Aim. To describe the morphological features of GFAP-positive cells in the basal magnocellular nucleus (BMN) of the rat brain of experimental rats under conditions of early pathogenetically substantiated correction of colchicine-induced neurodegeneration using citicoline, thiocetam, and HSF-1.

Materials and methods. Fifty male Wistar rats were divided into five groups (n = 10) as follows: group 1 – rats with intracerebroventricular (ICV) administration of 0.9 % NaCl (37 °C) (control); group 2 – rats with ICV administration of colchicine; group 3 – ICV colchicine followed by correction with citicoline; group 4 – ICV colchicine followed by correction with thiocetam; group 5 – ICV colchicine followed by correction with HSF-1. After 14 days of correction, the animals were withdrawn from the experiment by single-stage decapitation under anesthesia, after which the brain was immediately removed for subsequent standard histological processing and immunofluorescent analysis of GFAP-positive cells in the BMN.

Results. Colchicine administration (Group 2) induced maximum astrocyte activation in the BMN: cell density increased by 56.3 %, area by 254.5 %, and GFAP expression by 193.4 %, while the number of processes decreased by 75.0 % and their length increased by 18.8 %. The administration of neuroprotective agents (groups 3–5) significantly limited these changes compared to untreated animals. HSF-1 correction demonstrated the highest efficacy, reducing cell area by 39.6 % and 56.2 %, and GFAP expression by 16.8 % and 45.6 % compared to the citicoline and thiocetame groups, respectively. Furthermore, the therapy prevented the sharp reduction in process count and their pathological elongation.

Conclusions. In the basal magnocellular nucleus of experimental animals, hypertrophy and hyperplasia of astrocytes with increased GFAP expression and altered process morphology (elongation and reduced number) were observed on day 14 after intracerebroventricular colchicine injection. Early pathogenetically substantiated correction with citicoline, thiocetam and HSF-1 significantly reduced the indicators of GFAP+ astrocyte activation (density, area, and cytoskeletal protein expression) in the basal magnocellular nucleus compared with untreated animals; however, these parameters remained elevated relative to sham-operated controls. In the basal magnocellular nucleus, neuroprotective intervention with citicoline, thiocetam, and HSF-1 prevented the development of process-related morphological patterns characteristic of rats following intracerebroventricular colchicine injection, although the resulting changes did not reach the levels observed in sham-operated animals.