quiz 15 (activating systems and synapse learning

Question 1

4 activating systems

Answer 1

1. Dopaminergic
2. Cholinergic
3. Noradrenic
4. Seratonergic

Question 2

2 subclasses of the Dopaminergic pathway

Answer 2

1. Mesolimbic

2. Nigrostriatal

Question 3

Mesolimbic Dopaminergic pathway

originating nuclei, functions and complications

Answer 3

• Originates in the ventral tegmentum
• Most effected by addiction, stimulates response to stimuli, resulting in the stimuli being more attractive
• Overactive system correlated to schizophrenia

Question 4

Nigrostriatal Dopaminergic pathway

Answer 4

• Originates in the caudate nucleus
• Role in movement
• Decreased activity related to Parkinsons
• Frozen addict

Question 5

Seratonergic Pathway

Answer 5

• Originates in the Raphe nuclei
• Maintaining waking EEG, learning, depression = lower activity, szhizo = higher activity (possibly 2 types of each?), OCD is related to a decrease, and sleep apnea and sudden infant death syndrome are due to abnormalities

Question 6

Noradrenic pathway

Answer 6

• Originates in the Locus Coerulius
• Plays a role in learning (causes/ signals synaptic structure changes
• Behaviours and disorders are emotion related
• Depression - decreased NA neurons
• Mania - increased NA neuron activity

Question 7

Cholinergic pathway

Answer 7

• Originates in the midbrain nuclei
• Participates in learning, memory and waking behaviour
• Ex: Alzheimers - major loss of cholinergic receptors at autopsy
• 2 main treatments, both cholinergic in nature
  1. Increased nicotine receptors (thus, increased ACh activity)
  2. Ache enzyme inhibition (thus, increased ACh action)

Question 8

Main system in habituation

Answer 8

• ESPS in post synaptic neuron decrease, resulting in less AP
• Caused by reduced Ca2+ channel sensitivity as a result of persistent exposure
• Thus, less Ca2+ influx, so less NT released, less ESPS in the post syn

Question 9

Main system in Sensitization

Answer 9

Interneurons bind to a metabotrophic receptor, serotonin is released activating its G protein to bind it w adenyl cyclase
This results in an increase in cAMP production in the presyn of the sensory neuron
cAMP renders potassium channels less responsive, so APs last longer (less K+ efflux means Ca2+ influx occurs for a longer period.)

Question 10

The Frozen Addict (relevant content)

Answer 10

Synthetic heroin contains (MPTP ), which turns into MPP+
MPP+ selectively kills of dopaminergic receptors in the sub.nig.
Living neurons from fetal brains can fix the problem, not regular Parkinson’s tho bc its ongoing.

Question 11

Dendritic spines

Answer 11

Filopodia: where den. spines originate from
Long lasting ones have mushroom shaped heads
-Mediate learning that lasts by individually altering their own structure
-changes may include: chance in sin cleft size, change in dendrite stem length and width, increase in number of synthetic vesiceles, increase in terminal size or area, increase in density of contact zones, ect.