Clinical anesthesia causes permanent damage to the fetal guinea pig brain.

Exposure of the immature brain to general anesthesia is common. The safety of this practice has recently been challenged in view of evidence that general anesthetics can damage developing mammalian neurons. Initial reports on immature rats raised criticism regarding the possibly unique vulnerability of this species, short duration of their brain development and a lack of close monitoring of nutritional and cardiopulmonary homeostasis during anesthesia.

General anesthesia activates BDNF-dependent neuroapoptosis in the developing rat brain.

Brain-derived neurotrophic factor (BDNF) is important in supporting neuronal development. BDNF imbalance due to excessive neuronal inhibition can result in the apoptotic degeneration of developing neurons. Since general anesthetics cause profound depression of neuronal activity and are known to induce widespread degeneration in the developing brain, we studied their potential to activate BDNF-mediated developmental neuroapoptosis.

Melatonin reduces the severity of anesthesia-induced apoptotic neurodegeneration in the developing rat brain.

General anesthetics cause widespread apoptotic neurodegeneration in many regions of the developing rat brain. The activation of mitochondria-dependent apoptotic pathway is important in the early stages of anesthesia-induced developmental neuroapoptosis. To investigate potential means of protecting against this type of damage, we studied melatonin, a sleep-promoting agent and antioxidant known to inhibit apoptotic-type neuronal damage by improving mitochondrial homeostasis and stabilizing the inner mitochondrial membrane.

The anesthetics nitrous oxide and ketamine are more neurotoxic to old than to young rat brain.

Nitrous oxide (N2O) and ketamine are common general anesthetics and antagonists of N-methyl-D-aspartate (NMDA) glutamate receptors. In clinically relevant concentrations, they induce a psychotomimetic reaction in humans and pathomorphological changes in the rat brain. We have previously shown that ketamine and N2O in combination cause the neurotoxic reaction in young adult rat brain that is apparently synergistic.