A latrophilin/CL-1-like GPS domain in polycystin-1

The roles of different structures Limbic and frontal structures are best thought of as mediating declarative memory but what role do these different structures play in the process of memory? The hippocampus is divided into four ‘fields’ and one of these, CA1, receives inputs from all parts of the prefrontal cortex. Moreover, neurons in CA1 have a very high degree of interconnectivity. Memory for an event is thought to represent the integration of different aspects of information and, although there is no direct proof, it is thought that CA1 provides the anatomical basis and that other parts of the hippocampal formation ‘fix’ a particular event and then mediate storage of that event in the temporal cortex. Far less is known about the function of diencephalic structures in memory but one idea is that these are involved in encoding information which enables the time-based characteristics of a memory to be established. The frontal lobes are generally thought to be involved in more ‘strategic’ aspects of memory. These strategic processes involve the operations used to determine what aspects of an event are encoded and those that control how memories are retrieved. Thus, studies of patients with frontal lesions have shown that their free recall of information is often poor but improves dramatically with prompting. Also their learning processes often reveal a failure to attend to the most relevant aspects of an event. There is also evidence that the pre-frontal cortex is crucial for determining the truth of memories because, quite often in frontal lobe damage, patients suffer from ‘illusory memory’ or ‘confabulation’ in which they tend to remember things that have not actually happened. It should be obvious that the study of human memory is complex, not least because the problems can be approached on two fundamentally different levels — the biological and the psychological. There is progress in both these domains but it will be a long time before they come together to provide a single explanation of human memory.