The Effects of Prenatal Exposure to Pregabalin on the Development of Ventral Midbrain Dopaminergic Neurons

Abstract

Pregabalin is widely used as a treatment for multiple neurological disorders; however, it has been reported to have the potential for misuse. Due to a lack of safety studies in pregnancy, pregabalin is considered the last treatment option for various neurological diseases, such as neuropathic pain. Therefore, pregabalin abuse in pregnant women, even at therapeutic doses, may impair fetal development. We used primary mouse embryonic neurons to investigate whether exposure to pregabalin can impair the morphogenesis and differentiation of ventral midbrain neurons. This study focused on ventral midbrain dopaminergic neurons, as they are responsible for cognition, movement, and behavior. The results showed that pregabalin exposure during early brain development induced upregulation of the dopaminergic progenitor genes Lmx1a and Nurr1 and the mature dopaminergic gene Pitx3. Interestingly, pregabalin had different effects on the morphogenesis of non-dopaminergic ventral midbrain neurons. Importantly, our findings illustrated that a therapeutic dose of pregabalin (10 μM) did not affect the viability of neurons. However, it caused a decrease in ATP release in ventral midbrain neurons. We demonstrated that exposure to pregabalin during early brain development could interfere with the neurogenesis and morphogenesis of ventral midbrain dopaminergic neurons. These findings are crucial for clinical consideration of the use of pregabalin during pregnancy.

Keywords: embryonic neurons; neuropathic pain; pregabalin; ventral midbrain dopaminergic neurons.

Figure 1

Illustration showing the experimental design for the present study.

Figure 2

Demonstration of viability (A) and ATP release (B) in the pregabalin-treated and control cultures. Data are represented as mean ± SEM, n = 7 experiments. * p < 0.05.

Figure 3

Pregabalin induced the elongation in TH+ vmDA neurons’ total neurite length (A) and dominant neurite length (B), but there was no significant effect on the number of branches (C) or neurites (D). Representative images and illustrations for vmDA neurons immunolabeled with TH in both groups; control (E,E’) and pregabalin-treated (F,F’) groups showed an increase in neurite elongation in response to pregabalin exposure. Scale bar: 50 μm. Data are represented as mean ± SEM, n = 4 experiments. * p < 0.05.

Figure 4

Pregabalin exposure did not affect the total neurite length (A) nor the dominant neurite length (B), while the number of branches (C) and neurites (D) were significantly increased in VM non-dopaminergic neurons (TUJ1+/TH−). Representative images and illustrations for VM neurons immunolabeled with TUJ1 in both groups; control (E,E’) and pregabalin-treated (F,F’) groups showed increases in the numbers of branches and neurites in response to pregabalin exposure. Scale bar: 50 μm. Data are represented as mean ± SEM, n = 4 experiments. * p < 0.05.

Figure 5

Pregabalin exposure caused a significant upregulation in the expression of Lmx1a (A), Nurr1 (B), Pitx3 (D), Drd2 (G), Dat (H), and Bdnf (I), but there was no significant change in the expression of En1 (C), Th (E), or Chl1 (F). Data are represented as mean ± SEM, n = 3 experiments. * p < 0.05, ** p < 0.01.