Melasma Causes. Melasma is usually caused by the sun, hormones in birth control pills, hormone replacement therapy, medications and pregnancy. When Melasma is caused by pregnancy it is called chloasma. In some women, when the skin is exposed to sunlight, brown blotches of excess pigment form due to the interaction with hormones or chemicals. Melasma is believed to be hereditary and woman with darker skin tones tend to be more at risk for this disorder.
Some research suggests that the hippocampus may participate only in consolidation processes lasting a few years. The entorhinal cortex, on the other hand, gives evidence of temporally graded changes extending up to 20 years, suggesting that it is this region that participates in memory consolidation over decades. The entorhinal cortex is damaged in the early stages of Alzheimerâs disease.
Though the hippocampus is an essential brain structure for the proper functioning of long-term memory, it cannot be regarded as the âmemory centreâ in the same sense that the occipital cortex, for example, can be regarded as the centre for processing visual information.he hippocampus is a very old part of the cortex, evolutionarily, and is located in the inner fold of the temporal lobe. All of the pieces of information decoded in the various sensory areas of the cortex converge in the hippocampus, which then sends them back where they came from.