Types Of Response Patterns Research Articles

Circadian Rhythmicity in Photoperiodic Regulation of Regeneration in Begonia Leaves

AbstractThe mechanism of photoperiodic regulation of regeneration in Begonia leaves has been studied by the night interruption technique in 24, 48, and 72‐h cycles. The response to 30 min red light interruptions in 48 and 72‐h cycles indicated a circadian rhythm in red light sensitivity with typical photophile and scotophile phases. In 24‐h cycles two types of response patterns were observed. With a main photoperiod of 3 h the usual response pattern with only one light‐sensitive phase near the middle of the dark period was found, whereas with 8‐h photoperiods two light‐sensitive phases were observed as previously reported by Zimmer in Begonia flowering studies (Gartenbauwissenschaft 38: 57, 1973). Reversion studies with FR indicate that the reactions are mediated by phytochrome. The results are discussed in relation to alternative hypotheses for photoperiodic timing.

Response properties of cells in the dorsal lateral geniculate nucleus of the albino rat.

The response patterns of cells in the dorsal lateral geniculate nucleus of the albino rat were studied in order to examine the functional organization of the lateral geniculate nucleus. Both photic stimulation and electrical stimulation of the optic tract were used to activate single units in the lateral geniculate nuclei. Three different types of response patterns were found for principal cells, while interneurons all had similar response patterns. The first class of principal cells, E-S cells, responded to stimulation with a period of excitation, followed by a period when activity was suppressed. A second class of cells, S cells, responded to photic stimulation with an initial period when activity was suppressed. The final class of cells, E cells, responded with a period of excitation followed by a return to spontaneous rates of firing. The response patterns of E cells suggest that this type of principal neuron does not receive feedback inhibition of the type proposed in previous models of the lateral geniculate nuclei. Based on these and other observations, a new model of the functional organization of the lateral geniculate nuclei is proposed.

Quantitative analysis of unit response patterns in cat visual cortex

Extracellular recordings were made of the responses of 122 neurons in cat visual cortex to a momentary flash stimulus to the contralateral eye. Responses were compiled on-line into peristimulus time histograms and analyzed quantitatively in order to identify periods of significantly increased or decreased activity (called here “excitatory and inhibitory periods”). A striking diversity was seen among types of response pattern. Observed relationships among latencies, strengths, and durations of excitatory and inhibitory periods were shown to be accounted for by the assumption that trial-to-trial variance in response latency increases as latency itself increases. Type of response pattern was significantly related to cortical area. Cells in area 18 showed, on the average, more periods of excitatory and inhibitory activity than cells in area 17, and these periods were of greater overall strength and duration. Responses of greater complexity and often containing long-latency components were encountered relatively more frequently in area 18. Finally, it was noted that nearby cells in the same vertical column often showed related response patterns.

Response of cat retinal ganglion cell to moving stimuli

Responses elicited from cat retinal ganglion cells by moving stimuli of different intensities and heights were studied. Two types of response patterns were recorded: in type I cells, there was a decrease in the firing rate when the stimulus entered the periphery; in type II cells, there was no indication of the inhibition from the periphery. Evidence was presented that these correspond to the sustained and transient units reported by other investigators. Changes in the stimulus intensity and height did not change the measured size of the receptive field center which indicated that the center and surround components of the receptive field are changing proportionately.

Two types of response patterns from cat retinal ganglion cells to moving stimuli.

Deux Types de reponses apparaissent dans des cellules ganglionnaires du chat soumises a des stimuli mobiles. Ils correspondent aux unites repondant de facon transitoire ou durable et proviennent d'une difference dans la disposition spatiale du centre et de la peripherie du champ recepteur.

Statistical measurement of signal transmission in the central nervous system of the crayfish.

Transmission of nerve signals in the crayfish brain was studied by means of the transfer function derived from input-output analysis with random stimulation. The transfer function was measured in the form of frequency-response-function and represented by Bode plot. Two classes of the frequency-response-functions were discriminated, corresponding to two types of response patterns evoked by the constant frequency stimuli. The first type had the characteristics of a band pass filter similar to an underdamped resonant circuit. The second one had the characteristics of a phase lag circuit, occasionally, with additional small positive or negative peak at almost the same frequency as the resonance of the first type. A few possibilities for the resonance and the phase lag mechanisms were discussed.

PHOTIC DRIVING RESPONSE AND VISUALLYEVOKED RESPONSE IN EYE-OPENED STATE

1. Photic driving of the EEG and the average evoked response to photicstimulation were studied on 42 normal subjects between the ages of 17 and57. Photic stimulation was applied during the period of suppressed EEG, while the subjects kept their eyes open.2. Marked photic driving was observed in 15 subjects (35.7%). The frequencyresponse curve, showed two types of response pattern. The one was “sum-mation type” which showed the maximum amplitude at the stimulus frequencyof 7-8c/sec. The other was “non-summation type” which showed a gradualdecrease in parallel with frequency increase.3. The frequency response of the average evoked response produced thesame course of events as that of photic driving.4. The negative component of the evoked response with the peak latencyof 170 msec showed maximal percent recovery at 120-190 msec. interval ofpaired stimuli.5. It was suggested that the most indispensable component of the evokedresponse was VII, one of the secondary response, for the generation of photicdriving in the eye-opened state.

Single unit activity during behavioral conditioning: Arousal effects

Extracellular recordings of single unit activity in unanesthetized, unparalyzed squirrel monkeys demonstrated three types of response patterns which reflect alterations in levels of behavioral arousal. Other types of single unit activity were highly correlated with psychophysical measures of stimulus detection.