Schizophrenia - parkinson - psychoactive drugs

Parkinson’s disease

tremors, rigity, slowness, postural instability, involuntary posture shifting - deep brain stimulation - electrode on brain, pulse generator - stop effects.

Neurotransmitters

Dopamine, acetylcholine, noradrenaline, serotonin, glutamate

Acetylcholine

agonist = nicotine, black widow venom

antagonists = scopolamine, botulinum toxin

Agonists

drugs that bind to a cell receptor and trigger a response - often mimic naturally occurring substances.

Antagonists

blocks or suppresses agonist mediated responses.

Indirect agonists

enhances the release or action of a endogenous neurotransmitter

endogenous neurotransmitter

a naturally produced chemical messenger in the body that enables neurons to communicate with each other

Schizophrenia

positive (new psychological experiences outside normal range) - delusions, hallucinations, disorganised thinking

negative (loss of normal function) - blunted effect, apathy, poverty of speech

Cognitive (changes in cognitive functions) - poor working memory, disruption in executive function and attention

P.D and Schizophrenia

• dopamine antagonists have anti-schizophrenic effects = produce Parkinsons symptoms

• P.D associated with degeneration of the substansia nigra - mid-brain nucleus with output neurons that release dopamine.

• P.D can be treated with dopamine agonists (L-dopa and Bromocriptine)

Dopamine agonists

(Amphetamine, cocaine and L-Dopa) trigger schizophrenic episodes in normal individuals

Coffee

adenosine antagonist - feel more awake

Marijuana

CB1 receptor antagonist - more energy

Prozac

serotonin reuptake inhibitor (SSRI) - stay happy

Ecstacy (MDMA)

serotonin agonist (+na. +dop.) - more happy

Cocaine

dopamine agonist - intense euphoria, energy

Methamphetamine

indirect agonist of dopamine, noradrenaline and serotonin - cause energy, euphoria

Ketamine

blocks NMDA receptors - detaches from reality (worse effects long term)