Michael J. Marks

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This review provides insight for the judicious selection of nicotine dose ranges and routes of administration for in vivo studies. The literature is replete with reports in which a dosaging regimen chosen for a specific nicotine-mediated response was suboptimal for the species used. In many cases, such discrepancies could be attributed to the complex(More)
DBA mice were chronically treated with nicotine by continuous intravenous infusion of 4.0 mg/kg/hr for 10 d. Drug-treated mice were tolerant to the acute effects of nicotine on locomotor activity and body temperature. The effect of chronic treatment on the amount of L-3H-nicotine binding and RNA encoding for alpha 4, the most widely expressed nicotinic(More)
Genetic variation in CHRNA5, the gene encoding the α5 nicotinic acetylcholine receptor subunit, increases vulnerability to tobacco addiction and lung cancer, but the underlying mechanisms are unknown. Here we report markedly increased nicotine intake in mice with a null mutation in Chrna5. This effect was 'rescued' in knockout mice by re-expressing α5(More)
The binding of [3H]epibatidine, an alkaloid isolated from the skin of an Ecuadorean tree frog, was measured both in brain regions dissected from mouse brain and in tissue sections. Binding to each of 12 brain areas was saturable, but apparently monophasic; no indication of multiple binding sites was obtained. However, inhibition of epibatidine binding by(More)
Recent studies suggest that the neuronal nicotinic receptors (nAChRs) present in the habenulo-interpeduncular (Hb-IPn) system can modulate the reinforcing effect of addictive drugs and the anxiolytic effect of nicotine. Hb and IPn neurons express mRNAs for most nAChR subunits, thus making it difficult to establish the subunit composition of functional(More)
Pharmacological evaluation of nicotine-stimulated dopamine release from striatum has yielded data consistent with activation of a single population of nicotinic acetylcholine receptors (nAChR). However, discovery that alpha-conotoxin MII (alpha-CtxMII) partially inhibits the response indicates that two classes of presynaptic nAChRs mediate dopamine release.(More)
One function of the hippocampus is to ascertain the novelty of incoming sensations and encode significant new information into memory. The regulation of response to repeated stimuli may prevent overloading of this function by redundant sensory input. Recent pharmacological studies implicate the role of alpha-bungarotoxin-sensitive nicotinic cholinergic(More)
Understanding effects of chronic nicotine requires identifying the neurons and synapses whose responses to nicotine itself, and to endogenous acetylcholine, are altered by continued exposure to the drug. To address this problem, we developed mice whose alpha4 nicotinic receptor subunits are replaced by normally functioning fluorescently tagged subunits,(More)
The experiments reported here examined the time course of the development and loss of tolerance to nicotine as well as the time course for the up-regulation and return to basal levels of brain nicotinic receptors. Nicotine was administered by continuous i.v. infusion through cannulae implanted in the right jugular veins of DBA mice. Tolerance to the effects(More)