title: Behavioral response of human spermatozoa to a concentration jump of chemoattractants or intracellular cyclic nucleotides.
abstract: BACKGROUND
  A major question in mammalian sperm chemotaxis is whether the cells sense a chemoattractant gradient by comparing the chemoattractant concentration between time points or between spatial points.
  
  
  METHODS
  To resolve this question, we exposed human spermatozoa to a temporal chemoattractant gradient under conditions of no spatial gradient by rapidly mixing the cells with progesterone or bourgeonal on a microscope slide and analyzing their swimming with motion analysis software.
  
  
  RESULTS
  The cells responded within seconds with an increase in velocity and lateral head displacement, and with a decrease in the linearity of swimming, becoming hyperactivated at the peak of the response. All the responses were transient, lasting for a number of seconds. Essentially similar results were obtained upon intracellular photorelease of cyclic adenosine monophosphate or cyclic guanosine monophosphate, which are thought to be involved in mediating the chemotactic response.
  
  
  CONCLUSIONS
  These results suggest that human spermatozoa sense and respond to a temporal chemoattractant gradient. On the basis of these observations, we propose a potential model for the chemotactic response of spermatozoa in a spatial chemoattractant gradient.
authors.affiliation: Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Anna
authors.initials: A
authors.lastname: Gakamsky
authors.forename: Leah
authors.initials: L
authors.lastname: Armon
authors.forename: Michael
authors.initials: M
authors.lastname: Eisenbach
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D002630:Chemotactic Factors / Q000494:pharmacology*; D002633:Chemotaxis / Q000187:drug effects*; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008954:Models, Biological; D011374:Progesterone / Q000494:pharmacology; D011685:Purine Nucleotides / Q000494:pharmacology*; D012984:Software; D013075:Sperm Capacitation; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D013268:Stimulation, Chemical; D013997:Time Factors
chemical_list: D000447:Aldehydes; D002630:Chemotactic Factors; D011685:Purine Nucleotides; D011374:Progesterone; D000242:Cyclic AMP; D006152:Cyclic GMP; C473193:bourgeonal