Qualitative analysis of scopolamine-induced amnesia

Abstract

The neurochemistry of memory remains to be determined. Acetylcholine may be one of the neuotransmitters which mediates memory function, since the anticholinergic drug scopolamine produces amnesia in man. This study of scopolamine-induced memory deficits further defines those cognitive processes which are disrupted. The drug does not diminish attention, as assessed with an auditory vigilance task, or initial signal detection. More complex auditory decoding is affected, however. Scopolamine impairs aspects of initial memory acquisition (e. g., encoding and consolidation) and spontaneous memory retrieval. Retention is unaffected. Precise delineation of the neurochemistry of human memory will require comparative studies of amnesia-producing compounds, systematically examining the neuropsychological processes impaired by each.

Free recall and recognition in a network model of the hippocampus: simulating effects of scopolamine on human memory function

“…For a similar reason, we have not yet attempted to replicate the apparent sparing of implicit memory in the presence of scopolamine [117]. Despite this absence of an effect on recency and digit span, scopolamine has been shown to clearly impair recall performance on the Brown -Peterson task, which tests the free recall of a consonant trigram after performance of a distractor task for short periods [30,118]. This suggests a difference in mechanism for the short-term memory of a Brown -Peterson task versus the shortterm memory involved in recency.…”

“…Only a few studies have addressed the effects of scopolamine on paired associates. Scopolamine impaired encoding of paired associates in section VI of the Wechsler memory scale [29] encoding of number-color associations [22], and memory for self-generated paired associates [30]. A recent study using very strong pre-existing category associations showed no impairment [31].…”

Estrogen Treatment Effects on Anticholinergic-Induced Cognitive Dysfunction in Normal Postmenopausal Women

“…Beginning with studies by Drachman and colleagues (Drachman, 1977;Drachman and Leavitt, 1974), temporary blockade of muscarinic receptors produced impairments of learning and memory that resembled changes associated with normal aging (Ghoneim and Mewaldt, 1977;Peterson, 1977). This has been proposed as a model of the cognitive deficits in AD (Bartus et al, 1982;Caine et al, 1981;Sitaram et al, 1978). These studies were extended by Sunderland and Newhouse Sunderland et al, 1985), who showed that when elderly normals and elderly depressed patients were given SCOP, their performance declined to a level similar to AD patients.…”

Pharmacological Modulation of Behavioral and Neuronal Correlates of Repetition Priming

“…Although cholinergic modulation of learning, and corresponding neuronal activity, has been shown in many explicit learning paradigms (Caine et al, 1981;Frith et al, 1984;Nissen et al, 1987;Rusted and Warburton, 1988;Curran et al, 1991a;Furey et al, 2000), its effects on behavioral measures in implicit paradigms is more controversial. Psychopharmacological and electrophysiological evidence suggests an absence of cholinergic modulation on repetition priming, because several studies found no behavioral (Danion et al, 1990;Knopman, 1991;Schifano and Curran, 1994) or neuronal ) modulation of repetition effects after administration of the cholinergic antagonist scopolamine.…”