Hippocampal Area CA2: An Overlooked but Promising Therapeutic Target

While the hippocampus has long been recognized as a brain structure specialized in mapping ‘space’ in rodents, human studies and now recent data from rodents have shown that its function extends well beyond spatial coding. Recently, an overlooked area of the hippocampus, CA2, has emerged as a critical region for social memory. This area is also uniquely altered during several pathologies such as schizophrenia and age-related dementia. Because of its singular connectivity, we propose that area CA2 resides at the interface between emotional brain activity and higher cognitive function. Furthermore, because of the unique expression of multiple neuromodulator receptors in area CA2, we posit that this region may represent a fruitful therapeutic target for diseases where social dysfunction occurs.

TrendsThe hippocampal CA2 area of the brain displays unique properties and connectivity that may be linked to disease.CA2 pyramidal neurons play a crucial role in the formation of social memory.Inhibitory neurons are highly concentrated in area CA2 and are uniquely altered in the hippocampus during several neurological disorders.The CA2 area is preferentially altered during schizophrenia and neurodegenerative diseases, and may be responsible, at least in part, for the social memory dysfunction phenotype in these diseases.