Table 2. The mean concentrations of oxytocin and serotonin in horse blood plasma for different degrees of fearfulness in horses
Neurotransmitters
Degree of fearfulness
Low (n = 13)
Medium (n = 5)
High (n = 11)
OXT (pg/mL)
47.33 ± 2.42
46.13 ± 2.53
41.16 ± 1.92
5-HT (ng/mL)
94.54 ± 5.99
103.19 ± 7.39
82.85 ± 6.06