal damage was progressive, that is, changes in CA1 neurons were apparent even 1 day after 5 minutes of induced ischemia, and the CA1 neurons disappeared 7 days after 5 minutes of ischemia. Passive avoidance impairment after ischemia is related to damage of CA1 neurons. Changes in locomotor activity after induced ischemia do not seem to be linked to CA1 neuronal damage.

Liposome-Encapsulated Hemoglobin Ameliorates Impairment of Fear Memory and Hippocampal Dysfunction After Cerebral Ischemia in Rats

“…Previous studies have shown that at the first day after operation, the ischemia-induced increase in locomotor activity is most prominent. It decreases over the following two days, and at 5 -7 days after operation there is no difference between the controls and ischemic animals (39,40). In this study, as we conducted the open field test 8 days after occlusion, the present result regarding locomotor activity conforms to these previous reports.…”

Effect of Methamphetamine and Imipramine on Cerebral Ischemia-Induced Hyperactivity in Mongolian Gerbils

“…In addition, we surmised that this behavioral change induced by cerebral ischemia does not correlate directly with hippocampal damage. This is because we found that when Mongolian gerbils were subjected to 5-min ischemia again 1 month after the initial 5-min ischemia, which had caused complete degeneration of hippocampal CA1 neurons, locomotor activity even 1 day after was again significantly increased (15). Feeney and coworkers (35) reported a single dose of damphetamine given 24 h following unilateral sensorimotor cortex ablation in the rat resulted in an enduring enhancement of motor recovery.…”

“…The preparations were stained with hematoxylin-eosin and cresyl-violet by an investigator blind to the experimental conditions. Ischemic neuronal damage was graded on a scale of 0 -3 as follows: 0 (-), normal neurons; 1 (+), a few neurons damaged (as few as one neuron damaged); 2 (++), many neurons damaged; and 3 (+++), the majority of neurons damaged (15).…”

“…Although the delayed neuronal death in the hippocampal CA1 neuron is found 2 or 3 days after the transient ischemia, the hyperactivity can be seen from 2 or 3 h after the ischemia, reaches the peak 24 h later and continued for 7 days (15,16). It is conceivable that the abnormal release of neurotransmitters may be a trigger of ischemia-induced hyperactivity.…”

Alzheimer's Factors in Ischemic Brain Injury

“…Some spontaneous recovery of sensorimotor function has been demonstrated after brain ischemia . Following ischemic brain injury a locomotor hyperactivity has been noted for 7 days (Kuroiwa et al, 1991;Karasawa et al, 1994). Hyperactivity was directly connected with neuronal alterations in the ischemic hippocampus (Kuroiwa et al, 1991;Kiryk et al, 2011).…”