Lecture 8. Psychotropics and Psychostimulants: Use and Abuse Flashcards
What are the two main nuclei that the noradrenergic fibres of the brain stem from?
Locus coeruleus
Lateral tegmental area
What are the noradrenergic fibres in the forebrain responsible for?
Arousal/wakefulness/alertness
What are the noradrenergic fibres in the amygdala/hippocampus responsible for?
Mood
What are the noradrenergic fibres in the spinal cord responsible for?
Control of pain
What are the noradrenergic fibres in the hypothalamus & NTS responsible for?
Blood pressure/autonomic function
What dopaminergic neurones travel to the forebrain to carry out executive functioning (decision making)?
Ventral tegmental area
What dopaminergic neurones are responsible for Parkinson’s disease when they degrade?
Substantia nigra
What does the dopaminergic nigrostriatal system control?
Motor control
What do the dopaminergic mesolimbic/mesocortical systems control?
Behaviour/mood
What does the dopaminergic tuberohypophyseal system control?
Endocrine control
What are the two D₁-like dopamine receptors?
D₁, D₅
What are the three D₂-like dopamine receptors?
D₂, D₃, D₄
What G protein subtype are D₁-like dopamine receptors coupled with?
Gαs
What G protein subtype are D₂-like dopamine receptors coupled with?
Gαi
What are the typical second messengers of D₁-like dopamine receptors?
Increased cAMP & PKA activity
What are the typical second messengers of D₂-like dopamine receptors?
Reduced cAMP & PKA activity
Gβγ ↓voltage-gated Ca²⁺ channels
Gβγ opens K⁺ channels
What are the physiological responses caused by D₁-like dopamine receptors?
Voluntary movement (Parkinson’s disease)
Reward (drugs of abuse)
What are the physiological responses caused by D₂-like dopamine receptors?
Sleep regulation
Mood/cognition/attention (schizophrenia; ADHD)
Hormonal regulation (pituitary)
Sympathetic regulation
Nausea/vomiting
What is the primary nucleus responsible for the projection that produces serotonin (5-HT) within the brain?
Raphe nuclei
What 5-HT receptor subtype is not G protein coupled?
5-HT₃ (pentameric ionotropic receptor)
What physiological responses are caused by 5-HT (ignoring 5-HT₃)
Feeding
Mood/behaviour (antidepressants)
Sleep/wakefulness
Control of sensory pathways (hallucinations)
Pain (migraine)
Body temperature
What are the typical second messengers of 5-HT₃?
Na⁺
Ca²⁺