WT, homozygous, and heterozygous KO and KI mice on a conventional diet (1.71 mg/100 g thiamine) survive beyond six months without any signs of disease. Conversely, homozygous KO and KI mice on a thiamine-restricted diet (0.60 mg/100 g food) exhibit paralysis, weight loss, and immobility, succumbing within 12 and 30 days, respectively. On a more severely restricted diet (0.27 mg/100 g thiamine), these mice die within 14 and 18 days, respectively. Yet, WT and heterozygous KO and KI mice subjected to the same restricted diets survive over six months without disease symptoms^[2].

Thiamine monochloride (Vitamin B1) is crucial for converting food into cellular energy and supporting normal neuronal activities^[1].

Blood thiamine levels in homozygous knockout (KO) and knock-in (KI) mice on a standard diet at 7 weeks are reduced to 0.058±0.051 and 0.126±0.092 μM, respectively, compared to wild type (WT) mice, which show levels of 0.796±0.259 μM. Under a thiamine-restricted diet (0.60 mg/100 g food), the thiamine levels in WT, KO, and KI mice plummet to 0.010±0.009 and 0.010±0.006 μM at 5 and 14 days, respectively, versus 0.609±0.288 μM in WT mice. In brain homogenates of WT mice on a standard diet, thiamine concentrations are 3.81±2.18 nmol/g wet weight, compared to 1.33±0.96 and 2.16±1.55 nmol/g for KO and KI, respectively. For those on a thiamine-restricted diet for 5 and 14 days, thiamine levels in KO and KI mice's brain homogenates drop to 0.95±0.72 and 1.11±0.24 nmol/g, respectively, versus 3.65±1.02 nmol/g in WT mice, just before displaying disease symptoms^[2].