Here are several references and abstracts that provide information about some of the potential positive effects of nicotine. There are others as well, but that would make this post even longer than it is. Each of these was published in peer-reviewed journals.
Conners CK, Levin ED, Sparrow E, Hinton SC, Erhardt D, Meck WH, Rose JE, March J (1996) Nicotine and attention in adult attention deficit hyperactivity disorder (ADHD). Psychopharmacol Bulletin 32:67-73.
Abstract: Nicotine, like the psychostimulants methylphenidate and dextroamphetamine, acts as an indirect dopamine agonist and improves attention and arousal. Adults and adolescents with attention deficit hyperactivity disorder (ADHD) smoke much more frequently than normal individuals or those with other psychiatric conditions, perhaps as a form of self-medication for ADHD symptoms. Nicotine might therefore have some value as a treatment for ADHD. The present study is an acute double-blind crossover administration of nicotine and placebo with smokers (n = 6) and nonsmokers (n = 11) diagnosed with adult ADHD. The drug was delivered via a transdermal patch at a dosage of 7 mg/day for nonsmokers and 21 mg/day for smokers. Results indicate significant clinician-rated global improvement, self-rated vigor and concentration, and improved performance on chronometric measures of attention and timing accuracy. Side effects were minimal. These acute results indicate the need for a longer clinical trial and a comparison with other stimulants in adult ADHD treatment
De SR, jmone-Cat MA, Carnevale D, Minghetti L (2005) Activation of alpha7 nicotinic acetylcholine receptor by nicotine selectively up-regulates cyclooxygenase-2 and prostaglandin E2 in rat microglial cultures. J Neuroinflammation 2:4.
Abstract: BACKGROUND: Nicotinic acetylcholine (Ach) receptors are ligand-gated pentameric ion channels whose main function is to transmit signals for the neurotransmitter Ach in peripheral and central nervous system. However, the alpha7 nicotinic receptor has been recently found in several non-neuronal cells and described as an important regulator of cellular function. Nicotine and ACh have been recently reported to inhibit tumor necrosis factor-alpha (TNF-alpha) production in human macrophages as well as in mouse microglial cultures. In the present study, we investigated whether the stimulation of alpha7 nicotinic receptor by the specific agonist nicotine could affect the functional state of activated microglia by promoting and/or inhibiting the release of other important pro-inflammatory and lipid mediator such as prostaglandin E2. METHODS: Expression of alpha7 nicotinic receptor in rat microglial cell was examined by RT-PCR, immunofluorescence staining and Western blot. The functional effects of alpha7 receptor activation were analyzed in resting or lipopolysaccharide (LPS) stimulated microglial cells pre-treated with nicotine. Culture media were assayed for the levels of tumor necrosis factor, interleukin-1beta, nitric oxide, interleukin-10 and prostaglandin E2. Total RNA was assayed by RT-PCR for the expression of COX-2 mRNA. RESULTS: Rat microglial cells express alpha7 nicotinic receptor, and its activation by nicotine dose-dependently reduces the LPS-induced release of TNF-alpha, but has little or no effect on nitric oxide, interleukin-10 and interleukin-1beta. By contrast, nicotine enhances the expression of cyclooxygenase-2 and the synthesis of one of its major products, prostaglandin E2. CONCLUSIONS: Since prostaglandin E2 modulates several macrophage and lymphocyte functions, which are instrumental for inflammatory resolution, our study further supports the existence of a brain cholinergic anti-inflammatory pathway mediated by alpha7 nicotinic receptor that could be potentially exploited for novel treatments of several neuropathologies in which local inflammation, sustained by activated microglia, plays a crucial role
Heishman SJ, Kleykamp BA, Singleton EG (2010) Meta-analysis of the acute effects of nicotine and smoking on human performance. Psychopharmacology (Berl) 210:453-469.
