It has been observed that individuals who imbibe large quantities of ethanol may appear to be in conscious control of their behavior and may behave as if they have an intact memory, but on the following day after they have sobered up they have a blank memory for important events that they participated in during the inebriation episode. This phenomenon is referred to as a "blackout." It is most likely due to the important role that NMDA glutamate receptors play in memory. It has been shown that various drugs that block NMDA glutamate receptors interfere with the acquisition of memory. While under the influence of an NMDA receptor blocking drug, laboratory animals lose their ability to acquire new information and commit it to memory. However, they are still able to recall and act on information previously learned and committed to memory. Moreover, in the future when they are not under the influence of the drug they are able to acquire new information and commit it to memory. It has also been shown that NMDA receptor blocking drugs interfere with the phenomenon known as long-term potentiation (LTP), which is a synaptic mechanism that is thought to mediate memory functions. LTP has been studied extensively in the hippocampus, a brain region that is prominently involved in memory functions. It is well established that when NMDA glutamate receptors at synapses in the hippocampus are stimulated at a high frequency they become conditioned so that subsequent application of glutamate to the receptor elicits a much more robust (potentiated) response than if the receptor had not received the high-frequency stimulation. This conditioned status is referred to as LTP. Drugs that block NMDA receptors, including ethanol, interfere with the induction of LTP at hippocampal synapses. Thus, there is evidence at both a synaptic level and a behavioral level that ethanol, by its NMDA receptor blocking action, can interfere with memory functions in a way that would explain blackouts associated with heavy ethanol consumption. It is not known with certainty whether chronic heavy drinking with repetitive blackouts can result in permanent damage to memory mechanisms at a synaptic or molecular level or whether it entails only reversible effects on neural pathways that mediate memory function.

Alcohol No More

Alcohol No More

Do you love a drink from time to time? A lot of us do, often when socializing with acquaintances and loved ones. Drinking may be beneficial or harmful, depending upon your age and health status, and, naturally, how much you drink.

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