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Hallucination LSD. Aisha Shah November 5, 2013. Outline. What are hallucinations What is LSD Symptoms Mechanism of Action Brain activity . What are hallucinations?. What are hallucinations?. The word “hallucinate” comes from Latin words meaning “to wander in the mind.”
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HallucinationLSD Aisha Shah November 5, 2013
Outline • What are hallucinations • What is LSD • Symptoms • Mechanism of Action • Brain activity
What are hallucinations? • The word “hallucinate” comes from Latin words meaning “to wander in the mind.” • Defined as the perception of any of the five senses without the presence of external stimulus. • Hallucinations are generally defined as perceptions without stimuli (Asaad & Shapiro 1986; Brasic 1998; Kolmel 1993)
LSD Lysergic acid diethylamide • Comes from the ergot fungus that feeds off of rye (parasitic) • Lysergic acid is the raw material used to synthesize LSD • Most common way of administration is blotter acid
Symptoms There are four phases of LSD experience
Symptoms Phase 1: onset phase • Lasts about 30-60 minutes • Autonomic activation • Increased body temperature • Increased heart rate • Increased blood pressure • Increased blood glucose levels • Dilation of the pupils • Drowsiness • Nausea
Symptoms Phase II: Somatic phase • Distortions in time perception • Laughter • Euphoria • Mood swings • Giddiness
Symptoms Phase III: Perceptual phase • Visual hallucination • Sensory distortions • Alteration in thought, arousal and self image • Max effect of drug
Symptoms Phases IV: Calm down phase • Effects of drugs are diminished
Symptoms Adverse effects • Panic and paranoid • Flashbacks • Hallucinogen Persisting Perception Disorder Not addicitve
Mechanism of action LSD seems to target the serotonergic system in the brain • 5HT2A,5HT2C, 5HT1C • Specifically the 5HT2A receptors • Researcher are still not sure what the 5HT1C receptor does but it is uniquely potent, doing more than just activating the receptor
Mechanism of action Animal model • Rats trained to press lever A when LSD was given and press lever B when saline vehicle given • Shown that 5HT2A antagonist reduced lever A responses
Mechanism of action In vitro studies • Strong correlation between hallucinogenic potencies and 5HT2 receptor affinities • Correlation coefficient for the 5HT2 receptor was r=0.90 • Correlation coefficient for the 5HT1 receptor was averaged to r=0.79 • No evidence that the 5HT1 receptors caused hallucinogenic effects
Brain activity Disruption of serotonin activity in thalamus, striatum, and cortex which result in visual hallucinations Over stimulation of these brain areas which is what causes the hallucinations
Brain activity Reticular thalamic nucleus • RTN is responsible for organizing activity in the thalamic relay nuclei • RTN hyperpolarization causes poor sensory transmission