Unilateral injury of the sensorimotor cortex of the dominant or subdominant hemisphere in female Wistar rats determines the neurological and immune statuses of their offspring

Abstract

The modulating effect of the central nervous system (CNS) on the pattern of immune responses is now generally acknowledged. Disturbances in one system cause pathological changes in the other one. A unilateral injury of the brain shifts the equilibrium between the right-and left-hemispheric peptide factors in neuroendocrine structures, which, in turn, induces the functional asymmetry of motor functions [1]. The side of cerebral injury determines the pattern of the changes in immune reactivity; e.g., lymphocyte proliferation rate is enhanced in right-sided strokes and suppressed in left-sided ones [2]. Earlier, it was demonstrated that the changes in the motor, behavioral, and immune reactions of the offspring of ambidextrous female rats depended on the laterality of the injury in the brain of the mother [3]. Since animal nervous and humoral responses to injury and stress are determined not only by function laterality, but also by hemispheric dominance [4, 5], we searched for immune and motor disorders characteristic of young offspring of "righthanded" and "left-handed" female rats with injuries in the cerebral hemisphere dominant or subdominant with respect to motor preference. MATERIALS AND METHODSMotor preference in female Wistar rats was determined after a 48-h food deprivation by the method of Peterson [6] based on the preferential use of one of the legs in food-procuring activity. The rats that all of the ten times took hold of the food with the same (left or right) foreleg were conventionally regarded as left-and right-handed, respectively. One month before conception ( n = 12), the fragment of the sensorimotor cortex (1.0 × 2.0 mm in size) whose electric stimulation caused the flexion of the contralateral hind leg (injured side, IS) was extirpated from the right or left hemisphere. The opposite hemisphere was regarded as a conventionally healthy side (CHS). After the end of experiments, morphological examination was performed to select females with cortical lesions.The electromyographic (EMG) parameters of the frequencies of the spontaneous and electrically stimulated activities of hind-leg muscles (mm. tibialis ant. and mm. gastrocnemius) were recorded in the 30-to 35-day-old offspring (i.e., during the postnatal period) according to the method developed earlier [3].The functional activity of T lymphocytes was determined in one-month-old rats by means of the migration suppression test using peripheral blood leukocytes in flat five-channel capillaries in the presence of 20 µ g/ml PHA (Sigma, United States) or Con A (Sigma, United States) according to Artemova [7]. We used heparinized (50 U/ml) peripheral blood of one-month-old rats. The activity of natural killer (NK) cells was determined using a cytotoxic test for the lysis of target cells (TCs) labeled with [ 3 H]uridine. Human myeloleukemia cell line K-562 was used as TCs; and suspensions of rat splenocytes were used as tested effector cells (ECs).The experimental groups for estimating EMG parameters ( n 1 ) and immune reactivity ( n 2 ) consisted of the...