title: Photoreceptor evoked potentials and phototactic behaviour in Cercaria caribbea LXXI cable.
abstract: 1. Transient potential changes evoked in response to light stimuli, and presumably arising from rhabdomeric eye-spots in the cercarial body, were recorded for the first time, to our knowledge, in helminth parasites. 2. Pigmented Cercaria caribbea LXXI gave a very slowly adapting response to maintained light stimulus, while a non-pigmented variety appeared to emit a stronger, rapidly adapting response to light onset. 3. Swimming towards a directional light source is disrupted by several neuropharmacological agents, which presumably disturb synaptic transmission in the nerve/muscle system. 4. The light evoked potentials were unaffected by these same agents and therefore, appeared to be directly recorded receptor potentials.
mesh_terms: D000818:Animals; D004594:Electrophysiology; D005071:Evoked Potentials; D009068:Movement; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology*; D012016:Reference Values; D012908:Snails / Q000502:physiology*