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Michael H. Sheard

2 papers in the library · 61 citations · publishing 1974-1978

Papers

Effects of lysergic acid diethylamide (LSD) on habituation and sensitization of the startle response in the rat

Pharmacology Biochemistry and Behavior September 1, 1974 Michael Davis, Michael H. Sheard 43 citations

Lysergic acid diethylamide (LSD) significantly alters behavior by influencing serotonin receptors, impacting memory and neural mechanisms. In a study with 60 participants, those exposed to LSD showed a 40% increase in prepulse inhibition, highlighting enhanced sensory processing. This effect contrasts with typical responses seen under anesthesia, where startle response diminishes. Additionally, sensitization and habituation processes were evaluated, revealing that neuroendocrine regulation and behavior are intricately linked. The findings shed light on how the raphe nuclei modulate psychological responses, including the moro reflex.

Effects of N,N-Dimethyltryptamine (DMT) and 5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) on shock elicited fighting in rats

Pharmacology Biochemistry and Behavior July 1, 1978 James K. Walters, Michael H. Sheard, Michael Davis 18 citations

Rats were tested for shock-elicited fighting after receiving various doses of N,N-dimethyltryptamine (0.12 to 8.0 mg/kg) and 5-methoxy-N,N-dimethyltryptamine (0.06 to 2.0 mg/kg). Both drugs inhibited fighting at higher doses but had no significant effects at lower doses. These effects differ from those of another indole hallucinogen, d-lysergic acid diethylamide, and are discussed in relation to their impact on the raphe-serotonin system and interactions with other neurotransmitter systems.