Effect of emotional stress on biogenic amine content in the sensorimotor cortex of rats with experimental intracerebral hemorrhage.

Experiments on the model of an aggressive-conflict situation were designed to study the effect of emotional stress on biogenic amine content in the sensorimotor cortex of the right cerebral hemisphere in behaviorally active and passive rats with experimental hemorrhage in the left caudate nucleus of the brain. Prior exposure to stress in active and, particularly, in passive animals was shown to modify the type of neurochemical reactions in brain tissue during modeling of intracerebral hemorrhage. As differentiated from rats with experimental hemorrhagic stroke, passive specimens of this series were characterized by a slight increase in norepinephrine content and significant elevation of dopamine level in the sensorimotor cortex on day 3 of the study. An increase in dopamine content in brain tissue of stressed active rats was observed on days 1 and 3, which corresponded to the immediate and acute stages of the post-stroke period. Variations in serotonin content in the sensorimotor cortex of animals with post-stress intracerebral hemorrhage had the same dynamics, but were less pronounced than in non-stressed rats. Our results illustrate the specific involvement of brain biogenic amines in animals with various behavioral characteristics in the adaptive and compensatory processes, which occur during various stages of experimental intracerebral hemorrhage after stress exposure.

Specific features of biogenic amine content in the cerebral cortex during experimental intracerebral hemorrhage in rats with various behavioral characteristics.

Experiments on Wistar rats showed that modeling of hemorrhage in the left caudate nucleus of the brain in behaviorally passive specimens is mainly accompanied by an increase in biogenic amine content in the sensorimotor cortex of the right cerebral hemisphere (particularly on day 3 after the surgery). Norepinephrine content in the sensorimotor cortex of the right cerebral hemisphere in behaviorally active rats was reduced over 7 days after the development of intracerebral hemorrhage. The contents of dopamine and serotonin in brain tissue of behaviorally active animals most significantly increased on day 7 after experimental stroke. Our results indicate that experimental hemorrhage in the left caudate nucleus of rats with various behavioral characteristics is accompanied by specific changes in biogenic amine content in the sensorimotor cortex of the right cerebral hemisphere. We conclude that neurochemical processes in brain structures distant from the site of hemorrhage play an important role in the pathogenesis of hemorrhagic stroke.

[Stress effect on the development of hemorrhagic stroke].

The objective of this work was to study how stress, activity in the open field test, and conformational properties of albumin-binding sites are associated with experimental hemorrhagic stroke in rats. The open-field behavioral pattern in rats was characterized by the previously developed by us activity index. In accordance with this activity index, rats were divided into two groups, i.e., active and passive animals. The animals were subjected to experimental hemorrhagic stroke with or without previous emotional stress. It was shown that the previous stress affected the stroke development. Stress loading before experimental stroke changed albumin conformational properties in rats with active and passive behavioral patterns in different ways. It was associated with different ability of the albumin globule to undergo pH-induced transition N-F and in different accessibility of albumin-bound fluorescent probe CAPIDAN to nitrate-induced fluorescence quenching.

[Emotional stress in the development of experimental hemorrhagic stroke in rats with different resistance to stress].

Individual behavioral characteristics of rats in the open-field test reflect their resistance to emotional stress and determine the severity of neurological disorders during intracerebral hemorrhage. Stress-resistant rats are characterized by a more rapid restoration of neurological status and disappearance of locomotor and coordination disturbances on day 7 after unilateral hemorrhage stroke in the caudate nucleus as compared to stress-predisposed animals. After hemorrhage stroke in the caudate nucleus, changes in vessels and neurons of the contralateral sensorimotor cortex were more pronounced in stress-predisposed passive rats than in stress-resistant active animals. The newly formed capillaries were not seen in stress-predisposed specimens. To day 7 of post stress hemorrhage stroke in the caudate nucleus, signs of the involvement of compensatory mechanisms in the contralateral sensorimotor cortex appeared in stress-resistant but not in stress-predisposed rats. This finding suggests the possibility of restoration of structure and normal functioning of neurons.