title: The effects of nicotine on the human electroretinogram.
abstract: OBJECTIVE
  To examine the effects of nicotine on responses from the human retina measured electrophysiologically.
  
  
  METHODS
  Electroretinogram (ERG) responses were obtained from ten healthy, visually normal adults who were nonsmokers. Nicotine (2 and 4 mg) and a placebo were administered in the form of gum 30 minutes before testing in two separate experiments. ERG responses were collected and analyzed using a full-field ERG system. Responses were recorded from one eye of each subject using a bipolar contact-lens electrode. Intensity-response curves were obtained under both dark- and light-adapted conditions. In experiment 1, both dark- and light-adapted tests were completed sequentially. In experiment 2, only light-adapted testing was performed. Intensity-response functions were analyzed using the Naka-Rushton equation.
  
  
  RESULTS
  In experiment 1, compared with placebo, dark-adapted b-wave amplitude responses decreased significantly after chewing gum containing both 2 and 4 mg of nicotine. Under light-adapted conditions, the peak b-wave amplitude was significantly decreased after chewing gum containing 4 mg of nicotine. In experiment 2, light-adapted b-wave amplitudes were increased after 4 mg nicotine. Oscillatory potentials were measured but no significant effects under nicotine were observed.
  
  
  CONCLUSIONS
  To the knowledge of the authors, this is the first demonstration that nicotine by itself affects responses in the human retina. These data support reports of the expression of nicotinic acetylcholine receptors in rabbit and nonhuman primate retina.
authors: Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama 35294-4390, USA. stump@uab.edu
authors: Stefanie B
authors: SB
authors: Varghese
authors: Jamie C
authors: JC
authors: Reid
authors: E Eugenie
authors: EE
authors: Hartmann
authors: Kent T
authors: KT
authors: Keyser
mesh_terms: D000284:Administration, Oral; D000328:Adult; D003623:Dark Adaptation / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004596:Electroretinography / Q000187:drug effects*; D005260:Female; D005731:Ganglionic Stimulants / Q000008:administration & dosage; D006801:Humans; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D010775:Photic Stimulation; D012016:Reference Values; D012160:Retina / Q000187:drug effects* / Q000502:physiology; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology; D055815:Young Adult
chemical_list: D005731:Ganglionic Stimulants; D009538:Nicotine