Abstract: RATIONALE AND OBJECTIVE: Empirical studies indicate that nicotine enhances some aspects of attention and cognition, suggesting a role in the maintenance of tobacco dependence. The purpose of this review was to update the literature since our previous review (Heishman et al. Exp Clin Psychopharmacol 2:345-395, 1994) and to determine which aspects of human performance were most sensitive to the effects of nicotine and smoking. METHODS: We conducted a meta-analysis on the outcome measures of 41 double-blind, placebo-controlled laboratory studies published from 1994 to 2008. In all studies, nicotine was administered, and performance was assessed in healthy adult nonsmokers or smokers who were not tobacco-deprived or minimally deprived (<or=2 h). RESULTS: There were sufficient effect size data to conduct meta-analyses on nine performance domains, including motor abilities, alerting and orienting attention, and episodic and working memory. We found significant positive effects of nicotine or smoking on six domains: fine motor, alerting attention-accuracy and response time (RT), orienting attention-RT, short-term episodic memory-accuracy, and working memory-RT (effect size range = 0.16 to 0.44). CONCLUSIONS: The significant effects of nicotine on motor abilities, attention, and memory likely represent true performance enhancement because they are not confounded by withdrawal relief. The beneficial cognitive effects of nicotine have implications for initiation of smoking and maintenance of tobacco dependence
Huang LZ, Grady SR, Quik M (2011) Nicotine reduces L-DOPA-induced dyskinesias by acting at beta2* nicotinic receptors. J Pharmacol Exp Ther 338:932-941.
Abstract: L-DOPA-induced dyskinesias or abnormal involuntary movements (AIMs) are a debilitating adverse complication associated with prolonged L-DOPA administration for Parkinson's disease. Few treatments are currently available for dyskinesias. Our recent data showed that nicotine reduced L-DOPA-induced AIMs in parkinsonian animal models. An important question is the nicotinic acetylcholine receptor (nAChR) subtypes through which nicotine exerts this beneficial effect, because such knowledge would allow for the development of drugs that target the relevant receptor population(s). To address this, we used beta2 nAChR subunit knockout [beta2(-/-)] mice because beta2-containing nAChRs are key regulators of nigrostriatal dopaminergic function. All of the mice were lesioned by intracranial injection of 6-hydroxydopamine into the right medial forebrain bundle. Lesioning resulted in a similar degree of nigrostriatal damage and parkinsonism in beta2(-/-) and wild-type mice. All of the mice then were injected with L-DOPA (3 mg/kg) plus benserazide (15 mg/kg) once daily for 4 weeks until AIMs were fully developed. L-DOPA-induced AIMs were approximately 40% less in the beta2(-/-) mice compared with the wild-type mice. It is interesting to note that nicotine (300 mug/ml in drinking water) reduced L-DOPA-induced AIMs by 40% in wild-type mice but had no effect in beta2(-/-) mice with partial nigrostriatal damage. The nicotine-mediated decline in AIMs was much less pronounced in wild-type mice with near-complete degeneration, suggesting that presynaptic nAChRs on dopaminergic terminals have a major influence. These data demonstrate an essential role for beta2* nAChRs in the antidyskinetic effect of nicotine and suggest that drugs targeting these subtypes may be useful for the management of L-DOPA-induced dyskinesias in Parkinson's disease
Jarvik ME (1991) Beneficial effects of nicotine. Br J Addict 86:571-575.
Abstract: Nicotine in tobacco brings illness and death to millions of people. Yet nicotine in its pure form has the potential to be a valuable pharmaceutical agent. Nicotine fairly specifically binds to the cholinergic nicotinic gating site on cationic ion channels in receptors throughout the body. This action stimulates the release of a variety of neurotransmitters including especially catecholamines and serotonin. When chronically taken, nicotine may result in: (1) positive reinforcement, (2) negative reinforcement, (3) reduction of body weight, (4) enhancement of performance, and protection against; (5) Parkinson's disease (6) Tourette's disease (7) Alzheimers disease, (8) ulcerative colitis and (9) sleep apnea. The reliability of these effects varies greatly but justifies the search for more therapeutic applications for this interesting compound
Jones GM, Sahakian BJ, Levy R, Warburton DM, Gray JA (1992) Effects of acute subcutaneous nicotine on attention, information processing and short-term memory in Alzheimer's disease. Psychopharmacology (Berl) 108:485-494.
