Effect of mescaline and L.S.D. on evoked responses especially of the optic system of the cat

Rovetta, P

doi:10.1016/0013-4694(56)90028-1

Cited by 24 publications

(3 citation statements)

References 18 publications

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“…The sole example of this group was mescaline, the psychotropic actions of which were first described by Heffter in 1896. According to Marrazzi & Hart (1955), mescaline weakly depresses the transcallosal cortical response and, when applied topically, it raises the threshold for direct cortical stimulation (Rovetta, 1956). In the present investigation mescaline was only rather feebly depressant.…”

Section: Section Hisupporting

confidence: 55%

Actions of Certain Amines on Cerebral Cortical Neurones

Krnjević

Phillis

1963

British Journal of Pharmacology and Chemotherapy

202

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A number of derivatives of tryptamine and phenethylamine, and certain other compounds, were tested on neurones in the cerebral cortex of cats by iontophoretic release from micro-pipettes. The characteristic action of many of these compounds was a depression of the neuronal discharge initiated by synaptic activity or by the application of L-glutamate; imidazolylacetic acid, dopamine, ephedrine and ergometrine were particularly effective. Catechol amines, hydroxytryptamines and imidazolylacetic acid had a relatively quick and rapidly reversible action, not unlike that of y-aminobutyric acid, whereas ephedrine and derivatives of lysergic acid diethylamide caused a slower and more prolonged depression of the amplitude of spikes, rather like atropine. Several compounds, including 5-hydroxytryptamine, adrenaline and ergometrine, could also excite the same neurone when larger amounts were applied. A few substances, such as dopa and methylergometrine, had a predominantly excitant action.There has been much speculation during the course of the last decade concerning the significance of several indole and catechol amines which occur naturally in the brain. Interest in these substances has increased as a result of recent developments in the study of psychotropic compounds, some of which are structurally related to the indole and catechol amines (lysergic acid diethylamide, bufotenine, mescaline and others).Evaluation of the importance of these compounds in central nervous mechanisms (Marrazzi & Hart, 1955;Marrazzi, 1957). These findings were substantiated by Ochs, Booker & Aprison (1960), who showed that 5-hydroxytryptamine, applied topically, depressed cortical responses to direct stimulation;

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Section: Section Hisupporting

confidence: 55%

Actions of Certain Amines on Cerebral Cortical Neurones

Krnjević

Phillis

1963

British Journal of Pharmacology and Chemotherapy

202

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“…The present observations permit yet another postulate, namely, that lysergic acid diethylamide, and other tryptamine-like compounds with actions upon the central nervous system, are interfering with the synaptic activity of a transmitter identical with or similar to that responsible for the excitation of lateral geniculate neurones. It is also conceivable that at some central synapses 5-hydroxytryptamine is a transmitter, and consequently the effects produced by intravenous injections of tryptamine derivatives (Szara, 1957 ;Tedeschi, Tedeschi & Fellows, 1959 ;Vane, Collier, Come, Marley & Bradley, 1961) or by the systemic or intraventricular application of 5-hydroxytryptaMine analogues and antagonists (Gaddum & Vogt, 1956;Purpura, 1956aPurpura, , 1956bRovetta, 1956;Ginzel, 1957;Bradley, 1958;Malcolm, 1958;Smythies, Koella & Levy, 1960) will be complex phenomena depending upon which synapses are affected and whether the compounds mimic or block the action of the transmitters. The possibility must also be considered that 5-hydroxytryptamine-like compounds may be operating normally in the central nervous system, not as excitatory or inhibitory transmitters, but as postsynaptic blocking agents of transmitter action.…”

Section: Discussionmentioning

confidence: 99%

Pharmacological Studies Upon Neurones of the Lateral Geniculate Nucleus of the Cat

