 Drugs that interfere with NMDA receptors block LTP and have major effects on some types of memory, especially spatial memory.Genetically modified mice that are modified to disable the LTP mechanism, also generally show severe memory deficits.Age-related conditions such as Alzheimer's disease and other forms of dementia (for which hippocampal disruption is one of the earliest signs) have a severe impact on many types of cognition including memory.