Publications by authors named "Ashok Tehim"

Rationale: Disturbances in information processing and cognitive function are key features of schizophrenia. Nicotinic α7 acetylcholine receptors (α7-nAChR) are involved in sensory gating and cognition, thereby representing a viable therapeutic strategy.

Objectives And Methods: We investigated the effects of GTS-21, an α7-nAChR partial agonist, on prepulse inhibition (PPI) of acoustic startle in two pharmacologic impairment models in Wistar male rats: NMDA-glutamate receptor antagonism by MK-801 and dopamine receptor agonism by apomorphine.

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Neuronal nicotinic α7 acetylcholine receptors (α7nAChRs) are expressed primarily in the brain and are implicated in modulating many cognitive functions (e.g., attention, working and episodic memory).

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Varenicline, a partial alpha4beta2 and full alpha7 nicotinic receptor agonist, has been shown to inhibit nicotine self-administration and nicotine-induced increases in extracellular dopamine in the nucleus accumbens. In the present study, we investigated whether varenicline inhibits nicotine-enhanced electrical brain-stimulation reward (BSR), and if so, which receptor subtypes are involved. Systemic administration of nicotine (0.

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An effective treatment for age-related cognitive deficits remains an unmet medical need. Currently available drugs for the symptomatic treatment of Alzheimer's disease or other dementias have limited efficacy. This may be due to their action at only one of the many neurotransmitter systems involved in the complex mechanisms that underlie cognition.

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A series of N-[(3S)-1-benzylpyrrolidin-3-yl]-(2-thienyl)benzamides 8 has been prepared and found to bind with high affinity to the human D(4) (hD(4)) and 5-HT(2A) receptors. Several compounds displayed selectivity for these receptors versus hD(2) and alpha(1) adrenergic receptors of over 500-fold.

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A series of N-(1-benzylpyrrolidin-3-yl)arylbenzamides 8 has been prepared, and their structure-activity relationships studied. Potent ligands selective for human D(4) (hD(4)) over hD(2) and alpha(1) have been identified. One example was determined to be an antagonist in a cAMP assay, with an IC(50) of 1500 nM.

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A series of 3-(2-pyrrolidin-1-ylethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives (2) has been prepared using parallel synthesis techniques, and their structure-activity relationships studied. High affinity human 5-HT(1B/1D) (h5-HT(1B/1D)) ligands have been identified.

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A novel series of highly potent human 5-HT(1D) agonists, dimethyl-[2-[6-substituted-indol-1-yl]-ethyl]-amine, was synthesized. Structure-activity relationship (SAR) investigation revealed 4-[1-(2-dimethylamino-ethyl)-1H-indol-6-yl]-tetrahydro-thiopyran-4-ol, 11b (ALX-2732), as a potent (K(i)=2.4 nM) agonist at the human 5-HT(1D) receptor with good selectivity over the other serotonin receptor subtypes.

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A series of (R)-3-(N-methylpyrrolidin-2-ylmethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives (2) have been prepared using parallel synthesis, and their structure-activity relationship studied. High affinity human 5-HT(1B/1D) (h5-HT(1B/1D)) ligands have been identified.

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A novel series of 1-(bicyclopiperazinyl)ethylindole and 1-(homopiperazinyl)ethyl-indole derivatives was synthesized and found to be potent and selective 5-HT(7) receptor ligands.

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