Phycomyces: stimulus storage in light-initiated reactions.

The sporangiophores of Phycomyces blakesleeanus, a unicellular fungus, increase their growth rate temporarily when given a symmetric light pulse. When a sporangiophore is cooled until normal growth stops, the light pulse can still be perceived, and, after the sporangiophore is warmed to room temperature, the normal light-growth response is observed. Thus stimulus information can be "stored" at low temperatures in this sensory system.