Summary: An artificial neural network has identified a potential mechanism for the impaired decision-making often seen in schizophrenia patients, which involves the reduced activity of NMDA receptors.
Higher doses of ketamine administered to sheep completely reduced brain activity for a short period. Researchers report as the drug wore off and consciousness was regained, the animals' brain activity switched between high and low-frequency oscillations. The timing of the brain activity corresponds to the time human users report experiencing feelings that their brain 'disconnected' from their bodies after ketamine use.
NMDA receptor hypofunction is involved in the reduction of sleep spindles and delta oscillations, which appear in the brain during deep natural sleep. Findings confirm the role NMDA receptors play in sleep disorders that accompany psychotic states.
Brain connections strengthened with treatment from fast-acting antidepressants, such as ketamine, are consolidated during deep sleep. Researchers propose rapid antidepressant treatments share the ability to regulate both synaptic potentiation and homeostatic mechanisms, which may contribute to how the brain reorganizes its activity to defeat depression.
A single shot of ketamine administered to heavy drinkers following reactivation of their drinking memories led to a rapid decrease in the urge to drink. The effect lasted for over nine months.
The side effects of administering ketamine to treat major depressive disorder are mild and persist for no longer than four hours, researchers report. Most of the side effects peaked within an hour of treatment, and many patients reported the effects as being significantly reduced two hours post ketamine administration.
Ketamine reduced alcohol intake in male rat models of alcohol use disorder but increased the desire for alcohol in low-consumption females.
35% of patients who used ketamine to manage pain reported significant side effects ranging from hallucination, out-of-body experiences, visual disturbances, and urinary dysfunction. 20% of the side effects were linked directly to ketamine, and 15% associated with ketamine in combination with other drugs.