Effects of Acute and Chronic Administration of Reserpine on Test Performance

Abstract

The past few years have seen the development and widespread administration of tranquilizing drugs. They are given over long periods of time, usually to reduce anxiety. When considering the laboratory procedures designed to measure anxiety, usually minor variations on the conditioned-avoidance procedures have been employed, procedures which involve the application of a warning signal and a noxious stimulus. Allegedly, fear or anxiety is created when the warning stimulus elicits an overt response, such as jumping over a barrier, or disrupts a repetitive response, such as pressing a lever. When the warning signal fails to elicit the behavioral alteration after injection of the tranquilizer, one tends to think the drug has reduced the fear or anxiety.Even barring sensory or motor incapacitation, other factors might well be involved. One postulates particularly the more intellective abilities and broad motivational factors. Whatever the virtue of the avoidance task for testing drug effects, it places few intellectual demands on the animal. Also, since it restricts experimentation to noxious stim¬ uli, one cannot determine whether a general motivational or arousal decrement is pro¬ duced rather than a reduction of fear or

The Effect of two “Tranquillizers” on Auditory Discrimination and Delayed Response Performance of Monkeys

“…The lack of significant change in delayed response performance following reserpine treatment when the data for all the monkeys are grouped agrees with the findings of Hall, Warren and Harlow (1955) and Riopelle and Pfeiffer (1958). Perhaps the reasons that our animals tended to improve slightly in the delayed response after drug treatment were that we used a sliding scale of difficulty (neither Riopelle and Pfeiffer, nor Hall et al, used intermediate delay periods; their animals performed either near chance or over 85 per cent.)…”

“…Malmo's work (1942) suggests that factors tending to reduce sensory stimulation in the delay period lead to an improvement in delayed response, at least in monkeys with frontal cortical lesions. Riopelle and Pfeiffer (1958) have shown that reserpine can improve delayed response of brain-operated animals, and suggest similarly, that their result may have been due to decreased distractibility. Obviously, however, reserpine under these conditions cannot lead to complete sensory blockade, or the animals would not discriminate the baiting of the cup.…”

“…A functionally similar description would be one which stated that the background noise level is higher, so that only the stimuli least likely to be masked out by the noise would be detected. Riopelle and Pfeiffer (1958) have reported that reserpine had no effect on the learning of a visual multiple discrimination task by monkeys. This possible discrepancy between our results and theirs may be related to one or more of the following considerations: (a) Reserpine may decrease the inflow of auditory information and not affect the information necessary for visual problems.…”

“…If one of the drug's effects was to increase the latency of response, as has been shown to be the case under certain conditions (Riopelle and Pfeiffer, 1958 ;Kornetsky, 1958) then the delayed response performance probably would not be affected since the animal was given a long time to respond (30 sec.). On the other hand, such an increase in latency of response would cause a marked deficit in auditory discrimination performance since in this problem the animal must respond within 5 sec.…”

The Effect of two “Tranquillizers” on Auditory Discrimination and Delayed Response Performance of Monkeys

“…The lack of significant change in delayed response performance following reserpine treatment when the data for all the monkeys are grouped agrees with the findings of Hall, Warren and Harlow (1955) and Riopelle and Pfeiffer (1958). Perhaps the reasons that our animals tended to improve slightly in the delayed response after drug treatment were that we used a sliding scale of difficulty (neither Riopelle and Pfeiffer, nor Hall et al, used intermediate delay periods; their animals performed either near chance or over 85 per cent.)…”

“…Malmo's work (1942) suggests that factors tending to reduce sensory stimulation in the delay period lead to an improvement in delayed response, at least in monkeys with frontal cortical lesions. Riopelle and Pfeiffer (1958) have shown that reserpine can improve delayed response of brain-operated animals, and suggest similarly, that their result may have been due to decreased distractibility. Obviously, however, reserpine under these conditions cannot lead to complete sensory blockade, or the animals would not discriminate the baiting of the cup.…”

“…A functionally similar description would be one which stated that the background noise level is higher, so that only the stimuli least likely to be masked out by the noise would be detected. Riopelle and Pfeiffer (1958) have reported that reserpine had no effect on the learning of a visual multiple discrimination task by monkeys. This possible discrepancy between our results and theirs may be related to one or more of the following considerations: (a) Reserpine may decrease the inflow of auditory information and not affect the information necessary for visual problems.…”