Curtis

Davis

1962

British Journal of Pharmacology and Chemotherapy

117

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Indoles related to 5-hydroxytryptamine, lysergic acid derivatives, phenethylamine derivatives and some other compounds have been applied electrophoretically to the neurones of the lateral geniculate nucleus of the cat anaesthetized with pentobarbitone sodium. Many of these compounds, particularly 4-, 5-and 7-hydroxytryptamine and ergometrine, depress the orthodromic excitation of the neurones by volleys in optic nerve fibres, but do not affect antidromic excitation by volleys in the optic radiation or chemical excitation by L-glutamic acid. It is concluded that the active depressants either block the access of the excitatory transmitter to subsynaptic receptors or prevent the release of the transmitter from optic nerve terminals. The structure-activity relationships of the depressant substances are discussed.Of recent years considerable interest has been maintained in a series of chemical compounds which have been classified as psychotomimetics since their administration produces clinical syndromes bearing some similarity to naturally occurring psychoses. These substances can be divided into two major groups. One contains an indole nucleus and includes substances such as (+)-lysergic acid diethylamide, certain of the ergot alkaloids, bufotenine, psilocybin and harmine. Members of the other group are related to the catechol amines and include adrenochrome and mescaline. Both groups of substances are of importance since it is possible that their effects are associated with the presence of structurally related compounds as chemical synaptic transmitters within the nervous system. Thus the indolylalkylamine 5-hydroxytryptamine and the catechol amines adrenaline noradrenaline and 3-hydroxytryptamine have been considered as transmitters although definite evidence is lacking (

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“…Purpura14 found facilitation of visual cortical potentials with small doses, whereas Evarts8 found no significant effect with very large doses. Rovetta 18 used LSD topically and intravenously in small doses and reported an absence of effect onboth visual and auditory potentials. Large doses of the drug have been used infrequently.…”

Section: Introductionmentioning

confidence: 99%

Effects of Lysergic Acid Diethylamide (LSD) on Cortical Sensory Evoked Potentials in the Cat

Langfitt¹,

Finney²

1959

Archives of Neurology

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IntroductionSeveral authors have reported the effects of lysergic acid diethylamide (LSD) on evoked potentials in primary sensory path-$ ways. The areas studied were retina,2 lateral geniculate body,8 and visual,9,14,18 auditory,14,18 and somatic cortex.14 There is incomplete agreement on the effects of LSD on visual and auditory cortex. Purpura14 found facilitation of visual cortical potentials with small doses, whereas Evarts8 found no significant effect with very large doses. Rovetta 18 used LSD topically and intravenously in small doses and reported an absence of effect onboth visual and auditory potentials. Large doses of the drug have been used infrequently.Numerous authors have described the effects of LSD on the electrocorticogram of several species of animals.* There is a great variation in the dose reported to produce a significant change in frequency and amplitude, as well as disagreement regarding the character of the changes.The current study was designed to investigate the effects of LSD on cortical visual, auditory, and somatic evoked potentials and also to correlate these observations with the electrocorticogram by recording simultane¬ ously with a cathode-ray oscilloscope (CRO) and an ink-writing oscillograph. Finally, an attempt was made to determine the minimal change in evoked potentials indica¬ tive of a drug effect. MethodsA total of 89 cats were used in this study. Sensory evoked potentials were studied in 39 cats which received LSD one or more times. The data from 27 were analyzed in detail and appear in the text.Twenty animals were anesthetized with ether, then paralyzed with succinylcholine after the sur¬ gical procedures (Anectinized animals). Skin edges and pressure points were infiltrated with 0.5% procaine hydrochloride. Electrical recording was begun no less than two hours following cessa¬ tion of ether anesthesia. The initial paralyzing dose of succinylcholine chloride was 20 mg., fol¬ lowed by 20-mg. supplements as required to pre¬ vent spontaneous movement. The animals were ventilated with a Marshall respirator.Seven cats were anesthetized with pentobarbital sodium, 30 mg/kg., injected íntraperitoneally, and additional intravenous injections were given as required to produce moderately deep anesthesia. Most of the animals were artificially ventilated to obviate any possibility of hypoxia.Visual stimulation was produced by a small sealed bulb which delivered a narrow beam of light for 10 msec, to the eye contralateral to the record¬ ing electrode. Clicks from a loud-speaker mounted near the animal's head were used for auditory stimulation. Tactile stimulation was produced by a Goodman Industries "vibrator," mounted over a pad of the contralateral forefoot. All three sources of stimulation were operated by Tektromx pulse generators and wave-form generators with variable delays. In most experiments the three stimuli were delivered simultaneously at 2.5 second intervals.A bank of 10 electrodes was used for recording from the cortex. The electrodes were springmounted, cylindrical, ...

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Effect of mescaline and L.S.D. on evoked responses especially of the optic system of the cat

Cited by 24 publications

References 18 publications

Actions of Certain Amines on Cerebral Cortical Neurones

Actions of Certain Amines on Cerebral Cortical Neurones

Pharmacological Studies Upon Neurones of the Lateral Geniculate Nucleus of the Cat

Effects of Lysergic Acid Diethylamide (LSD) on Cortical Sensory Evoked Potentials in the Cat

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