A Functional Caudal Photoreceptor in Blind Cavernicolous Crayfish

Nature ◽  
1966 ◽  
Vol 210 (5032) ◽  
pp. 204-205 ◽  
Author(s):  
JAMES L. LARIMER
Keyword(s):  
Caudal Photoreceptor

Temperature acclimation of the caudal photoreceptor response in the crayfish Orconectes rusticus (Girard)

1988 ◽  
Vol 66 (5) ◽  
pp. 1168-1171 ◽  
Author(s):  
Jim H. Belanger
Keyword(s):  
Stimulus Intensity ◽  
Low Temperatures ◽  
Temperature Acclimation ◽  
Thermal Capacity ◽  
Maximum Frequency ◽  
Orconectes Rusticus ◽  
Temperature Dependent ◽  
Caudal Photoreceptor ◽  
Effects Of Temperature ◽  
Nerve Cords

Crayfish (Orconectes rusticus (Girard)) were acclimated for 3 weeks at 5 and 25 °C. The effects of temperature and temperature acclimation on the latency, maximum frequency, and sensitivity to stimulus intensity of the caudal photoreceptor response were examined in isolated abdominal nerve cords. Each of these components was temperature dependent. The maximum frequency of the response showed thermal capacity acclimation but latency did not. Caudal photoreceptor response was insensitive to stimulus intensity at low temperatures but acclimation improved sensitivity.

scholarly journals Afferent Stochastic Modulation of Crayfish Caudal Photoreceptor Units

1968 ◽  
Vol 51 (4) ◽  
pp. 534-551 ◽  
Author(s):  
Howard T. Hermann ◽  
Richard E. Olsen
Keyword(s):  
Inhibitory Effect ◽  
Fiber Optic Probe ◽  
Inhibitory Effects ◽  
Excitatory Effect ◽  
Multiple Pulses ◽  
Caudal Photoreceptor ◽  
Stochastic Modulation ◽  
The Mean ◽  
Optic Probe ◽  
Stimulation Of

When all roots to the sixth ganglion of the crayfish are cut, the caudal photoreceptor unit (PRU) fires at regular intervals. With an intact preparation, stimulation of caudal tactile hairs has predominantly inhibitory effects on the PRU: short bursts of afferent impulses, produced by momentary mechanical stimulation of tactile hairs, have (a) occasional immediate excitatory effect on the PRU, (b) prolonged inhibitory effect. The mean firing rate of the afferented and deafferented PRUs reacts similarly to a step increase in light, but the same unit fires faster after deafferentation. In the dark, deafferented units often fire paired or multiple pulses; the interval between pulses in a pair is similar to the short mode in afferented histograms. A fiber-optic probe of the caudal ganglion demonstrates the approximate location of the photosensitive element.

Mechanoreceptor and Photoreceptor Tonic Integration in the Crayfish

1973 ◽  
Vol 51 (12) ◽  
pp. 949-958 ◽  
Author(s):  
C. Galeano ◽  
S. Beliveau
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Average Frequency ◽  
Ipsilateral Side ◽  
Average Interval ◽  
Caudal Photoreceptor ◽  
Deviation Coefficient ◽  
Variation Interval ◽  
Density Results

The activity of the caudal photoreceptor of crayfish was studied in: (1) intact tail ganglion, (2) partially isolated, and (3) totally isolated ganglion preparations. Statistical analysis of the photoreceptor activity included average frequency, average interval, variance, standard deviation, coefficient of variation, interval histograms, auto-expectation density, and cross-expectation density. Results showed that the average influence of the mechanoreceptor synapses on the photoreceptors during a period of several seconds was inhibitory, strong on the contralateral and weak on the ipsilateral side.

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