title: The role of nicotine on respiratory sensory gating measured by respiratory-related evoked potentials.
abstract: Respiratory perception can be altered by changes in emotional or psychological states. This may be due to affective (i.e., anxiety) modulation of respiratory sensory gating. Nicotine withdrawal induces elevated anxiety and decreased somatosensory gating. Respiratory sensory gating is evidenced by decreased amplitude of the respiratory-related evoked potentials (RREP) N(1) peak for the second occlusion (S2) when two 150-ms occlusions are presented with a 500-ms interval during an inspiration. The N(1) peak amplitude ratio of the S2 and first occlusion (S1) (S2/S1) is <0.5 and due to central neural sensory gating. We hypothesized that withdrawal from nicotine is anxiogenic and reduces respiratory gating in smokers. The RREP was recorded in smokers with 12-h withdrawal from nicotine and nonsmokers using a paired occlusion protocol. In smokers, the RREP was measured after nicotine withdrawal, then with either nicotine or placebo gum, followed by the second RREP trial. Nonsmokers received only placebo gum. After nicotine withdrawal, the smokers had a higher state anxiety compared with nonsmokers. There was a significant interaction between groups (nonsmokers vs. smokers with nicotine vs. smokers with placebo) and test (pre- vs. posttreatment) in RREP N(1) peak amplitude S2/S1. The S2/S1 in the smokers were larger than in nonsmokers before treatment. After gum treatment, the smoker-with-placebo group had a significantly larger S2/S1 than the other two groups. The S2/S1 was significantly decreased after the administration of nicotine gum in smokers due to significantly decreased S2 amplitudes. The RREP N(f) and P(1) peaks were unaffected. These results demonstrated that respiratory sensory gating was decreased in smokers after nicotine withdrawal. Nicotine increased respiratory sensory gating in smokers with a S2/S1 similar to that of the nonsmokers. Nicotine did not change respiratory sensory information arrival, but secondary information processing in respiratory sensation.
authors.affiliation: Department of Physiological Sciences, University of Florida, Gainesville, Florida 32603, USA.
authors.forename: Pei-Ying Sarah
authors.initials: PY
authors.lastname: Chan
authors.forename: P W
authors.initials: PW
authors.lastname: Davenport
mesh_terms: D000284:Administration, Oral; D001007:Anxiety / Q000209:etiology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D002638:Chewing Gum; D004569:Electroencephalography; D004585:Electrooculography; D005071:Evoked Potentials / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D040542:Mechanotransduction, Cellular / Q000187:drug effects; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D010465:Perception / Q000187:drug effects; D011930:Reaction Time; D012119:Respiration; D012129:Respiratory Function Tests; D055139:Sensory Gating / Q000187:drug effects*; D012907:Smoking / Q000523:psychology; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D013997:Time Factors; D055815:Young Adult
chemical_list: D002638:Chewing Gum; D018722:Nicotinic Agonists; D009538:Nicotine