Поведенческие и гормонально-метаболические характеристики самок крыс, селекционированных по длительности пассивно-оборонительной реакции

Abstract

The study was conducted on the female GC (Genetic Catatonia) rats selectively bred for the duration of the passive defensive response to the weak stimuli. Only male rats of this line were used in the previous studies, therefore the aim of this study was to characterize the behavioral, hormonal and metabolic parameters of the female GC rats, and to elucidate the specific properties of their estrous cycle synchronization. We determined the estrous cycle phases using the vaginal smear classification. Other parameters were recorded in the running wheel: the turn and rocking counts, the overall motor activity (amount of runs, grooming, vertical postures, and occurrences on the central axis of the running wheel), and the excitability level in response to an auditory stimulus. We also assayed the progesterone, estradiol, cholesterol, and triglycerides blood levels. Based on the obtained results, we confirm the passive response type and elevated anxiety in female GC rats. The GS rats demonstrated lower fertility and lower body weight in comparison with the Wistar rats. The progesterone blood level was elevated in the proestrus phase in GC rats. The female GC rats demonstrated similarly low triglyceride blood level to the male rats of the same line. The progesterone levels in the synchronized phase were higher than in the unsynchronized one in both GC and Wistar rats. These data show that the selective breeding for the passive defensive response in GC female rats is associated with the moderate stress reactions, changes in the hormonal and metabolic profiles, and decreased fertility.