Effect of prenatal hyperhomocysteinemia on the development of NMDA receptors in the hippocampus in the early postnatal period

Homocysteine is a sulphur-containing amino acid synthesised from methionine. An increase in homocysteine concentration during pregnancy has been linked to an elevated risk of neuropathological diseases. The hippocampus, which plays a pivotal role in numerous functions, represents a crucial area of focus in understanding the effects of hyperhomocysteinemia. This study aimed to investigate the impact of prenatal hyperhomocysteinemia on the development of NMDA receptors in the early postnatal period. The experiment was conducted on Wistar rats. Pups with prenatal hyperhomocysteinemia were born from females who received daily methionine with food. Horizontal slices of the hippocampus were obtained from the rats at age P10-11. CNQX and bicuculline were used to block AMPA and GABA receptors, respectively. The whole-cell patch clamp method was employed to record evoked responses. The stimulation protocol comprised five bursts of five pulses at a frequency of 100 Hz, with an interval of 200 ms between bursts. Biexponential analysis was employed to analyse the decay phase, resulting in a significant reduction in the fast component of decay and an increase in the slow component of decay in the experimental group compared to the control group. Concurrently, no considerable alterations in the amplitudes of peaks normalised to the first peak were observed. The results may indicate a change in the subunit composition of hippocampal NMDA receptors, which may indicate a disruption in the transition from GluN2B and GluN2D (slow) subunits to GluN2A (fast).