The fear hypothesis revisited: Other variables affecting duration of the immobility reflex (animal hypnosis)

Smith, Gerald Birney; Klemm, W. R.

doi:10.1016/s0091-6773(77)91373-6

Cited by 9 publications

References 18 publications

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Depth‐duration profile of the immobility reflex: Theoretical implications for its triggering, sustaining, and terminating mechanisms

Rakshit

Klemm

1980

J of Neuroscience Research

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Immobility reflex (IR) durations of rabbits were remarkably consistent (weighted average range of 0.36-0.70 minutes/trial), under the special conditions when rabbits were "habituated" by approximately 25 preliminary trials and when termination of IR was operationally defined as the point at which any attempt, even abortive, at righting occurred. When the mean duration for each rabbit was normalized (into quartile duration points) and then rabbits were tested at these points to determine arousal threshold, each rabbit revealed a clear progressive decrease in the "depth" of IR as the duration of a given episode progressed. Both duration and depth were decreased when body hair was removed. The hippocampal EEg revealed persistent theta activity throughout a given trial; but the specific frequency of theta increased briefly just prior to induction of IR and decreased immediately afterwards. In short-duration trials, theta frequency increased progressively until the IR terminated spontaneously. In long-duration trials frequency changes oscillated. Each of these observations is interpreted to support the theory that, during IR, reverberating neural circuits (in the brainstem reticular formation) are activated and their output inhibits spinal motor neurons.

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Depth‐duration profile of the immobility reflex: Theoretical implications for its triggering, sustaining, and terminating mechanisms

Rakshit

Klemm

1980

J of Neuroscience Research

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Animal Hypnosis and Pain

Carli

1978

Hypnosis at Its Bicentennial

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Evidence for a cholinergic role in haloperidol-induced catalepsy

Klemm

1985

Psychopharmacology

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Experiments in mice tested previous evidence that activation of cholinergic systems promotes catalepsy and that cholinergic mechanisms need to be intact for full expression of neuroleptic-induced catalepsy. Large doses of the cholinomimetic, pilocarpine, could induce catalepsy when peripheral cholinergic receptors were blocked. Low doses of pilocarpine caused a pronounced enhancement of the catalepsy that was induced by the dopaminergic blocker, haloperidol. A muscarinic receptor blocker, atropine, disrupted haloperidol-induced catalepsy. Intracranial injection of an acetylcholine-synthesis inhibitor, hemicholinium, prevented the catalepsy that is usually induced by haloperidol. These findings suggest the hypothesis that the catalepsy that is produced by neuroleptics such as haloperidol is actually mediated by intrinsic central cholinergic systems. Alternatively, activation of central cholinergic systems could promote catalepsy by suppression of dopaminergic systems.

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The fear hypothesis revisited: Other variables affecting duration of the immobility reflex (animal hypnosis)

Cited by 9 publications

References 18 publications

Depth‐duration profile of the immobility reflex: Theoretical implications for its triggering, sustaining, and terminating mechanisms

Depth‐duration profile of the immobility reflex: Theoretical implications for its triggering, sustaining, and terminating mechanisms

Animal Hypnosis and Pain

Evidence for a cholinergic role in haloperidol-induced catalepsy

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