Abstract: This single-blind, placebo controlled study reports on the effects of administering three acute doses of nicotine (0.4, 0.6 and 0.8 mg) subcutaneously to a group of Alzheimer's disease (DAT) patients (n = 22), young adult controls (n = 24), and normal aged controls (n = 24). The study extends our previous findings obtained using smaller groups of subjects. Drug effects were examined on three computerised tests: the first measuring rapid visual information processing, sustained visual attention and reaction time (RVIP task); a delayed response matching to location-order task measuring sustained visual attention and visual short-term memory (DRMLO task); and a finger tapping test measuring simple reaction time (FT task). The critical flicker fusion test (CFF) was used as a measure of perception and the WAIS digit span forwards (DS), of auditory short-term memory. Tests were graded in difficulty, titrated to avoid floor and ceiling effects so that meaningful, direct comparisons between groups could be made. Nicotine significantly improved sustained visual attention (in both RVIP and DRMLO tasks), reaction time (in both FT and RVIP tasks), and perception (CFF task--both ascending and descending thresholds). Nicotine administration did not improve auditory and visual short-term memory. There were no consistent, overall patterns of difference in performance between smokers and non-smokers in the control groups, or between males and females in any group. Despite the absence of change in memory functioning, these results demonstrate that DAT patients have significant perceptual and visual attentional deficits which are improved by nicotine administration.(ABSTRACT TRUNCATED AT 250 WORDS)
Levin ED, Conners CK, Sparrow E, Hinton SC, Erhardt D, Meck WH, Rose JE, March J (1996) Nicotine effects on adults with attention-deficit/hyperactivity disorder. Psychopharmacology (Berl) 123:55-63.
Abstract: Several lines of evidence suggest that nicotine may be useful in treating the symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD). The current study was an acute, placebo-controlled double-blind experiment to determine whether nicotine might be useful as an alternative treatment of adults with ADHD symptomatology. Six smokers and 11 nonsmokers who were outpatient referrals for ADHD were diagnosed by DSM-IV criteria. Measures of treatment effect included the Clinical Global Impressions (CGI) scale, Hopkins' symptom check list (SCL-90-R), the Profile of Mood States (POMS), Conners' computerized Continuous Performance Test (CPT), the Stroop test, and an interval-timing task. The smokers underwent overnight deprivation from smoking and were given a 21 mg/day nicotine skin patch for 4.5 h during a morning session. The nonsmokers were given a 7 mg/day nicotine skin patch for 4.5 h during a morning session. Active and placebo patches were given in a counter-balanced order approximately 1 week apart. Nicotine caused a significant overall nicotine-induced improvement on the CGI. This effect was significant when only the nonsmokers were considered, which indicated that it was not due merely to withdrawal relief. Nicotine caused significantly increased vigor as measured by the POMS test. Nicotine caused an overall significant reduction in reaction time (RT) on the CPT, as well as, with the smokers, a significant reduction in another index of inattention, variability in reaction time over trial blocks. Nicotine improved accuracy of time estimation and lowered variability of time-estimation response curves. Because improvements occurred among nonsmokers, the nicotine effect appears not to be merely a relief of withdrawal symptoms. It is concluded that nicotine deserves further clinical trials with ADHD
Levin ED, Conners CK, Silva D, Canu W, March J (2001) Effects of chronic nicotine and methylphenidate in adults with attention deficit/hyperactivity disorder Exp Clin Psychopharmacol 9:83-90.
Abstract: Acute nicotine treatment has been found to reduce symptoms of attention deficit/hyperactivity disorder in adults (E. D. Levin, C. K. Conners, et al., 1996). In this study, chronic nicotine effects were compared with placebo and methylphenidate. Acute and chronic nicotine treatment significantly attenuated the rise in hit reaction time standard error over session blocks on the Conners Continuous Performance Test (C. K. Conners et al., 1996). Acute nicotine significantly reduced severity of clinical symptoms on the Clinical Global Impressions scale (National Institute of Mental Health, 1985). Nicotine caused a significant decrease in self-report of depressive mood as measured by the Profile of Mood States test (D. M. McNair, M. Lorr, & L. F. Droppleman, 1981). This small study (40 participants) provided evidence that nicotine treatment can reduce severity of attentional deficit symptoms and produce improvement on an objective
Quik M, Huang LZ, Parameswaran N, Bordia T, Campos C, Perez XA (2009) Multiple roles for nicotine in Parkinson's disease
Biochem Pharmacol 78:677-685.
