Stereotaxic Techniques and the Production of Lesions

Rowland, Vernon

doi:10.1016/b978-1-4832-3228-7.50011-6

Cited by 57 publications

(12 citation statements)

References 34 publications

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“…At a frequency of 50 c/s this means that the mean current flow (/LC) during each phase of the square-wave pulses is less than half that of the sine wave in this example. As a consequence the danger of a lesioning effect (Rowland, 1966) is less for the square-wave current. A further advantage is that the pulse duration of the square-wave current may be easily shortened or lengthened which weakens or strengthens respectively the stimulus.…”

Section: Discussionmentioning

confidence: 99%

A study of the parameters of electrical stimulation of unmyelinated fibres in the pituitary stalk

Harris¹,

Manabe²,

Ruf³

1969

The Journal of Physiology

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SUMMARY1. The milk-ejection response in lactating rabbits has been used to study the effect of electrical stimuli of different types applied to the supraopticohypophysial tract in the pituitary stalk.2. Sine-wave alternating-current pulses were compared with balanced biphasic square-wave pulses of the same frequency and peak-to-peak current strength. At a pulse duration of 2-4 msec the square-wave stimulation was less effective than the sine wave, but at a pulse duration of 8 msec and over, more effective.3. Above threshold levels of 0-12 mA for the current strength, and of 0 5 msec for the pulse duration, the response increased with increasing current strengths to 2-4 mA and increasing pulse durations to 10 msec.4. With constant and effective strength and duration of the pulse a slight diminution of the response was seen as the frequency was diminished from 100/sec to 50/sec. Further diminution in the frequency revealed that at some point between 50 and 10 c/s a sudden abrupt diminution in the magnitude of the responses occurred over a small range of frequency. This was a reversible phenomenon and it is suggested that it may be related to neurosecretory events occurring in the nerve terminals.5. Stimuli with parameters within the ranges mentioned above are effective in eliciting an oxytocic response on the uterus in the rabbit and ovulation responses (when applied to the hypothalamus) in rats and rabbits. It appears likely that stimuli with such parameters are suitable for experiments concerned with stimulation of the hypothalamus.

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Section: Discussionmentioning

confidence: 99%

A study of the parameters of electrical stimulation of unmyelinated fibres in the pituitary stalk

Harris¹,

Manabe²,

Ruf³

1969

The Journal of Physiology

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“…They were, however, used for stimulation of the reticular formation or the sciatic nerves. Pulse duration was 1 msec in the early, and changed to 0*5 msec in all later experiments to avoid electrolytic injury (see Rowland, 1966). Except for early experiments when stronger currents were used, the voltage for stimulation within the brain was so chosen that it was sufficient normally to elicit evoked responses either in the caudate nucleus or in the cortex, but to be so low that tissue damage during the prolonged stimulations was avoided or kept to a minimum.…”

Section: Transmitters Released From Caudate Nucleus 691mentioning

confidence: 99%

Release into the cerebral ventricles of substances with possible transmitter function in the caudate nucleus

Portig¹,

Vogt²

1969

The Journal of Physiology

158

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SUMMARY1. One caudate nucleus of the anaesthetized cat was superfused by perfusing the anterior horn of one lateral cerebral ventricle. The perfusates were examined for their content in acetylcholine (ACh), dopamine, homovanillic acid (HVA) and 5-hydroxytryptamine (5-HT), at rest and after a variety of stimuli.2. When prostigmine was added to the perfusion fluid, ACh appeared in the effluent; its concentration tended to rise in the course of an experiment. Various afferent stimuli, all of which caused evoked responses recorded from the contra-lateral caudate nucleus, increased the ACh content of the effluent. Effective stimuli were noise and electrical stimulation of afferent nerves or of certain regions of the brain including the ipsilateral substantia nigra.3. The dopamine content of the effluent was extremely low (of the order of 50 pg/min) at rest, but, on occasion, rose sharply when the substantia nigra was stimulated electrically with trains of pulses repeated once every 3 sec. The results were inconsistent. 4. Since dopamine in tissue is rapidly transformed enzymically into HVA, the appearance of this acid in the perfusate was examined.5. At rest, HVA was found to appear in the effluent at a rate of 2-8 ng/ min. Its concentration was rapidly depressed by increasing the depth of anaesthesia.6. Stimulation of the substantia nigra for periods of 3 or 4 min caused an increment in the HVA content of the effluent lasting 1 hr or more. It was frequently seen when two points of the substantia nigra were stimulated * Present address: Institut fuir Toxikologie und Pharmakologie der Universitit Marburg Lahn, Germany. P. J. PORTIG AND MARTHE VOGT simultaneously, less regularly with only one stimulating electrode, and rarely if this was placed in the most caudal part of the substantia nigra.7. These results strongly support the view that there is a dopaminergic nigro-striatal pathway. The following assumption would explain the erratic appearance of dopamine and the long duration of increments in HVA: many of the axons originating in the substantia nigra end either in the putamen or in parts of the caudate nucleus which are far away from the ventricular surface; any dopamine released from these axons will not reach the ventricular surface at all, and HVA will, at best, reach it very slowly.8. Small amounts of 5-HT appeared in the ventricular perfusate, and the quantity rose after the administration ofmonoamine oxidase inhibitors. It was not increased by the type of stimuli used in this work to elicit the release of ACh or HVA.

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“…It is shown here that electrical currents applied to the region of the ventromedial nucleus of the hypothalamus in amounts well within the range of 'physiological' stimulation [Roland, 1966] cause a prompt rise of serum radioimmunoassayable GH in the unanesthetized rabbit. The studies of Bernardis and Frohman [1971] mentioned above were done under anesthesia and with electrical energy delivered far in excess of that used here (5 /¿coulombs per pulse as compared to 0.3 /¿coulombs per pulse).…”

Section: Discussionmentioning

confidence: 99%

“…All stimulation was done monopolarly with a Grass S44 stimulator and constant current unit. Roland [1966] reported a detailed study of electrical parameters for brain lesioning and stimulating. He estimates that for 'physio logical' stimulation, thresholds are from 0.1 to 0.2 /¿coulombs per pulse and that the energy delivered should not exceed 0.5 /¿coulombs per pulse; pulses should be longer than 30 /¿sec but should not exceed 1 msec.…”

Section: Methodsmentioning

confidence: 99%

Physiological Control of Growth Hormone in the Rabbit

McINTYRE

Odell²

1974

Neuroendocrinology

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All experiments utilized blood samples obtained bychronic right atrial catheters. Growth hormone measurements, made by specific radioimmunoassay, showed that fasting and estrogen ad-ministration result in increased growth hormone secretion in the rabbit, although physical stress and exposure to cold do not. Insulin-induced hypoglycemia after fasting caused a decline in plasma growth hormone, and arginine infusion in the estrogen-primed rabbit resulted in an initial depression of plasma growth hormone followed by a renewed secretory phase. Electrical stimulation in the vicinity of the ventromedial nucleus of the hypothalamus caused an abrupt rise in serum growth hormone.

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Stereotaxic Techniques and the Production of Lesions

Cited by 57 publications

References 34 publications

A study of the parameters of electrical stimulation of unmyelinated fibres in the pituitary stalk

A study of the parameters of electrical stimulation of unmyelinated fibres in the pituitary stalk

Release into the cerebral ventricles of substances with possible transmitter function in the caudate nucleus

Physiological Control of Growth Hormone in the Rabbit

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