Trisynaptic Circuit

Hippocampal-Cortical Circuitry

AMNESIA…… …………..NOT A SOAP OPERA

Table 2. Anterograde memory test performance E. P.Control means (n = 8) Two-choice recognition memory Words (50) Faces (50) Complex design Copy (36) Recall (36)020.6 Paired-associate learning Trial 1 (10)06.0 Trial 2 (10)07.6 Trial 3 (10)08.9 Prose recall No delay (21)37.6 Delay (21)06.4 The mean scores for control subjects for these tests are from Squire and Shimamura (1986). The two-choice recognition memory scores are based on a 24 hr recognition test of 50 words or 50 faces (modified from Warrington, 1984; maximum score, 50; chance, 25). The complex design test score is based on the copy and delayed (12 min) reproduction of the Rey-Osterrieth figure (Osterrieth, 1944; maximum score, 36; see also Figure 6). The paired-associates scores are the number of word pairs recalled on three successive trials (maximum score, 10/trial). The Prose recall scores are based on the number of segments recalled from a short prose passage that was read to the subjects. Recall was tested immediately and after 12 min. Note that the no-delay test requires recall of more information than can be retained in immediate memory, and amnesic patients often obtain impaired scores on this test.

Hypoxia; hippocampus: Another area of selective vulnerability is the hippocampus. In this slide the hippocampus is shrunken, cavitated and discolored, the result of a severe episode of hypoxia. Next Slide will show a damaged hippocampus…..

Korsakoff’s Syndrome – Degeneration of Mammillary Bodies

Recall of famous faces

Basal Ganglia

Rat hippocampus

Hippocampal place field

‘Cognitive Map’ Dostrovsky & O’Keefe (1971)

Frontal Cortex

Prefrontal cortex neurons (Working memory)

Hippocampal & subicular recording

DNMS- neural recordings Hampson & Deadwyler, 2003