Abstract: There exists a remarkable diversity of neurotransmitter compounds in the striatum, a pivotal brain region in the pathology of Parkinson's disease, a movement disorder characterized by rigidity, tremor and bradykinesia. The striatal dopaminergic system, which is particularly vulnerable to neurodegeneration in this disorder, appears to be the major contributor to these motor problems. However, numerous other neurotransmitter systems in the striatum most likely also play a significant role, including the nicotinic cholinergic system. Indeed, there is an extensive anatomical overlap between dopaminergic and cholinergic neurons, and acetylcholine is well known to modulate striatal dopamine release both in vitro and in vivo. Nicotine, a drug that stimulates nicotinic acetylcholine receptors (nAChRs), influences several functions relevant to Parkinson's disease. Extensive studies in parkinsonian animals show that nicotine protects against nigrostriatal damage, findings that may explain the well-established decline in Parkinson's disease incidence with tobacco use. In addition, recent work shows that nicotine reduces l-dopa-induced abnormal involuntary movements, a debilitating complication of l-dopa therapy for Parkinson's disease. These combined observations suggest that nAChR stimulation may represent a useful treatment strategy for Parkinson's disease for neuroprotection and symptomatic treatment. Importantly, only selective nAChR subtypes are present in the striatum including the alpha4beta2*, alpha6beta2* and alpha7 nAChR populations. Treatment with nAChR ligands directed to these subtypes may thus yield optimal therapeutic benefit for Parkinson's disease, with a minimum of adverse side effects
Richardson CE, Morgan JM, Jasani B, Green JT, Rhodes J, Williams GT, Lindstrom J, Wonnacott S, Peel S, Thomas GA (2003) Effect of smoking and transdermal nicotine on colonic nicotinic acetylcholine receptors in ulcerative colitis. QJM 96:57-65.
Abstract: BACKGROUND: Ulcerative colitis (UC) is a disease largely of non-smokers, in which nicotine is of therapeutic value. The mode of action is unknown, but may involve nicotinic acetylcholine receptors (nAChRs) in the bowel wall. AIM: To investigate the presence of nAChRs in rectal mucosa, and the effect of smoking and nicotine on their expression. DESIGN: Prospective case-control study. METHODS: In situ hybridization (ISH) and immunocytochemistry (ICC) were used to show alpha3 nAChRs in colonic mucosa. Rectal mucosa was examined from controls (n=55) and patients with inactive UC (n=62), both smokers and non-smokers, by ICC, using two antibodies to show the density and distribution of receptors in the mucosa. Non-smokers with UC (n=43) were given transdermal nicotine or placebo patches for 6 months, and rectal biopsies, taken before and after treatment, were examined by ICC to show nAChRs. RESULTS: In normal colon, ISH and ICC showed alpha3 subunit in a wide variety of cells, including mucosal epithelium. In rectal biopsies, neither smoking nor nicotine influenced the expression of alpha3 immunoreactivity in epithelium, either in controls or UC. However, controls had a significantly greater density of immunodetectable mucosal epithelium alpha3 subunit, compared with UC patients. DISCUSSION: The presence of nAChRs in colonic epithelium may be pertinent to the beneficial effect of nicotine in UC, but since neither smoking nor nicotine treatment is associated with any change in the expression of epithelial alpha3 nAChRs, the effect may be due to functional changes in the receptor. The decreased number of alpha3 nAChRs in UC compared with controls may be related to an increased cell turnover in UC
Sahakian B, Jones G, Levy R, Gray J, Warburton D (1989) The effects of nicotine on attention, information processing, and short-term memory in patients with dementia of the Alzheimer type. Br J Psychiatry 154:797-800.
Abstract: Nicotine in patients with dementia of the Alzheimer type (DAT) produced a significant and marked improvement in discriminative sensitivity and reaction times on a computerised test of attention and information processing. Nicotine also improved the ability of DAT patients to detect a flickering light in a critical flicker fusion test. These results suggest that nicotine may be acting on cortical mechanisms involved in visual perception and attention, and support the hypothesis that acetylcholine transmission modulates vigilance and discrimination. Nicotine may therefore be of some value in treating deficits in attention and information processing in DAT patients
Ward RJ, Lallemand F, de WP, Dexter DT (2008) Neurochemical pathways involved in the protective effects of nicotine and ethanol in preventing the development of Parkinson's disease: potential targets for the development of new therapeutic agents Prog Neurobiol 85:135-147.
Abstract: In this short review, neurochemical targets are identified where nicotine, and possibly ethanol, may interact to prevent the occurrence of Parkinson's disease. These are (a) the nicotinic acetycholine receptors present in the nigrostriatal area or on the surface of microglia, (b) monoamine oxidases and (c) inducible nitric oxide synthase. If such induced changes can be verified in clinical studies, this may help in the design of new therapeutic drugs which may be of relevance to diminish the incidence and perhaps the progression of the debilitating condition of Parkinson's disease