“…If one of the drug's effects was to increase the latency of response, as has been shown to be the case under certain conditions (Riopelle and Pfeiffer, 1958 ;Kornetsky, 1958) then the delayed response performance probably would not be affected since the animal was given a long time to respond (30 sec.). On the other hand, such an increase in latency of response would cause a marked deficit in auditory discrimination performance since in this problem the animal must respond within 5 sec.…”

The Effect of two “Tranquillizers” on Auditory Discrimination and Delayed Response Performance of Monkeys

“…The lack of significant change in delayed response performance following reserpine treatment when the data for all the monkeys are grouped agrees with the findings of Hall, Warren and Harlow (1955) and Riopelle and Pfeiffer (1958). Perhaps the reasons that our animals tended to improve slightly in the delayed response after drug treatment were that we used a sliding scale of difficulty (neither Riopelle and Pfeiffer, nor Hall et al, used intermediate delay periods; their animals performed either near chance or over 85 per cent.)…”

“…Malmo's work (1942) suggests that factors tending to reduce sensory stimulation in the delay period lead to an improvement in delayed response, at least in monkeys with frontal cortical lesions. Riopelle and Pfeiffer (1958) have shown that reserpine can improve delayed response of brain-operated animals, and suggest similarly, that their result may have been due to decreased distractibility. Obviously, however, reserpine under these conditions cannot lead to complete sensory blockade, or the animals would not discriminate the baiting of the cup.…”

“…A functionally similar description would be one which stated that the background noise level is higher, so that only the stimuli least likely to be masked out by the noise would be detected. Riopelle and Pfeiffer (1958) have reported that reserpine had no effect on the learning of a visual multiple discrimination task by monkeys. This possible discrepancy between our results and theirs may be related to one or more of the following considerations: (a) Reserpine may decrease the inflow of auditory information and not affect the information necessary for visual problems.…”

“…If one of the drug's effects was to increase the latency of response, as has been shown to be the case under certain conditions (Riopelle and Pfeiffer, 1958 ;Kornetsky, 1958) then the delayed response performance probably would not be affected since the animal was given a long time to respond (30 sec.). On the other hand, such an increase in latency of response would cause a marked deficit in auditory discrimination performance since in this problem the animal must respond within 5 sec.…”

The Effect of two “Tranquillizers” on Auditory Discrimination and Delayed Response Performance of Monkeys

“…The lack of significant change in delayed response performance following reserpine treatment when the data for all the monkeys are grouped agrees with the findings of Hall, Warren and Harlow (1955) and Riopelle and Pfeiffer (1958). Perhaps the reasons that our animals tended to improve slightly in the delayed response after drug treatment were that we used a sliding scale of difficulty (neither Riopelle and Pfeiffer, nor Hall et al, used intermediate delay periods; their animals performed either near chance or over 85 per cent.)…”

“…Malmo's work (1942) suggests that factors tending to reduce sensory stimulation in the delay period lead to an improvement in delayed response, at least in monkeys with frontal cortical lesions. Riopelle and Pfeiffer (1958) have shown that reserpine can improve delayed response of brain-operated animals, and suggest similarly, that their result may have been due to decreased distractibility. Obviously, however, reserpine under these conditions cannot lead to complete sensory blockade, or the animals would not discriminate the baiting of the cup.…”

“…A functionally similar description would be one which stated that the background noise level is higher, so that only the stimuli least likely to be masked out by the noise would be detected. Riopelle and Pfeiffer (1958) have reported that reserpine had no effect on the learning of a visual multiple discrimination task by monkeys. This possible discrepancy between our results and theirs may be related to one or more of the following considerations: (a) Reserpine may decrease the inflow of auditory information and not affect the information necessary for visual problems.…”

“…If one of the drug's effects was to increase the latency of response, as has been shown to be the case under certain conditions (Riopelle and Pfeiffer, 1958 ;Kornetsky, 1958) then the delayed response performance probably would not be affected since the animal was given a long time to respond (30 sec.). On the other hand, such an increase in latency of response would cause a marked deficit in auditory discrimination performance since in this problem the animal must respond within 5 sec.…”