Pheromone pulses

Visualization of Pheromone Pulses in Goldfish Urine with Isosulfan Blue... 

Alarm pheromone pulse Prey odor patch Sex pheromone... 

Most goats in the northern hemisphere breed in fall and winter. Decreasing day length stimulates ovarian cycles. In addition to photoperiod, male pheromones stimulate pulse frequency of LH in the blood plasma of females (Martin etal., 1986). This not only enhances the seasonal onset of ovarian function, but also synchronizes breeding and subsequent lambing. 

Dusenbery, D. B. (1989) Calculated effect of pulsed pheromone release on range of attraction. J. Chem, Ecol. 15, 971-977. 

Natural stimuli are never block-shaped increases of concentration but rather continuous series of sharp rises and drops in concentrations across a wide dynamic range (Murlis et al., 1992). Odor quality may be encoded in the first 200 ms while the off-characterisitics determine the accuracy with which the end of stimulation and the separation of rapid odor pulses are detected. This has proven to be highly relevant for mechanism of oriented flight (Vickers and Baker, 1996). In fact such differences in ability to follow rapid sequences of odor pulses were demonstrated for two moth ORNs that respond to the same pheromone component but with different temporal accuracy (Almaas et al., 1991). If temporal patterns of activity in single ORNs depend on which odorant they respond to, some odors can be encoded with high temporal accuracy in one ORN, while leaving other... 

In the pheromone orientation system it has been shown how important time aspects are. Several species will not be attracted to a pheromone source unless the stimulus arrives in a pulsed fashion, mimicking the filamentous structure of a natural odor plume. Correlates to this requisite have been found among AL neurons, where both fast neurons, able to code fast fluctuations in concentration, and slow neurons, seemingly only coding qualitative aspects of the plume, are present. 

Female Goldfish release a spawning pheromone in their urine. They release urine in pulses every 2-4 min. These pulses can be made visible by a blue dye in the urine (Appelt and Sorensen 1999). 

It is known that some insects are able to detect a single molecule of a pheromone. The reported detection of single molecules of a dyestuff by repetitive laser pulsing shows that photochemists are now catching up with insects (Shera et al.). Luminescence-activated barometry in wind tunnels represents an unusual application of photophysics (Kavandi et al.). Wild and Renn have provided a useful review of new ideas for high-density information storage. 

In the MGC of M. sexta a small group of PNs has been found that appear to discriminate the duration and inter pulse of pheromone plumes at moderate frequency rates (10 Hz) [61]. 

C. Quero et al.. Responses of male Hehcoverpa zea to single pulses of sex pheromone and behavioural antagonist. Physiological Entomology 26 (2001) 106-115. 

JUSTUS, K.A., SCHOHELD, S.W., MURLIS, J., CARDE, R.T., Flight behaviour of Cadra cautella males in rapidly pulsed pheromone plumes. Phys. EntomoL, 2002, 27, 58-66. 

Baker TC, Willis MA, Haynes KF, Phelan PL (1985) A pulsed cloud of sex pheromone elicits upwind flight in male moths. Physiol Entomol 10(2) 57-265... 

Vickers NJ, Baker TC (1992) Male Heliothis virescens sustain upwind flight in response to experimentally pulsed filaments of their sex-pheromone. J Insect Behav 5 669-687... 

Mafra-Neto, A. Carde, R.T. 1996. Dissection of the pheromone-modulated flight of moths using single-pulse response as a template. Experientia 52 373—379. 

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