CHANGES IN CALBINDIN-CONTAINING NEURONS IN THE DORSAL HORN OF THE SPINAL CORD OF MICE AFTER SPACE FLIGHT IN BION-M1 BIOSATELLITE

Calbindin (CAB)-containing interneurons of the dorsal horn of upper thoracic segments of the spinal cord (SC) were studied with the use of immunohistochemistry and Western-blotting in male C57/BL6 mice (n = 3) after 30 days-long space flight in Bion-M1 biosatellite (“flight “group). The control group consisted of mice kept in a vivarium (n = 3). In the “flight “ group, the number of CAB-containing interneurons in laminae I and II was increased. Also, Western-blotting data showed that the expression of CAB in the SC increased after the flight. These results, as well as predominantly nuclear localization of СAB in neurons of laminae I-V, together with the lack of CAB immunoreactivity in interneurons of the medial edge of the dorsal horn, reduction of the average cross-sectional area of lamina II CAB-immunoreactive interneurons, an increase of the average cross-sectional area in CAB-immunoreactive interneurons of laminae III, IV and V in mice of the “flight “ group indicate an imbalance in the calcium buffer system of SC neurons after the space flight. It may be concluded that the calcium system of SC neuronal functional modules (primarily, of the motor module) undergoes substantial changes under conditions of the space flight.

spinal cord, dorsal horn, interneuron, calbindin, microgravitation