Scientists have discovered the functions of the part of the brain where Alzheimer's disease begins, offering hope in the development of future treatments.

The first symptoms of the progressive disorder, which results from degeneration of memory networks in the brain, are problems remembering the things that have happened to us.

This type of memory - the recollection of previous experiences and their context in terms of time, place and emotions - is called episodic memory.

Experts have carried out research at St Andrews and Edinburgh universities, focusing on one of the first areas of the brain to show changes in Alzheimer's - the lateral entorhinal cortex (LEC).

The LEC is made up of layers of cells which form complex networks of connections with other brain regions and contains sub-systems that have different memory functions.

A research team, led by Dr Brianna Vandrey of Edinburgh University, found when a particular connection between one of the layers of the LEC and the hippocampus malfunctions, episodic memory is affected but simpler forms of memory remain unaffected.

Dr James Ainge, at the University of St Andrews' school of psychology and neuroscience said the research provides "a very specific target when developing treatments".

He said: "This research is important as it gives us a very specific target when developing treatments and strategies to prevent neurodegeneration in Alzheimer's disease."

Around 90,000 people in Scotland have dementia and it is estimated that 66% of them have Alzheimer's.