Serine Racemase

2022-04-26: reference:

Serine Racemase #

Catalyzes conversion of L-Serine to D-Serine, with P5P and [Magnesium] as cofactors.

• Serine Racemase Deletion Affects the Excitatory/Inhibitory Balance of the Hippocampal CA1 Network
  • neither isolated NMDAR synaptic potentials nor LTP were altered in SR-KO mice. This was associated with a compensatory increase in hippocampal levels of glycine
  • SR-KO mice displayed no deficits in spatial learning, reference memory and cognitive flexibility. On the other hand, SR-KO mice showed a weaker LTP and a lower increase in NMDAR otentials compared to controls when GABAA receptors were pharmacologically blocked.
  • Depletion of endogenous D-serine caused a reduced inhibitory activity in CA1 hippocampal networks, altering the excitatory/inhibitory balance, which contributes to preserve functional plasticity at synapses and to maintain related cognitive abilities.
• Sociality deficits in serine racemase knockout mice
  • Not impaired in a cognitive test, but they displayed abnomal, schizophrenia-like symptoms: Reduced social approach and social investigation.
  • Two identical objects were placed and mice were allowed to explore. SR-KO mice spent like 50% longer investigation. Then after a break, the familiar object and a novel object were placed. The ratio of time spent investigating the novel object vs familiar was like twice lower than control.
  • Similar evidence for increased social withdrawal and decreased social exploratory behavior in response to NMDA blockade has also been observed in human subjects