introduction: the glutamatergic system plays an important role in learning and memory. administration of crocus sativus (saffron) or its constituent, crocin, facilitates the formation of memory. this research investigated the effect of crocin on antagonizing retrograde amnesia induced by ketamine, a glutamatergic receptor antagonist, in rats by shuttle box. methods:  male wistar rats were teste...

introduction: the n-methyl-d-aspartate (nmda) receptors, which have been implicated in memory formation, could be noncompetitively blocked by ketamine. the present study examines the short term effect of ketamine on induction of anterograde and retrograde amnesia in male rats using morris water maze (mwm). methods: male n-mri rats were randomly divided into nine experimental groups. mwm studies...

We describe a form of amnesia, which we have called visual memory-deficit amnesia, that is caused by damage to areas of the visual system that store visual information. Because it is caused by a deficit in access to stored visual material and not by an impaired ability to encode or retrieve new material, it has the otherwise infrequent properties of a more severe retrograde than anterograde amn...

Patients with mild to moderate Alzheimer's disease and normal controls were tested on a retrograde amnesia test with semantic content (Neologism and Vocabulary Test, or NVT), consisting of neologisms to be defined. Patients showed a decrement as compared to normal controls, pointing to retrograde amnesia within semantic memory. No evidence for a gradient within this amnesia was found, although ...

A case of transient global amnesia was studied in detail. Of note was a temporally extensive, although quite patchy, retrograde amnesia during the event for information recallable at other times. While a consolidation block can explain the anterograde amnesia in transient global amnesia, the profound retrograde amnesia requires an additional block in the retrieval of old, established memories.

Two patients with presumed hippocampal formation lesions and two patients with more extensive temporal lobe damage, all of whom became amnesic in a known year, were given tests of anterograde and retrograde memory function. The two patients with hippocampal formation lesions had moderately severe anterograde amnesia and limited retrograde amnesia for facts and events that affected, at most, the...

angiotensin-ii is a multifunctional hormone that regulates blood pressure, plasma volume, neuronal functions, electrolyte balance, thrust and various other vital mechanisms. it acts through its receptors at 1 and at 2 . the involvement of angiotensin-ii and its receptors in cognition is still ambiguous. therefore, the present study was designed to investigate the effect of angiotensin-ii (2 μg/...

The phenomenon of retrograde amnesia has important implications for understanding normal memory as well as its neural organization. Using 6 tests of remote memory, we evaluated the extent and severity of retrograde amnesia in 2 groups of amnesic patients-7 patients with alcoholic Korsakoff’s syndrome and 5 other patients with amnesia (anoxia or ischemia, N = 3; thalamic infarction, N = 1; unkno...