exceptional autobiographical memory

http://edition.cnn.com/2008/HEALTH/conditions/05/07/miraculous.memory/index.html?eref=rss_topstories

Give Brad Williams a date, and he can usually tell you not only what he was doing but what world events happened that day. He can do this for almost every day of his life.
Brad Williams has hyperthymestic syndrome, experts say, and remembers what he did on allmost every day of his life.
Williams is one of only three people in the world identified with this off-the-charts autobiographical memory, according to researchers at the University of California-Irvine who gave the condition its name: hyperthymestic syndrome, from the Greek words for excessive (hyper) and remembering (thymesis).

Man with virtually no memory

From http://scienceblogs.com/neurophilosophy/2007/09/life_without_memory.php

YouTube video of Clive Wearing who has anterograde amnesia, and incapable of forming new memories. He also has retrograde amnesia with nearly all his past episodic memories wiped out. An infection damaged his hippocampus, + frontal and temporal lobes. He is left mainly with just his consciousness of his own existence.

Sack’s article:

http://www.newyorker.com/reporting/2007/09/24/070924fa_fact_sacks

Protein injection erases long term memory in rats

Science 17 August 2007:
Vol. 317. no. 5840, pp. 951 – 953
DOI: 10.1126/science.1144334

Rapid Erasure of Long-Term Memory Associations in the Cortex by an Inhibitor of PKM{zeta}

Little is known about the neuronal mechanisms that subserve long-term memory persistence in the brain. The components of the remodeled synaptic machinery, and how they sustain the new synaptic or cellwide configuration over time, are yet to be elucidated. In the rat cortex, long-term associative memories vanished rapidly after local application of an inhibitor of the protein kinase C isoform, protein kinase M zeta (PKM{zeta}). The effect was observed for at least several weeks after encoding and may be irreversible. In the neocortex, which is assumed to be the repository of multiple types of long-term memory, persistence of memory is thus dependent on ongoing activity of a protein kinase long after that memory is considered to have consolidated into a long-term stable form.