What is the role of the perirhinal cortex in memory - Essay Example

Short-term memory is represented in the frontal and temporal cortices (Rolls, 2000). The perirhinal cortex is involved in consolidation and retrieval of memory (Biella et al, 2001). (Sweat, 2003). Information on various direct and indirect sensory inputs like the later stages of visual processing, hearing sensations, somatosensory sensations and the olfactory sensations reach the hippocampus and dentate gyrus via the perirhinal and entorhinal cortices, which are close to the hippocampus in the temporal lobe near the rhinal fissure.

The output information travels back using the same route in reverse manner. So we can conclude that the hippocampus and its associated cortices (perirhinal and entorhinal) are involved in the processing of cognition and memory (Sweatt, 2003). This memory of distinguishing spaces and positions and their relationships is possible through the hippocampus and the perirhinal and entorhinal cortices. In the Morris water maze learning, the various decisions taken by the animal depends on its memory of previous experiences (Sweatt, 2003).

Contextual fear conditioning helps it to decide whether a place is bad or not. The difference in the places is determined by context discrimination. Learning the number of right and left turns and the sequence in which the animal has to take these to go through the maze is also determined at the hippocampus level with its neighborhood cortices. EEG recordings show the firing at the hippocampus and neighborhood when the animal is exploring a new maze. Saunders and his colleagues (2005) investigated the pathways that the projections, from the perirhinal and entorhinal cortices to the medial thalamus, take in macaque monkeys.

The projections from the entorhinal cortex, parasubiculum, presubiculum and area 35 of the perirhinal cortex reached the anterior ventral nucleus of the thalamus. Denser projections from the presubiculum and parasubiculum reached the lateral dorsal nucleus through the