Deficits in cognition and working memory accompany several neurological and neuropsychiatric disorders. Effective treatment of these symptoms is of paramount importance for full recovery and for improving medication compliance. Similar concerns have now been directed towards the treatment of substance abuse. Abused drugs from different classes have been associated with impairments in cognition and working memory. Cognition impairment is clearly an impediment to treatment and to the maintenance of abstinence. We have been studying a small library of analogs of choline that were originally characterized based on their cytoprotective actions. Two lead compounds have been characterized as excellent cognition-enhancing agents with the ability to improve working memory, attention, and sensory gating in primate and rodent models. These exciting new compounds evoke their pharmacological actions by a unique mechanism: desensitization of nicotinic cholinergic receptors without the antecedent activation. Many analogs are potent in their actions but have thus far exhibited no overt side effects or toxicity. In addition we have characterized reversible pharmacological models for impairments in working memory in monkeys utilizing ketamine (hallucinogen);nomifensine (cocaine/amphetamine-like activity);and amitriptyline (biogenic amine uptake inhibitor/anticholinergic). In rodents we use a cognitive task battery that also includes estimation of working memory, attention and sensory gating. Combining these models we expect to establish a characteristic pattern of choline analog-induced task improvements that suggest broad activity in the clinical setting of cognitive impairment, including substance abuse. Therefore we propose a drug discovery project with the central hypothesis that analogs of choline can improve aspects of working memory, attention, and sensory gating for use as adjuncts in the treatment of substance abuse. We plan to evaluate 40 analogs of choline belonging to 4 primary chemical classes in rodent models of working memory, attention, and sensory gating. Ten of these will progress to studies in rat models of chronic morphine, cocaine, and nicotine self-administration. Subjects have access on a 24 hr basis, and they can be tested for impairments in working memory after chronic self-administration and during acute withdrawal and protracted withdrawal. These same 10 compounds will be evaluated in macaque models of reversible pharmacological impairment in working memory as indicated above. These studies could lead to a ground-breaking advance towards a new pharmacological approach for the treatment of drug addicts, and for treating other types of addictive behaviors. In addition to cognitive improvement, choline analogs could also prevent the neural toxicity associated with the chronic abuse of several addictive substances.
Abused drugs from different classes have been associated with impairments in cognition and working memory. Cognition impairment is clearly an impediment to treatment and to the maintenance of abstinence. We have been studying a small library of analogs of choline that were originally characterized based on their cytoprotective actions. These exciting new compounds evoke their pharmacological actions by a unique mechanism: desensitization of nicotinic cholinergic receptors without the antecedent activation. We propose a drug discovery project with the central hypothesis that analogs of choline can improve aspects of working memory, attention, and sensory gating for use as adjuncts in the treatment of substance abuse. We plan to evaluate 40 analogs of choline ten of which will progress to studies in rat models of chronic morphine, cocaine, and nicotine self-administration. They also will be evaluated in macaque models of reversible pharmacological impairment in working memory as indicated above. These studies could lead to a ground-breaking advance towards a new pharmacological approach for the treatment of drug addicts, and for treating other types of addictive behaviors. In addition to cognitive improvement, choline analogs could also prevent the neural toxicity associated with the chronic abuse of several addictive substances.
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